Improve error reporting from read_result

“ccache --dump-result” now prints the actual error.

diff --git a/src/ccache.c b/src/ccache.c
index 168943660667c3f9b443b8f4b5fc13af123eabd4..19d2b62022aa59672b1aa81917ff0b1438c17f47 100644 (file)
--- a/src/ccache.c
+++ b/src/ccache.c
@@ -3890,7 +3890,6 @@ ccache_main_options(int argc, char *argv[])
                case DUMP_RESULT:
                        initialize();
                        if (!result_dump(optarg, stdout)) {
-                               fprintf(stderr, "Error: Corrupt result file\n");
                                return 1;
                        }
                        break;

diff --git a/src/result.c b/src/result.c
index 5f176dd682852be28011e57f1eb59036fd1c4f9d..94bf6e2f7211468661de4b34e5c26321002b98a2 100644 (file)
--- a/src/result.c
+++ b/src/result.c
@@ -150,8 +150,10 @@ filelist_free(struct filelist *list)
        } while (false)
 
 static bool
-read_result(const char *path, struct filelist *list, FILE *dump_stream)
+read_result(
+       const char *path, struct filelist *list, FILE *dump_stream, char **errmsg)
 {
+       *errmsg = NULL;
        bool success = false;
        struct decompressor *decompressor = NULL;
        struct decompr_state *decompr_state = NULL;
@@ -160,25 +162,32 @@ read_result(const char *path, struct filelist *list, FILE *dump_stream)
        FILE *f = fopen(path, "rb");
        if (!f) {
                // Cache miss.
-               cc_log("No such result file");
+               *errmsg = x_strdup("No such result file");
                goto out;
        }
 
        char header[7];
        if (fread(header, 1, sizeof(header), f) != sizeof(header)) {
-               cc_log("Failed to read result file header");
+               *errmsg = x_strdup("Failed to read result file header");
                goto out;
        }
 
        if (memcmp(header, MAGIC, sizeof(MAGIC)) != 0) {
-               cc_log("Result file has bad magic value 0x%x%x%x%x",
-                      header[0], header[1], header[2], header[3]);
-               // TODO: Return error message like read_manifest does.
+               *errmsg = format(
+                       "Result file has bad magic value 0x%x%x%x%x",
+                       header[0], header[1], header[2], header[3]);
                goto out;
        }
 
-       // TODO: Verify version like read_manifest does.
        const uint8_t version = header[4];
+       if (version != RESULT_VERSION) {
+               *errmsg = format(
+                       "Unknown result version (actual %u, expected %u)",
+                       version,
+                       RESULT_VERSION);
+               goto out;
+       }
+
        const uint8_t compr_type = header[5];
 
        switch (compr_type) {
@@ -191,13 +200,13 @@ read_result(const char *path, struct filelist *list, FILE *dump_stream)
                break;
 
        default:
-               cc_log("Unknown compression type: %u", compr_type);
+               *errmsg = format("Unknown compression type: %u", compr_type);
                goto out;
        }
 
        decompr_state = decompressor->init(f);
        if (!decompr_state) {
-               cc_log("Failed to initialize decompressor");
+               *errmsg = x_strdup("Failed to initialize decompressor");
                goto out;
        }
 
@@ -227,7 +236,7 @@ read_result(const char *path, struct filelist *list, FILE *dump_stream)
                        continue;
 
                default:
-                       cc_log("Unknown entry type: %u", marker);
+                       *errmsg = format("Unknown entry type: %u", marker);
                        goto out;
                }
 
@@ -297,8 +306,8 @@ out:
        if (f) {
                fclose(f);
        }
-       if (!success) {
-               cc_log("Corrupt result file");
+       if (!success && !*errmsg) {
+               *errmsg = x_strdup("Corrupt result file");
        }
        return success;
 }
@@ -373,7 +382,14 @@ error:
 bool result_get(const char *path, struct filelist *list)
 {
        cc_log("Getting result %s", path);
-       return read_result(path, list, NULL);
+
+       char *errmsg;
+       bool success = read_result(path, list, NULL, &errmsg);
+       if (errmsg) {
+               cc_log("Error: %s", errmsg);
+               free(errmsg);
+       }
+       return success;
 }
 
 bool result_put(const char *path, struct filelist *list, int compression_level)
@@ -435,5 +451,11 @@ out:
 bool
 result_dump(const char *path, FILE *stream)
 {
-       return read_result(path, NULL, stream);
+       char *errmsg;
+       bool success = read_result(path, NULL, stream, &errmsg);
+       if (errmsg) {
+               fprintf(stderr, "Error: %s\n", errmsg);
+               free(errmsg);
+       }
+       return success;
 }