cmake: move cflag defaults into a separate module

1 files changed, 153 insertions, 0 deletions

diff --git a/cmake/DefaultCFlags.cmake b/cmake/DefaultCFlags.cmake
new file mode 100644
index 000000000..d122f6c25
--- /dev/null
+++ b/cmake/DefaultCFlags.cmake
@@ -0,0 +1,153 @@
+# Platform specific compilation flags
+if(MSVC)
+	add_definitions(-D_SCL_SECURE_NO_WARNINGS)
+	add_definitions(-D_CRT_SECURE_NO_DEPRECATE)
+	add_definitions(-D_CRT_NONSTDC_NO_DEPRECATE)
+
+	string(REPLACE "/Zm1000" " " CMAKE_C_FLAGS "${CMAKE_C_FLAGS}")
+
+	# /GF - String pooling
+	# /MP - Parallel build
+	set(CMAKE_C_FLAGS "/GF /MP /nologo ${CMAKE_C_FLAGS}")
+
+	# /Gd - explicitly set cdecl calling convention
+	set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} /Gd")
+
+	if(NOT (MSVC_VERSION LESS 1900))
+		# /guard:cf - Enable Control Flow Guard
+		set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} /guard:cf")
+	endif()
+
+	if(STATIC_CRT)
+		set(CRT_FLAG_DEBUG "/MTd")
+		set(CRT_FLAG_RELEASE "/MT")
+	else()
+		set(CRT_FLAG_DEBUG "/MDd")
+		set(CRT_FLAG_RELEASE "/MD")
+	endif()
+
+	if(WIN32_LEAKCHECK)
+		set(GIT_WIN32_LEAKCHECK 1)
+		set(CRT_FLAG_DEBUG "${CRT_FLAG_DEBUG}")
+		set(CMAKE_C_STANDARD_LIBRARIES "${CMAKE_C_STANDARD_LIBRARIES} Dbghelp.lib")
+	endif()
+
+	# /Zi - Create debugging information
+	# /Od - Disable optimization
+	# /D_DEBUG - #define _DEBUG
+	# /MTd - Statically link the multithreaded debug version of the CRT
+	# /MDd - Dynamically link the multithreaded debug version of the CRT
+	# /RTC1 - Run time checks
+	set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} /Zi /Od /D_DEBUG /RTC1 ${CRT_FLAG_DEBUG}")
+
+	# /DNDEBUG - Disables asserts
+	# /MT - Statically link the multithreaded release version of the CRT
+	# /MD - Dynamically link the multithreaded release version of the CRT
+	# /O2 - Optimize for speed
+	# /Oy - Enable frame pointer omission (FPO) (otherwise CMake will automatically turn it off)
+	# /GL - Link time code generation (whole program optimization)
+	# /Gy - Function-level linking
+	set(CMAKE_C_FLAGS_RELEASE "/DNDEBUG /O2 /Oy /GL /Gy ${CRT_FLAG_RELEASE}")
+
+	# /Oy- - Disable frame pointer omission (FPO)
+	set(CMAKE_C_FLAGS_RELWITHDEBINFO "/DNDEBUG /Zi /O2 /Oy- /GL /Gy ${CRT_FLAG_RELEASE}")
+
+	# /O1 - Optimize for size
+	set(CMAKE_C_FLAGS_MINSIZEREL "/DNDEBUG /O1 /Oy /GL /Gy ${CRT_FLAG_RELEASE}")
+
+	# /IGNORE:4221 - Ignore empty compilation units
+	set(CMAKE_STATIC_LINKER_FLAGS "/IGNORE:4221")
+
+	# /DYNAMICBASE - Address space load randomization (ASLR)
+	# /NXCOMPAT - Data execution prevention (DEP)
+	# /LARGEADDRESSAWARE - >2GB user address space on x86
+	# /VERSION - Embed version information in PE header
+	set(CMAKE_EXE_LINKER_FLAGS "/DYNAMICBASE /NXCOMPAT /LARGEADDRESSAWARE /VERSION:${libgit2_VERSION_MAJOR}.${libgit2_VERSION_MINOR}")
+
+	if(NOT (MSVC_VERSION LESS 1900))
+		# /GUARD:CF - Enable Control Flow Guard
+		set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} /GUARD:CF")
+	endif()
+
+	# /DEBUG - Create a PDB
+	# /LTCG - Link time code generation (whole program optimization)
+	# /OPT:REF /OPT:ICF - Fold out duplicate code at link step
