llvm-config.cpp
//===-- llvm-config.cpp - LLVM project configuration utility --------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This tool encapsulates information about an LLVM project configuration for
// use by other project's build environments (to determine installed path,
// available features, required libraries, etc.).
//
// Note that although this tool *may* be used by some parts of LLVM's build
// itself (i.e., the Makefiles use it to compute required libraries when linking
// tools), this tool is primarily designed to support external projects.
//
//===----------------------------------------------------------------------===//
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Config/config.h"
#include "llvm/Config/llvm-config.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/raw_ostream.h"
#include <cstdlib>
#include <set>
#include <vector>
using namespace llvm;
// Include the build time variables we can report to the user. This is generated
// at build time from the BuildVariables.inc.in file by the build system.
#include "BuildVariables.inc"
// Include the component table. This creates an array of struct
// AvailableComponent entries, which record the component name, library name,
// and required components for all of the available libraries.
//
// Not all components define a library, we also use "library groups" as a way to
// create entries for pseudo groups like x86 or all-targets.
#include "LibraryDependencies.inc"
/// \brief Traverse a single component adding to the topological ordering in
/// \arg RequiredLibs.
///
/// \param Name - The component to traverse.
/// \param ComponentMap - A prebuilt map of component names to descriptors.
/// \param VisitedComponents [in] [out] - The set of already visited components.
/// \param RequiredLibs [out] - The ordered list of required libraries.
static void VisitComponent(StringRef Name,
const StringMap<AvailableComponent*> &ComponentMap,
std::set<AvailableComponent*> &VisitedComponents,
std::vector<StringRef> &RequiredLibs) {
// Lookup the component.
AvailableComponent *AC = ComponentMap.lookup(Name);
assert(AC && "Invalid component name!");
// Add to the visited table.
if (!VisitedComponents.insert(AC).second) {
// We are done if the component has already been visited.
return;
}
// Otherwise, visit all the dependencies.
for (unsigned i = 0; AC->RequiredLibraries[i]; ++i) {
VisitComponent(AC->RequiredLibraries[i], ComponentMap, VisitedComponents,
RequiredLibs);
}
// Add to the required library list.
if (AC->Library)
RequiredLibs.push_back(AC->Library);
}
/// \brief Compute the list of required libraries for a given list of
/// components, in an order suitable for passing to a linker (that is, libraries
/// appear prior to their dependencies).
///
/// \param Components - The names of the components to find libraries for.
/// \param RequiredLibs [out] - On return, the ordered list of libraries that
/// are required to link the given components.
void ComputeLibsForComponents(const std::vector<StringRef> &Components,
std::vector<StringRef> &RequiredLibs) {
std::set<AvailableComponent*> VisitedComponents;
// Build a map of component names to information.
StringMap<AvailableComponent*> ComponentMap;
for (unsigned i = 0; i != array_lengthof(AvailableComponents); ++i) {
AvailableComponent *AC = &AvailableComponents[i];
ComponentMap[AC->Name] = AC;
}
// Visit the components.
for (unsigned i = 0, e = Components.size(); i != e; ++i) {
// Users are allowed to provide mixed case component names.
std::string ComponentLower = Components[i].lower();
// Validate that the user supplied a valid component name.
if (!ComponentMap.count(ComponentLower)) {
llvm::errs() << "llvm-config: unknown component name: " << Components[i]
<< "\n";
exit(1);
}
VisitComponent(ComponentLower, ComponentMap, VisitedComponents,
RequiredLibs);
}
// The list is now ordered with leafs first, we want the libraries to printed
// in the reverse order of dependency.
