Handle unknown manifest version gracefully in --dump-manifest

Previously “ccache --dump-manifest file” would crash with an assert when
the file did not have the expected version.

diff --git a/src/ccache.c b/src/ccache.c
index 7fa941461e9acff28e463b47f014790bac1cb3f5..423bc983b1703f3da5c0434d605823f9f4d37452 100644 (file)
--- a/src/ccache.c
+++ b/src/ccache.c
@@ -4045,6 +4045,7 @@ ccache_main_options(int argc, char *argv[])
               != -1) {
                switch (c) {
                case DUMP_MANIFEST:
+                       initialize();
                        manifest_dump(optarg, stdout);
                        break;
 

diff --git a/src/manifest.c b/src/manifest.c
index 5e0bcac62520fd82879172476d54cf914a8bcddc..0b85e90686a87415fb4bd6baddd1d41bc50ca0c6 100644 (file)
--- a/src/manifest.c
+++ b/src/manifest.c
@@ -224,27 +224,32 @@ create_empty_manifest(void)
 }
 
 static struct manifest *
-read_manifest(gzFile f)
+read_manifest(gzFile f, char **errmsg)
 {
+       *errmsg = NULL;
        struct manifest *mf = create_empty_manifest();
 
        uint32_t magic;
        READ_INT(4, magic);
        if (magic != MAGIC) {
-               cc_log("Manifest file has bad magic number %u", magic);
+               *errmsg = format("Manifest file has bad magic number %u", magic);
                goto error;
        }
 
        READ_BYTE(mf->version);
        if (mf->version != MANIFEST_VERSION) {
-               cc_log("Manifest file has unknown version %u", mf->version);
+               *errmsg = format(
+                       "Unknown manifest version (actual %u, expected %u)",
+                       mf->version,
+                       MANIFEST_VERSION);
                goto error;
        }
 
        READ_BYTE(mf->hash_size);
        if (mf->hash_size != 16) {
                // Temporary measure until we support different hash algorithms.
-               cc_log("Manifest file has unsupported hash size %u", mf->hash_size);
+               *errmsg =
+                       format("Manifest file has unsupported hash size %u", mf->hash_size);
                goto error;
        }
 
@@ -283,7 +288,9 @@ read_manifest(gzFile f)
        return mf;
 
 error:
-       cc_log("Corrupt manifest file");
+       if (!errmsg) {
+               *errmsg = x_strdup("Corrupt manifest file");
+       }
        free_manifest(mf);
        return NULL;
 }
@@ -592,9 +599,11 @@ manifest_get(struct conf *conf, const char *manifest_path)
                cc_log("Failed to gzdopen manifest file");
                goto out;
        }
-       mf = read_manifest(f);
+
+       char *errmsg;
+       mf = read_manifest(f, &errmsg);
        if (!mf) {
-               cc_log("Error reading manifest file");
+               cc_log("%s", errmsg);
                goto out;
        }
 
@@ -653,9 +662,12 @@ manifest_put(const char *manifest_path, struct file_hash *object_hash,
                        close(fd1);
                        goto out;
                }
-               mf = read_manifest(f1);
+               char *errmsg;
+               mf = read_manifest(f1, &errmsg);
                gzclose(f1);
                if (!mf) {
+                       cc_log("%s", errmsg);
+                       free(errmsg);
                        cc_log("Failed to read manifest file; deleting it");
                        x_unlink(manifest_path);
                        mf = create_empty_manifest();
@@ -741,9 +753,11 @@ manifest_dump(const char *manifest_path, FILE *stream)
                close(fd);
                goto out;
        }
-       mf = read_manifest(f);
+       char *errmsg;
+       mf = read_manifest(f, &errmsg);
        if (!mf) {
-               fprintf(stderr, "Error reading manifest file\n");
+               fprintf(stderr, "%s\n", errmsg);
+               free(errmsg);
                goto out;
        }