builder: remove unused cacheKey parameter

This key was intended as some sort of cache key (as the name indicates)
but that never happened. Let's remove it to avoid clutter. The cacheLoad
and cacheStore functions are only used for C libraries (libc,
compiler-rt) so their caching behavior is a bit different from other
things worth caching.

builder/buildcache.go

@@ -30,10 +30,7 @@ func cacheTimestamp(paths []string) (time.Time, error) {
 // Try to load a given file from the cache. Return "", nil if no cached file can
 // be found (or the file is stale), return the absolute path if there is a cache
 // and return an error on I/O errors.
-//
-// TODO: the configKey is currently ignored. It is supposed to be used as extra
-// data for the cache key, like the compiler version and arguments.
-func cacheLoad(name, configKey string, sourceFiles []string) (string, error) {
+func cacheLoad(name string, sourceFiles []string) (string, error) {
 	cachepath := filepath.Join(goenv.Get("GOCACHE"), name)
 	cacheStat, err := os.Stat(cachepath)
 	if os.IsNotExist(err) {
@@ -58,9 +55,7 @@ func cacheLoad(name, configKey string, sourceFiles []string) (string, error) {
 
 // Store the file located at tmppath in the cache with the given name. The
 // tmppath may or may not be gone afterwards.
-//
-// Note: the configKey is ignored, see cacheLoad.
-func cacheStore(tmppath, name, configKey string, sourceFiles []string) (string, error) {
+func cacheStore(tmppath, name string, sourceFiles []string) (string, error) {
 	// get the last modified time
 	if len(sourceFiles) == 0 {
 		panic("cache: no source files")

builder/library.go

@@ -71,7 +71,7 @@ func (l *Library) load(target, tmpdir string) (path string, job *compileJob, err
 	outfile := l.name + "-" + target + ".a"
 
 	// Try to fetch this library from the cache.
-	if path, err := cacheLoad(outfile, commands["clang"][0], l.sourcePaths(target)); path != "" || err != nil {
+	if path, err := cacheLoad(outfile, l.sourcePaths(target)); path != "" || err != nil {
 		// Cache hit.
 		return path, nil, err
 	}
@@ -112,7 +112,7 @@ func (l *Library) load(target, tmpdir string) (path string, job *compileJob, err
 				return err
 			}
 			// Store this archive in the cache.
-			_, err = cacheStore(arpath, outfile, commands["clang"][0], l.sourcePaths(target))
+			_, err = cacheStore(arpath, outfile, l.sourcePaths(target))
 			return err
 		},
 	}