Commit b6c60f14 authored by Brad King's avatar Brad King

macOS: Default to arm64 architecture on Apple Silicon hosts

Detect `arm64` hardware using a method that pierces Rosetta.  If
`CMAKE_OSX_ARCHITECTURES` is not set, pass explicit flags to the
toolchain to use `arm64` instead of letting the toolchain pick.

Fixes: #20989
parent 383e81aa
Pipeline #191943 waiting for manual action with stages
in 64 minutes and 3 seconds
......@@ -46,10 +46,21 @@ if(CMAKE_HOST_UNIX)
if(CMAKE_HOST_SYSTEM_NAME MATCHES "Linux|CYGWIN.*|Darwin|^GNU$|Android")
exec_program(${CMAKE_UNAME} ARGS -m OUTPUT_VARIABLE CMAKE_HOST_SYSTEM_PROCESSOR
RETURN_VALUE val)
if(CMAKE_HOST_SYSTEM_NAME STREQUAL "Darwin" AND
CMAKE_HOST_SYSTEM_PROCESSOR STREQUAL "Power Macintosh")
# OS X ppc 'uname -m' may report 'Power Macintosh' instead of 'powerpc'
set(CMAKE_HOST_SYSTEM_PROCESSOR "powerpc")
if(CMAKE_HOST_SYSTEM_NAME STREQUAL "Darwin")
if(CMAKE_HOST_SYSTEM_PROCESSOR STREQUAL "x86_64")
# Check whether we are running under Rosetta on arm64 hardware.
execute_process(COMMAND sysctl -q hw.optional.arm64
OUTPUT_VARIABLE _sysctl_stdout
ERROR_VARIABLE _sysctl_stderr
RESULT_VARIABLE _sysctl_result
)
if(_sysctl_result EQUAL 0 AND _sysctl_stdout MATCHES "hw.optional.arm64: 1")
set(CMAKE_HOST_SYSTEM_PROCESSOR "arm64")
endif()
elseif(CMAKE_HOST_SYSTEM_PROCESSOR STREQUAL "Power Macintosh")
# OS X ppc 'uname -m' may report 'Power Macintosh' instead of 'powerpc'
set(CMAKE_HOST_SYSTEM_PROCESSOR "powerpc")
endif()
endif()
elseif(CMAKE_HOST_SYSTEM_NAME MATCHES "OpenBSD")
exec_program(arch ARGS -s OUTPUT_VARIABLE CMAKE_HOST_SYSTEM_PROCESSOR
......
......@@ -20,6 +20,17 @@ execute_process(COMMAND sw_vers -productVersion
set(CMAKE_OSX_ARCHITECTURES "$ENV{CMAKE_OSX_ARCHITECTURES}" CACHE STRING
"Build architectures for OSX")
if(NOT CMAKE_CROSSCOMPILING AND
CMAKE_SYSTEM_NAME STREQUAL "Darwin" AND
CMAKE_HOST_SYSTEM_PROCESSOR STREQUAL "arm64" AND
CMAKE_SYSTEM_PROCESSOR STREQUAL "arm64")
# When building on Apple Silicon (arm64), we need to explicitly specify
# the architecture to the toolchain since it will otherwise guess the
# architecture based on that of the build system tool.
# Set an *internal variable* to tell the generators to do this.
set(_CMAKE_APPLE_ARCHS_DEFAULT "arm64")
endif()
# macOS, iOS, tvOS, and watchOS should lookup compilers from
# Platform/Apple-${CMAKE_CXX_COMPILER_ID}-<LANG>
set(CMAKE_EFFECTIVE_SYSTEM_NAME "Apple")
......
......@@ -3193,6 +3193,9 @@ void cmGeneratorTarget::GetAppleArchs(const std::string& config,
if (archs) {
cmExpandList(*archs, archVec);
}
if (archVec.empty()) {
this->Makefile->GetDefExpandList("_CMAKE_APPLE_ARCHS_DEFAULT", archVec);
}
}
void cmGeneratorTarget::AddCUDAArchitectureFlags(std::string& flags) const
......
......@@ -4023,6 +4023,10 @@ void cmGlobalXCodeGenerator::ComputeArchitectures(cmMakefile* mf)
mf->GetDefExpandList("CMAKE_OSX_ARCHITECTURES", this->Architectures);
}
if (this->Architectures.empty()) {
mf->GetDefExpandList("_CMAKE_APPLE_ARCHS_DEFAULT", this->Architectures);
}
if (this->Architectures.empty()) {
// With no ARCHS we use ONLY_ACTIVE_ARCH and possibly a
// platform-specific default ARCHS placeholder value.
......
......@@ -18,6 +18,8 @@ if("${CMAKE_GENERATOR}" MATCHES "Makefile|Xcode|Ninja" AND
endif()
if(CMAKE_OSX_ARCHITECTURES)
list(APPEND C_FLAGS -arch ${CMAKE_OSX_ARCHITECTURES})
elseif("${CMAKE_SYSTEM_NAME};${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "Darwin;arm64")
list(APPEND C_FLAGS -arch arm64)
endif()
# Clang on OS X, and perhaps other compilers, do not support -g
# for both generating and assembling, so drop it from generating.
......
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