compiler-rt: add support for building for Windows

[compnerd]

Summary

This introduces a new platform of clang_windows with a PIC configuration (pic).
This allows us to build compiler-rt for Windows ARMv7 (NT), X86, and X64. It
requires that a sysroot be provided which can be constructed from the MSVCRT
headers.

[abdulras]

ping

[samsonov]

FYI makefile-based build system in compiler-rt is kind of in "support mode" - we try to keep it in working state on Linux/Darwin, but I am not aware of its owner, and we don't plan to extend it. I'd be really happy if you're able to use CMake for your purposes.

[compnerd]

macho-embedded was added rather recently. Unfortunately, CMake is far more complicated to add support for this IMO (at least for me).

[t.p.northover]

Hi Saleem,

I obviously have nothing useful to say about the Windows specific details, so I'm probably not the best person to review this.

But this seems not to build on Linux (with an error about "lipo", so I assume the generic infrastructure is expecting OS X). There's also a file missing; I suppose the two could be related.

Cheers.

Tim.

make/platform/clang_windows.mk

6

This file is missing.

[compnerd]

The make based build was long ago deprecated.

make/platform/clang_windows.mk

+
+Description = compiler runtime library for clang/Windows
+
+###
+
+CheckArchSource := $(ProjSrcRoot)/make/platform/clang_windows_test_input.c
+CheckArch = \
+  $(shell                                                                       \
+      result="" ;                                                               \
+      for arch in $(1) ; do                                                     \
+  if $(CC) -target $$arch-windows-msvc -c $(CheckArchSource)              \
+     -o /dev/null >/dev/null 2>&1 ; then                            \
+    result="$$result$$arch " ;                                            \
+  else                                                                    \
+    printf 1>&2 "warning: windows.mk: dropping arch '$$arch' from lib\n"; \
+  fi                                                                      \
+      done ;                                                                    \
+    echo $$result)
+
+###
+
+AR     := ar
+CC     := clang
+RANLIB := ranlib
+STRIP  := strip
+
+CFLAGS.base := -fms-compatibility -ffreestanding -fomit-frame-pointer -Wall -Werror
+
+CFLAGS.armv7.sysroot :=
+ifneq ($(LLVM_WINDOWS_ARM_NT_SYSROOT),)
+  CFLAGS.armv7.sysroot := -isystem $(LLVM_WINDOWS_ARM_NT_SYSROOT)/usr/include -D_ARM_WINAPI_PARTITION_DESKTOP_SDK_AVAILABLE
+endif
+
+CFLAGS.i686.sysroot :=
+ifneq ($(LLVM_WINDOWS_X86_SYSROOT),)
+  CFLAGS.i686.sysroot := -isystem $(LLVM_WINDOWS_X86_SYSROOT)/usr/include
+endif
+
+CFLAGS.x86_64.sysroot :=
+ifneq ($(LLVM_WINDOWS_X86_64_SYSROOT),)
+  CFLAGS.x86_64.sysroot := -isystem $(LLVM_WINDOWS_X86_64_SYSROOT)/usr/include
+endif
+
+# NOTE: the use of the itanium environment is due to the ARM assembly syntax;
+# the environment here is fully compatible with "msvc".  Explicitly add a -mcpu
+# option to enable the use of sdiv/udiv on the target.
+Platform.clang_windows.CFLAGS.pic.armv7 := -target thumbv7-windows-itanium $(CFLAGS.armv7.sysroot) -Os -fPIC $(CFLAGS.base) -mfloat-abi=hard -mcpu=cortex-a7 -mfpu=neon
+Platform.clang_windows.CFLAGS.pic.i686 := -target i686-windows-msvc $(CFLAGS.i686.sysroot) -Os -fPIC $(CFLAGS.base)
+Platform.clang_windows.CFLAGS.pic.x86_64 := -target x86_64-windows-msvc $(CFLAGS.x86_64.sysroot) -Os -fPIC $(CFLAGS.base)
+
+###
+
+# Unwanted functions:
+#   + apple_versioning - Apple specific
+#   + enable_execute_stack - Windows disables executable stacks
+#   + eprintf - Apple specific
+#   + trampoline_step - PPC specific
+
+# TODO: _Atomic collides with the MSVC extension, resulting in compilation
+# failures for atomic routines.  Once that has been resolved, it should be added
+# to the common functions.
+FUNCTIONS.common := absvdi2 absvsi2 absvti2             \
