printer.h
#ifndef HALIDE_RUNTIME_PRINTER_H
#define HALIDE_RUNTIME_PRINTER_H
namespace Halide {
namespace Runtime {
namespace Internal {
enum PrinterType { BasicPrinter = 0,
ErrorPrinter = 1,
StringStreamPrinter = 2 };
// A class for constructing debug messages from the runtime. Dumps
// items into a stack array, then prints them when the object leaves
// scope using halide_print. Think of it as a stringstream that prints
// when it dies. Use it like this:
// debug(user_context) << "A" << b << c << "\n";
// If you use it like this:
// debug d(user_context);
// d << "A";
// d << b;
// d << c << "\n";
// Then remember the print only happens when the debug object leaves
// scope, which may print at a confusing time.
namespace {
template<int type, uint64_t length = 1024>
class Printer {
public:
char *buf, *dst, *end;
void *user_context;
bool own_mem;
char scratch[length <= 256 ? length : 1];
Printer(void *ctx, char *mem = nullptr)
: user_context(ctx), own_mem(mem == nullptr) {
if (mem != nullptr) {
buf = mem;
} else if (length <= sizeof(scratch)) {
buf = scratch;
} else {
buf = (char *)malloc(length);
}
dst = buf;
if (dst) {
end = buf + (length - 1);
*end = 0;
} else {
// Pointers equal ensures no writes to buffer via formatting code
end = dst;
}
}
Printer &operator<<(const char *arg) {
// Crashing on nullptr here is a big debugging time sink.
if (arg == nullptr) {
dst = halide_string_to_string(dst, end, "<nullptr>");
} else {
dst = halide_string_to_string(dst, end, arg);
}
return *this;
}
Printer &operator<<(int64_t arg) {
dst = halide_int64_to_string(dst, end, arg, 1);
return *this;
}
Printer &operator<<(int32_t arg) {
dst = halide_int64_to_string(dst, end, arg, 1);
return *this;
}
Printer &operator<<(uint64_t arg) {
dst = halide_uint64_to_string(dst, end, arg, 1);
return *this;
}
Printer &operator<<(uint32_t arg) {
dst = halide_uint64_to_string(dst, end, arg, 1);
return *this;
}
Printer &operator<<(double arg) {
dst = halide_double_to_string(dst, end, arg, 1);
return *this;
}
Printer &operator<<(float arg) {
dst = halide_double_to_string(dst, end, arg, 0);
return *this;
}
Printer &operator<<(const void *arg) {
dst = halide_pointer_to_string(dst, end, arg);
return *this;
}
Printer &write_float16_from_bits(const uint16_t arg) {
double value = halide_float16_bits_to_double(arg);
dst = halide_double_to_string(dst, end, value, 1);
return *this;
}
Printer &operator<<(const halide_type_t &t) {
dst = halide_type_to_string(dst, end, &t);
return *this;
}
Printer &operator<<(const halide_buffer_t &buf) {
dst = halide_buffer_to_string(dst, end, &buf);
return *this;
}
// Use it like a stringstream.
const char *str() {
if (buf) {
if (type == StringStreamPrinter) {
msan_annotate_is_initialized();
}
return buf;
} else {
return allocation_error();
}
}
// Clear it. Useful for reusing a stringstream.
void clear() {
dst = buf;
if (dst) {
dst[0] = 0;
}
}
// Returns the number of characters in the buffer
uint64_t size() const {
return (uint64_t)(dst - buf);
}
uint64_t capacity() const {
return length;
}
// Delete the last N characters
void erase(int n) {
if (dst) {
dst -= n;
if (dst < buf) {
dst = buf;
}
dst[0] = 0;
}
}
const char *allocation_error() {
return "Printer buffer allocation failed.\n";
}
void msan_annotate_is_initialized() {
(void)halide_msan_annotate_memory_is_initialized(user_context, buf, dst - buf + 1);
}
~Printer() {
if (!buf) {
halide_error(user_context, allocation_error());
} else {
msan_annotate_is_initialized();
if (type == ErrorPrinter) {
halide_error(user_context, buf);
} else if (type == BasicPrinter) {
halide_print(user_context, buf);
} else {
// It's a stringstream. Do nothing.
}
}
if (own_mem && buf != scratch) {
free(buf);
}
}
};
// A class that supports << with all the same types as Printer, but
// does nothing and should compile to a no-op.
class SinkPrinter {
public:
SinkPrinter(void *user_context) {
}
};
template<typename T>
SinkPrinter operator<<(const SinkPrinter &s, T) {
return s;
}
typedef Printer<BasicPrinter> print;
typedef Printer<ErrorPrinter> error;
typedef Printer<StringStreamPrinter> stringstream;
#ifdef DEBUG_RUNTIME
typedef Printer<BasicPrinter> debug;
#else
typedef SinkPrinter debug;
#endif
} // namespace
} // namespace Internal
} // namespace Runtime
} // namespace Halide
#endif