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<a name="Tiny-C-Compiler-Reference-Documentation"></a>
<h1 class="settitle">Tiny C Compiler Reference Documentation</h1>
<p>This manual documents version 0.9.26 of the Tiny C Compiler.
</p>
<table class="menu" border="0" cellspacing="0">
<tr><td align="left" valign="top"><a href="#Introduction">1. Introduction</a></td><td> </td><td align="left" valign="top"> Introduction to tcc.
</td></tr>
<tr><td align="left" valign="top"><a href="#Invoke">2. Command line invocation</a></td><td> </td><td align="left" valign="top"> Invocation of tcc (command line, options).
</td></tr>
<tr><td align="left" valign="top"><a href="#Clang">3. C language support</a></td><td> </td><td align="left" valign="top"> ANSI C and extensions.
</td></tr>
<tr><td align="left" valign="top"><a href="#asm">4. TinyCC Assembler</a></td><td> </td><td align="left" valign="top"> Assembler syntax.
</td></tr>
<tr><td align="left" valign="top"><a href="#linker">5. TinyCC Linker</a></td><td> </td><td align="left" valign="top"> Output file generation and supported targets.
</td></tr>
<tr><td align="left" valign="top"><a href="#Bounds">6. TinyCC Memory and Bound checks</a></td><td> </td><td align="left" valign="top"> Automatic bounds-checking of C code.
</td></tr>
<tr><td align="left" valign="top"><a href="#Libtcc">7. The <code>libtcc</code> library</a></td><td> </td><td align="left" valign="top"> The libtcc library.
</td></tr>
<tr><td align="left" valign="top"><a href="#devel">8. Developer’s guide</a></td><td> </td><td align="left" valign="top"> Guide for Developers.
</td></tr>
</table>
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<a name="Introduction-1"></a>
<h1 class="chapter">1. Introduction</h1>
<p>TinyCC (aka TCC) is a small but hyper fast C compiler. Unlike other C
compilers, it is meant to be self-relying: you do not need an
external assembler or linker because TCC does that for you.
</p>
<p>TCC compiles so <em>fast</em> that even for big projects <code>Makefile</code>s may
not be necessary.
</p>
<p>TCC not only supports ANSI C, but also most of the new ISO C99
standard and many GNUC extensions including inline assembly.
</p>
<p>TCC can also be used to make <em>C scripts</em>, i.e. pieces of C source
that you run as a Perl or Python script. Compilation is so fast that
your script will be as fast as if it was an executable.
</p>
<p>TCC can also automatically generate memory and bound checks
(see section <a href="#Bounds">TinyCC Memory and Bound checks</a>) while allowing all C pointers operations. TCC can do
these checks even if non patched libraries are used.
</p>
<p>With <code>libtcc</code>, you can use TCC as a backend for dynamic code
generation (see section <a href="#Libtcc">The <code>libtcc</code> library</a>).
</p>
<p>TCC mainly supports the i386 target on Linux and Windows. There are alpha
ports for the ARM (<code>arm-tcc</code>) and the TMS320C67xx targets
(<code>c67-tcc</code>). More information about the ARM port is available at
<a href="http://lists.gnu.org/archive/html/tinycc-devel/2003-10/msg00044.html">http://lists.gnu.org/archive/html/tinycc-devel/2003-10/msg00044.html</a>.
</p>
<p>For usage on Windows, see also <a href="tcc-win32.txt">tcc-win32.txt</a>.
</p>
<hr size="6">
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<a name="Command-line-invocation"></a>
<h1 class="chapter">2. Command line invocation</h1>
<hr size="6">
<a name="Quick-start"></a>
<table cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Invoke" title="Previous section in reading order"> < </a>]</td>
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</tr></table>
<h2 class="section">2.1 Quick start</h2>
<table><tr><td> </td><td><pre class="example">usage: tcc [options] [<var>infile1</var> <var>infile2</var>…] [‘<samp>-run</samp>’ <var>infile</var> <var>args</var>…]
</pre></td></tr></table>
<p>TCC options are a very much like gcc options. The main difference is that TCC
can also execute directly the resulting program and give it runtime
arguments.
</p>
<p>Here are some examples to understand the logic:
</p>
<dl compact="compact">
<dt> <code>‘<samp>tcc -run a.c</samp>’</code></dt>
<dd><p>Compile ‘<tt>a.c</tt>’ and execute it directly
</p>
</dd>
<dt> <code>‘<samp>tcc -run a.c arg1</samp>’</code></dt>
<dd><p>Compile a.c and execute it directly. arg1 is given as first argument to
the <code>main()</code> of a.c.
</p>
</dd>
<dt> <code>‘<samp>tcc a.c -run b.c arg1</samp>’</code></dt>
<dd><p>Compile ‘<tt>a.c</tt>’ and ‘<tt>b.c</tt>’, link them together and execute them. arg1 is given
as first argument to the <code>main()</code> of the resulting program.
</p>
</dd>
<dt> <code>‘<samp>tcc -o myprog a.c b.c</samp>’</code></dt>
<dd><p>Compile ‘<tt>a.c</tt>’ and ‘<tt>b.c</tt>’, link them and generate the executable ‘<tt>myprog</tt>’.
</p>
</dd>
<dt> <code>‘<samp>tcc -o myprog a.o b.o</samp>’</code></dt>
<dd><p>link ‘<tt>a.o</tt>’ and ‘<tt>b.o</tt>’ together and generate the executable ‘<tt>myprog</tt>’.
</p>
</dd>
<dt> <code>‘<samp>tcc -c a.c</samp>’</code></dt>
<dd><p>Compile ‘<tt>a.c</tt>’ and generate object file ‘<tt>a.o</tt>’.
</p>
</dd>
<dt> <code>‘<samp>tcc -c asmfile.S</samp>’</code></dt>
<dd><p>Preprocess with C preprocess and assemble ‘<tt>asmfile.S</tt>’ and generate
object file ‘<tt>asmfile.o</tt>’.
</p>
</dd>
<dt> <code>‘<samp>tcc -c asmfile.s</samp>’</code></dt>
<dd><p>Assemble (but not preprocess) ‘<tt>asmfile.s</tt>’ and generate object file
‘<tt>asmfile.o</tt>’.
</p>
</dd>
<dt> <code>‘<samp>tcc -r -o ab.o a.c b.c</samp>’</code></dt>
<dd><p>Compile ‘<tt>a.c</tt>’ and ‘<tt>b.c</tt>’, link them together and generate the object file ‘<tt>ab.o</tt>’.
</p>
</dd>
</dl>
<p>Scripting:
</p>
<p>TCC can be invoked from <em>scripts</em>, just as shell scripts. You just
need to add <code>#!/usr/local/bin/tcc -run</code> at the start of your C source:
</p>
<table><tr><td> </td><td><pre class="example">#!/usr/local/bin/tcc -run
#include <stdio.h>
int main()
{
printf("Hello World\n");
return 0;
}
</pre></td></tr></table>
<p>TCC can read C source code from <em>standard input</em> when ‘<samp>-</samp>’ is used in
place of ‘<samp>infile</samp>’. Example:
</p>
<table><tr><td> </td><td><pre class="example">echo 'main(){puts("hello");}' | tcc -run -
</pre></td></tr></table>
<hr size="6">
<a name="Option-summary"></a>
<table cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Quick-start" title="Previous section in reading order"> < </a>]</td>
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<td valign="middle" align="left">[<a href="#Top" title="Cover (top) of document">Top</a>]</td>
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<td valign="middle" align="left">[<a href="#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<h2 class="section">2.2 Option summary</h2>
<p>General Options:
</p>
<dl compact="compact">
<dt> ‘<samp>-c</samp>’</dt>
<dd><p>Generate an object file.
</p>
</dd>
<dt> ‘<samp>-o outfile</samp>’</dt>
<dd><p>Put object file, executable, or dll into output file ‘<tt>outfile</tt>’.
</p>
</dd>
<dt> ‘<samp>-run source [args...]</samp>’</dt>
<dd><p>Compile file <var>source</var> and run it with the command line arguments
<var>args</var>. In order to be able to give more than one argument to a
script, several TCC options can be given <em>after</em> the
‘<samp>-run</samp>’ option, separated by spaces:
</p><table><tr><td> </td><td><pre class="example">tcc "-run -L/usr/X11R6/lib -lX11" ex4.c
</pre></td></tr></table>
<p>In a script, it gives the following header:
</p><table><tr><td> </td><td><pre class="example">#!/usr/local/bin/tcc -run -L/usr/X11R6/lib -lX11
</pre></td></tr></table>
</dd>
<dt> ‘<samp>-dumpversion</samp>’</dt>
<dd><p>Print only the compiler version and nothing else.
</p>
</dd>
<dt> ‘<samp>-v</samp>’</dt>
<dd><p>Display TCC version.
</p>
</dd>
<dt> ‘<samp>-vv</samp>’</dt>
<dd><p>Show included files. As sole argument, print search dirs (as below).
</p>
</dd>
<dt> ‘<samp>-bench</samp>’</dt>
<dd><p>Display compilation statistics.
</p>
</dd>
<dt> ‘<samp>-print-search-dirs</samp>’</dt>
<dd><p>Print the configured installation directory and a list of library
and include directories tcc will search.
</p>
</dd>
</dl>
<p>Preprocessor options:
</p>
<dl compact="compact">
<dt> ‘<samp>-Idir</samp>’</dt>
<dd><p>Specify an additional include path. Include paths are searched in the
order they are specified.