+	# /INCREMENTAL:NO - Required to use /LTCG
+	# /DEBUGTYPE:cv,fixup - Additional data embedded in the PDB (requires /INCREMENTAL:NO, so not on for Debug)
+	set(CMAKE_EXE_LINKER_FLAGS_DEBUG "/DEBUG")
+	set(CMAKE_EXE_LINKER_FLAGS_RELEASE "/RELEASE /LTCG /OPT:REF /OPT:ICF /INCREMENTAL:NO")
+	set(CMAKE_EXE_LINKER_FLAGS_RELWITHDEBINFO "/DEBUG /RELEASE /LTCG /OPT:REF /OPT:ICF /INCREMENTAL:NO /DEBUGTYPE:cv,fixup")
+	set(CMAKE_EXE_LINKER_FLAGS_MINSIZEREL "/RELEASE /LTCG /OPT:REF /OPT:ICF /INCREMENTAL:NO")
+
+	# Same linker settings for DLL as EXE
+	set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS}")
+	set(CMAKE_SHARED_LINKER_FLAGS_DEBUG "${CMAKE_EXE_LINKER_FLAGS_DEBUG}")
+	set(CMAKE_SHARED_LINKER_FLAGS_RELEASE "${CMAKE_EXE_LINKER_FLAGS_RELEASE}")
+	set(CMAKE_SHARED_LINKER_FLAGS_RELWITHDEBINFO "${CMAKE_EXE_LINKER_FLAGS_RELWITHDEBINFO}")
+	set(CMAKE_SHARED_LINKER_FLAGS_MINSIZEREL "${CMAKE_EXE_LINKER_FLAGS_MINSIZEREL}")
+else()
+	if(ENABLE_REPRODUCIBLE_BUILDS)
+		set(CMAKE_C_ARCHIVE_CREATE "<CMAKE_AR> Dqc <TARGET> <LINK_FLAGS> <OBJECTS>")
+		set(CMAKE_C_ARCHIVE_APPEND "<CMAKE_AR> Dq  <TARGET> <LINK_FLAGS> <OBJECTS>")
+		set(CMAKE_C_ARCHIVE_FINISH "<CMAKE_RANLIB> -D <TARGET>")
+	endif()
+
+	if(NOT BUILD_SHARED_LIBS)
+		set(CMAKE_FIND_LIBRARY_SUFFIXES ".a")
+	endif()
+
+	set(CMAKE_C_FLAGS "-D_GNU_SOURCE ${CMAKE_C_FLAGS}")
+
+	enable_warnings(all)
+	enable_warnings(extra)
+
+	if(CMAKE_SYSTEM_NAME MATCHES "(Solaris|SunOS)")
+		set(CMAKE_C_FLAGS "-D_POSIX_C_SOURCE=200112L -D__EXTENSIONS__ -D_POSIX_PTHREAD_SEMANTICS ${CMAKE_C_FLAGS}")
+	endif()
+
+	set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -D_DEBUG -O0")
+
+	if(MINGW OR MSYS) # MinGW and MSYS always do PIC and complain if we tell them to
+		string(REGEX REPLACE "-fPIC" "" CMAKE_SHARED_LIBRARY_C_FLAGS "${CMAKE_SHARED_LIBRARY_C_FLAGS}")
+	elseif(BUILD_SHARED_LIBS)
+		add_c_flag_IF_SUPPORTED(-fvisibility=hidden)
+
+		set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fPIC")
+	endif()
+
+	if(MINGW)
+		# MinGW >= 3.14 uses the C99-style stdio functions
+		# automatically, but forks like mingw-w64 still want
+		# us to define this in order to use them
+		add_definitions(-D__USE_MINGW_ANSI_STDIO=1)
+	endif()
+
+	enable_warnings(documentation)
+	disable_warnings(documentation-deprecated-sync)
+	disable_warnings(missing-field-initializers)
+	enable_warnings(strict-aliasing)
+	enable_warnings(strict-prototypes)
+	enable_warnings(declaration-after-statement)
+	enable_warnings(shift-count-overflow)
+	enable_warnings(unused-const-variable)
+	enable_warnings(unused-function)
+	enable_warnings(int-conversion)
+	enable_warnings(c11-extensions)
+	enable_warnings(c99-c11-compat)
+
+	# MinGW uses gcc, which expects POSIX formatting for printf, but
+	# uses the Windows C library, which uses its own format specifiers.
+	# Disable format specifier warnings.
+	if(MINGW)
+		disable_warnings(format)
+		disable_warnings(format-security)
+	else()
+		enable_warnings(format)
+		enable_warnings(format-security)
+	endif()
+endif()
+
+# Ensure that MinGW provides the correct header files.
+if(WIN32 AND NOT CYGWIN)
+	add_definitions(-DWIN32 -D_WIN32_WINNT=0x0600)
+endif()