[flang] Disable libstdc++ assertions in the runtime library

Differential Revision: https://reviews.llvm.org/D143168

Author: jayfoad

flang/lib/Decimal/CMakeLists.txt

@@ -42,7 +42,9 @@ if (FLANG_RUNTIME_HAS_FNO_LTO_FLAG)
   append("-fno-lto" CMAKE_CXX_FLAGS)
 endif()
 
-
+# Disable libstdc++ assertions, even in an LLVM_ENABLE_ASSERTIONS build, to
+# avoid an unwanted dependency on libstdc++.so.
+add_definitions(-U_GLIBCXX_ASSERTIONS)
 
 add_flang_library(FortranDecimal INSTALL_WITH_TOOLCHAIN
   binary-to-decimal.cpp

flang/runtime/CMakeLists.txt

@@ -86,6 +86,10 @@ include_directories(AFTER ${CMAKE_CURRENT_BINARY_DIR})
 append(${NO_LTO_FLAGS} CMAKE_C_FLAGS)
 append(${NO_LTO_FLAGS} CMAKE_CXX_FLAGS)
 
+# Disable libstdc++ assertions, even in an LLVM_ENABLE_ASSERTIONS build, to
+# avoid an unwanted dependency on libstdc++.so.
+add_definitions(-U_GLIBCXX_ASSERTIONS)
+
 add_subdirectory(FortranMain)
 
 add_flang_library(FortranRuntime