</p>
<p>System include paths are always searched after. The default system
include paths are: ‘<tt>/usr/local/include</tt>’, ‘<tt>/usr/include</tt>’
and ‘<tt>PREFIX/lib/tcc/include</tt>’. (‘<tt>PREFIX</tt>’ is usually
‘<tt>/usr</tt>’ or ‘<tt>/usr/local</tt>’).
</p>
</dd>
<dt> ‘<samp>-Dsym[=val]</samp>’</dt>
<dd><p>Define preprocessor symbol ‘<samp>sym</samp>’ to
val. If val is not present, its value is ‘<samp>1</samp>’. Function-like macros can
also be defined: ‘<samp>-DF(a)=a+1</samp>’
</p>
</dd>
<dt> ‘<samp>-Usym</samp>’</dt>
<dd><p>Undefine preprocessor symbol ‘<samp>sym</samp>’.
</p></dd>
</dl>
<p>Compilation flags:
</p>
<p>Note: each of the following warning options has a negative form beginning with
‘<samp>-fno-</samp>’.
</p>
<dl compact="compact">
<dt> ‘<samp>-funsigned-char</samp>’</dt>
<dd><p>Let the <code>char</code> type be unsigned.
</p>
</dd>
<dt> ‘<samp>-fsigned-char</samp>’</dt>
<dd><p>Let the <code>char</code> type be signed.
</p>
</dd>
<dt> ‘<samp>-fno-common</samp>’</dt>
<dd><p>Do not generate common symbols for uninitialized data.
</p>
</dd>
<dt> ‘<samp>-fleading-underscore</samp>’</dt>
<dd><p>Add a leading underscore at the beginning of each C symbol.
</p>
</dd>
</dl>
<p>Warning options:
</p>
<dl compact="compact">
<dt> ‘<samp>-w</samp>’</dt>
<dd><p>Disable all warnings.
</p>
</dd>
</dl>
<p>Note: each of the following warning options has a negative form beginning with
‘<samp>-Wno-</samp>’.
</p>
<dl compact="compact">
<dt> ‘<samp>-Wimplicit-function-declaration</samp>’</dt>
<dd><p>Warn about implicit function declaration.
</p>
</dd>
<dt> ‘<samp>-Wunsupported</samp>’</dt>
<dd><p>Warn about unsupported GCC features that are ignored by TCC.
</p>
</dd>
<dt> ‘<samp>-Wwrite-strings</samp>’</dt>
<dd><p>Make string constants be of type <code>const char *</code> instead of <code>char
*</code>.
</p>
</dd>
<dt> ‘<samp>-Werror</samp>’</dt>
<dd><p>Abort compilation if warnings are issued.
</p>
</dd>
<dt> ‘<samp>-Wall</samp>’ </dt>
<dd><p>Activate all warnings, except ‘<samp>-Werror</samp>’, ‘<samp>-Wunusupported</samp>’ and
‘<samp>-Wwrite-strings</samp>’.
</p>
</dd>
</dl>
<p>Linker options:
</p>
<dl compact="compact">
<dt> ‘<samp>-Ldir</samp>’</dt>
<dd><p>Specify an additional static library path for the ‘<samp>-l</samp>’ option. The
default library paths are ‘<tt>/usr/local/lib</tt>’, ‘<tt>/usr/lib</tt>’ and ‘<tt>/lib</tt>’.
</p>
</dd>
<dt> ‘<samp>-lxxx</samp>’</dt>
<dd><p>Link your program with dynamic library libxxx.so or static library
libxxx.a. The library is searched in the paths specified by the
‘<samp>-L</samp>’ option.
</p>
</dd>
<dt> ‘<samp>-Bdir</samp>’</dt>
<dd><p>Set the path where the tcc internal libraries (and include files) can be
found (default is ‘<tt>PREFIX/lib/tcc</tt>’).
</p>
</dd>
<dt> ‘<samp>-shared</samp>’</dt>
<dd><p>Generate a shared library instead of an executable.
</p>
</dd>
<dt> ‘<samp>-soname name</samp>’</dt>
<dd><p>set name for shared library to be used at runtime
</p>
</dd>
<dt> ‘<samp>-static</samp>’</dt>
<dd><p>Generate a statically linked executable (default is a shared linked
executable).
</p>
</dd>
<dt> ‘<samp>-rdynamic</samp>’</dt>
<dd><p>Export global symbols to the dynamic linker. It is useful when a library
opened with <code>dlopen()</code> needs to access executable symbols.
</p>
</dd>
<dt> ‘<samp>-r</samp>’</dt>
<dd><p>Generate an object file combining all input files.
</p>
</dd>
<dt> ‘<samp>-Wl,-rpath=path</samp>’</dt>
<dd><p>Put custom seatch path for dynamic libraries into executable.
</p>
</dd>
<dt> ‘<samp>-Wl,--oformat=fmt</samp>’</dt>
<dd><p>Use <var>fmt</var> as output format. The supported output formats are:
</p><dl compact="compact">
<dt> <code>elf32-i386</code></dt>
<dd><p>ELF output format (default)
</p></dd>
<dt> <code>binary</code></dt>
<dd><p>Binary image (only for executable output)
</p></dd>
<dt> <code>coff</code></dt>
<dd><p>COFF output format (only for executable output for TMS320C67xx target)
</p></dd>
</dl>
</dd>
<dt> ‘<samp>-Wl,-subsystem=console/gui/wince/...</samp>’</dt>
<dd><p>Set type for PE (Windows) executables.
</p>
</dd>
<dt> ‘<samp>-Wl,-[Ttext=# | section-alignment=# | file-alignment=# | image-base=# | stack=#]</samp>’</dt>
<dd><p>Modify executable layout.
</p>
</dd>
<dt> ‘<samp>-Wl,-Bsymbolic</samp>’</dt>
<dd><p>Set DT_SYMBOLIC tag.
</p>
</dd>
</dl>
<p>Debugger options:
</p>
<dl compact="compact">
<dt> ‘<samp>-g</samp>’</dt>
<dd><p>Generate run time debug information so that you get clear run time
error messages: <code> test.c:68: in function 'test5()': dereferencing
invalid pointer</code> instead of the laconic <code>Segmentation
fault</code>.
</p>
</dd>
<dt> ‘<samp>-b</samp>’</dt>
<dd><p>Generate additional support code to check
memory allocations and array/pointer bounds. ‘<samp>-g</samp>’ is implied. Note
that the generated code is slower and bigger in this case.
</p>
<p>Note: ‘<samp>-b</samp>’ is only available on i386 for the moment.
</p>
</dd>
<dt> ‘<samp>-bt N</samp>’</dt>
<dd><p>Display N callers in stack traces. This is useful with ‘<samp>-g</samp>’ or
‘<samp>-b</samp>’.
</p>
</dd>
</dl>
<p>Misc options:
</p>
<dl compact="compact">
<dt> ‘<samp>-MD</samp>’</dt>
<dd><p>Generate makefile fragment with dependencies.
</p>
</dd>
<dt> ‘<samp>-MF depfile</samp>’</dt>
<dd><p>Use ‘<tt>depfile</tt>’ as output for -MD.
</p>
</dd>
</dl>
<p>Note: GCC options ‘<samp>-Ox</samp>’, ‘<samp>-fx</samp>’ and ‘<samp>-mx</samp>’ are
ignored.
</p>
<hr size="6">
<a name="Clang"></a>
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<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<a name="C-language-support"></a>
<h1 class="chapter">3. C language support</h1>
<hr size="6">
<a name="ANSI-C"></a>
<table cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Clang" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#ISOC99-extensions" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="#Clang" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#Clang" title="Up section"> Up </a>]</td>
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<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<h2 class="section">3.1 ANSI C</h2>
<p>TCC implements all the ANSI C standard, including structure bit fields
and floating point numbers (<code>long double</code>, <code>double</code>, and
<code>float</code> fully supported).
</p>
<hr size="6">
<a name="ISOC99-extensions"></a>
<table cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#ANSI-C" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#GNU-C-extensions" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="#Clang" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#Clang" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#asm" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<h2 class="section">3.2 ISOC99 extensions</h2>
<p>TCC implements many features of the new C standard: ISO C99. Currently
missing items are: complex and imaginary numbers and variable length
arrays.
</p>
<p>Currently implemented ISOC99 features:
</p>
<ul>
<li> 64 bit <code>long long</code> types are fully supported.
</li><li> The boolean type <code>_Bool</code> is supported.
</li><li> <code>__func__</code> is a string variable containing the current
function name.
</li><li> Variadic macros: <code>__VA_ARGS__</code> can be used for
function-like macros:
<table><tr><td> </td><td><pre class="example"> #define dprintf(level, __VA_ARGS__) printf(__VA_ARGS__)
</pre></td></tr></table>
<p><code>dprintf</code> can then be used with a variable number of parameters.
</p>
</li><li> Declarations can appear anywhere in a block (as in C++).
</li><li> Array and struct/union elements can be initialized in any order by
using designators:
<table><tr><td> </td><td><pre class="example"> struct { int x, y; } st[10] = { [0].x = 1, [0].y = 2 };
int tab[10] = { 1, 2, [5] = 5, [9] = 9};
</pre></td></tr></table>
</li><li> Compound initializers are supported:
<table><tr><td> </td><td><pre class="example"> int *p = (int []){ 1, 2, 3 };
</pre></td></tr></table>
<p>to initialize a pointer pointing to an initialized array. The same
works for structures and strings.
</p>
</li><li> Hexadecimal floating point constants are supported:
<table><tr><td> </td><td><pre class="example"> double d = 0x1234p10;
</pre></td></tr></table>
<p>is the same as writing
</p><table><tr><td> </td><td><pre class="example"> double d = 4771840.0;
</pre></td></tr></table>
</li><li> <code>inline</code> keyword is ignored.
