From a8d13df4127808f89e94b92a773e4debb8ea77f4 Mon Sep 17 00:00:00 2001
From: David Tenty <daltenty@ibm.com>
Date: Fri, 7 Jun 2019 15:45:25 +0000
Subject: [PATCH] Build with _XOPEN_SOURCE defined on AIX

Summary:
It is useful to build with _XOPEN_SOURCE defined on AIX, enabling X/Open
and POSIX compatibility mode, to work around stray macros and other
bugs in the headers provided by the system and build compiler.

This patch adds the config to cmake to build with _XOPEN_SOURCE defined
on AIX with a few exceptions. Google Test internals require access to
platform specific thread info constructs on AIX so in that case we build
with _ALL_SOURCE defined instead. Libclang also uses header which needs
_ALL_SOURCE on AIX so we leave that as is as well.

We also add building on AIX with the large file API and doing CMake
header checks with X/OPEN definitions so the results are consistent with
the environment that will be present in the build.

Reviewers: hubert.reinterpretcast, xingxue, andusy

Reviewed By: hubert.reinterpretcast

Subscribers: mgorny, jsji, cfe-commits, llvm-commits

Tags: #llvm, #clang

Differential Revision: https://reviews.llvm.org/D62533

llvm-svn: 362808
---
 clang/tools/libclang/CMakeLists.txt | 5 +++++
 llvm/CMakeLists.txt                 | 7 +++++++
 llvm/cmake/config-ix.cmake          | 7 +++++++
 llvm/utils/unittest/CMakeLists.txt  | 6 ++++++
 4 files changed, 25 insertions(+)

diff --git a/clang/tools/libclang/CMakeLists.txt b/clang/tools/libclang/CMakeLists.txt
index 2de5b2956d53..a2804ab17ccb 100644
--- a/clang/tools/libclang/CMakeLists.txt
+++ b/clang/tools/libclang/CMakeLists.txt
@@ -89,6 +89,11 @@ else()
   set(output_name "clang")
 endif()
 
+# libclang requires headers which need _ALL_SOURCE to build on AIX
+if (UNIX AND ${CMAKE_SYSTEM_NAME} MATCHES "AIX")
+    remove_definitions("-D_XOPEN_SOURCE=700")
+endif()
+
 add_clang_library(libclang ${ENABLE_SHARED} ${ENABLE_STATIC}
   OUTPUT_NAME ${output_name}
   ${SOURCES}
diff --git a/llvm/CMakeLists.txt b/llvm/CMakeLists.txt
index 71434bcb3e71..c3647ed88bfd 100644
--- a/llvm/CMakeLists.txt
+++ b/llvm/CMakeLists.txt
@@ -819,6 +819,13 @@ if(APPLE AND DARWIN_LTO_LIBRARY)
     "${CMAKE_MODULE_LINKER_FLAGS} -Wl,-lto_library -Wl,${DARWIN_LTO_LIBRARY}")
 endif()
 
+# Build with _XOPEN_SOURCE on AIX, as stray macros in _ALL_SOURCE mode tend to
+# break things. In this case we need to enable the large-file API as well.
+if (UNIX AND ${CMAKE_SYSTEM_NAME} MATCHES "AIX")
+          add_definitions("-D_XOPEN_SOURCE=700")
+          add_definitions("-D_LARGE_FILE_API")
+endif()
+
 # Work around a broken bfd ld behavior. When linking a binary with a
 # foo.so library, it will try to find any library that foo.so uses and
 # check its symbols. This is wasteful (the check was done when foo.so
diff --git a/llvm/cmake/config-ix.cmake b/llvm/cmake/config-ix.cmake
index e1e5cd3198b2..0218d42eb891 100644
--- a/llvm/cmake/config-ix.cmake
+++ b/llvm/cmake/config-ix.cmake
@@ -23,6 +23,13 @@ if( CMAKE_SYSTEM MATCHES "FreeBSD-9.2-RELEASE" AND
   list(APPEND CMAKE_REQUIRED_LIBRARIES "cxxrt")
 endif()
 
+# Do checks with _XOPEN_SOURCE and large-file API on AIX, because we will build
+# with those too.
+if (UNIX AND ${CMAKE_SYSTEM_NAME} MATCHES "AIX")
+          list(APPEND CMAKE_REQUIRED_DEFINITIONS "-D_XOPEN_SOURCE=700")
+          list(APPEND CMAKE_REQUIRED_DEFINITIONS "-D_LARGE_FILE_API")
+endif()
+
 # include checks
 check_include_file(dlfcn.h HAVE_DLFCN_H)
 check_include_file(errno.h HAVE_ERRNO_H)
diff --git a/llvm/utils/unittest/CMakeLists.txt b/llvm/utils/unittest/CMakeLists.txt
index 5b5cbf5d745f..0850d49e3a35 100644
--- a/llvm/utils/unittest/CMakeLists.txt
+++ b/llvm/utils/unittest/CMakeLists.txt
@@ -28,6 +28,12 @@ if(WIN32)
   add_definitions(-DGTEST_OS_WINDOWS=1)
 endif()
 
+# Google Test requires headers which need _ALL_SOURCE to build on AIX
+if (UNIX AND ${CMAKE_SYSTEM_NAME} MATCHES "AIX")
+  remove_definitions("-D_XOPEN_SOURCE=700")
+  add_definitions("-D_ALL_SOURCE")
+endif()
+
 if(SUPPORTS_VARIADIC_MACROS_FLAG)
   add_definitions("-Wno-variadic-macros")
 endif()
-- 
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