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.

8 files changed, 82 insertions, 63 deletions

diff --git a/platform/android/detect.py b/platform/android/detect.py
index 5623274050..6c67067db7 100644
--- a/platform/android/detect.py
+++ b/platform/android/detect.py
@@ -150,19 +150,21 @@ def configure(env):
     if (env["target"].startswith("release")):
         if (env["optimize"] == "speed"): #optimize for speed (default)
             env.Append(LINKFLAGS=['-O2'])
-            env.Append(CPPFLAGS=['-O2', '-DNDEBUG', '-fomit-frame-pointer'])
+            env.Append(CCFLAGS=['-O2', '-fomit-frame-pointer'])
+            env.Append(CPPFLAGS=['-DNDEBUG'])
         else: #optimize for size
-            env.Append(CPPFLAGS=['-Os', '-DNDEBUG'])
+            env.Append(CCFLAGS=['-Os'])
+            env.Append(CPPFLAGS=['-DNDEBUG'])
             env.Append(LINKFLAGS=['-Os'])
 
         if (can_vectorize):
-            env.Append(CPPFLAGS=['-ftree-vectorize'])
+            env.Append(CCFLAGS=['-ftree-vectorize'])
         if (env["target"] == "release_debug"):
             env.Append(CPPFLAGS=['-DDEBUG_ENABLED'])
     elif (env["target"] == "debug"):
         env.Append(LINKFLAGS=['-O0'])
-        env.Append(CPPFLAGS=['-O0', '-D_DEBUG', '-UNDEBUG', '-DDEBUG_ENABLED',
-                             '-DDEBUG_MEMORY_ENABLED', '-g', '-fno-limit-debug-info'])
+        env.Append(CCFLAGS=['-O0', '-g', '-fno-limit-debug-info'])
+        env.Append(CPPFLAGS=['-D_DEBUG', '-UNDEBUG', '-DDEBUG_ENABLED', '-DDEBUG_MEMORY_ENABLED'])
 
     ## Compiler configuration
 
@@ -216,15 +218,16 @@ def configure(env):
     if env['android_stl']:
         env.Append(CPPFLAGS=["-isystem", env["ANDROID_NDK_ROOT"] + "/sources/cxx-stl/llvm-libc++/include"])
         env.Append(CPPFLAGS=["-isystem", env["ANDROID_NDK_ROOT"] + "/sources/cxx-stl/llvm-libc++abi/include"])
-        env.Append(CXXFLAGS=['-frtti',"-std=gnu++14"])
+        env.Append(CXXFLAGS=['-frtti', "-std=gnu++14"])
     else:
-        env.Append(CXXFLAGS=['-fno-rtti', '-fno-exceptions', '-DNO_SAFE_CAST'])
+        env.Append(CXXFLAGS=['-fno-rtti', '-fno-exceptions'])
+        env.Append(CPPFLAGS=['-DNO_SAFE_CAST'])
 
     ndk_version = get_ndk_version(env["ANDROID_NDK_ROOT"])
     if ndk_version != None and LooseVersion(ndk_version) >= LooseVersion("15.0.4075724"):
         print("Using NDK unified headers")
         sysroot = env["ANDROID_NDK_ROOT"] + "/sysroot"
-        env.Append(CPPFLAGS=["--sysroot="+sysroot])
+        env.Append(CPPFLAGS=["--sysroot=" + sysroot])
         env.Append(CPPFLAGS=["-isystem", sysroot + "/usr/include/" + abi_subpath])
         env.Append(CPPFLAGS=["-isystem", env["ANDROID_NDK_ROOT"] + "/sources/android/support/include"])
         # For unified headers this define has to be set manually
@@ -233,48 +236,51 @@ def configure(env):
         print("Using NDK deprecated headers")
         env.Append(CPPFLAGS=["-isystem", lib_sysroot + "/usr/include"])
 
