From cbb83a1d64a5505c6fe8d505641109e405358a7d Mon Sep 17 00:00:00 2001 From: Victor Costan Date: Mon, 16 Aug 2021 18:22:31 +0000 Subject: Migrate feature detection macro checks from #ifdef to #if. The #if predicate evaluates to false if the macro is undefined, or defined to 0. #ifdef (and its synonym #if defined) evaluates to false only if the macro is undefined. The new setup allows differentiating between setting a macro to 0 (to express that the capability definitely does not exist / should not be used) and leaving a macro undefined (to express not knowing whether a capability exists / not caring if a capability is used). PiperOrigin-RevId: 391094241 --- cmake/config.h.in | 30 +++++++++++++++--------------- snappy-internal.h | 5 +++-- snappy-stubs-internal.h | 24 ++++++++++++------------ snappy-test.cc | 2 +- snappy-test.h | 18 +++++++++--------- snappy_test_tool.cc | 4 ++-- snappy_unittest.cc | 4 ++-- 7 files changed, 44 insertions(+), 43 deletions(-) diff --git a/cmake/config.h.in b/cmake/config.h.in index 872bd3c..306c7e2 100644 --- a/cmake/config.h.in +++ b/cmake/config.h.in @@ -2,46 +2,46 @@ #define THIRD_PARTY_SNAPPY_OPENSOURCE_CMAKE_CONFIG_H_ /* Define to 1 if the compiler supports __attribute__((always_inline)). */ -#cmakedefine HAVE_ATTRIBUTE_ALWAYS_INLINE 1 +#cmakedefine01 HAVE_ATTRIBUTE_ALWAYS_INLINE /* Define to 1 if the compiler supports __builtin_ctz and friends. */ -#cmakedefine HAVE_BUILTIN_CTZ 1 +#cmakedefine01 HAVE_BUILTIN_CTZ /* Define to 1 if the compiler supports __builtin_expect. */ -#cmakedefine HAVE_BUILTIN_EXPECT 1 +#cmakedefine01 HAVE_BUILTIN_EXPECT /* Define to 1 if you have a definition for mmap() in . */ -#cmakedefine HAVE_FUNC_MMAP 1 +#cmakedefine01 HAVE_FUNC_MMAP /* Define to 1 if you have a definition for sysconf() in . */ -#cmakedefine HAVE_FUNC_SYSCONF 1 +#cmakedefine01 HAVE_FUNC_SYSCONF /* Define to 1 if you have the `lzo2' library (-llzo2). */ -#cmakedefine HAVE_LIBLZO2 1 +#cmakedefine01 HAVE_LIBLZO2 /* Define to 1 if you have the `z' library (-lz). */ -#cmakedefine HAVE_LIBZ 1 +#cmakedefine01 HAVE_LIBZ /* Define to 1 if you have the `lz4' library (-llz4). */ -#cmakedefine HAVE_LIBLZ4 1 +#cmakedefine01 HAVE_LIBLZ4 /* Define to 1 if you have the header file. */ -#cmakedefine HAVE_SYS_MMAN_H 1 +#cmakedefine01 HAVE_SYS_MMAN_H /* Define to 1 if you have the header file. */ -#cmakedefine HAVE_SYS_RESOURCE_H 1 +#cmakedefine01 HAVE_SYS_RESOURCE_H /* Define to 1 if you have the header file. */ -#cmakedefine HAVE_SYS_TIME_H 1 +#cmakedefine01 HAVE_SYS_TIME_H /* Define to 1 if you have the header file. */ -#cmakedefine HAVE_SYS_UIO_H 1 +#cmakedefine01 HAVE_SYS_UIO_H /* Define to 1 if you have the header file. */ -#cmakedefine HAVE_UNISTD_H 1 +#cmakedefine01 HAVE_UNISTD_H /* Define to 1 if you have the header file. */ -#cmakedefine HAVE_WINDOWS_H 1 +#cmakedefine01 HAVE_WINDOWS_H /* Define to 1 if you target processors with SSSE3+ and have . */ #cmakedefine01 