diff options
Diffstat (limited to 'SConstruct')
| -rw-r--r-- | SConstruct | 75 |
1 files changed, 56 insertions, 19 deletions
diff --git a/SConstruct b/SConstruct index 785686d428..f2c20ea91e 100644 --- a/SConstruct +++ b/SConstruct @@ -309,19 +309,6 @@ if selected_platform in platform_list: env['LINKFLAGS'] = '' env.Append(LINKFLAGS=str(LINKFLAGS).split()) - # Set our C and C++ standard requirements. - # Prepending to make it possible to override - if not env.msvc: - # Specifying GNU extensions support explicitly, which are supported by - # both GCC and Clang. This mirrors GCC and Clang's current default - # compile flags if no -std is specified. - env.Prepend(CFLAGS=['-std=gnu11']) - env.Prepend(CXXFLAGS=['-std=gnu++14']) - else: - # MSVC doesn't have clear C standard support, /std only covers C++. - # We apply it to CCFLAGS (both C and C++ code) in case it impacts C features. - env.Prepend(CCFLAGS=['/std:c++14', '/permissive-']) - # Platform specific flags flag_list = platform_flags[selected_platform] for f in flag_list: @@ -331,6 +318,58 @@ if selected_platform in platform_list: # Must happen after the flags definition, so that they can be used by platform detect detect.configure(env) + # Set our C and C++ standard requirements. + # C++17 is required as we need guaranteed copy elision as per GH-36436. + # Prepending to make it possible to override. + # This needs to come after `configure`, otherwise we don't have env.msvc. + if not env.msvc: + # Specifying GNU extensions support explicitly, which are supported by + # both GCC and Clang. Both currently default to gnu11 and gnu++14. + env.Prepend(CFLAGS=['-std=gnu11']) + env.Prepend(CXXFLAGS=['-std=gnu++17']) + else: + # MSVC doesn't have clear C standard support, /std only covers C++. + # We apply it to CCFLAGS (both C and C++ code) in case it impacts C features. + env.Prepend(CCFLAGS=['/std:c++17', '/permissive-']) + + # Enforce our minimal compiler version requirements + cc_version = methods.get_compiler_version(env) or [-1, -1] + cc_version_major = cc_version[0] + cc_version_minor = cc_version[1] + + if methods.using_gcc(env): + # GCC 8 before 8.4 has a regression in the support of guaranteed copy elision + # which causes a build failure: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86521 + if cc_version_major == 8 and cc_version_minor < 4: + print("Detected GCC 8 version < 8.4, which is not supported due to a " + "regression in its C++17 guaranteed copy elision support. Use a " + "newer GCC version, or Clang 6 or later by passing \"use_llvm=yes\" " + "to the SCons command line.") + sys.exit(255) + elif cc_version_major < 7: + print("Detected GCC version older than 7, which does not fully support " + "C++17. Supported versions are GCC 7, 9 and later. Use a newer GCC " + "version, or Clang 6 or later by passing \"use_llvm=yes\" to the " + "SCons command line.") + sys.exit(255) + elif methods.using_clang(env): + # Apple LLVM versions differ from upstream LLVM version \o/, compare + # in https://en.wikipedia.org/wiki/Xcode#Toolchain_versions + if env["platform"] == "osx" or env["platform"] == "iphone": + vanilla = methods.is_vanilla_clang(env) + if vanilla and cc_version_major < 6: + print("Detected Clang version older than 6, which does not fully support " + "C++17. Supported versions are Clang 6 and later.") + sys.exit(255) + elif not vanilla and cc_version_major < 10: + print("Detected Apple Clang version older than 10, which does not fully " + "support C++17. Supported versions are Apple Clang 10 and later.") + sys.exit(255) + elif cc_version_major < 6: + print("Detected Clang version older than 6, which does not fully support " + "C++17. Supported versions are Clang 6 and later.") + sys.exit(255) + # Configure compiler warnings if env.msvc: # Truncations, narrowing conversions, signed/unsigned comparisons... @@ -354,13 +393,10 @@ if selected_platform in platform_list: all_plus_warnings = ['-Wwrite-strings'] if methods.using_gcc(env): - version = methods.get_compiler_version(env) - if version != None and version[0] >= '7': + if cc_version_major >= 7: shadow_local_warning = ['-Wshadow-local'] if (env["warnings"] == 'extra'): - # Note: enable -Wimplicit-fallthrough for Clang (already part of -Wextra for GCC) - # once we switch to C++11 or later (necessary for our FALLTHROUGH macro). env.Append(CCFLAGS=['-Wall', '-Wextra', '-Wno-unused-parameter'] + all_plus_warnings + shadow_local_warning) env.Append(CXXFLAGS=['-Wctor-dtor-privacy', '-Wnon-virtual-dtor']) @@ -370,9 +406,10 @@ if selected_platform in platform_list: '-Wstringop-overflow=4', '-Wlogical-op']) # -Wnoexcept was removed temporarily due to GH-36325. env.Append(CXXFLAGS=['-Wplacement-new=1']) - version = methods.get_compiler_version(env) - if version != None and version[0] >= '9': + if cc_version_major >= 9: env.Append(CCFLAGS=['-Wattribute-alias=2']) + if methods.using_clang(env): + env.Append(CCFLAGS=['-Wimplicit-fallthrough']) elif (env["warnings"] == 'all'): env.Append(CCFLAGS=['-Wall'] + shadow_local_warning) elif (env["warnings"] == 'moderate'): |