-    env.Append(CPPFLAGS='-fpic -ffunction-sections -funwind-tables -fstack-protector-strong -fvisibility=hidden -fno-strict-aliasing'.split())
+    env.Append(CCFLAGS='-fpic -ffunction-sections -funwind-tables -fstack-protector-strong -fvisibility=hidden -fno-strict-aliasing'.split())
     env.Append(CPPFLAGS='-DNO_STATVFS -DGLES_ENABLED'.split())
 
     env['neon_enabled'] = False
     if env['android_arch'] == 'x86':
         target_opts = ['-target', 'i686-none-linux-android']
         # The NDK adds this if targeting API < 21, so we can drop it when Godot targets it at least
-        env.Append(CPPFLAGS=['-mstackrealign'])
+        env.Append(CCFLAGS=['-mstackrealign'])
 
     elif env['android_arch'] == 'x86_64':
         target_opts = ['-target', 'x86_64-none-linux-android']
 
     elif env["android_arch"] == "armv6":
         target_opts = ['-target', 'armv6-none-linux-androideabi']
-        env.Append(CPPFLAGS='-D__ARM_ARCH_6__ -march=armv6 -mfpu=vfp -mfloat-abi=softfp'.split())
+        env.Append(CCFLAGS='-march=armv6 -mfpu=vfp -mfloat-abi=softfp'.split())
+        env.Append(CPPFLAGS=['-D__ARM_ARCH_6__'])
 
     elif env["android_arch"] == "armv7":
         target_opts = ['-target', 'armv7-none-linux-androideabi']
-        env.Append(CPPFLAGS='-D__ARM_ARCH_7__ -D__ARM_ARCH_7A__ -march=armv7-a -mfloat-abi=softfp'.split())
+        env.Append(CCFLAGS='-march=armv7-a -mfloat-abi=softfp'.split())
+        env.Append(CPPFLAGS='-D__ARM_ARCH_7__ -D__ARM_ARCH_7A__'.split())
         if env['android_neon']:
             env['neon_enabled'] = True
-            env.Append(CPPFLAGS=['-mfpu=neon', '-D__ARM_NEON__'])
+            env.Append(CCFLAGS=['-mfpu=neon'])
+            env.Append(CPPFLAGS=['-D__ARM_NEON__'])
         else:
-            env.Append(CPPFLAGS=['-mfpu=vfpv3-d16'])
+            env.Append(CCFLAGS=['-mfpu=vfpv3-d16'])
 
     elif env["android_arch"] == "arm64v8":
         target_opts = ['-target', 'aarch64-none-linux-android']
+        env.Append(CCFLAGS=['-mfix-cortex-a53-835769'])
         env.Append(CPPFLAGS=['-D__ARM_ARCH_8A__'])
-        env.Append(CPPFLAGS=['-mfix-cortex-a53-835769'])
 
-    env.Append(CPPFLAGS=target_opts)
-    env.Append(CPPFLAGS=common_opts)
+    env.Append(CCFLAGS=target_opts)
+    env.Append(CCFLAGS=common_opts)
 
