Bug 836078 - Replace all gcc __GNUC__ version checks with MOZ_GCC_VERSION_AT_LEAST macro. r=dvander

js/public/Utility.h

@@ -9,6 +9,7 @@
 
 #include "mozilla/Assertions.h"
 #include "mozilla/Attributes.h"
+#include "mozilla/Compiler.h"
 #include "mozilla/Scoped.h"
 
 #include <stdlib.h>
@@ -229,8 +230,21 @@ __BitScanReverse64(unsigned __int64 val)
 # define js_bitscan_clz64(val)  __BitScanReverse64(val)
 # define JS_HAS_BUILTIN_BITSCAN64
 #endif
-#elif (__GNUC__ >= 4) || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
+#elif MOZ_IS_GCC
 
+#if MOZ_GCC_VERSION_AT_LEAST(3, 4, 0)
+# define USE_BUILTIN_CTZ
+#endif
+
+#elif defined(__clang__)
+
+#if __has_builtin(__builtin_ctz)
+# define USE_BUILTIN_CTZ
+#endif
+
+#endif
+
+#if defined(USE_BUILTIN_CTZ)
 # define js_bitscan_ctz32(val)  __builtin_ctz(val)
 # define js_bitscan_clz32(val)  __builtin_clz(val)
 # define JS_HAS_BUILTIN_BITSCAN32
@@ -240,6 +254,8 @@ __BitScanReverse64(unsigned __int64 val)
 #  define JS_HAS_BUILTIN_BITSCAN64
 # endif
 
+# undef USE_BUILTIN_CTZ
+
 #endif
 
 /*

js/src/jsutil.h

@@ -12,6 +12,7 @@
 #define jsutil_h___
 
 #include "mozilla/Attributes.h"
+#include "mozilla/Compiler.h"
 #include "mozilla/GuardObjects.h"
 
 #include "js/Utility.h"
@@ -370,7 +371,9 @@ typedef size_t jsbitmap;
         { expr; }                                                             \
         _Pragma("clang diagnostic pop")                                       \
     JS_END_MACRO
-#elif (__GNUC__ >= 5) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6)
+#elif MOZ_IS_GCC
+
+#if MOZ_GCC_VERSION_AT_LEAST(4, 6, 0)
 # define JS_SILENCE_UNUSED_VALUE_IN_EXPR(expr)                                \
     JS_BEGIN_MACRO                                                            \
         _Pragma("GCC diagnostic push")                                        \
@@ -378,7 +381,10 @@ typedef size_t jsbitmap;
         expr;                                                                 \
         _Pragma("GCC diagnostic pop")                                         \
     JS_END_MACRO
-#else
+#endif
+#endif
+
+#if !defined(JS_SILENCE_UNUSED_VALUE_IN_EXPR)
 # define JS_SILENCE_UNUSED_VALUE_IN_EXPR(expr)                                \
     JS_BEGIN_MACRO                                                            \
         expr;                                                                 \

mfbt/Compiler.h

@@ -9,6 +9,8 @@
 #define mozilla_Compiler_h_
 
 #if !defined(__clang__) && defined(__GNUC__)
+
+#define MOZ_IS_GCC 1
    /*
     * This macro should simplify gcc version checking. For example, to check
     * for gcc 4.5.1 or later, check `#ifdef MOZ_GCC_VERSION_AT_LEAST(4, 5, 1)`.
@@ -19,6 +21,11 @@
 #if !MOZ_GCC_VERSION_AT_LEAST(4, 4, 0)
 #  error "mfbt (and Gecko) require at least gcc 4.4 to build."
 #endif
+
+#else
+
+#define MOZ_IS_GCC 0
+
 #endif
 
 #endif  /* mozilla_Compiler_h_ */

toolkit/mozapps/update/updater/updater.cpp

@@ -50,6 +50,8 @@
 
 #include "updatelogging.h"
 
+#include "mozilla/Compiler.h"
+
 // Amount of the progress bar to use in each of the 3 update stages,
 // should total 100.0.
 #define PROGRESS_PREPARE_SIZE 20.0f
@@ -119,12 +121,20 @@ static bool sUseHardLinks = true;
 
 // This variable lives in libbz2.  It's declared in bzlib_private.h, so we just
 // declare it here to avoid including that entire header file.
-#if (__GNUC__ >= 4) || (__GNUC__ == 3 && __GNUC_MINOR__ >= 3)
+#define BZ2_CRC32TABLE_UNDECLARED
+
+#if MOZ_IS_GCC
+#if MOZ_GCC_VERSION_AT_LEAST(3, 3, 0)
 extern "C"  __attribute__((visibility("default"))) unsigned int BZ2_crc32Table[256];
+#undef BZ2_CRC32TABLE_UNDECLARED
+#endif
 #elif defined(__SUNPRO_C) || defined(__SUNPRO_CC)
 extern "C" __global unsigned int BZ2_crc32Table[256];
-#else
+#undef BZ2_CRC32TABLE_UNDECLARED
+#endif
+#if defined(BZ2_CRC32TABLE_UNDECLARED)
 extern "C" unsigned int BZ2_crc32Table[256];
+#undef BZ2_CRC32TABLE_UNDECLARED
 #endif
 
 static unsigned int

xpcom/reflect/xptcall/src/md/unix/xptcinvoke_arm.cpp

@@ -7,14 +7,18 @@
 
 #include "xptcprivate.h"
 
+#include "mozilla/Compiler.h"
+
 #if !defined(__arm__) && !(defined(LINUX) || defined(ANDROID))
 #error "This code is for Linux ARM only. Check that it works on your system, too.\nBeware that this code is highly compiler dependent."
 #endif
 
-#if defined(__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)) \
+#if MOZ_IS_GCC
+#if MOZ_GCC_VERSION_AT_LEAST(4, 5, 0) \
     && defined(__ARM_EABI__) && !defined(__ARM_PCS_VFP) && !defined(__ARM_PCS)
 #error "Can't identify floating point calling conventions.\nPlease ensure that your toolchain defines __ARM_PCS or __ARM_PCS_VFP."
 #endif
+#endif
 
 #ifndef __ARM_PCS_VFP