SCons: Review uses of CCFLAGS, CXXFLAGS and CPPFLAGS

Many contributors (me included) did not fully understand what CCFLAGS,
CXXFLAGS and CPPFLAGS refer to exactly, and were thus not using them
in the way they are intended to be.

As per the SCons manual: https://www.scons.org/doc/HTML/scons-user/apa.html

- CCFLAGS: General options that are passed to the C and C++ compilers.
- CFLAGS: General options that are passed to the C compiler (C only;
  not C++).
- CXXFLAGS: General options that are passed to the C++ compiler. By
  default, this includes the value of $CCFLAGS, so that setting
  $CCFLAGS affects both C and C++ compilation.
- CPPFLAGS: User-specified C preprocessor options. These will be
  included in any command that uses the C preprocessor, including not
  just compilation of C and C++ source files [...], but also [...]
  Fortran [...] and [...] assembly language source file[s].

TL;DR: Compiler options go to CCFLAGS, unless they must be restricted
to either C (CFLAGS) or C++ (CXXFLAGS). Preprocessor defines go to
CPPFLAGS.

1 files changed, 9 insertions, 7 deletions

diff --git a/platform/osx/detect.py b/platform/osx/detect.py
index 36a753e683..8024897195 100644
--- a/platform/osx/detect.py
+++ b/platform/osx/detect.py
@@ -53,16 +53,18 @@ def configure(env):
 
     elif (env["target"] == "release_debug"):
         if (env["optimize"] == "speed"): #optimize for speed (default)
-            env.Prepend(CCFLAGS=['-O2', '-DDEBUG_ENABLED'])
+            env.Prepend(CCFLAGS=['-O2'])
         else: #optimize for size
-            env.Prepend(CCFLAGS=['-Os', '-DDEBUG_ENABLED'])
+            env.Prepend(CCFLAGS=['-Os'])
+        env.Prepend(CPPFLAGS=['-DDEBUG_ENABLED'])
         if (env["debug_symbols"] == "yes"):
             env.Prepend(CCFLAGS=['-g1'])
         if (env["debug_symbols"] == "full"):
             env.Prepend(CCFLAGS=['-g2'])
 
     elif (env["target"] == "debug"):
-        env.Prepend(CCFLAGS=['-g3', '-DDEBUG_ENABLED', '-DDEBUG_MEMORY_ENABLED'])
+        env.Prepend(CCFLAGS=['-g3'])
+        env.Prepend(CPPFLAGS=['-DDEBUG_ENABLED', '-DDEBUG_MEMORY_ENABLED'])
 
     ## Architecture
 
@@ -88,10 +90,10 @@ def configure(env):
             env['AR'] = mpprefix + "/libexec/llvm-" + mpclangver + "/bin/llvm-ar"
             env['RANLIB'] = mpprefix + "/libexec/llvm-" + mpclangver + "/bin/llvm-ranlib"
             env['AS'] = mpprefix + "/libexec/llvm-" + mpclangver + "/bin/llvm-as"
-            env.Append(CCFLAGS=['-D__MACPORTS__']) #hack to fix libvpx MM256_BROADCASTSI128_SI256 define
+            env.Append(CPPFLAGS=['-D__MACPORTS__']) #hack to fix libvpx MM256_BROADCASTSI128_SI256 define
 
         detect_darwin_sdk_path('osx', env)
-        env.Append(CPPFLAGS=['-isysroot', '$MACOS_SDK_PATH'])
+        env.Append(CCFLAGS=['-isysroot', '$MACOS_SDK_PATH'])
         env.Append(LINKFLAGS=['-isysroot', '$MACOS_SDK_PATH'])
 
     else: # osxcross build
@@ -110,7 +112,7 @@ def configure(env):
         env['AR'] = basecmd + "ar"
         env['RANLIB'] = basecmd + "ranlib"
         env['AS'] = basecmd + "as"
-        env.Append(CCFLAGS=['-D__MACPORTS__']) #hack to fix libvpx MM256_BROADCASTSI128_SI256 define
+        env.Append(CPPFLAGS=['-D__MACPORTS__']) #hack to fix libvpx MM256_BROADCASTSI128_SI256 define
 
     if (env["CXX"] == "clang++"):
         env.Append(CPPFLAGS=['-DTYPED_METHOD_BIND'])
@@ -129,5 +131,5 @@ def configure(env):
     env.Append(LINKFLAGS=['-framework', 'Cocoa', '-framework', 'Carbon', '-framework', 'OpenGL', '-framework', 'AGL', '-framework', 'AudioUnit', '-framework', 'CoreAudio', '-framework', 'CoreMIDI', '-lz', '-framework', 'IOKit', '-framework', 'ForceFeedback', '-framework', 'CoreVideo'])
     env.Append(LIBS=['pthread'])
 
-    env.Append(CPPFLAGS=['-mmacosx-version-min=10.9'])
+    env.Append(CCFLAGS=['-mmacosx-version-min=10.9'])
     env.Append(LINKFLAGS=['-mmacosx-version-min=10.9'])