     ## Link flags
     if ndk_version != None and LooseVersion(ndk_version) >= LooseVersion("15.0.4075724"):
         if LooseVersion(ndk_version) >= LooseVersion("17.1.4828580"):
-            env.Append(LINKFLAGS=['-Wl,--exclude-libs,libgcc.a','-Wl,--exclude-libs,libatomic.a','-nostdlib++'])
+            env.Append(LINKFLAGS=['-Wl,--exclude-libs,libgcc.a', '-Wl,--exclude-libs,libatomic.a', '-nostdlib++'])
         else:
-            env.Append(LINKFLAGS=[env["ANDROID_NDK_ROOT"] +"/sources/cxx-stl/llvm-libc++/libs/"+arch_subpath+"/libandroid_support.a"])
+            env.Append(LINKFLAGS=[env["ANDROID_NDK_ROOT"] + "/sources/cxx-stl/llvm-libc++/libs/" + arch_subpath + "/libandroid_support.a"])
         env.Append(LINKFLAGS=['-shared', '--sysroot=' + lib_sysroot, '-Wl,--warn-shared-textrel'])
-        env.Append(LIBPATH=[env["ANDROID_NDK_ROOT"] + "/sources/cxx-stl/llvm-libc++/libs/"+arch_subpath+"/"])
-        env.Append(LINKFLAGS=[env["ANDROID_NDK_ROOT"] +"/sources/cxx-stl/llvm-libc++/libs/"+arch_subpath+"/libc++_shared.so"])
+        env.Append(LIBPATH=[env["ANDROID_NDK_ROOT"] + "/sources/cxx-stl/llvm-libc++/libs/" + arch_subpath + "/"])
+        env.Append(LINKFLAGS=[env["ANDROID_NDK_ROOT"] +"/sources/cxx-stl/llvm-libc++/libs/" + arch_subpath + "/libc++_shared.so"])
     else:
         env.Append(LINKFLAGS=['-shared', '--sysroot=' + lib_sysroot, '-Wl,--warn-shared-textrel'])
         if mt_link:
diff --git a/platform/haiku/detect.py b/platform/haiku/detect.py
index ae8cc58a4a..874b1ab1fb 100644
--- a/platform/haiku/detect.py
+++ b/platform/haiku/detect.py
@@ -150,6 +150,6 @@ def configure(env):
     env.Append(CPPPATH=['#platform/haiku'])
     env.Append(CPPFLAGS=['-DUNIX_ENABLED', '-DOPENGL_ENABLED', '-DGLES_ENABLED'])
     env.Append(CPPFLAGS=['-DMEDIA_KIT_ENABLED'])
-    # env.Append(CCFLAGS=['-DFREETYPE_ENABLED'])
+    # env.Append(CPPFLAGS=['-DFREETYPE_ENABLED'])
     env.Append(CPPFLAGS=['-DPTHREAD_NO_RENAME'])  # TODO: enable when we have pthread_setname_np
     env.Append(LIBS=['be', 'game', 'media', 'network', 'bnetapi', 'z', 'GL'])
diff --git a/platform/iphone/detect.py b/platform/iphone/detect.py
index 853f24379e..d56e28a4af 100644
--- a/platform/iphone/detect.py
+++ b/platform/iphone/detect.py
@@ -45,20 +45,21 @@ def configure(env):
     if (env["target"].startswith("release")):
         env.Append(CPPFLAGS=['-DNDEBUG', '-DNS_BLOCK_ASSERTIONS=1'])
         if (env["optimize"] == "speed"): #optimize for speed (default)
-            env.Append(CPPFLAGS=['-O2', '-ftree-vectorize', '-fomit-frame-pointer'])
+            env.Append(CCFLAGS=['-O2', '-ftree-vectorize', '-fomit-frame-pointer'])
             env.Append(LINKFLAGS=['-O2'])
         else: #optimize for size
-            env.Append(CPPFLAGS=['-Os', '-ftree-vectorize'])
+            env.Append(CCFLAGS=['-Os', '-ftree-vectorize'])
             env.Append(LINKFLAGS=['-Os'])
 
         if env["target"] == "release_debug":
             env.Append(CPPFLAGS=['-DDEBUG_ENABLED'])
 
     elif (env["target"] == "debug"):
-        env.Append(CPPFLAGS=['-D_DEBUG', '-DDEBUG=1', '-gdwarf-2', '-O0', '-DDEBUG_ENABLED', '-DDEBUG_MEMORY_ENABLED'])
+        env.Append(CCFLAGS=['-gdwarf-2', '-O0'])
+        env.Append(CPPFLAGS=['-D_DEBUG', '-DDEBUG=1', '-DDEBUG_ENABLED', '-DDEBUG_MEMORY_ENABLED'])
 
     if (env["use_lto"]):
-        env.Append(CPPFLAGS=['-flto'])
+        env.Append(CCFLAGS=['-flto'])
         env.Append(LINKFLAGS=['-flto'])
 