</li><li> <code>restrict</code> keyword is ignored.
</li></ul>
<hr size="6">
<a name="GNU-C-extensions"></a>
<table cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#ISOC99-extensions" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#TinyCC-extensions" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="#Clang" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#Clang" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#asm" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<h2 class="section">3.3 GNU C extensions</h2>
<p>TCC implements some GNU C extensions:
</p>
<ul>
<li> array designators can be used without ’=’:
<table><tr><td> </td><td><pre class="example"> int a[10] = { [0] 1, [5] 2, 3, 4 };
</pre></td></tr></table>
</li><li> Structure field designators can be a label:
<table><tr><td> </td><td><pre class="example"> struct { int x, y; } st = { x: 1, y: 1};
</pre></td></tr></table>
<p>instead of
</p><table><tr><td> </td><td><pre class="example"> struct { int x, y; } st = { .x = 1, .y = 1};
</pre></td></tr></table>
</li><li> <code>\e</code> is ASCII character 27.
</li><li> case ranges : ranges can be used in <code>case</code>s:
<table><tr><td> </td><td><pre class="example"> switch(a) {
case 1 … 9:
printf("range 1 to 9\n");
break;
default:
printf("unexpected\n");
break;
}
</pre></td></tr></table>
<a name="index-aligned-attribute"></a>
<a name="index-packed-attribute"></a>
<a name="index-section-attribute"></a>
<a name="index-unused-attribute"></a>
<a name="index-cdecl-attribute"></a>
<a name="index-stdcall-attribute"></a>
<a name="index-regparm-attribute"></a>
<a name="index-dllexport-attribute"></a>
</li><li> The keyword <code>__attribute__</code> is handled to specify variable or
function attributes. The following attributes are supported:
<ul>
<li> <code>aligned(n)</code>: align a variable or a structure field to n bytes
(must be a power of two).
</li><li> <code>packed</code>: force alignment of a variable or a structure field to
1.
</li><li> <code>section(name)</code>: generate function or data in assembly section
name (name is a string containing the section name) instead of the default
section.
</li><li> <code>unused</code>: specify that the variable or the function is unused.
</li><li> <code>cdecl</code>: use standard C calling convention (default).
</li><li> <code>stdcall</code>: use Pascal-like calling convention.
</li><li> <code>regparm(n)</code>: use fast i386 calling convention. <var>n</var> must be
between 1 and 3. The first <var>n</var> function parameters are respectively put in
registers <code>%eax</code>, <code>%edx</code> and <code>%ecx</code>.
</li><li> <code>dllexport</code>: export function from dll/executable (win32 only)
</li></ul>
<p>Here are some examples:
</p><table><tr><td> </td><td><pre class="example"> int a __attribute__ ((aligned(8), section(".mysection")));
</pre></td></tr></table>
<p>align variable <code>a</code> to 8 bytes and put it in section <code>.mysection</code>.
</p>
<table><tr><td> </td><td><pre class="example"> int my_add(int a, int b) __attribute__ ((section(".mycodesection")))
{
return a + b;
}
</pre></td></tr></table>
<p>generate function <code>my_add</code> in section <code>.mycodesection</code>.
</p>
</li><li> GNU style variadic macros:
<table><tr><td> </td><td><pre class="example"> #define dprintf(fmt, args…) printf(fmt, ## args)
dprintf("no arg\n");
dprintf("one arg %d\n", 1);
</pre></td></tr></table>
</li><li> <code>__FUNCTION__</code> is interpreted as C99 <code>__func__</code>
(so it has not exactly the same semantics as string literal GNUC
where it is a string literal).
</li><li> The <code>__alignof__</code> keyword can be used as <code>sizeof</code>
to get the alignment of a type or an expression.
</li><li> The <code>typeof(x)</code> returns the type of <code>x</code>.
<code>x</code> is an expression or a type.
</li><li> Computed gotos: <code>&&label</code> returns a pointer of type
<code>void *</code> on the goto label <code>label</code>. <code>goto *expr</code> can be
used to jump on the pointer resulting from <code>expr</code>.
</li><li> Inline assembly with asm instruction:
<a name="index-inline-assembly"></a>
<a name="index-assembly_002c-inline"></a>
<a name="index-_005f_005fasm_005f_005f"></a>
<table><tr><td> </td><td><pre class="example">static inline void * my_memcpy(void * to, const void * from, size_t n)
{
int d0, d1, d2;
__asm__ __volatile__(
"rep ; movsl\n\t"
"testb $2,%b4\n\t"
"je 1f\n\t"
"movsw\n"
"1:\ttestb $1,%b4\n\t"
"je 2f\n\t"
"movsb\n"
"2:"
: "=&c" (d0), "=&D" (d1), "=&S" (d2)
:"0" (n/4), "q" (n),"1" ((long) to),"2" ((long) from)
: "memory");
return (to);
}
</pre></td></tr></table>
<a name="index-gas"></a>
<p>TCC includes its own x86 inline assembler with a <code>gas</code>-like (GNU
assembler) syntax. No intermediate files are generated. GCC 3.x named
operands are supported.
</p>
</li><li> <code>__builtin_types_compatible_p()</code> and <code>__builtin_constant_p()</code>
are supported.
</li><li> <code>#pragma pack</code> is supported for win32 compatibility.
</li></ul>
<hr size="6">
<a name="TinyCC-extensions"></a>
<table cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#GNU-C-extensions" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#asm" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left"> </td>
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<td valign="middle" align="left">[<a href="#Clang" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#asm" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<h2 class="section">3.4 TinyCC extensions</h2>
<ul>
<li> <code>__TINYC__</code> is a predefined macro to <code>1</code> to
indicate that you use TCC.
</li><li> <code>#!</code> at the start of a line is ignored to allow scripting.
</li><li> Binary digits can be entered (<code>0b101</code> instead of
<code>5</code>).
</li><li> <code>__BOUNDS_CHECKING_ON</code> is defined if bound checking is activated.
</li></ul>
<hr size="6">
<a name="asm"></a>
<table cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#TinyCC-extensions" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#Syntax" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="#Clang" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#Top" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#linker" title="Next chapter"> >> </a>]</td>
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<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<a name="TinyCC-Assembler"></a>
<h1 class="chapter">4. TinyCC Assembler</h1>
<p>Since version 0.9.16, TinyCC integrates its own assembler. TinyCC
assembler supports a gas-like syntax (GNU assembler). You can
desactivate assembler support if you want a smaller TinyCC executable
(the C compiler does not rely on the assembler).
</p>
<p>TinyCC Assembler is used to handle files with ‘<tt>.S</tt>’ (C
preprocessed assembler) and ‘<tt>.s</tt>’ extensions. It is also used to
handle the GNU inline assembler with the <code>asm</code> keyword.
</p>
<hr size="6">
<a name="Syntax"></a>
<table cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#asm" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#Expressions" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="#asm" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#asm" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#linker" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<h2 class="section">4.1 Syntax</h2>
<p>TinyCC Assembler supports most of the gas syntax. The tokens are the
same as C.
</p>
<ul>
<li> C and C++ comments are supported.
</li><li> Identifiers are the same as C, so you cannot use ’.’ or ’$’.
</li><li> Only 32 bit integer numbers are supported.
</li></ul>
<hr size="6">
<a name="Expressions"></a>
<table cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Syntax" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#Labels" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="#asm" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#asm" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#linker" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<h2 class="section">4.2 Expressions</h2>
<ul>
<li> Integers in decimal, octal and hexa are supported.
</li><li> Unary operators: +, -, ~.
</li><li> Binary operators in decreasing priority order:
<ol>
<li> *, /, %
</li><li> &, |, ^
</li><li> +, -
</li></ol>
</li><li> A value is either an absolute number or a label plus an offset.
All operators accept absolute values except ’+’ and ’-’. ’+’ or ’-’ can be
used to add an offset to a label. ’-’ supports two labels only if they
are the same or if they are both defined and in the same section.
</li></ul>
<hr size="6">
<a name="Labels"></a>
<table cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Expressions" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#Directives" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="#asm" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#asm" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#linker" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<h2 class="section">4.3 Labels</h2>
<ul>
<li> All labels are considered as local, except undefined ones.
</li><li> Numeric labels can be used as local <code>gas</code>-like labels.
They can be defined several times in the same source. Use ’b’
(backward) or ’f’ (forward) as suffix to reference them:
<table><tr><td> </td><td><pre class="example"> 1:
jmp 1b /* jump to '1' label before */
jmp 1f /* jump to '1' label after */
1:
</pre></td></tr></table>
</li></ul>
<hr size="6">
<a name="Directives"></a>
<table cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Labels" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#X86-Assembler" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="#asm" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#asm" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#linker" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<h2 class="section">4.4 Directives</h2>
<a name="index-assembler-directives"></a>
<a name="index-directives_002c-assembler"></a>
<a name="index-align-directive"></a>
<a name="index-skip-directive"></a>
<a name="index-space-directive"></a>
<a name="index-byte-directive"></a>
<a name="index-word-directive"></a>
<a name="index-short-directive"></a>
<a name="index-int-directive"></a>
<a name="index-long-directive"></a>
<a name="index-quad-directive"></a>
<a name="index-globl-directive"></a>
<a name="index-global-directive"></a>
<a name="index-section-directive"></a>
<a name="index-text-directive"></a>
<a name="index-data-directive"></a>
<a name="index-bss-directive"></a>
<a name="index-fill-directive"></a>
<a name="index-org-directive"></a>
<a name="index-previous-directive"></a>
<a name="index-string-directive"></a>
<a name="index-asciz-directive"></a>
<a name="index-ascii-directive"></a>
<p>All directives are preceeded by a ’.’. The following directives are
supported:
</p>
<ul>
<li> .align n[,value]
</li><li> .skip n[,value]
</li><li> .space n[,value]
</li><li> .byte value1[,...]