std::reverse(RequiredLibs.begin(), RequiredLibs.end());
}
/* *** */
void usage() {
errs() << "\
usage: llvm-config <OPTION>... [<COMPONENT>...]\n\
\n\
Get various configuration information needed to compile programs which use\n\
LLVM. Typically called from 'configure' scripts. Examples:\n\
llvm-config --cxxflags\n\
llvm-config --ldflags\n\
llvm-config --libs engine bcreader scalaropts\n\
\n\
Options:\n\
--version Print LLVM version.\n\
--prefix Print the installation prefix.\n\
--src-root Print the source root LLVM was built from.\n\
--obj-root Print the object root used to build LLVM.\n\
--bindir Directory containing LLVM executables.\n\
--includedir Directory containing LLVM headers.\n\
--libdir Directory containing LLVM libraries.\n\
--cppflags C preprocessor flags for files that include LLVM headers.\n\
--cflags C compiler flags for files that include LLVM headers.\n\
--cxxflags C++ compiler flags for files that include LLVM headers.\n\
--ldflags Print Linker flags.\n\
--libs Libraries needed to link against LLVM components.\n\
--libnames Bare library names for in-tree builds.\n\
--libfiles Fully qualified library filenames for makefile depends.\n\
--components List of all possible components.\n\
--targets-built List of all targets currently built.\n\
--host-target Target triple used to configure LLVM.\n\
--build-mode Print build mode of LLVM tree (e.g. Debug or Release).\n\
Typical components:\n\
all All LLVM libraries (default).\n\
engine Either a native JIT or a bitcode interpreter.\n";
exit(1);
}
/// \brief Compute the path to the main executable.
llvm::sys::Path GetExecutablePath(const char *Argv0) {
// This just needs to be some symbol in the binary; C++ doesn't
// allow taking the address of ::main however.
void *P = (void*) (intptr_t) GetExecutablePath;
return llvm::sys::Path::GetMainExecutable(Argv0, P);
}
int main(int argc, char **argv) {
std::vector<StringRef> Components;
bool PrintLibs = false, PrintLibNames = false, PrintLibFiles = false;
bool HasAnyOption = false;
// llvm-config is designed to support being run both from a development tree
// and from an installed path. We try and auto-detect which case we are in so
// that we can report the correct information when run from a development
// tree.
bool IsInDevelopmentTree;
enum { MakefileStyle, CMakeStyle, CMakeBuildModeStyle } DevelopmentTreeLayout;
llvm::SmallString<256> CurrentPath(GetExecutablePath(argv[0]).str());
std::string CurrentExecPrefix;
std::string ActiveObjRoot;
// Create an absolute path, and pop up one directory (we expect to be inside a
// bin dir).
sys::fs::make_absolute(CurrentPath);
CurrentExecPrefix = sys::path::parent_path(
sys::path::parent_path(CurrentPath)).str();
// Check to see if we are inside a development tree by comparing to possible
// locations (prefix style or CMake style). This could be wrong in the face of
// symbolic links, but is good enough.
if (CurrentExecPrefix == std::string(LLVM_OBJ_ROOT) + "/" + LLVM_BUILDMODE) {
IsInDevelopmentTree = true;
DevelopmentTreeLayout = MakefileStyle;
// If we are in a development tree, then check if we are in a BuildTools
// directory. This indicates we are built for the build triple, but we
// always want to provide information for the host triple.
if (sys::path::filename(LLVM_OBJ_ROOT) == "BuildTools") {
ActiveObjRoot = sys::path::parent_path(LLVM_OBJ_ROOT);
} else {
ActiveObjRoot = LLVM_OBJ_ROOT;
}
} else if (CurrentExecPrefix == std::string(LLVM_OBJ_ROOT)) {
IsInDevelopmentTree = true;
DevelopmentTreeLayout = CMakeStyle;
ActiveObjRoot = LLVM_OBJ_ROOT;
} else if (CurrentExecPrefix == std::string(LLVM_OBJ_ROOT) + "/bin") {
IsInDevelopmentTree = true;
DevelopmentTreeLayout = CMakeBuildModeStyle;
ActiveObjRoot = LLVM_OBJ_ROOT;
} else {
IsInDevelopmentTree = false;
DevelopmentTreeLayout = MakefileStyle; // Initialized to avoid warnings.
}
// Compute various directory locations based on the derived location
// information.
std::string ActivePrefix, ActiveBinDir, ActiveIncludeDir, ActiveLibDir;
std::string ActiveIncludeOption;
if (IsInDevelopmentTree) {
ActiveIncludeDir = std::string(LLVM_SRC_ROOT) + "/include";
ActivePrefix = CurrentExecPrefix;
// CMake organizes the products differently than a normal prefix style
// layout.
switch (DevelopmentTreeLayout) {
case MakefileStyle:
ActiveBinDir = ActiveObjRoot + "/" + LLVM_BUILDMODE + "/bin";
ActiveLibDir = ActiveObjRoot + "/" + LLVM_BUILDMODE + "/lib";
break;
case CMakeStyle:
ActiveBinDir = ActiveObjRoot + "/bin";
ActiveLibDir = ActiveObjRoot + "/lib";
break;
case CMakeBuildModeStyle:
ActiveBinDir = ActiveObjRoot + "/bin/" + LLVM_BUILDMODE;
ActiveLibDir = ActiveObjRoot + "/lib/" + LLVM_BUILDMODE;
break;
}
// We need to include files from both the source and object trees.
