Fix a use after free I introduced and that Bill caught in code review

(thanks!) by deferring the free of the filename until we finish writing
the coverage data to that file.

Bill, let me know if you'd prefer a different approach!

llvm-svn: 184895

1 files changed, 13 insertions, 14 deletions

diff --git a/compiler-rt/lib/profile/GCDAProfiling.c b/compiler-rt/lib/profile/GCDAProfiling.c
index 33803976a38..4420dbb488c 100644
--- a/compiler-rt/lib/profile/GCDAProfiling.c
+++ b/compiler-rt/lib/profile/GCDAProfiling.c
@@ -271,7 +271,6 @@ void llvm_gcda_start_file(const char *orig_filename, const char version[4]) {
         fprintf(stderr, "profiling: %s: cannot open: %s\n", filename,
                 strerror(errnum));
 #endif
-        free(filename);
         return;
       }
     }
@@ -303,8 +302,6 @@ void llvm_gcda_start_file(const char *orig_filename, const char version[4]) {
   write_bytes(version, 4);
   write_bytes("MVLL", 4);
 
-  free(filename);
-
 #ifdef DEBUG_GCDAPROFILING
   fprintf(stderr, "llvmgcda: [%s]\n", orig_filename);
 #endif
@@ -409,19 +406,21 @@ void llvm_gcda_emit_arcs(uint32_t num_counters, uint64_t *counters) {
 
 void llvm_gcda_end_file() {
   /* Write out EOF record. */
-  if (!output_file) return;
-  write_bytes("\0\0\0\0\0\0\0\0", 8);
+  if (output_file) {
+    write_bytes("\0\0\0\0\0\0\0\0", 8);
+
+    if (new_file) {
+      fwrite(write_buffer, cur_pos, 1, output_file);
+      free(write_buffer);
+    } else {
+      unmap_file();
+    }
 
-  if (new_file) {
-    fwrite(write_buffer, cur_pos, 1, output_file);
-    free(write_buffer);
-  } else {
-    unmap_file();
+    fclose(output_file);
+    output_file = NULL;
+    write_buffer = NULL;
   }
-
-  fclose(output_file);
-  output_file = NULL;
-  write_buffer = NULL;
+  free(filename);
 
 #ifdef DEBUG_GCDAPROFILING
   fprintf(stderr, "llvmgcda: -----\n");