     ## Architecture
@@ -104,7 +105,7 @@ def configure(env):
         detect_darwin_sdk_path('iphonesimulator', env)
         env['ENV']['MACOSX_DEPLOYMENT_TARGET'] = '10.9'
         arch_flag = "i386" if env["arch"] == "x86" else env["arch"]
-        env.Append(CCFLAGS=('-arch ' + arch_flag + ' -fobjc-abi-version=2 -fobjc-legacy-dispatch -fmessage-length=0 -fpascal-strings -fblocks -fasm-blocks -isysroot $IPHONESDK -mios-simulator-version-min=10.0 -DCUSTOM_MATRIX_TRANSFORM_H=\\\"build/iphone/matrix4_iphone.h\\\" -DCUSTOM_VECTOR3_TRANSFORM_H=\\\"build/iphone/vector3_iphone.h\\\"').split())
+        env.Append(CCFLAGS=('-arch ' + arch_flag + ' -fobjc-abi-version=2 -fobjc-legacy-dispatch -fmessage-length=0 -fpascal-strings -fblocks -fasm-blocks -isysroot $IPHONESDK -mios-simulator-version-min=10.0').split())
     elif (env["arch"] == "arm"):
         detect_darwin_sdk_path('iphone', env)
         env.Append(CCFLAGS='-fno-objc-arc -arch armv7 -fmessage-length=0 -fno-strict-aliasing -fdiagnostics-print-source-range-info -fdiagnostics-show-category=id -fdiagnostics-parseable-fixits -fpascal-strings -fblocks -isysroot $IPHONESDK -fvisibility=hidden -mthumb "-DIBOutlet=__attribute__((iboutlet))" "-DIBOutletCollection(ClassName)=__attribute__((iboutletcollection(ClassName)))" "-DIBAction=void)__attribute__((ibaction)" -miphoneos-version-min=10.0 -MMD -MT dependencies'.split())
@@ -115,9 +116,9 @@ def configure(env):
         env.Append(CPPFLAGS=['-DLIBYUV_DISABLE_NEON'])
 
     if env['ios_exceptions']:
-        env.Append(CPPFLAGS=['-fexceptions'])
+        env.Append(CCFLAGS=['-fexceptions'])
     else:
-        env.Append(CPPFLAGS=['-fno-exceptions'])
+        env.Append(CCFLAGS=['-fno-exceptions'])
 
     ## Link flags
 
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'])
diff --git a/platform/server/detect.py b/platform/server/detect.py
index f13ee72fd2..5306a2bf69 100644
--- a/platform/server/detect.py
+++ b/platform/server/detect.py
@@ -63,9 +63,10 @@ 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'])
@@ -73,7 +74,8 @@ def configure(env):
             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'])
         env.Append(LINKFLAGS=['-rdynamic'])
 
     ## Architecture
diff --git a/platform/uwp/detect.py b/platform/uwp/detect.py
index f8f1b066f6..17f8242466 100644
--- a/platform/uwp/detect.py
+++ b/platform/uwp/detect.py
@@ -53,18 +53,20 @@ def configure(env):
     ## Build type
 
     if (env["target"] == "release"):
-        env.Append(CPPFLAGS=['/O2', '/GL'])
-        env.Append(CPPFLAGS=['/MD'])
+        env.Append(CCFLAGS=['/O2', '/GL'])
+        env.Append(CCFLAGS=['/MD'])
         env.Append(LINKFLAGS=['/SUBSYSTEM:WINDOWS', '/LTCG'])
 
     elif (env["target"] == "release_debug"):
-        env.Append(CCFLAGS=['/O2', '/Zi', '/DDEBUG_ENABLED'])
-        env.Append(CPPFLAGS=['/MD'])
+        env.Append(CCFLAGS=['/O2', '/Zi'])
+        env.Append(CCFLAGS=['/MD'])
+        env.Append(CPPFLAGS=['/DDEBUG_ENABLED'])
         env.Append(LINKFLAGS=['/SUBSYSTEM:CONSOLE'])
 
