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Start using optimization (-O0/-O2/-O3/-Os) and debug (-g) flags from CMAKE_CXX_FLAGS_${CFLAGS_BUILD_TYPE} #33388

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Merged
merged 7 commits into from
Aug 18, 2020
Merged

Start using optimization (-O0/-O2/-O3/-Os) and debug (-g) flags from CMAKE_CXX_FLAGS_${CFLAGS_BUILD_TYPE} #33388

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6612d8c
Start using optimization (-O0/-O2/-O3/-Os) and debug (-g) flags from …
kubamracek Aug 10, 2020
7ccbc75
Use -gline-tables-only from CMAKE_CXX_FLAGS_... too
kubamracek Aug 11, 2020
cd2c471
Avoid CMake's default -O3 for Release builds
kubamracek Aug 13, 2020
5066bea
Set CMAKE_CXX_FLAGS_RELEASE only for non-MSVC compilers
kubamracek Aug 16, 2020
108708f
Add explaning comments
kubamracek Aug 17, 2020
7e50def
Tweak comment and remove unnecessary -Os/-O2 appending
kubamracek Aug 17, 2020
8ff768f
Set CMAKE_CXX_FLAGS_RELEASE to just "-O2", add explaining comment
kubamracek Aug 17, 2020
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15 changes: 15 additions & 0 deletions CMakeLists.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -629,6 +629,21 @@ if("${CMAKE_C_COMPILER_ID}" STREQUAL "MSVC" OR "${CMAKE_CXX_SIMULATE_ID}" STREQU
set(SWIFT_COMPILER_IS_MSVC_LIKE TRUE)
endif()

if(NOT SWIFT_COMPILER_IS_MSVC_LIKE)
# CMake's default for CMAKE_CXX_FLAGS_RELEASE is "-O3 -DNDEBUG". Let's avoid "-O3" for consistency
# between Release and RelWithDebInfo. And let's not set -DNDEBUG because we're setting that manually
# based on LLVM_ENABLE_ASSERTIONS.
set(CMAKE_CXX_FLAGS_RELEASE "-O2")

_compute_lto_flag("${SWIFT_TOOLS_ENABLE_LTO}" _lto_flag_out)
if(_lto_flag_out)
set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_RELEASE} -gline-tables-only")
set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "${CMAKE_CXX_FLAGS_RELWITHDEBINFO} -gline-tables-only")
endif()
else()

endif()

#
# Configure SDKs.
#
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38 changes: 9 additions & 29 deletions cmake/modules/AddSwift.cmake
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Original file line number Diff line number Diff line change
Expand Up @@ -130,17 +130,18 @@ function(_add_host_variant_c_compile_flags target)
_add_host_variant_c_compile_link_flags(${target})

is_build_type_optimized("${CMAKE_BUILD_TYPE}" optimized)
if(optimized)
if("${CMAKE_BUILD_TYPE}" STREQUAL "MinSizeRel")
target_compile_options(${target} PRIVATE -Os)
else()
target_compile_options(${target} PRIVATE -O2)
endif()
is_build_type_with_debuginfo("${CMAKE_BUILD_TYPE}" debuginfo)

# Add -O0/-O2/-O3/-Os/-g/-momit-leaf-frame-pointer/... based on CMAKE_BUILD_TYPE.
target_compile_options(${target} PRIVATE "${CMAKE_CXX_FLAGS_${CMAKE_BUILD_TYPE}}")

if(optimized)
# Omit leaf frame pointers on x86 production builds (optimized, no debug
# info, and no asserts).
is_build_type_with_debuginfo("${CMAKE_BUILD_TYPE}" debug)
if(NOT debug AND NOT LLVM_ENABLE_ASSERTIONS)
if(NOT debuginfo AND NOT LLVM_ENABLE_ASSERTIONS)
# Unfortunately, this cannot be folded into the standard
# CMAKE_CXX_FLAGS_... because Apple multi-SDK builds use different
# architectures for different SDKs.
if(SWIFT_HOST_VARIANT_ARCH MATCHES "i?86")
if(NOT SWIFT_COMPILER_IS_MSVC_LIKE)
target_compile_options(${target} PRIVATE -momit-leaf-frame-pointer)
Expand All @@ -149,27 +150,6 @@ function(_add_host_variant_c_compile_flags target)
endif()
endif()
endif()
else()
if(NOT SWIFT_COMPILER_IS_MSVC_LIKE)
target_compile_options(${target} PRIVATE -O0)
else()
target_compile_options(${target} PRIVATE /Od)
endif()
endif()

