[compiler-rt] Normalize i?86 to i386 and armv* to arm for COMPILER_RT_DEFAULT_TARGET_ARCH

[mstorsjo]

Summary

This corresponds to getArchNameForCompilerRTLib in clang; any
32 bit x86 architecture triple (except on android, but those
exceptions are already handled in compiler-rt on a different level)
get the compiler rt library names with i386; arm targets get either
"arm" or "armhf". (Mapping to "armhf" is handled in the toplevel
CMakeLists.txt.)

[rprichard]

I think this is OK for Android.

The toplevel armhf mapping seems redundant now -- can it be removed? (https://github.com/llvm/llvm-project/blob/1200f85818d16e4f0a57c503e186df7a8ad92435/compiler-rt/CMakeLists.txt#L114)

I suppose this wildcard is also redundant: https://github.com/llvm/llvm-project/blob/1200f85818d16e4f0a57c503e186df7a8ad92435/compiler-rt/cmake/base-config-ix.cmake#L171.

[mstorsjo]

In D98173#2613207, @rprichard wrote:

I think this is OK for Android.

The toplevel armhf mapping seems redundant now -- can it be removed? (https://github.com/llvm/llvm-project/blob/1200f85818d16e4f0a57c503e186df7a8ad92435/compiler-rt/CMakeLists.txt#L114)

Yep, I was planning to remove that one afterwards.

I suppose this wildcard is also redundant: https://github.com/llvm/llvm-project/blob/1200f85818d16e4f0a57c503e186df7a8ad92435/compiler-rt/cmake/base-config-ix.cmake#L171.

Not all of it, this patch only normalizes the 32 bit ones. I guess one could try to normalize amd64 into x86_64 too, but this would still need to be at least i386 + x86_64.

[phosek]

LGTM

compiler-rt/cmake/Modules/CompilerRTUtils.cmake

macro(construct_compiler_rt_default_triple)
   if(DEFINED COMPILER_RT_TEST_TARGET_TRIPLE)
     # Backwards compatibility: this variable used to be called
     # COMPILER_RT_TEST_TARGET_TRIPLE.
     set(COMPILER_RT_DEFAULT_TARGET_TRIPLE ${COMPILER_RT_TEST_TARGET_TRIPLE})
   endif()
 
   string(REPLACE "-" ";" TARGET_TRIPLE_LIST ${COMPILER_RT_DEFAULT_TARGET_TRIPLE})
   list(GET TARGET_TRIPLE_LIST 0 COMPILER_RT_DEFAULT_TARGET_ARCH)
+
+  # Map various forms of the architecture names to the canonical forms
+  # (as they are used by clang, see getArchNameForCompilerRTLib).
+  if("${COMPILER_RT_DEFAULT_TARGET_ARCH}" MATCHES "^i.86$")
+    # Android uses i686, but that's remapped at a later stage.
+    set(COMPILER_RT_DEFAULT_TARGET_ARCH "i386")
+  elseif ("${COMPILER_RT_DEFAULT_TARGET_ARCH}" MATCHES "^arm" AND
+          NOT "${COMPILER_RT_DEFAULT_TARGET_ARCH}" MATCHES "^arm64")
+    if ("${COMPILER_RT_DEFAULT_TARGET_TRIPLE}" MATCHES ".*hf$")
+      set(COMPILER_RT_DEFAULT_TARGET_ARCH "armhf")
+    else()
+      set(COMPILER_RT_DEFAULT_TARGET_ARCH "arm")
+    endif()
+  endif()
+
   # Determine if test target triple is specified explicitly, and doesn't match the
   # default.
   if(NOT COMPILER_RT_DEFAULT_TARGET_TRIPLE STREQUAL TARGET_TRIPLE)
     set(COMPILER_RT_HAS_EXPLICIT_DEFAULT_TARGET_TRIPLE TRUE)
   else()
     set(COMPILER_RT_HAS_EXPLICIT_DEFAULT_TARGET_TRIPLE FALSE)
   endif()
 endmacro()