From ba02e4f4a74ec3b6317ce3117ddc9296012eeb45 Mon Sep 17 00:00:00 2001
From: Sam Clegg <sbc@chromium.org>
Date: Fri, 5 Jan 2024 11:44:33 -0800
Subject: [PATCH] Use `-isystem` for port include paths (#21014)

This means that they will get searched after any user include paths.

Without this change, since the results of process_args are pre-pended to
the compiler flags, it is not possible for the user to override these
include paths with their own.
---
 ChangeLog.md            | 3 +++
 tools/ports/bullet.py   | 2 +-
 tools/ports/cocos2d.py  | 2 +-
 tools/ports/freetype.py | 2 +-
 tools/ports/harfbuzz.py | 2 +-
 tools/ports/sdl2.py     | 2 +-
 6 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/ChangeLog.md b/ChangeLog.md
index e24fe2b2c8aa..757355b940f2 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -20,6 +20,9 @@ See docs/process.md for more on how version tagging works.
 
 3.1.52 (in development)
 -----------------------
+- Include paths added by ports (e.g. `-sUSE_SDL=2`) now use `-isystem` rather
+  then `-I`.  This means that files in user-specified include directories will
+  now take precedence over port includes. (#21014)
 - Certain settings that only apply when generating JavaScript output will now
   trigger a warning if used when generating only Wasm.
 - Fix bug where `main` was mistakenly included in debug builds but not in
diff --git a/tools/ports/bullet.py b/tools/ports/bullet.py
index 74b681c6ad54..0f6dedc1ef9e 100644
--- a/tools/ports/bullet.py
+++ b/tools/ports/bullet.py
@@ -52,7 +52,7 @@ def clear(ports, settings, shared):
 
 
 def process_args(ports):
-  return ['-I' + ports.get_include_dir('bullet')]
+  return ['-isystem', ports.get_include_dir('bullet')]
 
 
 def show():
diff --git a/tools/ports/cocos2d.py b/tools/ports/cocos2d.py
index b1f3d624852c..6ffe7cb79087 100644
--- a/tools/ports/cocos2d.py
+++ b/tools/ports/cocos2d.py
@@ -69,7 +69,7 @@ def process_dependencies(settings):
 def process_args(ports):
   args = []
   for include in make_includes(ports.get_include_dir('cocos2d')):
-    args.append('-I' + include)
+    args += ['-isystem', include]
   return args
 
 
diff --git a/tools/ports/freetype.py b/tools/ports/freetype.py
index 83ef166a91cd..d419bd53c618 100644
--- a/tools/ports/freetype.py
+++ b/tools/ports/freetype.py
@@ -112,7 +112,7 @@ def clear(ports, settings, shared):
 
 
 def process_args(ports):
-  return ['-I' + ports.get_include_dir('freetype2')]
+  return ['-isystem', ports.get_include_dir('freetype2')]
 
 
 def show():
diff --git a/tools/ports/harfbuzz.py b/tools/ports/harfbuzz.py
index 133bbfdc3ca4..73d35c7d8a12 100644
--- a/tools/ports/harfbuzz.py
+++ b/tools/ports/harfbuzz.py
@@ -148,7 +148,7 @@ def process_dependencies(settings):
 
 
 def process_args(ports):
-  return ['-I' + ports.get_include_dir('harfbuzz')]
+  return ['-isystem', ports.get_include_dir('harfbuzz')]
 
 
 def show():
diff --git a/tools/ports/sdl2.py b/tools/ports/sdl2.py
index 24dd8757195f..3378084372e6 100644
--- a/tools/ports/sdl2.py
+++ b/tools/ports/sdl2.py
@@ -87,7 +87,7 @@ def linker_setup(ports, settings):
 
 
 def process_args(ports):
-  return ['-I' + ports.get_include_dir('SDL2')]
+  return ['-isystem', ports.get_include_dir('SDL2')]
 
 
 def show():