Address a few of the issues in GCDAProfiling I noted when looking
through Bill's patch:
1) Correctly test the file descriptor after the sceond attempt at
creating the file.
2) Make the filename a global so that we can issue error messages from
other routines.
3) Check errno in several places and print it out so that errors are
easier to track down.
I don't really expect any of these to fix the current failures I'm
seeing, but I'm hopeful they'll at least let me debug them.
git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@184799 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/profile/GCDAProfiling.c b/lib/profile/GCDAProfiling.c
index ce1b03c..de1bb74 100644
--- a/lib/profile/GCDAProfiling.c
+++ b/lib/profile/GCDAProfiling.c
@@ -20,6 +20,7 @@
|*
\*===----------------------------------------------------------------------===*/
+#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
@@ -45,6 +46,11 @@
*/
/*
+ * The current file name we're outputting. Used primarily for error logging.
+ */
+static char *filename = NULL;
+
+/*
* The current file we're outputting.
*/
static FILE *output_file = NULL;
@@ -196,17 +202,32 @@
}
}
-static void map_file() {
+static int map_file() {
fseek(output_file, 0L, SEEK_END);
file_size = ftell(output_file);
write_buffer = mmap(0, file_size, PROT_READ | PROT_WRITE,
MAP_FILE | MAP_SHARED, fd, 0);
+ if (write_buffer == (void *)-1) {
+ int errnum = errno;
+ fprintf(stderr, "profiling: %s: cannot map: %s\n", filename,
+ strerror(errnum));
+ return -1;
+ }
+ return 0;
}
static void unmap_file() {
- msync(write_buffer, file_size, MS_SYNC);
- munmap(write_buffer, file_size);
+ if (msync(write_buffer, file_size, MS_SYNC) == -1) {
+ int errnum = errno;
+ fprintf(stderr, "profiling: %s: cannot msync: %s\n", filename,
+ strerror(errnum));
+ }
+
+ /* We explicitly ignore errors from unmapping because at this point the data
+ * is written and we don't care.
+ */
+ (void)munmap(write_buffer, file_size);
write_buffer = NULL;
file_size = 0;
}
@@ -220,8 +241,8 @@
* started at a time.
*/
void llvm_gcda_start_file(const char *orig_filename, const char version[4]) {
- char *filename = mangle_filename(orig_filename);
const char *mode = "r+b";
+ filename = mangle_filename(orig_filename);
/* Try just opening the file. */
new_file = 0;
@@ -236,9 +257,11 @@
/* Try creating the directories first then opening the file. */
recursive_mkdir(filename);
fd = open(filename, O_RDWR | O_CREAT, 0644);
- if (!output_file) {
+ if (fd == -1) {
/* Bah! It's hopeless. */
- fprintf(stderr, "profiling:%s: cannot open\n", filename);
+ int errnum = errno;
+ fprintf(stderr, "profiling: %s: cannot open: %s\n", filename,
+ strerror(errnum));
free(filename);
return;
}
@@ -256,7 +279,14 @@
resize_write_buffer(WRITE_BUFFER_SIZE);
memset(write_buffer, 0, WRITE_BUFFER_SIZE);
} else {
- map_file();
+ if (map_file() == -1) {
+ /* mmap failed, try to recover by clobbering */
+ new_file = 1;
+ write_buffer = NULL;
+ cur_buffer_size = 0;
+ resize_write_buffer(WRITE_BUFFER_SIZE);
+ memset(write_buffer, 0, WRITE_BUFFER_SIZE);
+ }
}
/* gcda file, version, stamp LLVM. */
