[libc-commits] [libc] [libc] remove MPFR and related tests in full build (PR #87693)

[Schrodinger ZHU Yifan via libc-commits]

https://github.com/SchrodingerZhu updated https://github.com/llvm/llvm-project/pull/87693

>From 697b8811f50d0b7a76fd202a113d28b0a5b66048 Mon Sep 17 00:00:00 2001
From: Schrodinger ZHU Yifan <yifanzhu at rochester.edu>
Date: Thu, 4 Apr 2024 15:58:57 -0400
Subject: [PATCH 1/3] [libc] avoid c++ includes from MPFR

---
 libc/utils/MPFRWrapper/mpfr_inc.h | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/libc/utils/MPFRWrapper/mpfr_inc.h b/libc/utils/MPFRWrapper/mpfr_inc.h
index 58fa7b25a9f210..0d8afbed39859f 100644
--- a/libc/utils/MPFRWrapper/mpfr_inc.h
+++ b/libc/utils/MPFRWrapper/mpfr_inc.h
@@ -17,7 +17,21 @@
 // MPFR header can be included in manner allowed in that repo.
 #include "CustomMPFRIncluder.h"
 #else
+
+extern "C" {
+#pragma push_macro("__cplusplus")
+#if defined(__clang__)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wbuiltin-macro-redefined"
+#endif
+#undef __cplusplus
 #include <mpfr.h>
+#if defined(__clang__)
+#pragma clang diagnostic pop
+#endif
+#pragma pop_macro("__cplusplus")
+}
+
 #endif
 
 #endif // LLVM_LIBC_UTILS_MPFRWRAPPER_MPFR_INC_H

>From 133bb48d22caef6bc0da11a3b028108000d56b91 Mon Sep 17 00:00:00 2001
From: Schrodinger ZHU Yifan <yifanzhu at rochester.edu>
Date: Sun, 7 Apr 2024 17:11:10 -0400
Subject: [PATCH 2/3] [libc] remove MPFR and related tests in full build

---
 libc/cmake/modules/LLVMLibCCheckMPFR.cmake |  2 +-
 libc/utils/MPFRWrapper/CMakeLists.txt      |  8 +-------
 libc/utils/MPFRWrapper/mpfr_inc.h          | 14 --------------
 3 files changed, 2 insertions(+), 22 deletions(-)

diff --git a/libc/cmake/modules/LLVMLibCCheckMPFR.cmake b/libc/cmake/modules/LLVMLibCCheckMPFR.cmake
index bbaeb9f0dc053f..532b0b9bfae392 100644
--- a/libc/cmake/modules/LLVMLibCCheckMPFR.cmake
+++ b/libc/cmake/modules/LLVMLibCCheckMPFR.cmake
@@ -2,7 +2,7 @@ set(LLVM_LIBC_MPFR_INSTALL_PATH "" CACHE PATH "Path to where MPFR is installed (
 
 if(LLVM_LIBC_MPFR_INSTALL_PATH)
   set(LIBC_TESTS_CAN_USE_MPFR TRUE)
-elseif(LIBC_TARGET_OS_IS_GPU)
+elseif(LIBC_TARGET_OS_IS_GPU OR LLVM_LIBC_FULL_BUILD)
   set(LIBC_TESTS_CAN_USE_MPFR FALSE)
 else()
   try_compile(
diff --git a/libc/utils/MPFRWrapper/CMakeLists.txt b/libc/utils/MPFRWrapper/CMakeLists.txt
index 2f2b0ac09df9a8..6af6fd77070418 100644
--- a/libc/utils/MPFRWrapper/CMakeLists.txt
+++ b/libc/utils/MPFRWrapper/CMakeLists.txt
@@ -5,12 +5,6 @@ if(LIBC_TESTS_CAN_USE_MPFR)
     mpfr_inc.h
   )
   target_compile_options(libcMPFRWrapper PRIVATE -O3)
-  if (LLVM_LIBC_FULL_BUILD)
-    # It is not easy to make libcMPFRWrapper a standalone library because gmp.h may unconditionally
-    # pull in some STL headers. As a result, targets using this library will need to link against
-    # C++ and unwind libraries. Since we are using MPFR anyway, we directly specifies the GNU toolchain.
-    target_link_libraries(libcMPFRWrapper PUBLIC -lstdc++ -lgcc_s)
-  endif()
   add_dependencies(
     libcMPFRWrapper
     libc.src.__support.CPP.string_view
@@ -24,6 +18,6 @@ if(LIBC_TESTS_CAN_USE_MPFR)
     target_link_directories(libcMPFRWrapper PUBLIC ${LLVM_LIBC_MPFR_INSTALL_PATH}/lib)
   endif()
   target_link_libraries(libcMPFRWrapper PUBLIC LibcFPTestHelpers.unit LibcTest.unit mpfr gmp)
-elseif(NOT LIBC_TARGET_OS_IS_GPU)
+elseif(NOT LIBC_TARGET_OS_IS_GPU AND NOT LLVM_LIBC_FULL_BUILD)
   message(WARNING "Math tests using MPFR will be skipped.")
 endif()
diff --git a/libc/utils/MPFRWrapper/mpfr_inc.h b/libc/utils/MPFRWrapper/mpfr_inc.h
index 0d8afbed39859f..58fa7b25a9f210 100644
--- a/libc/utils/MPFRWrapper/mpfr_inc.h
+++ b/libc/utils/MPFRWrapper/mpfr_inc.h
@@ -17,21 +17,7 @@
 // MPFR header can be included in manner allowed in that repo.
 #include "CustomMPFRIncluder.h"
 #else
-
-extern "C" {
-#pragma push_macro("__cplusplus")
-#if defined(__clang__)
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wbuiltin-macro-redefined"
-#endif
-#undef __cplusplus
 #include <mpfr.h>
-#if defined(__clang__)
-#pragma clang diagnostic pop
-#endif
-#pragma pop_macro("__cplusplus")
-}
-
 #endif
 
 #endif // LLVM_LIBC_UTILS_MPFRWRAPPER_MPFR_INC_H

>From 58ec1616c24303cb9d34bdf4704bcd4d51e74adb Mon Sep 17 00:00:00 2001
From: Schrodinger ZHU Yifan <yifanzhu at rochester.edu>
Date: Mon, 8 Apr 2024 12:41:26 -0400
Subject: [PATCH 3/3] comment

---
 libc/cmake/modules/LLVMLibCCheckMPFR.cmake | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libc/cmake/modules/LLVMLibCCheckMPFR.cmake b/libc/cmake/modules/LLVMLibCCheckMPFR.cmake
index 532b0b9bfae392..45334a54431ef4 100644
--- a/libc/cmake/modules/LLVMLibCCheckMPFR.cmake
+++ b/libc/cmake/modules/LLVMLibCCheckMPFR.cmake
@@ -3,6 +3,8 @@ set(LLVM_LIBC_MPFR_INSTALL_PATH "" CACHE PATH "Path to where MPFR is installed (
 if(LLVM_LIBC_MPFR_INSTALL_PATH)
   set(LIBC_TESTS_CAN_USE_MPFR TRUE)
 elseif(LIBC_TARGET_OS_IS_GPU OR LLVM_LIBC_FULL_BUILD)
+  # In full build mode, the MPFR library should be built using our own facilities,
+  # which is currently not possible.
   set(LIBC_TESTS_CAN_USE_MPFR FALSE)
 else()
   try_compile(