Add signal handler to clean up temporary files at unexpected program exit

diff --git a/ccache.c b/ccache.c
index dc5498d67a1a6685ac4e1fbd673bcb11fc0d5706..2a78aa54403714af2d944480400c6abc622fc049 100644 (file)
--- a/ccache.c
+++ b/ccache.c
@@ -197,6 +197,14 @@ enum fromcache_call_mode {
        FROMCACHE_COMPILED_MODE
 };
 
+struct pending_tmp_file {
+       char *path;
+       struct pending_tmp_file *next;
+};
+
+/* Temporary files to remove at program exit. */
+static struct pending_tmp_file *pending_tmp_files = NULL;
+
 /*
  * This is a string that identifies the current "version" of the hash sum
  * computed by ccache. If, for any reason, we want to force the hash sum to be
@@ -231,25 +239,33 @@ failed(void)
 }
 
 static void
-clean_up_tmp_files()
+add_pending_tmp_file(const char *path)
 {
-       /* delete intermediate pre-processor file if needed */
-       if (i_tmpfile) {
-               if (!direct_i_file) {
-                       tmp_unlink(i_tmpfile);
-               }
-               free(i_tmpfile);
-               i_tmpfile = NULL;
-       }
+       struct pending_tmp_file *e = x_malloc(sizeof(*e));
+       e->path = x_strdup(path);
+       e->next = pending_tmp_files;
+       pending_tmp_files = e;
+}
 
-       /* delete the cpp stderr file if necessary */
-       if (cpp_stderr) {
-               tmp_unlink(cpp_stderr);
-               free(cpp_stderr);
-               cpp_stderr = NULL;
+static void
+clean_up_pending_tmp_files(void)
+{
+       struct pending_tmp_file *p = pending_tmp_files;
+       while (p) {
+               tmp_unlink(p->path);
+               p = p->next;
+               /* Leak p->path and p here because clean_up_pending_tmp_files needs to be signal
+                * safe. */
        }
 }
 
+static void
+signal_handler(int signo)
+{
+       (void)signo;
+       clean_up_pending_tmp_files();
+}
+
 /*
  * Transform a name to a full path into the cache directory, creating needed
  * sublevels if needed. Caller frees.
@@ -749,14 +765,16 @@ get_object_name_from_cpp(struct args *args, struct mdfour *hash)
                input_base[10] = 0;
        }
 
-       /* now the run */
-       path_stdout = format("%s/%s.tmp.%s.%s",
-                            temp_dir, input_base, tmp_string(), i_extension);
        path_stderr = format("%s/tmp.cpp_stderr.%s", temp_dir, tmp_string());
+       add_pending_tmp_file(path_stderr);
 
        time_of_compilation = time(NULL);
 
        if (!direct_i_file) {
+               path_stdout = format("%s/%s.tmp.%s.%s",
+                                    temp_dir, input_base, tmp_string(), i_extension);
+               add_pending_tmp_file(path_stdout);
+
                /* run cpp on the input file to obtain the .i */
                args_add(args, "-E");
                args_add(args, input_file);
@@ -776,10 +794,6 @@ get_object_name_from_cpp(struct args *args, struct mdfour *hash)
        }
 
        if (status != 0) {
-               if (!direct_i_file) {
-                       tmp_unlink(path_stdout);
-               }
-               tmp_unlink(path_stderr);
                cc_log("Preprocessor gave exit status %d", status);
                stats_update(STATS_PREPROCESSOR);
                failed();
@@ -796,7 +810,6 @@ get_object_name_from_cpp(struct args *args, struct mdfour *hash)
                hash_delimiter(hash, "unifycpp");
                if (unify_hash(hash, path_stdout) != 0) {
                        stats_update(STATS_ERROR);
-                       tmp_unlink(path_stderr);
                        cc_log("Failed to unify %s", path_stdout);
                        failed();
                }
@@ -804,7 +817,6 @@ get_object_name_from_cpp(struct args *args, struct mdfour *hash)
                hash_delimiter(hash, "cpp");
                if (!process_preprocessed_file(hash, path_stdout)) {
                        stats_update(STATS_ERROR);
-                       tmp_unlink(path_stderr);
                        failed();
                }
        }
@@ -824,7 +836,6 @@ get_object_name_from_cpp(struct args *args, struct mdfour *hash)
                 */
                cpp_stderr = path_stderr;
        } else {
-               tmp_unlink(path_stderr);
                free(path_stderr);
        }
 
@@ -2248,9 +2259,13 @@ ccache_main(int argc, char *argv[])
        char *p;
        char *program_name;
 
+       signal(SIGHUP, signal_handler);
+       signal(SIGINT, signal_handler);
+       signal(SIGTERM, signal_handler);
+
        exitfn_init();
        exitfn_add_nullary(stats_flush);
-       exitfn_add_nullary(clean_up_tmp_files);
+       exitfn_add_nullary(clean_up_pending_tmp_files);
 
        /* check for logging early so cc_log messages start working ASAP */
        cache_logfile = getenv("CCACHE_LOGFILE");