SNAPPY_HAVE_SSSE3 @@ -51,6 +51,6 @@ /* Define to 1 if your processor stores words with the most significant byte first (like Motorola and SPARC, unlike Intel and VAX). */ -#cmakedefine SNAPPY_IS_BIG_ENDIAN 1 +#cmakedefine01 SNAPPY_IS_BIG_ENDIAN #endif // THIRD_PARTY_SNAPPY_OPENSOURCE_CMAKE_CONFIG_H_ diff --git a/snappy-internal.h b/snappy-internal.h index f1aafa9..8530071 100644 --- a/snappy-internal.h +++ b/snappy-internal.h @@ -153,8 +153,9 @@ char* CompressFragment(const char* input, // loading from s2 + n. // // Separate implementation for 64-bit, little-endian cpus. -#if !defined(SNAPPY_IS_BIG_ENDIAN) && \ - (defined(__x86_64__) || defined(_M_X64) || defined(ARCH_PPC) || defined(ARCH_ARM)) +#if !SNAPPY_IS_BIG_ENDIAN && \ + (defined(__x86_64__) || defined(_M_X64) || defined(ARCH_PPC) || \ + defined(ARCH_ARM)) static inline std::pair FindMatchLength(const char* s1, const char* s2, const char* s2_limit, diff --git a/snappy-stubs-internal.h b/snappy-stubs-internal.h index c2a838f..7d43c92 100644 --- a/snappy-stubs-internal.h +++ b/snappy-stubs-internal.h @@ -31,7 +31,7 @@ #ifndef THIRD_PARTY_SNAPPY_OPENSOURCE_SNAPPY_STUBS_INTERNAL_H_ #define THIRD_PARTY_SNAPPY_OPENSOURCE_SNAPPY_STUBS_INTERNAL_H_ -#ifdef HAVE_CONFIG_H +#if HAVE_CONFIG_H #include "config.h" #endif @@ -43,11 +43,11 @@ #include #include -#ifdef HAVE_SYS_MMAN_H +#if HAVE_SYS_MMAN_H #include #endif -#ifdef HAVE_UNISTD_H +#if HAVE_UNISTD_H #include #endif @@ -90,20 +90,20 @@ #define ARRAYSIZE(a) int{sizeof(a) / sizeof(*(a))} // Static prediction hints. -#ifdef HAVE_BUILTIN_EXPECT +#if HAVE_BUILTIN_EXPECT #define SNAPPY_PREDICT_FALSE(x) (__builtin_expect(x, 0)) #define SNAPPY_PREDICT_TRUE(x) (__builtin_expect(!!(x), 1)) #else #define SNAPPY_PREDICT_FALSE(x) x #define SNAPPY_PREDICT_TRUE(x) x -#endif +#endif // HAVE_BUILTIN_EXPECT // Inlining hints. -#ifdef HAVE_ATTRIBUTE_ALWAYS_INLINE +#if HAVE_ATTRIBUTE_ALWAYS_INLINE #define SNAPPY_ATTRIBUTE_ALWAYS_INLINE __attribute__((always_inline)) #else #define SNAPPY_ATTRIBUTE_ALWAYS_INLINE -#endif +#endif // HAVE_ATTRIBUTE_ALWAYS_INLINE // Stubbed version of ABSL_FLAG. // @@ -235,11 +235,11 @@ class LittleEndian { } static inline constexpr bool IsLittleEndian() { -#if defined(SNAPPY_IS_BIG_ENDIAN) +#if SNAPPY_IS_BIG_ENDIAN return false; #else return true; -#endif // defined(SNAPPY_IS_BIG_ENDIAN) +#endif // SNAPPY_IS_BIG_ENDIAN } }; @@ -265,7 +265,7 @@ class Bits { void operator=(const Bits&); }; -#if defined(HAVE_BUILTIN_CTZ) +#if HAVE_BUILTIN_CTZ inline int Bits::Log2FloorNonZero(uint32_t n) { assert(n != 0); @@ -354,7 +354,7 @@ inline int Bits::FindLSBSetNonZero(uint32_t n) { #endif // End portable versions. -#if defined(HAVE_BUILTIN_CTZ) +#if HAVE_BUILTIN_CTZ inline int Bits::FindLSBSetNonZero64(uint64_t n) { assert(n != 0); @@ -388,7 +388,7 @@ inline int Bits::FindLSBSetNonZero64(uint64_t n) { } } -#endif // End portable version. +#endif // HAVE_BUILTIN_CTZ // Variable-length integer encoding. class