[flang] Set compile definitions for flang-rt build on AIX (#127919)
After commit b55f751, the flang-rt build on AIX is missing `-D_LARGE_FILE_API
-D_XOPEN_SOURCE=700` in compiling the source. This patch is to add the
compile definitions.
---------
Co-authored-by: Michael Kruse <github@meinersbur.de>
diff --git a/flang-rt/CMakeLists.txt b/flang-rt/CMakeLists.txt
index 50d1a5c..76e612a 100644
--- a/flang-rt/CMakeLists.txt
+++ b/flang-rt/CMakeLists.txt
@@ -227,6 +227,12 @@
find_compiler_rt_library(builtins FLANG_RT_BUILTINS_LIBRARY)
endif ()
+# Build with _XOPEN_SOURCE on AIX to avoid errors caused by _ALL_SOURCE.
+# We need to enable the large-file API as well.
+if (UNIX AND CMAKE_SYSTEM_NAME MATCHES "AIX")
+ add_compile_definitions(_XOPEN_SOURCE=700)
+ add_compile_definitions(_LARGE_FILE_API)
+endif ()
# Check whether the compiler can undefine a macro using the "-U" flag.
# Aternatively, we could use
