stdin.patch

commit b8a8c3f5ff88f444d67cdedac4e192821a93e1c5
Author: Tor Arne Vestbø <torarnv@gmail.com>
Date:   Tue Aug 18 23:31:53 2026 +0200

    gcc_wrapper: Recognize Objective-C and Objective-C++ source files
    
    is_source_file() only knew about .c, .cc, .cpp and .cxx. For an .m or
    .mm compilation get_input_files() therefore returned an empty list,
    which disabled direct mode, and maybe_generate_dependency_file() found
    no source file and threw. That happens after the cache entry has already
    been restored, so handle_command() aborted and buildcache fell back to
    running the compiler. An Objective-C++ compilation thus paid for both a
    full preprocessing pass and a full compilation on every build.
    
    Objective-C and Objective-C++ entries stored by earlier versions become
    unreachable, since the source file argument is now filtered out of the
    hashed arguments. HASH_VERSION is left alone so that entries for the
    other languages remain valid.

diff --git a/src/wrappers/gcc_wrapper.cpp b/src/wrappers/gcc_wrapper.cpp
index 84368e1..0e85618 100644
--- a/src/wrappers/gcc_wrapper.cpp
+++ b/src/wrappers/gcc_wrapper.cpp
@@ -188,8 +188,10 @@ bool gcc_wrapper_t::is_arg_plus_file_name(const std::string& arg) {
 }
 
 bool gcc_wrapper_t::is_source_file(const std::string& arg) {
+  static const std::set<std::string> source_exts = {
+      ".c", ".cc", ".cpp", ".cxx", ".m", ".mm"};
   const auto ext = lower_case(file::get_extension(arg));
-  return ((ext == ".cpp") || (ext == ".cc") || (ext == ".cxx") || (ext == ".c"));
+  return source_exts.find(ext) != source_exts.end();
 }
 
 gcc_wrapper_t::gcc_wrapper_t(const file::exe_path_t& exe_path,