/*===- 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 <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#ifdef _WIN32
#include <direct.h>
#endif
#ifndef _MSC_VER
#include <stdint.h>
#else
typedef unsigned int uint32_t;
typedef unsigned int uint64_t;
#endif
/* #define DEBUG_GCDAPROFILING */
/*
* --- GCOV file format I/O primitives ---
*/
/*
* The current file we're outputting.
*/
static FILE *output_file = NULL;
/*
* A list of flush functions that our __gcov_flush() function should call.
*/
typedef void (*flush_fn)();
struct flush_fn_node {
flush_fn fn;
struct flush_fn_node *next;
};
struct flush_fn_node *flush_fn_head = NULL;
struct flush_fn_node *flush_fn_tail = 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 uint32_t read_int32() {
uint32_t tmp;
if (fread(&tmp, 1, 4, output_file) != 4)
return (uint32_t)-1;
return tmp;
}
static uint64_t read_int64() {
uint64_t tmp;
if (fread(&tmp, 1, 8, output_file) != 8)
return (uint64_t)-1;
return tmp;
}
static char *mangle_filename(const char *orig_filename) {
char *filename = 0;
int prefix_len = 0;
int prefix_strip = 0;
int level = 0;
const char *fname = orig_filename, *ptr = NULL;
const char *prefix = getenv("GCOV_PREFIX");
const char *tmp = getenv("GCOV_PREFIX_STRIP");
if (!prefix)
return strdup(orig_filename);
if (tmp) {
prefix_strip = atoi(tmp);
/* Negative GCOV_PREFIX_STRIP values are ignored */
if (prefix_strip < 0)
prefix_strip = 0;
}
prefix_len = strlen(prefix);
filename = malloc(prefix_len + 1 + strlen(orig_filename) + 1);
strcpy(filename, prefix);
if (prefix[prefix_len - 1] != '/')
strcat(filename, "/");
for (ptr = fname + 1; *ptr != '\0' && level < prefix_strip; ++ptr) {
if (*ptr != '/') continue;
fname = ptr;
++level;
}
strcat(filename, fname);
return filename;
}
static void recursive_mkdir(char *filename) {
int i;
for (i = 1; filename[i] != '\0'; ++i) {
if (filename[i] != '/') continue;
filename[i] = '\0';
#ifdef _WIN32
_mkdir(filename);
#else
mkdir(filename, 0755); /* Some of these will fail, ignore it. */
#endif
filename[i] = '/';
}
}
/*
* --- 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, const char version[4]) {
char *filename = mangle_filename(orig_filename);
/* Try just opening the file. */
output_file = fopen(filename, "r+b");
if (!output_file) {
/* Try opening the file, creating it if necessary. */
output_file = fopen(filename, "w+b");
if (!output_file) {
/* Try creating the directories first then opening the file. */
recursive_mkdir(filename);
output_file = fopen(filename, "w+b");
if (!output_file) {
/* Bah! It's hopeless. */
fprintf(stderr, "profiling:%s: cannot open\n", filename);
free(filename);
return;
}
}
}
/* gcda file, version, stamp LLVM. */
fwrite("adcg", 4, 1, output_file);
fwrite(version, 4, 1, output_file);
fwrite("MVLL", 4, 1, output_file);
free(filename);
#ifdef DEBUG_GCDAPROFILING
fprintf(stderr, "llvmgcda: [%s]\n", orig_filename);
#endif
}
/* 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
fprintf(stderr,
"llvmgcda: increment_indirect_counter counters=%08llx, pred=%u\n",
*counter, *predecessor);
#endif
}
void llvm_gcda_emit_function(uint32_t ident, const char *function_name,
uint8_t use_extra_checksum) {
uint32_t len = 2;
if (use_extra_checksum)
len++;
#ifdef DEBUG_GCDAPROFILING
fprintf(stderr, "llvmgcda: function id=0x%08x name=%s\n", ident,
function_name ? function_name : "NULL");
#endif
if (!output_file) return;
/* function tag */
fwrite("\0\0\0\1", 4, 1, output_file);
if (function_name)
len += 1 + length_of_string(function_name);
write_int32(len);
write_int32(ident);
write_int32(0);
if (use_extra_checksum)
write_int32(0);
if (function_name)
write_string(function_name);
}
void llvm_gcda_emit_arcs(uint32_t num_counters, uint64_t *counters) {
uint32_t i;
uint64_t *old_ctrs = NULL;
uint32_t val = 0;
long pos = 0;
if (!output_file) return;
pos = ftell(output_file);
val = read_int32();
if (val != (uint32_t)-1) {
/* There are counters present in the file. Merge them. */
uint32_t j;
if (val != 0x01a10000) {
fprintf(stderr, "profiling: invalid magic number (0x%08x)\n", val);
return;
}
val = read_int32();
if (val == (uint32_t)-1 || val / 2 != num_counters) {
fprintf(stderr, "profiling: invalid number of counters (%d)\n", val);
return;
}
old_ctrs = malloc(sizeof(uint64_t) * num_counters);
for (j = 0; j < num_counters; ++j)
old_ctrs[j] = read_int64();
}
/* Reset for writing. */
fseek(output_file, pos, SEEK_SET);
/* Counter #1 (arcs) tag */
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] + (old_ctrs ? old_ctrs[i] : 0));
free(old_ctrs);
#ifdef DEBUG_GCDAPROFILING
fprintf(stderr, "llvmgcda: %u arcs\n", num_counters);
for (i = 0; i < num_counters; ++i)
fprintf(stderr, "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
fprintf(stderr, "llvmgcda: -----\n");
#endif
}
void llvm_register_flush_function(flush_fn fn) {
struct flush_fn_node *new_node = malloc(sizeof(struct flush_fn_node));
new_node->fn = fn;
new_node->next = NULL;
if (!flush_fn_head) {
flush_fn_head = flush_fn_tail = new_node;
} else {
flush_fn_tail->next = new_node;
flush_fn_tail = new_node;
}
}
void __gcov_flush() {
struct flush_fn_node *curr = flush_fn_head;
while (curr) {
curr->fn();
curr = curr->next;
}
}
void llvm_delete_flush_function_list() {
while (flush_fn_head) {
struct flush_fn_node *node = flush_fn_head;
flush_fn_head = flush_fn_head->next;
free(node);
}
flush_fn_head = flush_fn_tail = NULL;
}