blob: f2dc4f79881f205756f70deb4de10f4da6bdc9ec [file] [log] [blame]
/*===- GCDAProfiling.c - Support library for GCDA file emission -----------===*\
|*
|* The LLVM Compiler Infrastructure
|*
|* This file is distributed under the University of Illinois Open Source
|* License. See LICENSE.TXT for details.
|*
|*===----------------------------------------------------------------------===*|
|*
|* This file implements the call back routines for the gcov profiling
|* instrumentation pass. Link against this library when running code through
|* the -insert-gcov-profiling LLVM pass.
|*
|* We emit files in a corrupt version of GCOV's "gcda" file format. These files
|* are only close enough that LCOV will happily parse them. Anything that lcov
|* ignores is missing.
|*
|* TODO: gcov is multi-process safe by having each exit open the existing file
|* and append to it. We'd like to achieve that and be thread-safe too.
|*
\*===----------------------------------------------------------------------===*/
#include "llvm/Support/DataTypes.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#ifdef _WIN32
#include <direct.h>
#endif
/* #define DEBUG_GCDAPROFILING */
/*
* --- GCOV file format I/O primitives ---
*/
static FILE *output_file = NULL;
static void write_int32(uint32_t i) {
fwrite(&i, 4, 1, output_file);
}
static void write_int64(uint64_t i) {
uint32_t lo = i >> 0;
uint32_t hi = i >> 32;
write_int32(lo);
write_int32(hi);
}
static uint32_t length_of_string(const char *s) {
return (strlen(s) / 4) + 1;
}
static void write_string(const char *s) {
uint32_t len = length_of_string(s);
write_int32(len);
fwrite(s, strlen(s), 1, output_file);
fwrite("\0\0\0\0", 4 - (strlen(s) % 4), 1, output_file);
}
static char *mangle_filename(const char *orig_filename) {
/* TODO: handle GCOV_PREFIX_STRIP */
const char *prefix;
char *filename = 0;
prefix = getenv("GCOV_PREFIX");
if (!prefix)
return strdup(orig_filename);
filename = malloc(strlen(prefix) + 1 + strlen(orig_filename) + 1);
strcpy(filename, prefix);
strcat(filename, "/");
strcat(filename, orig_filename);
return filename;
}
static void recursive_mkdir(const char *filename) {
char *pathname;
int i, e;
for (i = 1, e = strlen(filename); i != e; ++i) {
if (filename[i] != '/') continue;
pathname = malloc(i + 1);
strncpy(pathname, filename, i);
pathname[i] = '\0';
#ifdef _WIN32
_mkdir(pathname);
#else
mkdir(pathname, 0750); /* some of these will fail, ignore it. */
#endif
free(pathname);
}
}
/*
* --- LLVM line counter API ---
*/
/* A file in this case is a translation unit. Each .o file built with line
* profiling enabled will emit to a different file. Only one file may be
* started at a time.
*/
void llvm_gcda_start_file(const char *orig_filename) {
char *filename;
filename = mangle_filename(orig_filename);
recursive_mkdir(filename);
output_file = fopen(filename, "w+b");
if (!output_file) {
const char *cptr = strrchr(orig_filename, '/');
output_file = fopen(cptr ? cptr + 1 : orig_filename, "w+b");
if (!output_file) {
fprintf(stderr, "LLVM profiling runtime: cannot open '%s': ",
cptr ? cptr + 1 : orig_filename);
perror("");
free(filename);
return;
}
}
/* gcda file, version 404*, stamp LLVM. */
#ifdef __APPLE__
fwrite("adcg*204MVLL", 12, 1, output_file);
#else
fwrite("adcg*404MVLL", 12, 1, output_file);
#endif
#ifdef DEBUG_GCDAPROFILING
printf("llvmgcda: [%s]\n", orig_filename);
#endif
free(filename);
}
/* Given an array of pointers to counters (counters), increment the n-th one,
* where we're also given a pointer to n (predecessor).
*/
void llvm_gcda_increment_indirect_counter(uint32_t *predecessor,
uint64_t **counters) {
uint64_t *counter;
uint32_t pred;
pred = *predecessor;
if (pred == 0xffffffff)
return;
counter = counters[pred];
/* Don't crash if the pred# is out of sync. This can happen due to threads,
or because of a TODO in GCOVProfiling.cpp buildEdgeLookupTable(). */
if (counter)
++*counter;
#ifdef DEBUG_GCDAPROFILING
else
printf("llvmgcda: increment_indirect_counter counters=%x, pred=%u\n",
state_table_row, *predecessor);
#endif
}
void llvm_gcda_emit_function(uint32_t ident, const char *function_name) {
#ifdef DEBUG_GCDAPROFILING
printf("llvmgcda: function id=%x\n", ident);
#endif
if (!output_file) return;
/* function tag */
fwrite("\0\0\0\1", 4, 1, output_file);
write_int32(3 + 1 + length_of_string(function_name));
write_int32(ident);
write_int32(0);
write_int32(0);
write_string(function_name);
}
void llvm_gcda_emit_arcs(uint32_t num_counters, uint64_t *counters) {
uint32_t i;
/* Counter #1 (arcs) tag */
if (!output_file) return;
fwrite("\0\0\xa1\1", 4, 1, output_file);
write_int32(num_counters * 2);
for (i = 0; i < num_counters; ++i)
write_int64(counters[i]);
#ifdef DEBUG_GCDAPROFILING
printf("llvmgcda: %u arcs\n", num_counters);
for (i = 0; i < num_counters; ++i)
printf("llvmgcda: %llu\n", (unsigned long long)counters[i]);
#endif
}
void llvm_gcda_end_file() {
/* Write out EOF record. */
if (!output_file) return;
fwrite("\0\0\0\0\0\0\0\0", 8, 1, output_file);
fclose(output_file);
output_file = NULL;
#ifdef DEBUG_GCDAPROFILING
printf("llvmgcda: -----\n");
#endif
}