[clang] 99153c8 - [CMake][Fuchsia] Build libc++ on top libc for baremetal (#99009)

[via cfe-commits]

Author: Petr Hosek
Date: 2024-07-16T09:33:33-07:00
New Revision: 99153c84dc321a7493dd4c5888973f525bf9f65e

URL: https://github.com/llvm/llvm-project/commit/99153c84dc321a7493dd4c5888973f525bf9f65e
DIFF: https://github.com/llvm/llvm-project/commit/99153c84dc321a7493dd4c5888973f525bf9f65e.diff

LOG: [CMake][Fuchsia] Build libc++ on top libc for baremetal (#99009)

This is mostly a proof of concept requiring a number of workarounds, but
demonstrates that it is feasible.

Added: 
    

Modified: 
    clang/cmake/caches/Fuchsia-stage2.cmake

Removed: 
    


################################################################################
diff  --git a/clang/cmake/caches/Fuchsia-stage2.cmake b/clang/cmake/caches/Fuchsia-stage2.cmake
index 2d35c8d0a818a..04efd0683dbc4 100644
--- a/clang/cmake/caches/Fuchsia-stage2.cmake
+++ b/clang/cmake/caches/Fuchsia-stage2.cmake
@@ -325,7 +325,9 @@ foreach(target armv6m-unknown-eabi;armv7m-unknown-eabi;armv8m.main-unknown-eabi)
   set(RUNTIMES_${target}_CMAKE_BUILD_TYPE MinSizeRel CACHE STRING "")
   set(RUNTIMES_${target}_CMAKE_TRY_COMPILE_TARGET_TYPE STATIC_LIBRARY CACHE STRING "")
   foreach(lang C;CXX;ASM)
-    set(RUNTIMES_${target}_CMAKE_${lang}_FLAGS "--target=${target} -mthumb -Wno-atomic-alignment" CACHE STRING "")
+    # TODO: The preprocessor defines workaround various issues in libc and libc++ integration.
+    # These should be addressed and removed over time.
+    set(RUNTIMES_${target}_CMAKE_${lang}_FLAGS "--target=${target} -mthumb -Wno-atomic-alignment -D'vfprintf(stream, format, vlist)=vprintf(format, vlist)' -D'fprintf(stream, format, ...)=printf(format)' -D'timeval=struct timeval{int tv_sec; int tv_usec;}' -D'gettimeofday(tv, tz)' -D_LIBCPP_PRINT=1" CACHE STRING "")
   endforeach()
   foreach(type SHARED;MODULE;EXE)
     set(RUNTIMES_${target}_CMAKE_${type}_LINKER_FLAGS "-fuse-ld=lld" CACHE STRING "")
@@ -335,7 +337,7 @@ foreach(target armv6m-unknown-eabi;armv7m-unknown-eabi;armv8m.main-unknown-eabi)
   set(RUNTIMES_${target}_LIBCXX_ABI_VERSION 2 CACHE STRING "")
   set(RUNTIMES_${target}_LIBCXX_CXX_ABI none CACHE STRING "")
   set(RUNTIMES_${target}_LIBCXX_ENABLE_SHARED OFF CACHE BOOL "")
-  set(RUNTIMES_${target}_LIBCXX_ENABLE_STATIC OFF CACHE BOOL "")
+  set(RUNTIMES_${target}_LIBCXX_ENABLE_STATIC ON CACHE BOOL "")
   set(RUNTIMES_${target}_LIBCXX_ENABLE_FILESYSTEM OFF CACHE BOOL "")
   set(RUNTIMES_${target}_LIBCXX_ENABLE_RANDOM_DEVICE OFF CACHE BOOL "")
   set(RUNTIMES_${target}_LIBCXX_ENABLE_LOCALIZATION OFF CACHE BOOL "")
@@ -373,7 +375,9 @@ foreach(target riscv32-unknown-elf)
   set(RUNTIMES_${target}_CMAKE_BUILD_TYPE MinSizeRel CACHE STRING "")
   set(RUNTIMES_${target}_CMAKE_TRY_COMPILE_TARGET_TYPE STATIC_LIBRARY CACHE STRING "")
   foreach(lang C;CXX;ASM)
-    set(RUNTIMES_${target}_CMAKE_${lang}_FLAGS "--target=${target} -march=rv32imafc -mabi=ilp32f" CACHE STRING "")
+    # TODO: The preprocessor defines workaround various issues in libc and libc++ integration.
+    # These should be addressed and removed over time.
+    set(RUNTIMES_${target}_CMAKE_${lang}_FLAGS "--target=${target} -march=rv32imafc -mabi=ilp32f -D'vfprintf(stream, format, vlist)=vprintf(format, vlist)' -D'fprintf(stream, format, ...)=printf(format)' -D'timeval=struct timeval{int tv_sec; int tv_usec;}' -D'gettimeofday(tv, tz)' -D_LIBCPP_PRINT=1" CACHE STRING "")
   endforeach()
   foreach(type SHARED;MODULE;EXE)
     set(RUNTIMES_${target}_CMAKE_${type}_LINKER_FLAGS "-fuse-ld=lld" CACHE STRING "")
@@ -383,7 +387,7 @@ foreach(target riscv32-unknown-elf)
   set(RUNTIMES_${target}_LIBCXX_ABI_VERSION 2 CACHE STRING "")
   set(RUNTIMES_${target}_LIBCXX_CXX_ABI none CACHE STRING "")
   set(RUNTIMES_${target}_LIBCXX_ENABLE_SHARED OFF CACHE BOOL "")
-  set(RUNTIMES_${target}_LIBCXX_ENABLE_STATIC OFF CACHE BOOL "")
+  set(RUNTIMES_${target}_LIBCXX_ENABLE_STATIC ON CACHE BOOL "")
   set(RUNTIMES_${target}_LIBCXX_ENABLE_FILESYSTEM OFF CACHE BOOL "")
   set(RUNTIMES_${target}_LIBCXX_ENABLE_RANDOM_DEVICE OFF CACHE BOOL "")
   set(RUNTIMES_${target}_LIBCXX_ENABLE_LOCALIZATION OFF CACHE BOOL "")