     elif (env["target"] == "debug"):
-        env.Append(CCFLAGS=['/Zi', '/DDEBUG_ENABLED', '/DDEBUG_MEMORY_ENABLED'])
-        env.Append(CPPFLAGS=['/MDd'])
+        env.Append(CCFLAGS=['/Zi'])
+        env.Append(CCFLAGS=['/MDd'])
+        env.Append(CPPFLAGS=['/DDEBUG_ENABLED', '/DDEBUG_MEMORY_ENABLED'])
         env.Append(LINKFLAGS=['/SUBSYSTEM:CONSOLE'])
         env.Append(LINKFLAGS=['/DEBUG'])
 
@@ -136,18 +138,19 @@ def configure(env):
     ## Compile flags
 
     env.Append(CPPPATH=['#platform/uwp', '#drivers/windows'])
-    env.Append(CCFLAGS=['/DUWP_ENABLED', '/DWINDOWS_ENABLED', '/DTYPED_METHOD_BIND'])
-    env.Append(CCFLAGS=['/DGLES_ENABLED', '/DGL_GLEXT_PROTOTYPES', '/DEGL_EGLEXT_PROTOTYPES', '/DANGLE_ENABLED'])
+    env.Append(CPPFLAGS=['/DUWP_ENABLED', '/DWINDOWS_ENABLED', '/DTYPED_METHOD_BIND'])
+    env.Append(CPPFLAGS=['/DGLES_ENABLED', '/DGL_GLEXT_PROTOTYPES', '/DEGL_EGLEXT_PROTOTYPES', '/DANGLE_ENABLED'])
     winver = "0x0602" # Windows 8 is the minimum target for UWP build
-    env.Append(CCFLAGS=['/DWINVER=%s' % winver, '/D_WIN32_WINNT=%s' % winver])
+    env.Append(CPPFLAGS=['/DWINVER=%s' % winver, '/D_WIN32_WINNT=%s' % winver])
 
-    env.Append(CPPFLAGS=['/D', '__WRL_NO_DEFAULT_LIB__', '/D', 'WIN32', '/DPNG_ABORT=abort'])
+    env.Append(CPPFLAGS=['/D__WRL_NO_DEFAULT_LIB__', '/DWIN32', '/DPNG_ABORT=abort'])
 
     env.Append(CPPFLAGS=['/AI', vc_base_path + 'lib/store/references'])
     env.Append(CPPFLAGS=['/AI', vc_base_path + 'lib/x86/store/references'])
 
-    env.Append(CCFLAGS='/FS /MP /GS /wd"4453" /wd"28204" /wd"4291" /Zc:wchar_t /Gm- /fp:precise /D "_UNICODE" /D "UNICODE" /D "WINAPI_FAMILY=WINAPI_FAMILY_APP" /errorReport:prompt /WX- /Zc:forScope /Gd /EHsc /nologo'.split())
-    env.Append(CXXFLAGS='/ZW /FS'.split())
+    env.Append(CCFLAGS='/FS /MP /GS /wd"4453" /wd"28204" /wd"4291" /Zc:wchar_t /Gm- /fp:precise /errorReport:prompt /WX- /Zc:forScope /Gd /EHsc /nologo'.split())
+    env.Append(CPPFLAGS=['/D_UNICODE', '/DUNICODE', '/D "WINAPI_FAMILY=WINAPI_FAMILY_APP"'])
+    env.Append(CXXFLAGS=['/ZW'])
     env.Append(CCFLAGS=['/AI', vc_base_path + '\\vcpackages', '/AI', os.environ['WINDOWSSDKDIR'] + '\\References\\CommonConfiguration\\Neutral'])
 
