Add support for NaCl in atomicops.

This does additionally a significant cleanup in platform_macros.h (initially
pulled from v8).
It implemented some subtleties that we don't use like the HOST/TARGET arch
distinction.

Changes related to NaCl support come from Chromium's build/build_config.h.

BUG=392

1 files changed, 12 insertions, 77 deletions

diff --git a/src/google/protobuf/stubs/platform_macros.h b/src/google/protobuf/stubs/platform_macros.h
index 0cda2b4c..cba9fbd0 100644
--- a/src/google/protobuf/stubs/platform_macros.h
+++ b/src/google/protobuf/stubs/platform_macros.h
@@ -38,92 +38,27 @@
 //   http://www.agner.org/optimize/calling_conventions.pdf
 //   or with gcc, run: "echo | gcc -E -dM -"
 #if defined(_M_X64) || defined(__x86_64__)
-#define GOOGLE_PROTOBUF_HOST_ARCH_X64 1
-#define GOOGLE_PROTOBUF_HOST_ARCH_64_BIT 1
-#define GOOGLE_PROTOBUF_HOST_CAN_READ_UNALIGNED 1
+#define GOOGLE_PROTOBUF_ARCH_X64 1
+#define GOOGLE_PROTOBUF_ARCH_64_BIT 1
 #elif defined(_M_IX86) || defined(__i386__)
-#define GOOGLE_PROTOBUF_HOST_ARCH_IA32 1
-#define GOOGLE_PROTOBUF_HOST_ARCH_32_BIT 1
-#define GOOGLE_PROTOBUF_HOST_CAN_READ_UNALIGNED 1
+#define GOOGLE_PROTOBUF_ARCH_IA32 1
+#define GOOGLE_PROTOBUF_ARCH_32_BIT 1
 #elif defined(__ARMEL__)
-#define GOOGLE_PROTOBUF_HOST_ARCH_ARM 1
-#define GOOGLE_PROTOBUF_HOST_ARCH_32_BIT 1
-// Some CPU-OS combinations allow unaligned access on ARM. We assume
-// that unaligned accesses are not allowed unless the build system
-// defines the CAN_USE_UNALIGNED_ACCESSES macro to be non-zero.
-#if CAN_USE_UNALIGNED_ACCESSES
-#define GOOGLE_PROTOBUF_HOST_CAN_READ_UNALIGNED 1
-#endif
+#define GOOGLE_PROTOBUF_ARCH_ARM 1
+#define GOOGLE_PROTOBUF_ARCH_32_BIT 1
 #elif defined(__MIPSEL__)
-#define GOOGLE_PROTOBUF_HOST_ARCH_MIPS 1
-#define GOOGLE_PROTOBUF_HOST_ARCH_32_BIT 1
+#define GOOGLE_PROTOBUF_ARCH_MIPS 1
+#define GOOGLE_PROTOBUF_ARCH_32_BIT 1
+#elif defined(__pnacl__)
+#define GOOGLE_PROTOBUF_ARCH_32_BIT 1
 #else
 #error Host architecture was not detected as supported by protobuf
 #endif
 
-// Target architecture detection. This may be set externally. If not, detect
-// in the same way as the host architecture, that is, target the native
-// environment as presented by the compiler.
-#if !defined(GOOGLE_PROTOBUF_TARGET_ARCH_X64) && \
-    !defined(GOOGLE_PROTOBUF_TARGET_ARCH_IA32) && \
-    !defined(GOOGLE_PROTOBUF_TARGET_ARCH_ARM) && \
-    !defined(GOOGLE_PROTOBUF_TARGET_ARCH_MIPS)
-#if defined(_M_X64) || defined(__x86_64__)
-#define GOOGLE_PROTOBUF_TARGET_ARCH_X64 1
-#elif defined(_M_IX86) || defined(__i386__)
-#define GOOGLE_PROTOBUF_TARGET_ARCH_IA32 1
-#elif defined(__ARMEL__)
-#define GOOGLE_PROTOBUF_TARGET_ARCH_ARM 1
-#elif defined(__MIPSEL__)
-#define GOOGLE_PROTOBUF_TARGET_ARCH_MIPS 1
-#else
-#error Target architecture was not detected as supported by protobuf
-#endif
-#endif
-
-// Check for supported combinations of host and target architectures.
-#if defined(GOOGLE_PROTOBUF_TARGET_ARCH_IA32) && \
-    !defined(GOOGLE_PROTOBUF_HOST_ARCH_IA32)
-#error Target architecture ia32 is only supported on ia32 host
-#endif
-#if defined(GOOGLE_PROTOBUF_TARGET_ARCH_X64) && \
-    !defined(GOOGLE_PROTOBUF_HOST_ARCH_X64)
-#error Target architecture x64 is only supported on x64 host
-#endif
-#if (defined(GOOGLE_PROTOBUF_TARGET_ARCH_ARM) && \
-    !(defined(GOOGLE_PROTOBUF_HOST_ARCH_IA32) || \
-      defined(GOOGLE_PROTOBUF_HOST_ARCH_ARM)))
-#error Target architecture arm is only supported on arm and ia32 host
-#endif
-#if (defined(GOOGLE_PROTOBUF_TARGET_ARCH_MIPS) && \
-    !(defined(GOOGLE_PROTOBUF_HOST_ARCH_IA32) || \
-      defined(GOOGLE_PROTOBUF_HOST_ARCH_MIPS)))
-#error Target architecture mips is only supported on mips and ia32 host
-#endif
-
-// Define unaligned read for the target architectures supporting it.
-#if defined(GOOGLE_PROTOBUF_TARGET_ARCH_X64) || \
-    defined(GOOGLE_PROTOBUF_TARGET_ARCH_IA32)
-#define GOOGLE_PROTOBUF_TARGET_CAN_READ_UNALIGNED 1
-#elif GOOGLE_PROTOBUF_TARGET_ARCH_ARM
-// Some CPU-OS combinations allow unaligned access on ARM. We assume
-// that unaligned accesses are not allowed unless the build system
-// defines the CAN_USE_UNALIGNED_ACCESSES macro to be non-zero.
-#if CAN_USE_UNALIGNED_ACCESSES
-#define GOOGLE_PROTOBUF_TARGET_CAN_READ_UNALIGNED 1
-#endif
-#elif GOOGLE_PROTOBUF_TARGET_ARCH_MIPS
-#else
-#error Target architecture is not supported by protobuf
-#endif
-
-#if (defined(__APPLE__) && defined(__MACH__)) || \
-    defined(__FreeBSD__) || defined(__OpenBSD__)
-#define GOOGLE_PROTOBUF_USING_BSD_ABI
-#endif
-
 #if defined(__APPLE__)
 #define GOOGLE_PROTOBUF_OS_APPLE
+#elif defined(__native_client__)
+#define GOOGLE_PROTOBUF_OS_NACL
 #endif
 
 #endif  // GOOGLE_PROTOBUF_PLATFORM_MACROS_H_