Varint { diff --git a/snappy-test.cc b/snappy-test.cc index 7eb490a..aae6072 100644 --- a/snappy-test.cc +++ b/snappy-test.cc @@ -151,7 +151,7 @@ LogMessageCrash::~LogMessageCrash() { #pragma warning(pop) #endif -#ifdef HAVE_LIBZ +#if HAVE_LIBZ ZLib::ZLib() : comp_init_(false), diff --git a/snappy-test.h b/snappy-test.h index f80d343..65f3725 100644 --- a/snappy-test.h +++ b/snappy-test.h @@ -31,25 +31,25 @@ #ifndef THIRD_PARTY_SNAPPY_OPENSOURCE_SNAPPY_TEST_H_ #define THIRD_PARTY_SNAPPY_OPENSOURCE_SNAPPY_TEST_H_ -#ifdef HAVE_CONFIG_H +#if HAVE_CONFIG_H #include "config.h" #endif #include "snappy-stubs-internal.h" -#ifdef HAVE_SYS_MMAN_H +#if HAVE_SYS_MMAN_H #include #endif -#ifdef HAVE_SYS_RESOURCE_H +#if HAVE_SYS_RESOURCE_H #include #endif -#ifdef HAVE_SYS_TIME_H +#if HAVE_SYS_TIME_H #include #endif -#ifdef HAVE_WINDOWS_H +#if HAVE_WINDOWS_H // Needed to be able to use std::max without workarounds in the source code. // https://support.microsoft.com/en-us/help/143208/prb-using-stl-in-windows-program-can-cause-min-max-conflicts #define NOMINMAX @@ -58,15 +58,15 @@ #define InitGoogle(argv0, argc, argv, remove_flags) ((void)(0)) -#ifdef HAVE_LIBZ +#if HAVE_LIBZ #include "zlib.h" #endif -#ifdef HAVE_LIBLZO2 +#if HAVE_LIBLZO2 #include "lzo/lzo1x.h" #endif -#ifdef HAVE_LIBLZ4 +#if HAVE_LIBLZ4 #include "lz4.h" #endif @@ -216,7 +216,7 @@ class LogMessageVoidify { #define CHECK_GT(a, b) CRASH_UNLESS((a) > (b)) #define CHECK_OK(cond) (cond).ok() -#ifdef HAVE_LIBZ +#if HAVE_LIBZ // Object-oriented wrapper around zlib. class ZLib { diff --git a/snappy_test_tool.cc b/snappy_test_tool.cc index 24ac1ee..a7c779b 100644 --- a/snappy_test_tool.cc +++ b/snappy_test_tool.cc @@ -66,7 +66,7 @@ namespace snappy { namespace { -#if defined(HAVE_FUNC_MMAP) && defined(HAVE_FUNC_SYSCONF) +#if HAVE_FUNC_MMAP && HAVE_FUNC_SYSCONF // To test against code that reads beyond its input, this class copies a // string to a newly allocated group of pages, the last of which @@ -112,7 +112,7 @@ class DataEndingAtUnreadablePage { size_t size_; }; -#else // defined(HAVE_FUNC_MMAP) && defined(HAVE_FUNC_SYSCONF) +#else // HAVE_FUNC_MMAP && HAVE_FUNC_SYSCONF // Fallback for systems without mmap. using DataEndingAtUnreadablePage = std::string; diff --git a/snappy_unittest.cc b/snappy_unittest.cc index 8782b52..292004c 100644 --- a/snappy_unittest.cc +++ b/snappy_unittest.cc @@ -50,7 +50,7 @@ namespace snappy { namespace { -#if defined(HAVE_FUNC_MMAP) && defined(HAVE_FUNC_SYSCONF) +#if HAVE_FUNC_MMAP && HAVE_FUNC_SYSCONF // To test against code that reads beyond its input, this class copies a // string to a newly allocated group of pages, the last of which @@ -96,7 +96,7 @@ class DataEndingAtUnreadablePage { size_t size_; }; -#else // defined(HAVE_FUNC_MMAP) && defined(HAVE_FUNC_SYSCONF) +#else // HAVE_FUNC_MMAP) && HAVE_FUNC_SYSCONF // Fallback for systems without mmap. using DataEndingAtUnreadablePage = std::string; -- cgit v1.2.1