# CMake automatically adds the flags for debug info if we use MSVC/clang-cl.
if(NOT SWIFT_COMPILER_IS_MSVC_LIKE)
is_build_type_with_debuginfo("${CMAKE_BUILD_TYPE}" debuginfo)
if(debuginfo)
_compute_lto_flag("${SWIFT_TOOLS_ENABLE_LTO}" _lto_flag_out)
if(_lto_flag_out)
target_compile_options(${target} PRIVATE -gline-tables-only)
else()
target_compile_options(${target} PRIVATE -g)
endif()
else()
target_compile_options(${target} PRIVATE -g0)
endif()
endif()

if(SWIFT_HOST_VARIANT_SDK STREQUAL WINDOWS)
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38 changes: 9 additions & 29 deletions stdlib/cmake/modules/AddSwiftStdlib.cmake
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Original file line number Diff line number Diff line change
Expand Up @@ -179,17 +179,18 @@ function(_add_target_variant_c_compile_flags)
MACCATALYST_BUILD_FLAVOR "${CFLAGS_MACCATALYST_BUILD_FLAVOR}")

is_build_type_optimized("${CFLAGS_BUILD_TYPE}" optimized)
if(optimized)
if("${CFLAGS_BUILD_TYPE}" STREQUAL "MinSizeRel")
list(APPEND result "-Os")
else()
list(APPEND result "-O2")
endif()
is_build_type_with_debuginfo("${CFLAGS_BUILD_TYPE}" debuginfo)

# Add -O0/-O2/-O3/-Os/-g/... based on CFLAGS_BUILD_TYPE.
list(APPEND result "${CMAKE_CXX_FLAGS_${CFLAGS_BUILD_TYPE}}")

if(optimized)
# Omit leaf frame pointers on x86 production builds (optimized, no debug
# info, and no asserts).
is_build_type_with_debuginfo("${CFLAGS_BUILD_TYPE}" debug)
if(NOT debug AND NOT CFLAGS_ENABLE_ASSERTIONS)
if(NOT debuginfo AND NOT CFLAGS_ENABLE_ASSERTIONS)
# Unfortunately, this cannot be folded into the standard
# CMAKE_CXX_FLAGS_... because Apple multi-SDK builds use different
# architectures for different SDKs (CFLAGS_ARCH isn't constant here).
if("${CFLAGS_ARCH}" STREQUAL "i386" OR "${CFLAGS_ARCH}" STREQUAL "i686")
if(NOT SWIFT_COMPILER_IS_MSVC_LIKE)
list(APPEND result "-momit-leaf-frame-pointer")
Expand All @@ -198,27 +199,6 @@ function(_add_target_variant_c_compile_flags)
endif()
endif()
endif()
else()
if(NOT SWIFT_COMPILER_IS_MSVC_LIKE)
list(APPEND result "-O0")
else()
list(APPEND result "/Od")
endif()
endif()

# CMake automatically adds the flags for debug info if we use MSVC/clang-cl.
if(NOT SWIFT_COMPILER_IS_MSVC_LIKE)
is_build_type_with_debuginfo("${CFLAGS_BUILD_TYPE}" debuginfo)
if(debuginfo)
_compute_lto_flag("${CFLAGS_ENABLE_LTO}" _lto_flag_out)
if(_lto_flag_out)
list(APPEND result "-gline-tables-only")
else()
list(APPEND result "-g")
endif()
else()
list(APPEND result "-g0")
endif()
endif()

if("${CFLAGS_SDK}" STREQUAL "WINDOWS")
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4 changes: 0 additions & 4 deletions utils/build-script-impl
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Original file line number Diff line number Diff line change
Expand Up @@ -1574,8 +1574,6 @@ for host in "${ALL_HOSTS[@]}"; do
"${cmake_options[@]}"
-DCMAKE_C_FLAGS="$(llvm_c_flags ${host})"
-DCMAKE_CXX_FLAGS="$(llvm_c_flags ${host})"
-DCMAKE_C_FLAGS_RELWITHDEBINFO="-O2 -DNDEBUG"
-DCMAKE_CXX_FLAGS_RELWITHDEBINFO="-O2 -DNDEBUG"
-DCMAKE_BUILD_TYPE:STRING="${LLVM_BUILD_TYPE}"
-DLLVM_TOOL_SWIFT_BUILD:BOOL=NO
-DLLVM_TOOL_LLD_BUILD:BOOL=TRUE
Expand Down Expand Up @@ -1754,8 +1752,6 @@ for host in "${ALL_HOSTS[@]}"; do
"${cmake_options[@]}"
-DCMAKE_C_FLAGS="$(swift_c_flags ${host})"
-DCMAKE_CXX_FLAGS="$(swift_c_flags ${host})"
-DCMAKE_C_FLAGS_RELWITHDEBINFO="-O2 -DNDEBUG"
-DCMAKE_CXX_FLAGS_RELWITHDEBINFO="-O2 -DNDEBUG"
-DCMAKE_BUILD_TYPE:STRING="${SWIFT_BUILD_TYPE}"
-DLLVM_ENABLE_ASSERTIONS:BOOL=$(true_false "${SWIFT_ENABLE_ASSERTIONS}")
-DSWIFT_ANALYZE_CODE_COVERAGE:STRING=$(toupper "${SWIFT_ANALYZE_CODE_COVERAGE}")
Expand Down