     ## Link flags
diff --git a/platform/windows/detect.py b/platform/windows/detect.py
index e986c47b40..5c38eebf04 100644
--- a/platform/windows/detect.py
+++ b/platform/windows/detect.py
@@ -273,7 +273,8 @@ def configure_mingw(env):
            env.Prepend(CCFLAGS=['-g2'])
 
     elif (env["target"] == "release_debug"):
-        env.Append(CCFLAGS=['-O2', '-DDEBUG_ENABLED'])
+        env.Append(CCFLAGS=['-O2'])
+        env.Append(CPPFLAGS=['-DDEBUG_ENABLED'])
         if (env["debug_symbols"] == "yes"):
            env.Prepend(CCFLAGS=['-g1'])
         if (env["debug_symbols"] == "full"):
@@ -284,7 +285,8 @@ def configure_mingw(env):
            env.Prepend(CCFLAGS=['-Os'])
 
     elif (env["target"] == "debug"):
-        env.Append(CCFLAGS=['-g3', '-DDEBUG_ENABLED', '-DDEBUG_MEMORY_ENABLED'])
+        env.Append(CCFLAGS=['-g3'])
+        env.Append(CPPFLAGS=['-DDEBUG_ENABLED', '-DDEBUG_MEMORY_ENABLED'])
 
     ## Compiler configuration
 
@@ -325,11 +327,12 @@ def configure_mingw(env):
 
     ## Compile flags
 
-    env.Append(CCFLAGS=['-DWINDOWS_ENABLED', '-mwindows'])
-    env.Append(CCFLAGS=['-DOPENGL_ENABLED'])
-    env.Append(CCFLAGS=['-DWASAPI_ENABLED'])
-    env.Append(CCFLAGS=['-DWINMIDI_ENABLED'])
-    env.Append(CCFLAGS=['-DWINVER=%s' % env['target_win_version'], '-D_WIN32_WINNT=%s' % env['target_win_version']])
+    env.Append(CCFLAGS=['-mwindows'])
+    env.Append(CPPFLAGS=['-DWINDOWS_ENABLED'])
+    env.Append(CPPFLAGS=['-DOPENGL_ENABLED'])
+    env.Append(CPPFLAGS=['-DWASAPI_ENABLED'])
+    env.Append(CPPFLAGS=['-DWINMIDI_ENABLED'])
+    env.Append(CPPFLAGS=['-DWINVER=%s' % env['target_win_version'], '-D_WIN32_WINNT=%s' % env['target_win_version']])
     env.Append(LIBS=['mingw32', 'opengl32', 'dsound', 'ole32', 'd3d9', 'winmm', 'gdi32', 'iphlpapi', 'shlwapi', 'wsock32', 'ws2_32', 'kernel32', 'oleaut32', 'dinput8', 'dxguid', 'ksuser', 'imm32', 'bcrypt', 'avrt', 'uuid'])
 
     env.Append(CPPFLAGS=['-DMINGW_ENABLED'])
diff --git a/platform/x11/detect.py b/platform/x11/detect.py
index 94a87a7c90..1905b035e6 100644
--- a/platform/x11/detect.py
+++ b/platform/x11/detect.py
@@ -98,9 +98,10 @@ 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'])
@@ -108,7 +109,8 @@ def configure(env):
             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'])
         env.Append(LINKFLAGS=['-rdynamic'])
 
     ## Architecture
@@ -315,10 +317,10 @@ def configure(env):
     ## Cross-compilation
 
     if (is64 and env["bits"] == "32"):
-        env.Append(CPPFLAGS=['-m32'])
+        env.Append(CCFLAGS=['-m32'])
         env.Append(LINKFLAGS=['-m32', '-L/usr/lib/i386-linux-gnu'])
     elif (not is64 and env["bits"] == "64"):
-        env.Append(CPPFLAGS=['-m64'])
+        env.Append(CCFLAGS=['-m64'])
         env.Append(LINKFLAGS=['-m64', '-L/usr/lib/i686-linux-gnu'])
 
     # Link those statically for portability