[Preprocessor] Implement __is_target_{arch|vendor|os|environment} function-like
builtin macros
This patch implements the __is_target_arch, __is_target_vendor, __is_target_os,
and __is_target_environment Clang preprocessor extensions that were proposed by
@compnerd in Bob's cfe-dev post:
http://lists.llvm.org/pipermail/cfe-dev/2017-November/056166.html.
These macros can be used to examine the components of the target triple at
compile time. A has_builtin(is_target_???) preprocessor check can be used to
check for their availability.
__is_target_arch allows you to check if an arch is specified without worring
about a specific subarch, e.g.
__is_target_arch(arm) returns 1 for the target arch "armv7"
__is_target_arch(armv7) returns 1 for the target arch "armv7"
__is_target_arch(armv6) returns 0 for the target arch "armv7"
__is_target_vendor and __is_target_environment match the specific vendor
or environment. __is_target_os matches the specific OS, but
__is_target_os(darwin) will match any Darwin-based OS. "Unknown" can be used
to test if the triple's component is specified.
rdar://35753116
Differential Revision: https://reviews.llvm.org/D41087
llvm-svn: 320734
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 2ff984d..2ec1431 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -110,6 +110,10 @@
If a gcc installation is found, it still prefers ``.ctors`` if the found
gcc is older than 4.7.0.
+- The new builtin preprocessor macros ``__is_target_arch``,
+ ``__is_target_vendor``, ``__is_target_os``, and ``__is_target_environment``
+ can be used to to examine the individual components of the target triple.
+
New Compiler Flags
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