ActiveIncludeOption = ("-I" + ActiveIncludeDir + " " +
"-I" + ActiveObjRoot + "/include");
} else {
ActivePrefix = CurrentExecPrefix;
ActiveIncludeDir = ActivePrefix + "/include";
ActiveBinDir = ActivePrefix + "/bin";
ActiveLibDir = ActivePrefix + "/lib";
ActiveIncludeOption = "-I" + ActiveIncludeDir;
}
raw_ostream &OS = outs();
for (int i = 1; i != argc; ++i) {
StringRef Arg = argv[i];
if (Arg.startswith("-")) {
HasAnyOption = true;
if (Arg == "--version") {
OS << PACKAGE_VERSION << '\n';
} else if (Arg == "--prefix") {
OS << ActivePrefix << '\n';
} else if (Arg == "--bindir") {
OS << ActiveBinDir << '\n';
} else if (Arg == "--includedir") {
OS << ActiveIncludeDir << '\n';
} else if (Arg == "--libdir") {
OS << ActiveLibDir << '\n';
} else if (Arg == "--cppflags") {
OS << ActiveIncludeOption << ' ' << LLVM_CPPFLAGS << '\n';
} else if (Arg == "--cflags") {
OS << ActiveIncludeOption << ' ' << LLVM_CFLAGS << '\n';
} else if (Arg == "--cxxflags") {
OS << ActiveIncludeOption << ' ' << LLVM_CXXFLAGS << '\n';
} else if (Arg == "--ldflags") {
OS << "-L" << ActiveLibDir << ' ' << LLVM_LDFLAGS
<< ' ' << LLVM_SYSTEM_LIBS << '\n';
} else if (Arg == "--libs") {
PrintLibs = true;
} else if (Arg == "--libnames") {
PrintLibNames = true;
} else if (Arg == "--libfiles") {
PrintLibFiles = true;
} else if (Arg == "--components") {
for (unsigned j = 0; j != array_lengthof(AvailableComponents); ++j) {
OS << ' ';
OS << AvailableComponents[j].Name;
}
OS << '\n';
} else if (Arg == "--targets-built") {
OS << LLVM_TARGETS_BUILT << '\n';
} else if (Arg == "--host-target") {
OS << LLVM_DEFAULT_TARGET_TRIPLE << '\n';
} else if (Arg == "--build-mode") {
OS << LLVM_BUILDMODE << '\n';
} else if (Arg == "--obj-root") {
OS << LLVM_OBJ_ROOT << '\n';
} else if (Arg == "--src-root") {
OS << LLVM_SRC_ROOT << '\n';
} else {
usage();
}
} else {
Components.push_back(Arg);
}
}
if (!HasAnyOption)
usage();
if (PrintLibs || PrintLibNames || PrintLibFiles) {
// If no components were specified, default to "all".
if (Components.empty())
Components.push_back("all");
// Construct the list of all the required libraries.
std::vector<StringRef> RequiredLibs;
ComputeLibsForComponents(Components, RequiredLibs);
for (unsigned i = 0, e = RequiredLibs.size(); i != e; ++i) {
StringRef Lib = RequiredLibs[i];
if (i)
OS << ' ';
if (PrintLibNames) {
OS << Lib;
} else if (PrintLibFiles) {
OS << ActiveLibDir << '/' << Lib;
} else if (PrintLibs) {
// If this is a typical library name, include it using -l.
if (Lib.startswith("lib") && Lib.endswith(".a")) {
OS << "-l" << Lib.slice(3, Lib.size()-2);
continue;
}
// Otherwise, print the full path.
OS << ActiveLibDir << '/' << Lib;
}
}
OS << '\n';
} else if (!Components.empty()) {
errs() << "llvm-config: error: components given, but unused\n\n";
usage();
}
return 0;
}