+        adddf3 addsf3                       \
+        addvdi3 addvsi3 addvti3             \
+        ashldi3 ashlti3                     \
+        ashrdi3 ashrti3                     \
+        clear_cache                         \
+        clzdi2 clzsi2 clzti2                \
+        cmpdi2 cmpti2                       \
+        comparedf2 comparesf2 comparetf2    \
+        ctzdi2 ctzsi2 ctzti2                \
+        divdc3 divdf3 divdi3                \
+        divmoddi4 divmodsi4                 \
+        divsc3 divsf3 divsi3                \
+        divti3 divxc3                       \
+        extendsfdf2                         \
+        ffsdi2 ffsti2                       \
+        fixdfdi fixdfsi fixdfti             \
+        fixsfdi fixsfsi fixsfti             \
+        fixunsdfdi fixunsdfsi fixunsdfti    \
+        fixunssfdi fixunssfsi fixunssfti    \
+        fixunsxfdi fixunsxfsi fixunsxfti    \
+        fixxfdi fixxfti                     \
+        floatdidf floatdisf floatdixf       \
+        floatsidf floatsisf                 \
+        floattidf floattisf floattixf       \
+        floatundidf floatundisf floatundixf \
+        floatunsidf floatunsisf             \
+        floatuntidf floatuntisf floatuntixf \
+        gcc_personality_v0                  \
+        int_util                            \
+        lshrdi3 lshrti3                     \
+        moddi3 modsi3 modti3                \
+        muldc3 muldf3 muldi3                \
+        mulodi4 mulosi4 muloti4             \
+        mulsc3 mulsf3                       \
+        multi3                              \
+        mulvdi3 mulvsi3 mulvti3             \
+        mulxc3                              \
+        negdf2 negdi2                       \
+        negsf2                              \
+        negti2                              \
+        negvdi2 negvsi2 negvti2             \
+        paritydi2 paritysi2 parityti2       \
+        popcountdi2 popcountsi2 popcountti2 \
+        powidf2 powisf2 powitf2 powixf2     \
+        subdf3 subsf3                       \
+        subvdi3 subvsi3 subvti3             \
+        truncdfsf2                          \
+        ucmpdi2 ucmpti2                     \
+        udivdi3                             \
+        udivmoddi4 udivmodsi4 udivmodti4    \
+        udivsi3 udivti3                     \
+        umoddi3 umodsi3 umodti3             \
+        $(NULL)
+
+# Unwanted Functions:
+#   + aeabi_*: Windows does not conform to AEABI
+#   + {restore,save}_vfp_d8_d15_regs: designed for Thumb1 SJLJ exceptions
+#   + switch{16,32,8,u8}: designed for Thumb1 CPUs to generate switch tables
+#   + sync_synchronize: for Thumb1 GCC __sync_synchronize intrinsic usage
+#   + *vfp: designed for Thumb1 CPUs with VFPv2
+
+FUNCTIONS.armv7 := bswapdi2 bswapsi2                    \
+       sync_fetch_and_add_4                 \
+       sync_fetch_and_sub_4                 \
+       sync_fetch_and_and_4                 \
+       sync_fetch_and_or_4                  \
+       sync_fetch_and_xor_4                 \
+       sync_fetch_and_nand_4                \
+       sync_fetch_and_max_4                 \
+       sync_fetch_and_umax_4                \
+       sync_fetch_and_min_4                 \
+       sync_fetch_and_umin_4                \
+       sync_fetch_and_add_8                 \
+       sync_fetch_and_sub_8                 \
+       sync_fetch_and_and_8                 \
+       sync_fetch_and_or_8                  \
+       sync_fetch_and_xor_8                 \
+       sync_fetch_and_nand_8                \
+       sync_fetch_and_max_8                 \
+       sync_fetch_and_umax_8                \
+       sync_fetch_and_min_8                 \
+       sync_fetch_and_umin_8                \
+       $(NULL)
+
+FUNCTIONS.pic := $(FUNCTIONS.common)
+FUNCTIONS.pic.armv7 := $(FUNCTIONS.common) $(FUNCTIONS.armv7)
+
+Arch :=
+Configs := pic
+
+Arch.pic := $(call CheckArch,armv7 i686 x86_64)
+