</li><li> .word value1[,...]
</li><li> .short value1[,...]
</li><li> .int value1[,...]
</li><li> .long value1[,...]
</li><li> .quad immediate_value1[,...]
</li><li> .globl symbol
</li><li> .global symbol
</li><li> .section section
</li><li> .text
</li><li> .data
</li><li> .bss
</li><li> .fill repeat[,size[,value]]
</li><li> .org n
</li><li> .previous
</li><li> .string string[,...]
</li><li> .asciz string[,...]
</li><li> .ascii string[,...]
</li></ul>
<hr size="6">
<a name="X86-Assembler"></a>
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<h2 class="section">4.5 X86 Assembler</h2>
<a name="index-assembler"></a>
<p>All X86 opcodes are supported. Only ATT syntax is supported (source
then destination operand order). If no size suffix is given, TinyCC
tries to guess it from the operand sizes.
</p>
<p>Currently, MMX opcodes are supported but not SSE ones.
</p>
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<a name="TinyCC-Linker"></a>
<h1 class="chapter">5. TinyCC Linker</h1>
<a name="index-linker"></a>
<hr size="6">
<a name="ELF-file-generation"></a>
<table cellpadding="1" cellspacing="1" border="0">
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</tr></table>
<h2 class="section">5.1 ELF file generation</h2>
<a name="index-ELF"></a>
<p>TCC can directly output relocatable ELF files (object files),
executable ELF files and dynamic ELF libraries without relying on an
external linker.
</p>
<p>Dynamic ELF libraries can be output but the C compiler does not generate
position independent code (PIC). It means that the dynamic library
code generated by TCC cannot be factorized among processes yet.
</p>
<p>TCC linker eliminates unreferenced object code in libraries. A single pass is
done on the object and library list, so the order in which object files and
libraries are specified is important (same constraint as GNU ld). No grouping
options (‘<samp>--start-group</samp>’ and ‘<samp>--end-group</samp>’) are supported.
</p>
<hr size="6">
<a name="ELF-file-loader"></a>
<table cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#ELF-file-generation" title="Previous section in reading order"> < </a>]</td>
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</tr></table>
<h2 class="section">5.2 ELF file loader</h2>
<p>TCC can load ELF object files, archives (.a files) and dynamic
libraries (.so).
</p>
<hr size="6">
<a name="PE_002di386-file-generation"></a>
<table cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#ELF-file-loader" title="Previous section in reading order"> < </a>]</td>
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</tr></table>
<h2 class="section">5.3 PE-i386 file generation</h2>
<a name="index-PE_002di386"></a>
<p>TCC for Windows supports the native Win32 executable file format (PE-i386). It
generates EXE files (console and gui) and DLL files.
</p>
<p>For usage on Windows, see also tcc-win32.txt.
</p>
<hr size="6">
<a name="GNU-Linker-Scripts"></a>
<table cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#PE_002di386-file-generation" title="Previous section in reading order"> < </a>]</td>
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</tr></table>
<h2 class="section">5.4 GNU Linker Scripts</h2>
<a name="index-scripts_002c-linker"></a>
<a name="index-linker-scripts"></a>
<a name="index-GROUP_002c-linker-command"></a>
<a name="index-FILE_002c-linker-command"></a>
<a name="index-OUTPUT_005fFORMAT_002c-linker-command"></a>
<a name="index-TARGET_002c-linker-command"></a>
<p>Because on many Linux systems some dynamic libraries (such as
‘<tt>/usr/lib/libc.so</tt>’) are in fact GNU ld link scripts (horrible!),
the TCC linker also supports a subset of GNU ld scripts.
</p>
<p>The <code>GROUP</code> and <code>FILE</code> commands are supported. <code>OUTPUT_FORMAT</code>
and <code>TARGET</code> are ignored.
</p>
<p>Example from ‘<tt>/usr/lib/libc.so</tt>’:
</p><table><tr><td> </td><td><pre class="example">/* GNU ld script
Use the shared library, but some functions are only in
the static library, so try that secondarily. */
GROUP ( /lib/libc.so.6 /usr/lib/libc_nonshared.a )
</pre></td></tr></table>
<hr size="6">
<a name="Bounds"></a>
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<a name="TinyCC-Memory-and-Bound-checks"></a>
<h1 class="chapter">6. TinyCC Memory and Bound checks</h1>
<a name="index-bound-checks"></a>
<a name="index-memory-checks"></a>
<p>This feature is activated with the ‘<samp>-b</samp>’ (see section <a href="#Invoke">Command line invocation</a>).
</p>
<p>Note that pointer size is <em>unchanged</em> and that code generated
with bound checks is <em>fully compatible</em> with unchecked
code. When a pointer comes from unchecked code, it is assumed to be
valid. Even very obscure C code with casts should work correctly.
</p>
<p>For more information about the ideas behind this method, see
<a href="http://www.doc.ic.ac.uk/~phjk/BoundsChecking.html">http://www.doc.ic.ac.uk/~phjk/BoundsChecking.html</a>.
</p>
<p>Here are some examples of caught errors:
</p>
<dl compact="compact">
<dt> Invalid range with standard string function:</dt>
<dd><table><tr><td> </td><td><pre class="example">{
char tab[10];
memset(tab, 0, 11);
}
</pre></td></tr></table>
</dd>
<dt> Out of bounds-error in global or local arrays:</dt>
<dd><table><tr><td> </td><td><pre class="example">{
int tab[10];
for(i=0;i<11;i++) {
sum += tab[i];
}
}
</pre></td></tr></table>
</dd>
<dt> Out of bounds-error in malloc’ed data:</dt>
<dd><table><tr><td> </td><td><pre class="example">{
int *tab;
tab = malloc(20 * sizeof(int));
for(i=0;i<21;i++) {
sum += tab4[i];
}
free(tab);
}
</pre></td></tr></table>
</dd>
<dt> Access of freed memory:</dt>
<dd><table><tr><td> </td><td><pre class="example">{
int *tab;
tab = malloc(20 * sizeof(int));
free(tab);
for(i=0;i<20;i++) {
sum += tab4[i];
}
}
</pre></td></tr></table>
</dd>
<dt> Double free:</dt>
<dd><table><tr><td> </td><td><pre class="example">{
int *tab;
tab = malloc(20 * sizeof(int));
free(tab);
free(tab);
}
</pre></td></tr></table>
</dd>
</dl>
<hr size="6">
<a name="Libtcc"></a>
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<a name="The-libtcc-library"></a>
<h1 class="chapter">7. The <code>libtcc</code> library</h1>
<p>The <code>libtcc</code> library enables you to use TCC as a backend for
dynamic code generation.
</p>
<p>Read the ‘<tt>libtcc.h</tt>’ to have an overview of the API. Read
‘<tt>libtcc_test.c</tt>’ to have a very simple example.
</p>
<p>The idea consists in giving a C string containing the program you want
to compile directly to <code>libtcc</code>. Then you can access to any global
symbol (function or variable) defined.
</p>
<hr size="6">
<a name="devel"></a>
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<a name="Developer_0027s-guide"></a>
<h1 class="chapter">8. Developer’s guide</h1>
<p>This chapter gives some hints to understand how TCC works. You can skip
it if you do not intend to modify the TCC code.
</p>
<hr size="6">
<a name="File-reading"></a>
<table cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#devel" title="Previous section in reading order"> < </a>]</td>
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</tr></table>
<h2 class="section">8.1 File reading</h2>
<p>The <code>BufferedFile</code> structure contains the context needed to read a
file, including the current line number. <code>tcc_open()</code> opens a new
file and <code>tcc_close()</code> closes it. <code>inp()</code> returns the next
character.
</p>
<hr size="6">
<a name="Lexer"></a>
<table cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#File-reading" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#Parser" title="Next section in reading order"> > </a>]</td>
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</tr></table>
<h2 class="section">8.2 Lexer</h2>
<p><code>next()</code> reads the next token in the current
file. <code>next_nomacro()</code> reads the next token without macro
expansion.
</p>
<p><code>tok</code> contains the current token (see <code>TOK_xxx</code>)
constants. Identifiers and keywords are also keywords. <code>tokc</code>
contains additional infos about the token (for example a constant value
if number or string token).
</p>
<hr size="6">
<a name="Parser"></a>
<table cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Lexer" title="Previous section in reading order"> < </a>]</td>
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</tr></table>
<h2 class="section">8.3 Parser</h2>
<p>The parser is hardcoded (yacc is not necessary). It does only one pass,
except:
</p>
<ul>
<li> For initialized arrays with unknown size, a first pass
is done to count the number of elements.
</li><li> For architectures where arguments are evaluated in
reverse order, a first pass is done to reverse the argument order.
</li></ul>
<hr size="6">
<a name="Types"></a>
<table cellpadding="1" cellspacing="1" border="0">
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<h2 class="section">8.4 Types</h2>
<p>The types are stored in a single ’int’ variable. It was choosen in the
first stages of development when tcc was much simpler. Now, it may not
be the best solution.
