Compilation issue with sdl2 & SDK 15.3

[simonjwright]

Output of brew config

HOMEBREW_VERSION: 4.2.12
ORIGIN: https://github.com/Homebrew/brew
HEAD: 780fbbc65e90fbe09629aba180a1839e9e7dbaf2
Last commit: 22 hours ago
Core tap JSON: 12 Mar 09:30 UTC
Core cask tap JSON: 12 Mar 09:30 UTC
HOMEBREW_PREFIX: /opt/homebrew
HOMEBREW_CASK_OPTS: []
HOMEBREW_DISPLAY: /private/tmp/com.apple.launchd.MTx2llhtwO/org.xquartz:0
HOMEBREW_EDITOR: /Applications/Emacs.app/Contents/MacOS/bin/emacsclient
HOMEBREW_MAKE_JOBS: 8
Homebrew Ruby: 3.1.4 => /opt/homebrew/Library/Homebrew/vendor/portable-ruby/3.1.4/bin/ruby
CPU: octa-core 64-bit arm_firestorm_icestorm
Clang: 15.0.0 build 1500
Git: 2.43.0 => /opt/homebrew/bin/git
Curl: 8.4.0 => /usr/bin/curl
macOS: 14.3.1-arm64
CLT: 15.3.0.0.1.1708646388
Xcode: 15.2 => /Users/simon/Applications/Xcode.app/Contents/Developer
Rosetta 2: false

Output of brew doctor

Warning: Unbrewed header files were found in /usr/local/include.
If you didn't put them there on purpose they could cause problems when
building Homebrew formulae, and may need to be deleted.

Unexpected header files:
  /usr/local/include/node/cppgc/allocation.h
  /usr/local/include/node/cppgc/common.h
....
  /usr/local/include/node/zlib.h

Description of issue

Compiling against sdl2 with gcc-13.2.0-aarch64 and CommandLineTools 15.3 results in 3 occurrences of

In file included from /opt/homebrew/include/SDL2/SDL_platform.h:76,
                 from /opt/homebrew/include/SDL2/SDL_config.h:33,
                 from /opt/homebrew/include/SDL2/SDL_stdinc.h:31,
                 from /opt/homebrew/include/SDL2/SDL_main.h:25,
                 from /opt/homebrew/include/SDL2/SDL.h:32,
                 from /opt/homebrew/include/SDL2/SDL_image.h:32,
                 from /Users/simon/.cache/alire/builds/sdlada_2.5.20_cd53c280_398763973916d92d55b58f6ca78d6933164c6a776b2ffaaf7400d98752e8e8d2/src/image/version_images.c:4:
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/TargetConditionals.h:140:50: error: missing binary operator before token "("
  140 | #if !defined(__has_extension) || !__has_extension(define_target_os_macros)
      |                                                  ^

I tried with just this in tc.c

#include <TargetConditionals.h>

and sure enough gcc 13.2.0 gives

In file included from tc.c:1:
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/TargetConditionals.h:140:50: error: missing binary operator before token "("
  140 | #if !defined(__has_extension) || !__has_extension(define_target_os_macros)
      |                                                  ^

whereas clang and gcc-14.0.1 (20240223) compile without error.

[fxcoudert]

This is fixed in current GCC (future GCC 14). For GCC 13, sadly, __has_extension is not available. The issue is really with the SDK headers :( Apple does not really test them with another compiler than its own clang.

[simonjwright]

Looks as tho future 13.3 has fixed the issue too.