1 /*===- GCDAProfiling.c - Support library for GCDA file emission -----------===*\
3 |* The LLVM Compiler Infrastructure
5 |* This file is distributed under the University of Illinois Open Source
6 |* License. See LICENSE.TXT for details.
8 |*===----------------------------------------------------------------------===*|
10 |* This file implements the call back routines for the gcov profiling
11 |* instrumentation pass. Link against this library when running code through
12 |* the -insert-gcov-profiling LLVM pass.
14 |* We emit files in a corrupt version of GCOV's "gcda" file format. These files
15 |* are only close enough that LCOV will happily parse them. Anything that lcov
16 |* ignores is missing.
18 |* TODO: gcov is multi-process safe by having each exit open the existing file
19 |* and append to it. We'd like to achieve that and be thread-safe too.
21 \*===----------------------------------------------------------------------===*/
23 #include "llvm/Support/DataTypes.h"
28 #include <sys/types.h>
33 /* #define DEBUG_GCDAPROFILING */
36 * --- GCOV file format I/O primitives ---
39 static FILE *output_file = NULL;
41 static void write_int32(uint32_t i) {
42 fwrite(&i, 4, 1, output_file);
45 static void write_int64(uint64_t i) {
54 static uint32_t length_of_string(const char *s) {
55 return (strlen(s) / 4) + 1;
58 static void write_string(const char *s) {
59 uint32_t len = length_of_string(s);
61 fwrite(s, strlen(s), 1, output_file);
62 fwrite("\0\0\0\0", 4 - (strlen(s) % 4), 1, output_file);
65 static char *mangle_filename(const char *orig_filename) {
66 /* TODO: handle GCOV_PREFIX_STRIP */
70 prefix = getenv("GCOV_PREFIX");
73 return strdup(orig_filename);
75 filename = malloc(strlen(prefix) + 1 + strlen(orig_filename) + 1);
76 strcpy(filename, prefix);
77 strcat(filename, "/");
78 strcat(filename, orig_filename);
83 static void recursive_mkdir(const char *filename) {
87 for (i = 1, e = strlen(filename); i != e; ++i) {
88 if (filename[i] == '/') {
89 pathname = malloc(i + 1);
90 strncpy(pathname, filename, i);
95 mkdir(pathname, 0750); /* some of these will fail, ignore it. */
103 * --- LLVM line counter API ---
106 /* A file in this case is a translation unit. Each .o file built with line
107 * profiling enabled will emit to a different file. Only one file may be
110 void llvm_gcda_start_file(const char *orig_filename) {
112 filename = mangle_filename(orig_filename);
113 recursive_mkdir(filename);
114 output_file = fopen(filename, "wb");
116 /* gcda file, version 404*, stamp LLVM. */
118 fwrite("adcg*204MVLL", 12, 1, output_file);
120 fwrite("adcg*404MVLL", 12, 1, output_file);
123 #ifdef DEBUG_GCDAPROFILING
124 printf("llvmgcda: [%s]\n", orig_filename);
130 /* Given an array of pointers to counters (counters), increment the n-th one,
131 * where we're also given a pointer to n (predecessor).
133 void llvm_gcda_increment_indirect_counter(uint32_t *predecessor,
134 uint64_t **counters) {
139 if (pred == 0xffffffff)
141 counter = counters[pred];
143 /* Don't crash if the pred# is out of sync. This can happen due to threads,
144 or because of a TODO in GCOVProfiling.cpp buildEdgeLookupTable(). */
147 #ifdef DEBUG_GCDAPROFILING
149 printf("llvmgcda: increment_indirect_counter counters=%x, pred=%u\n",
150 state_table_row, *predecessor);
154 void llvm_gcda_emit_function(uint32_t ident, const char *function_name) {
155 #ifdef DEBUG_GCDAPROFILING
156 printf("llvmgcda: function id=%x\n", ident);
160 fwrite("\0\0\0\1", 4, 1, output_file);
161 write_int32(3 + 1 + length_of_string(function_name));
165 write_string(function_name);
168 void llvm_gcda_emit_arcs(uint32_t num_counters, uint64_t *counters) {
170 /* counter #1 (arcs) tag */
171 fwrite("\0\0\xa1\1", 4, 1, output_file);
172 write_int32(num_counters * 2);
173 for (i = 0; i < num_counters; ++i) {
174 write_int64(counters[i]);
177 #ifdef DEBUG_GCDAPROFILING
178 printf("llvmgcda: %u arcs\n", num_counters);
179 for (i = 0; i < num_counters; ++i) {
180 printf("llvmgcda: %llu\n", (unsigned long long)counters[i]);
185 void llvm_gcda_end_file() {
186 /* Write out EOF record. */
187 fwrite("\0\0\0\0\0\0\0\0", 8, 1, output_file);
191 #ifdef DEBUG_GCDAPROFILING
192 printf("llvmgcda: -----\n");