</p>
<table><tr><td> </td><td><pre class="example">#define VT_INT 0 /* integer type */
#define VT_BYTE 1 /* signed byte type */
#define VT_SHORT 2 /* short type */
#define VT_VOID 3 /* void type */
#define VT_PTR 4 /* pointer */
#define VT_ENUM 5 /* enum definition */
#define VT_FUNC 6 /* function type */
#define VT_STRUCT 7 /* struct/union definition */
#define VT_FLOAT 8 /* IEEE float */
#define VT_DOUBLE 9 /* IEEE double */
#define VT_LDOUBLE 10 /* IEEE long double */
#define VT_BOOL 11 /* ISOC99 boolean type */
#define VT_LLONG 12 /* 64 bit integer */
#define VT_LONG 13 /* long integer (NEVER USED as type, only
during parsing) */
#define VT_BTYPE 0x000f /* mask for basic type */
#define VT_UNSIGNED 0x0010 /* unsigned type */
#define VT_ARRAY 0x0020 /* array type (also has VT_PTR) */
#define VT_VLA 0x20000 /* VLA type (also has VT_PTR and VT_ARRAY) */
#define VT_BITFIELD 0x0040 /* bitfield modifier */
#define VT_CONSTANT 0x0800 /* const modifier */
#define VT_VOLATILE 0x1000 /* volatile modifier */
#define VT_SIGNED 0x2000 /* signed type */
#define VT_STRUCT_SHIFT 18 /* structure/enum name shift (14 bits left) */
</pre></td></tr></table>
<p>When a reference to another type is needed (for pointers, functions and
structures), the <code>32 - VT_STRUCT_SHIFT</code> high order bits are used to
store an identifier reference.
</p>
<p>The <code>VT_UNSIGNED</code> flag can be set for chars, shorts, ints and long
longs.
</p>
<p>Arrays are considered as pointers <code>VT_PTR</code> with the flag
<code>VT_ARRAY</code> set. Variable length arrays are considered as special
arrays and have flag <code>VT_VLA</code> set instead of <code>VT_ARRAY</code>.
</p>
<p>The <code>VT_BITFIELD</code> flag can be set for chars, shorts, ints and long
longs. If it is set, then the bitfield position is stored from bits
VT_STRUCT_SHIFT to VT_STRUCT_SHIFT + 5 and the bit field size is stored
from bits VT_STRUCT_SHIFT + 6 to VT_STRUCT_SHIFT + 11.
</p>
<p><code>VT_LONG</code> is never used except during parsing.
</p>
<p>During parsing, the storage of an object is also stored in the type
integer:
</p>
<table><tr><td> </td><td><pre class="example">#define VT_EXTERN 0x00000080 /* extern definition */
#define VT_STATIC 0x00000100 /* static variable */
#define VT_TYPEDEF 0x00000200 /* typedef definition */
#define VT_INLINE 0x00000400 /* inline definition */
#define VT_IMPORT 0x00004000 /* win32: extern data imported from dll */
#define VT_EXPORT 0x00008000 /* win32: data exported from dll */
#define VT_WEAK 0x00010000 /* win32: data exported from dll */
</pre></td></tr></table>
<hr size="6">
<a name="Symbols"></a>
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</tr></table>
<h2 class="section">8.5 Symbols</h2>
<p>All symbols are stored in hashed symbol stacks. Each symbol stack
contains <code>Sym</code> structures.
</p>
<p><code>Sym.v</code> contains the symbol name (remember
an idenfier is also a token, so a string is never necessary to store
it). <code>Sym.t</code> gives the type of the symbol. <code>Sym.r</code> is usually
the register in which the corresponding variable is stored. <code>Sym.c</code> is
usually a constant associated to the symbol like its address for normal
symbols, and the number of entries for symbols representing arrays.
Variable length array types use <code>Sym.c</code> as a location on the stack
which holds the runtime sizeof for the type.
</p>
<p>Four main symbol stacks are defined:
</p>
<dl compact="compact">
<dt> <code>define_stack</code></dt>
<dd><p>for the macros (<code>#define</code>s).
</p>
</dd>
<dt> <code>global_stack</code></dt>
<dd><p>for the global variables, functions and types.
</p>
</dd>
<dt> <code>local_stack</code></dt>
<dd><p>for the local variables, functions and types.
</p>
</dd>
<dt> <code>global_label_stack</code></dt>
<dd><p>for the local labels (for <code>goto</code>).
</p>
</dd>
<dt> <code>label_stack</code></dt>
<dd><p>for GCC block local labels (see the <code>__label__</code> keyword).
</p>
</dd>
</dl>
<p><code>sym_push()</code> is used to add a new symbol in the local symbol
stack. If no local symbol stack is active, it is added in the global
symbol stack.
</p>
<p><code>sym_pop(st,b)</code> pops symbols from the symbol stack <var>st</var> until
the symbol <var>b</var> is on the top of stack. If <var>b</var> is NULL, the stack
is emptied.
</p>
<p><code>sym_find(v)</code> return the symbol associated to the identifier
<var>v</var>. The local stack is searched first from top to bottom, then the
global stack.
</p>
<hr size="6">
<a name="Sections"></a>
<table cellpadding="1" cellspacing="1" border="0">
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</tr></table>
<h2 class="section">8.6 Sections</h2>
<p>The generated code and datas are written in sections. The structure
<code>Section</code> contains all the necessary information for a given
section. <code>new_section()</code> creates a new section. ELF file semantics
is assumed for each section.
</p>
<p>The following sections are predefined:
</p>
<dl compact="compact">
<dt> <code>text_section</code></dt>
<dd><p>is the section containing the generated code. <var>ind</var> contains the
current position in the code section.
</p>
</dd>
<dt> <code>data_section</code></dt>
<dd><p>contains initialized data
</p>
</dd>
<dt> <code>bss_section</code></dt>
<dd><p>contains uninitialized data
</p>
</dd>
<dt> <code>bounds_section</code></dt>
<dt> <code>lbounds_section</code></dt>
<dd><p>are used when bound checking is activated
</p>
</dd>
<dt> <code>stab_section</code></dt>
<dt> <code>stabstr_section</code></dt>
<dd><p>are used when debugging is actived to store debug information
</p>
</dd>
<dt> <code>symtab_section</code></dt>
<dt> <code>strtab_section</code></dt>
<dd><p>contain the exported symbols (currently only used for debugging).
</p>
</dd>
</dl>
<hr size="6">
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<table cellpadding="1" cellspacing="1" border="0">
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</tr></table>
<h2 class="section">8.7 Code generation</h2>
<a name="index-code-generation"></a>
<hr size="6">
<a name="Introduction-2"></a>
<table cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Code-generation" title="Previous section in reading order"> < </a>]</td>
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</tr></table>
<h3 class="subsection">8.7.1 Introduction</h3>
<p>The TCC code generator directly generates linked binary code in one
pass. It is rather unusual these days (see gcc for example which
generates text assembly), but it can be very fast and surprisingly
little complicated.
</p>
<p>The TCC code generator is register based. Optimization is only done at
the expression level. No intermediate representation of expression is
kept except the current values stored in the <em>value stack</em>.
</p>
<p>On x86, three temporary registers are used. When more registers are
needed, one register is spilled into a new temporary variable on the stack.
</p>
<hr size="6">
<a name="The-value-stack"></a>
<table cellpadding="1" cellspacing="1" border="0">
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</tr></table>
<h3 class="subsection">8.7.2 The value stack</h3>
<a name="index-value-stack_002c-introduction"></a>
<p>When an expression is parsed, its value is pushed on the value stack
(<var>vstack</var>). The top of the value stack is <var>vtop</var>. Each value
stack entry is the structure <code>SValue</code>.
</p>
<p><code>SValue.t</code> is the type. <code>SValue.r</code> indicates how the value is
currently stored in the generated code. It is usually a CPU register
index (<code>REG_xxx</code> constants), but additional values and flags are
defined:
</p>
<table><tr><td> </td><td><pre class="example">#define VT_CONST 0x00f0
#define VT_LLOCAL 0x00f1
#define VT_LOCAL 0x00f2
#define VT_CMP 0x00f3
#define VT_JMP 0x00f4
#define VT_JMPI 0x00f5
#define VT_LVAL 0x0100
#define VT_SYM 0x0200
#define VT_MUSTCAST 0x0400
#define VT_MUSTBOUND 0x0800
#define VT_BOUNDED 0x8000
#define VT_LVAL_BYTE 0x1000
#define VT_LVAL_SHORT 0x2000
#define VT_LVAL_UNSIGNED 0x4000
#define VT_LVAL_TYPE (VT_LVAL_BYTE | VT_LVAL_SHORT | VT_LVAL_UNSIGNED)
</pre></td></tr></table>
<dl compact="compact">
<dt> <code>VT_CONST</code></dt>
<dd><p>indicates that the value is a constant. It is stored in the union
<code>SValue.c</code>, depending on its type.
</p>
</dd>
<dt> <code>VT_LOCAL</code></dt>
<dd><p>indicates a local variable pointer at offset <code>SValue.c.i</code> in the
stack.
</p>
</dd>
<dt> <code>VT_CMP</code></dt>
<dd><p>indicates that the value is actually stored in the CPU flags (i.e. the
value is the consequence of a test). The value is either 0 or 1. The
actual CPU flags used is indicated in <code>SValue.c.i</code>.
</p>
<p>If any code is generated which destroys the CPU flags, this value MUST be
put in a normal register.
</p>
</dd>
<dt> <code>VT_JMP</code></dt>
<dt> <code>VT_JMPI</code></dt>
<dd><p>indicates that the value is the consequence of a conditional jump. For VT_JMP,
it is 1 if the jump is taken, 0 otherwise. For VT_JMPI it is inverted.
