Amd/dev/rlieberm/reland flang rt (llvm#1159)

Author: ronlieb

flang-rt/CMakeLists.txt

@@ -294,14 +294,14 @@ elseif (FLANG_RT_GCC_RESOURCE_DIR)
 endif ()
 
 # Check if 128-bit float computations can be done via long double.
-check_cxx_source_compiles(
-  "#include <cfloat>
-   #if LDBL_MANT_DIG != 113
-   #error LDBL_MANT_DIG != 113
-   #endif
-   int main() { return 0; }
-  "
-  HAVE_LDBL_MANT_DIG_113)
+#check_cxx_source_compiles(
+#  "#include <cfloat>
+#   #if LDBL_MANT_DIG != 113
+#   #error LDBL_MANT_DIG != 113
+#   #endif
+#   int main() { return 0; }
+#  "
+#  HAVE_LDBL_MANT_DIG_113)
 
 
 #####################
@@ -325,7 +325,9 @@ set(CMAKE_CXX_STANDARD_REQUIRED YES)
 
 
 configure_file(cmake/config.h.cmake.in config.h)
-
+if (FLANG_RT_INCLUDE_QUADMATH_H)
+  configure_file("cmake/quadmath_wrapper.h.in" "${FLANG_RT_BINARY_DIR}/quadmath_wrapper.h")
+endif ()
 
 # The bootstrap build will create a phony target with the same as the top-level
 # directory ("flang-rt") and delegate it to the runtimes build dir.

flang-rt/cmake/clang_gcc_root.cpp

@@ -0,0 +1 @@
+int main() { return 0; }

flang-rt/cmake/quadmath_wrapper.h.in

@@ -0,0 +1,9 @@
+/*===-- cmake/quadmath_wrapper.h.in ---------------------=-----------*- C -*-===
+ *
+ * Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+ * See https://llvm.org/LICENSE.txt for license information.
+ * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+ *
+ *===----------------------------------------------------------------------===*/
+
+#include ${FLANG_RT_INCLUDE_QUADMATH_H}

flang-rt/lib/quadmath/CMakeLists.txt

@@ -78,8 +78,7 @@ target_include_directories(FortranFloat128MathILib INTERFACE
 
 if (FLANG_RUNTIME_F128_MATH_LIB)
   if (${FLANG_RUNTIME_F128_MATH_LIB} STREQUAL "libquadmath")
-    check_include_file(quadmath.h FOUND_QUADMATH_HEADER)
-    if(FOUND_QUADMATH_HEADER)
+    if(FLANG_RT_INCLUDE_QUADMATH_H)
       add_compile_definitions(HAS_QUADMATHLIB)
     else()
       message(FATAL_ERROR

flang-rt/lib/quadmath/complex-math.h

@@ -13,7 +13,7 @@
 #include "flang/Runtime/entry-names.h"
 
 #if HAS_QUADMATHLIB
-#include "quadmath.h"
+#include "quadmath_wrapper.h"
 #define CAbs(x) cabsq(x)
 #define CAcos(x) cacosq(x)
 #define CAcosh(x) cacoshq(x)

flang-rt/lib/quadmath/math-entries.h

@@ -112,7 +112,7 @@ DEFINE_FALLBACK_F128(Yn)
 
 #if HAS_QUADMATHLIB
 // Define wrapper callers for libquadmath.
-#include "quadmath.h"
+#include "quadmath_wrapper.h"
 DEFINE_SIMPLE_ALIAS(Abs, fabsq)
 DEFINE_SIMPLE_ALIAS(Acos, acosq)
 DEFINE_SIMPLE_ALIAS(Acosh, acoshq)

flang/EnableFlangRT

@@ -132,6 +132,12 @@ elseif (CMAKE_CXX_COMPILER_ID MATCHES "XL")
   set(NO_RTTI_FLAGS "-qnoeh -qnortti")
 endif ()
 
+# When compiling LLVM_ENABLE_RUNTIMES=flang-rt, the build system looks for the
+# full path of quadmath.h. In this non-runtimes build, preserve the old behavior
+# of just including <quadmath.h>.
+set(FLANG_RT_INCLUDE_QUADMATH_H "<quadmath.h>")
+configure_file("${FLANG_RT_SOURCE_DIR}/cmake/quadmath_wrapper.h.in" "quadmath_wrapper.h")
+
 configure_file("${FLANG_RT_SOURCE_DIR}/cmake/config.h.cmake.in" config.h)
 # include_directories is used here instead of target_include_directories
 # because add_flang_library creates multiple objects (STATIC/SHARED, OBJECT)