</p>
<p>These values are used to compile the <code>||</code> and <code>&&</code> logical
operators.
</p>
<p>If any code is generated, this value MUST be put in a normal
register. Otherwise, the generated code won’t be executed if the jump is
taken.
</p>
</dd>
<dt> <code>VT_LVAL</code></dt>
<dd><p>is a flag indicating that the value is actually an lvalue (left value of
an assignment). It means that the value stored is actually a pointer to
the wanted value.
</p>
<p>Understanding the use <code>VT_LVAL</code> is very important if you want to
understand how TCC works.
</p>
</dd>
<dt> <code>VT_LVAL_BYTE</code></dt>
<dt> <code>VT_LVAL_SHORT</code></dt>
<dt> <code>VT_LVAL_UNSIGNED</code></dt>
<dd><p>if the lvalue has an integer type, then these flags give its real
type. The type alone is not enough in case of cast optimisations.
</p>
</dd>
<dt> <code>VT_LLOCAL</code></dt>
<dd><p>is a saved lvalue on the stack. <code>VT_LLOCAL</code> should be eliminated
ASAP because its semantics are rather complicated.
</p>
</dd>
<dt> <code>VT_MUSTCAST</code></dt>
<dd><p>indicates that a cast to the value type must be performed if the value
is used (lazy casting).
</p>
</dd>
<dt> <code>VT_SYM</code></dt>
<dd><p>indicates that the symbol <code>SValue.sym</code> must be added to the constant.
</p>
</dd>
<dt> <code>VT_MUSTBOUND</code></dt>
<dt> <code>VT_BOUNDED</code></dt>
<dd><p>are only used for optional bound checking.
</p>
</dd>
</dl>
<hr size="6">
<a name="Manipulating-the-value-stack"></a>
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</tr></table>
<h3 class="subsection">8.7.3 Manipulating the value stack</h3>
<a name="index-value-stack"></a>
<p><code>vsetc()</code> and <code>vset()</code> pushes a new value on the value
stack. If the previous <var>vtop</var> was stored in a very unsafe place(for
example in the CPU flags), then some code is generated to put the
previous <var>vtop</var> in a safe storage.
</p>
<p><code>vpop()</code> pops <var>vtop</var>. In some cases, it also generates cleanup
code (for example if stacked floating point registers are used as on
x86).
</p>
<p>The <code>gv(rc)</code> function generates code to evaluate <var>vtop</var> (the
top value of the stack) into registers. <var>rc</var> selects in which
register class the value should be put. <code>gv()</code> is the <em>most
important function</em> of the code generator.
</p>
<p><code>gv2()</code> is the same as <code>gv()</code> but for the top two stack
entries.
</p>
<hr size="6">
<a name="CPU-dependent-code-generation"></a>
<table cellpadding="1" cellspacing="1" border="0">
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</tr></table>
<h3 class="subsection">8.7.4 CPU dependent code generation</h3>
<a name="index-CPU-dependent"></a>
<p>See the ‘<tt>i386-gen.c</tt>’ file to have an example.
</p>
<dl compact="compact">
<dt> <code>load()</code></dt>
<dd><p>must generate the code needed to load a stack value into a register.
</p>
</dd>
<dt> <code>store()</code></dt>
<dd><p>must generate the code needed to store a register into a stack value
lvalue.
</p>
</dd>
<dt> <code>gfunc_start()</code></dt>
<dt> <code>gfunc_param()</code></dt>
<dt> <code>gfunc_call()</code></dt>
<dd><p>should generate a function call
</p>
</dd>
<dt> <code>gfunc_prolog()</code></dt>
<dt> <code>gfunc_epilog()</code></dt>
<dd><p>should generate a function prolog/epilog.
</p>
</dd>
<dt> <code>gen_opi(op)</code></dt>
<dd><p>must generate the binary integer operation <var>op</var> on the two top
entries of the stack which are guaranted to contain integer types.
</p>
<p>The result value should be put on the stack.
</p>
</dd>
<dt> <code>gen_opf(op)</code></dt>
<dd><p>same as <code>gen_opi()</code> for floating point operations. The two top
entries of the stack are guaranted to contain floating point values of
same types.
</p>
</dd>
<dt> <code>gen_cvt_itof()</code></dt>
<dd><p>integer to floating point conversion.
</p>
</dd>
<dt> <code>gen_cvt_ftoi()</code></dt>
<dd><p>floating point to integer conversion.
</p>
</dd>
<dt> <code>gen_cvt_ftof()</code></dt>
<dd><p>floating point to floating point of different size conversion.
</p>
</dd>
<dt> <code>gen_bounded_ptr_add()</code></dt>
<dt> <code>gen_bounded_ptr_deref()</code></dt>
<dd><p>are only used for bounds checking.
</p>
</dd>
</dl>
<hr size="6">
<a name="Optimizations-done"></a>
<table cellpadding="1" cellspacing="1" border="0">
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</tr></table>
<h2 class="section">8.8 Optimizations done</h2>
<a name="index-optimizations"></a>
<a name="index-constant-propagation"></a>
<a name="index-strength-reduction"></a>
<a name="index-comparison-operators"></a>
<a name="index-caching-processor-flags"></a>
<a name="index-flags_002c-caching"></a>
<a name="index-jump-optimization"></a>
<p>Constant propagation is done for all operations. Multiplications and
divisions are optimized to shifts when appropriate. Comparison
operators are optimized by maintaining a special cache for the
processor flags. &&, || and ! are optimized by maintaining a special
’jump target’ value. No other jump optimization is currently performed
because it would require to store the code in a more abstract fashion.
</p>
<hr size="6">
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<table cellpadding="1" cellspacing="1" border="0">
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<td valign="middle" align="left">[<a href="#SEC_About" title="About (help)"> ? </a>]</td>
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<h1 class="unnumbered">Concept Index</h1>
<table><tr><th valign="top">Jump to: </th><td><a href="#Concept-Index_cp_symbol-1" class="summary-letter"><b>_</b></a>
<br>
<a href="#Concept-Index_cp_letter-A" class="summary-letter"><b>A</b></a>
<a href="#Concept-Index_cp_letter-B" class="summary-letter"><b>B</b></a>
<a href="#Concept-Index_cp_letter-C" class="summary-letter"><b>C</b></a>
<a href="#Concept-Index_cp_letter-D" class="summary-letter"><b>D</b></a>
<a href="#Concept-Index_cp_letter-E" class="summary-letter"><b>E</b></a>
<a href="#Concept-Index_cp_letter-F" class="summary-letter"><b>F</b></a>
<a href="#Concept-Index_cp_letter-G" class="summary-letter"><b>G</b></a>
<a href="#Concept-Index_cp_letter-I" class="summary-letter"><b>I</b></a>
<a href="#Concept-Index_cp_letter-J" class="summary-letter"><b>J</b></a>
<a href="#Concept-Index_cp_letter-L" class="summary-letter"><b>L</b></a>
<a href="#Concept-Index_cp_letter-M" class="summary-letter"><b>M</b></a>
<a href="#Concept-Index_cp_letter-O" class="summary-letter"><b>O</b></a>
<a href="#Concept-Index_cp_letter-P" class="summary-letter"><b>P</b></a>
<a href="#Concept-Index_cp_letter-Q" class="summary-letter"><b>Q</b></a>
<a href="#Concept-Index_cp_letter-R" class="summary-letter"><b>R</b></a>
<a href="#Concept-Index_cp_letter-S" class="summary-letter"><b>S</b></a>
<a href="#Concept-Index_cp_letter-T" class="summary-letter"><b>T</b></a>
<a href="#Concept-Index_cp_letter-U" class="summary-letter"><b>U</b></a>
<a href="#Concept-Index_cp_letter-V" class="summary-letter"><b>V</b></a>
<a href="#Concept-Index_cp_letter-W" class="summary-letter"><b>W</b></a>
</td></tr></table>
<table border="0" class="index-cp">
<tr><td></td><th align="left">Index Entry</th><th align="left"> Section</th></tr>
<tr><td colspan="3"> <hr></td></tr>
<tr><th><a name="Concept-Index_cp_symbol-1">_</a></th><td></td><td></td></tr>
<tr><td></td><td valign="top"><a href="#index-_005f_005fasm_005f_005f">__asm__</a></td><td valign="top"><a href="#GNU-C-extensions">3.3 GNU C extensions</a></td></tr>
<tr><td colspan="3"> <hr></td></tr>
<tr><th><a name="Concept-Index_cp_letter-A">A</a></th><td></td><td></td></tr>
<tr><td></td><td valign="top"><a href="#index-align-directive">align directive</a></td><td valign="top"><a href="#Directives">4.4 Directives</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-aligned-attribute">aligned attribute</a></td><td valign="top"><a href="#GNU-C-extensions">3.3 GNU C extensions</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-ascii-directive">ascii directive</a></td><td valign="top"><a href="#Directives">4.4 Directives</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-asciz-directive">asciz directive</a></td><td valign="top"><a href="#Directives">4.4 Directives</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-assembler">assembler</a></td><td valign="top"><a href="#X86-Assembler">4.5 X86 Assembler</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-assembler-directives">assembler directives</a></td><td valign="top"><a href="#Directives">4.4 Directives</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-assembly_002c-inline">assembly, inline</a></td><td valign="top"><a href="#GNU-C-extensions">3.3 GNU C extensions</a></td></tr>
<tr><td colspan="3"> <hr></td></tr>
<tr><th><a name="Concept-Index_cp_letter-B">B</a></th><td></td><td></td></tr>
<tr><td></td><td valign="top"><a href="#index-bound-checks">bound checks</a></td><td valign="top"><a href="#Bounds">6. TinyCC Memory and Bound checks</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-bss-directive">bss directive</a></td><td valign="top"><a href="#Directives">4.4 Directives</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-byte-directive">byte directive</a></td><td valign="top"><a href="#Directives">4.4 Directives</a></td></tr>
<tr><td colspan="3"> <hr></td></tr>
<tr><th><a name="Concept-Index_cp_letter-C">C</a></th><td></td><td></td></tr>
<tr><td></td><td valign="top"><a href="#index-caching-processor-flags">caching processor flags</a></td><td valign="top"><a href="#Optimizations-done">8.8 Optimizations done</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-cdecl-attribute">cdecl attribute</a></td><td valign="top"><a href="#GNU-C-extensions">3.3 GNU C extensions</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-code-generation">code generation</a></td><td valign="top"><a href="#Code-generation">8.7 Code generation</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-comparison-operators">comparison operators</a></td><td valign="top"><a href="#Optimizations-done">8.8 Optimizations done</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-constant-propagation">constant propagation</a></td><td valign="top"><a href="#Optimizations-done">8.8 Optimizations done</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-CPU-dependent">CPU dependent</a></td><td valign="top"><a href="#CPU-dependent-code-generation">8.7.4 CPU dependent code generation</a></td></tr>
<tr><td colspan="3"> <hr></td></tr>
<tr><th><a name="Concept-Index_cp_letter-D">D</a></th><td></td><td></td></tr>
<tr><td></td><td valign="top"><a href="#index-data-directive">data directive</a></td><td valign="top"><a href="#Directives">4.4 Directives</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-directives_002c-assembler">directives, assembler</a></td><td valign="top"><a href="#Directives">4.4 Directives</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-dllexport-attribute">dllexport attribute</a></td><td valign="top"><a href="#GNU-C-extensions">3.3 GNU C extensions</a></td></tr>
<tr><td colspan="3"> <hr></td></tr>
<tr><th><a name="Concept-Index_cp_letter-E">E</a></th><td></td><td></td></tr>
<tr><td></td><td valign="top"><a href="#index-ELF">ELF</a></td><td valign="top"><a href="#ELF-file-generation">5.1 ELF file generation</a></td></tr>
<tr><td colspan="3"> <hr></td></tr>
<tr><th><a name="Concept-Index_cp_letter-F">F</a></th><td></td><td></td></tr>
<tr><td></td><td valign="top"><a href="#index-FILE_002c-linker-command">FILE, linker command</a></td><td valign="top"><a href="#GNU-Linker-Scripts">5.4 GNU Linker Scripts</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-fill-directive">fill directive</a></td><td valign="top"><a href="#Directives">4.4 Directives</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-flags_002c-caching">flags, caching</a></td><td valign="top"><a href="#Optimizations-done">8.8 Optimizations done</a></td></tr>
<tr><td colspan="3"> <hr></td></tr>
<tr><th><a name="Concept-Index_cp_letter-G">G</a></th><td></td><td></td></tr>
<tr><td></td><td valign="top"><a href="#index-gas">gas</a></td><td valign="top"><a href="#GNU-C-extensions">3.3 GNU C extensions</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-global-directive">global directive</a></td><td valign="top"><a href="#Directives">4.4 Directives</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-globl-directive">globl directive</a></td><td valign="top"><a href="#Directives">4.4 Directives</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-GROUP_002c-linker-command">GROUP, linker command</a></td><td valign="top"><a href="#GNU-Linker-Scripts">5.4 GNU Linker Scripts</a></td></tr>
<tr><td colspan="3"> <hr></td></tr>
<tr><th><a name="Concept-Index_cp_letter-I">I</a></th><td></td><td></td></tr>
<tr><td></td><td valign="top"><a href="#index-inline-assembly">inline assembly</a></td><td valign="top"><a href="#GNU-C-extensions">3.3 GNU C extensions</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-int-directive">int directive</a></td><td valign="top"><a href="#Directives">4.4 Directives</a></td></tr>
<tr><td colspan="3"> <hr></td></tr>
<tr><th><a name="Concept-Index_cp_letter-J">J</a></th><td></td><td></td></tr>
<tr><td></td><td valign="top"><a href="#index-jump-optimization">jump optimization</a></td><td valign="top"><a href="#Optimizations-done">8.8 Optimizations done</a></td></tr>
<tr><td colspan="3"> <hr></td></tr>
<tr><th><a name="Concept-Index_cp_letter-L">L</a></th><td></td><td></td></tr>
<tr><td></td><td valign="top"><a href="#index-linker">linker</a></td><td valign="top"><a href="#linker">5. TinyCC Linker</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-linker-scripts">linker scripts</a></td><td valign="top"><a href="#GNU-Linker-Scripts">5.4 GNU Linker Scripts</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-long-directive">long directive</a></td><td valign="top"><a href="#Directives">4.4 Directives</a></td></tr>
<tr><td colspan="3"> <hr></td></tr>
<tr><th><a name="Concept-Index_cp_letter-M">M</a></th><td></td><td></td></tr>
<tr><td></td><td valign="top"><a href="#index-memory-checks">memory checks</a></td><td valign="top"><a href="#Bounds">6. TinyCC Memory and Bound checks</a></td></tr>
<tr><td colspan="3"> <hr></td></tr>
<tr><th><a name="Concept-Index_cp_letter-O">O</a></th><td></td><td></td></tr>
<tr><td></td><td valign="top"><a href="#index-optimizations">optimizations</a></td><td valign="top"><a href="#Optimizations-done">8.8 Optimizations done</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-org-directive">org directive</a></td><td valign="top"><a href="#Directives">4.4 Directives</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-OUTPUT_005fFORMAT_002c-linker-command">OUTPUT_FORMAT, linker command</a></td><td valign="top"><a href="#GNU-Linker-Scripts">5.4 GNU Linker Scripts</a></td></tr>
<tr><td colspan="3"> <hr></td></tr>
<tr><th><a name="Concept-Index_cp_letter-P">P</a></th><td></td><td></td></tr>
<tr><td></td><td valign="top"><a href="#index-packed-attribute">packed attribute</a></td><td valign="top"><a href="#GNU-C-extensions">3.3 GNU C extensions</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-PE_002di386">PE-i386</a></td><td valign="top"><a href="#PE_002di386-file-generation">5.3 PE-i386 file generation</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-previous-directive">previous directive</a></td><td valign="top"><a href="#Directives">4.4 Directives</a></td></tr>
<tr><td colspan="3"> <hr></td></tr>
<tr><th><a name="Concept-Index_cp_letter-Q">Q</a></th><td></td><td></td></tr>
<tr><td></td><td valign="top"><a href="#index-quad-directive">quad directive</a></td><td valign="top"><a href="#Directives">4.4 Directives</a></td></tr>
<tr><td colspan="3"> <hr></td></tr>
<tr><th><a name="Concept-Index_cp_letter-R">R</a></th><td></td><td></td></tr>
<tr><td></td><td valign="top"><a href="#index-regparm-attribute">regparm attribute</a></td><td valign="top"><a href="#GNU-C-extensions">3.3 GNU C extensions</a></td></tr>
<tr><td colspan="3"> <hr></td></tr>
<tr><th><a name="Concept-Index_cp_letter-S">S</a></th><td></td><td></td></tr>
<tr><td></td><td valign="top"><a href="#index-scripts_002c-linker">scripts, linker</a></td><td valign="top"><a href="#GNU-Linker-Scripts">5.4 GNU Linker Scripts</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-section-attribute">section attribute</a></td><td valign="top"><a href="#GNU-C-extensions">3.3 GNU C extensions</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-section-directive">section directive</a></td><td valign="top"><a href="#Directives">4.4 Directives</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-short-directive">short directive</a></td><td valign="top"><a href="#Directives">4.4 Directives</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-skip-directive">skip directive</a></td><td valign="top"><a href="#Directives">4.4 Directives</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-space-directive">space directive</a></td><td valign="top"><a href="#Directives">4.4 Directives</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-stdcall-attribute">stdcall attribute</a></td><td valign="top"><a href="#GNU-C-extensions">3.3 GNU C extensions</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-strength-reduction">strength reduction</a></td><td valign="top"><a href="#Optimizations-done">8.8 Optimizations done</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-string-directive">string directive</a></td><td valign="top"><a href="#Directives">4.4 Directives</a></td></tr>
<tr><td colspan="3"> <hr></td></tr>
<tr><th><a name="Concept-Index_cp_letter-T">T</a></th><td></td><td></td></tr>
<tr><td></td><td valign="top"><a href="#index-TARGET_002c-linker-command">TARGET, linker command</a></td><td valign="top"><a href="#GNU-Linker-Scripts">5.4 GNU Linker Scripts</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-text-directive">text directive</a></td><td valign="top"><a href="#Directives">4.4 Directives</a></td></tr>
<tr><td colspan="3"> <hr></td></tr>
<tr><th><a name="Concept-Index_cp_letter-U">U</a></th><td></td><td></td></tr>
<tr><td></td><td valign="top"><a href="#index-unused-attribute">unused attribute</a></td><td valign="top"><a href="#GNU-C-extensions">3.3 GNU C extensions</a></td></tr>
<tr><td colspan="3"> <hr></td></tr>
<tr><th><a name="Concept-Index_cp_letter-V">V</a></th><td></td><td></td></tr>
<tr><td></td><td valign="top"><a href="#index-value-stack">value stack</a></td><td valign="top"><a href="#Manipulating-the-value-stack">8.7.3 Manipulating the value stack</a></td></tr>
<tr><td></td><td valign="top"><a href="#index-value-stack_002c-introduction">value stack, introduction</a></td><td valign="top"><a href="#The-value-stack">8.7.2 The value stack</a></td></tr>
<tr><td colspan="3"> <hr></td></tr>
<tr><th><a name="Concept-Index_cp_letter-W">W</a></th><td></td><td></td></tr>
<tr><td></td><td valign="top"><a href="#index-word-directive">word directive</a></td><td valign="top"><a href="#Directives">4.4 Directives</a></td></tr>
<tr><td colspan="3"> <hr></td></tr>
</table>
<table><tr><th valign="top">Jump to: </th><td><a href="#Concept-Index_cp_symbol-1" class="summary-letter"><b>_</b></a>
<br>
<a href="#Concept-Index_cp_letter-A" class="summary-letter"><b>A</b></a>
<a href="#Concept-Index_cp_letter-B" class="summary-letter"><b>B</b></a>
<a href="#Concept-Index_cp_letter-C" class="summary-letter"><b>C</b></a>
<a href="#Concept-Index_cp_letter-D" class="summary-letter"><b>D</b></a>
<a href="#Concept-Index_cp_letter-E" class="summary-letter"><b>E</b></a>
<a href="#Concept-Index_cp_letter-F" class="summary-letter"><b>F</b></a>
<a href="#Concept-Index_cp_letter-G" class="summary-letter"><b>G</b></a>
<a href="#Concept-Index_cp_letter-I" class="summary-letter"><b>I</b></a>
<a href="#Concept-Index_cp_letter-J" class="summary-letter"><b>J</b></a>
<a href="#Concept-Index_cp_letter-L" class="summary-letter"><b>L</b></a>
<a href="#Concept-Index_cp_letter-M" class="summary-letter"><b>M</b></a>
<a href="#Concept-Index_cp_letter-O" class="summary-letter"><b>O</b></a>
<a href="#Concept-Index_cp_letter-P" class="summary-letter"><b>P</b></a>
<a href="#Concept-Index_cp_letter-Q" class="summary-letter"><b>Q</b></a>
<a href="#Concept-Index_cp_letter-R" class="summary-letter"><b>R</b></a>
<a href="#Concept-Index_cp_letter-S" class="summary-letter"><b>S</b></a>
<a href="#Concept-Index_cp_letter-T" class="summary-letter"><b>T</b></a>
<a href="#Concept-Index_cp_letter-U" class="summary-letter"><b>U</b></a>
<a href="#Concept-Index_cp_letter-V" class="summary-letter"><b>V</b></a>
<a href="#Concept-Index_cp_letter-W" class="summary-letter"><b>W</b></a>
</td></tr></table>
<hr size="6">
<a name="SEC_Contents"></a>
<table cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<h1>Table of Contents</h1>
<div class="contents">
<ul class="toc">
<li><a name="toc-Introduction-1" href="#Introduction">1. Introduction</a></li>
<li><a name="toc-Command-line-invocation" href="#Invoke">2. Command line invocation</a>
<ul class="toc">
<li><a name="toc-Quick-start" href="#Quick-start">2.1 Quick start</a></li>
<li><a name="toc-Option-summary" href="#Option-summary">2.2 Option summary</a></li>
</ul></li>
<li><a name="toc-C-language-support" href="#Clang">3. C language support</a>
<ul class="toc">
<li><a name="toc-ANSI-C" href="#ANSI-C">3.1 ANSI C</a></li>
<li><a name="toc-ISOC99-extensions" href="#ISOC99-extensions">3.2 ISOC99 extensions</a></li>
<li><a name="toc-GNU-C-extensions" href="#GNU-C-extensions">3.3 GNU C extensions</a></li>
<li><a name="toc-TinyCC-extensions" href="#TinyCC-extensions">3.4 TinyCC extensions</a></li>
</ul></li>
<li><a name="toc-TinyCC-Assembler" href="#asm">4. TinyCC Assembler</a>
<ul class="toc">
<li><a name="toc-Syntax" href="#Syntax">4.1 Syntax</a></li>
<li><a name="toc-Expressions" href="#Expressions">4.2 Expressions</a></li>
<li><a name="toc-Labels" href="#Labels">4.3 Labels</a></li>
<li><a name="toc-Directives" href="#Directives">4.4 Directives</a></li>
<li><a name="toc-X86-Assembler" href="#X86-Assembler">4.5 X86 Assembler</a></li>
</ul></li>
<li><a name="toc-TinyCC-Linker" href="#linker">5. TinyCC Linker</a>
<ul class="toc">
<li><a name="toc-ELF-file-generation" href="#ELF-file-generation">5.1 ELF file generation</a></li>
<li><a name="toc-ELF-file-loader" href="#ELF-file-loader">5.2 ELF file loader</a></li>
<li><a name="toc-PE_002di386-file-generation" href="#PE_002di386-file-generation">5.3 PE-i386 file generation</a></li>
<li><a name="toc-GNU-Linker-Scripts" href="#GNU-Linker-Scripts">5.4 GNU Linker Scripts</a></li>
</ul></li>
<li><a name="toc-TinyCC-Memory-and-Bound-checks" href="#Bounds">6. TinyCC Memory and Bound checks</a></li>
<li><a name="toc-The-libtcc-library" href="#Libtcc">7. The <code>libtcc</code> library</a></li>
<li><a name="toc-Developer_0027s-guide" href="#devel">8. Developer’s guide</a>
<ul class="toc">
<li><a name="toc-File-reading" href="#File-reading">8.1 File reading</a></li>
<li><a name="toc-Lexer" href="#Lexer">8.2 Lexer</a></li>
<li><a name="toc-Parser" href="#Parser">8.3 Parser</a></li>
<li><a name="toc-Types" href="#Types">8.4 Types</a></li>
<li><a name="toc-Symbols" href="#Symbols">8.5 Symbols</a></li>
<li><a name="toc-Sections" href="#Sections">8.6 Sections</a></li>
<li><a name="toc-Code-generation" href="#Code-generation">8.7 Code generation</a>
<ul class="toc">
<li><a name="toc-Introduction-2" href="#Introduction-2">8.7.1 Introduction</a></li>
<li><a name="toc-The-value-stack" href="#The-value-stack">8.7.2 The value stack</a></li>
<li><a name="toc-Manipulating-the-value-stack" href="#Manipulating-the-value-stack">8.7.3 Manipulating the value stack</a></li>
<li><a name="toc-CPU-dependent-code-generation" href="#CPU-dependent-code-generation">8.7.4 CPU dependent code generation</a></li>
</ul></li>
<li><a name="toc-Optimizations-done" href="#Optimizations-done">8.8 Optimizations done</a></li>
</ul></li>
<li><a name="toc-Concept-Index" href="#Concept-Index">Concept Index</a></li>
</ul>
</div>
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<tr><td valign="middle" align="left">[<a href="#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<h1>About This Document</h1>
<p>
This document was generated by <em>Thomas Preud'homme</em> on <em>February 15, 2013</em> using <a href="http://www.nongnu.org/texi2html/"><em>texi2html 1.82</em></a>.
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<td align="center">Back</td>
<td>Previous section in reading order</td>
<td>1.2.2</td>
</tr>
<tr>
<td align="center"> [ > ] </td>
<td align="center">Forward</td>
<td>Next section in reading order</td>
<td>1.2.4</td>
</tr>
<tr>
<td align="center"> [ << ] </td>
<td align="center">FastBack</td>
<td>Beginning of this chapter or previous chapter</td>
<td>1</td>
</tr>
<tr>
<td align="center"> [ Up ] </td>
<td align="center">Up</td>
<td>Up section</td>
<td>1.2</td>
</tr>
<tr>
<td align="center"> [ >> ] </td>
<td align="center">FastForward</td>
<td>Next chapter</td>
<td>2</td>
</tr>
<tr>
<td align="center"> [Top] </td>
<td align="center">Top</td>
<td>Cover (top) of document</td>
<td> </td>
</tr>
<tr>
<td align="center"> [Contents] </td>
<td align="center">Contents</td>
<td>Table of contents</td>
<td> </td>
</tr>
<tr>
<td align="center"> [Index] </td>
<td align="center">Index</td>
<td>Index</td>
<td> </td>
</tr>
<tr>
<td align="center"> [ ? ] </td>
<td align="center">About</td>
<td>About (help)</td>
<td> </td>
</tr>
</table>
<p>
where the <strong> Example </strong> assumes that the current position is at <strong> Subsubsection One-Two-Three </strong> of a document of the following structure:
</p>
<ul>
<li> 1. Section One
<ul>
<li>1.1 Subsection One-One
<ul>
<li>...</li>
</ul>
</li>
<li>1.2 Subsection One-Two
<ul>
<li>1.2.1 Subsubsection One-Two-One</li>
<li>1.2.2 Subsubsection One-Two-Two</li>
<li>1.2.3 Subsubsection One-Two-Three
<strong><== Current Position </strong></li>
<li>1.2.4 Subsubsection One-Two-Four</li>
</ul>
</li>
<li>1.3 Subsection One-Three
<ul>
<li>...</li>
</ul>
</li>
<li>1.4 Subsection One-Four</li>
</ul>
</li>
</ul>
<hr size="1">
<p>
<font size="-1">
This document was generated by <em>Thomas Preud'homme</em> on <em>February 15, 2013</em> using <a href="http://www.nongnu.org/texi2html/"><em>texi2html 1.82</em></a>.
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