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Merge "Build with traps on signed overflow" into main

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jade 2024-03-28 20:27:32 +00:00 committed by Gerrit Code Review
commit 61d394e344
4 changed files with 29 additions and 7 deletions
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9
local.mk
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@ -1,4 +1,11 @@
GLOBAL_CXXFLAGS += -Wno-deprecated-declarations -Werror=switch
# 2024-03-24: jade benchmarked the default sanitize reporting in clang and got
# a regression of about 10% on hackage-packages.nix with clang. So we are trapping instead.
#
# This has an overhead of 0-4% on gcc and unmeasurably little on clang, in
# Nix evaluation benchmarks.
DEFAULT_SANITIZE_FLAGS = -fsanitize=signed-integer-overflow -fsanitize-undefined-trap-on-error
GLOBAL_CXXFLAGS += -Wno-deprecated-declarations -Werror=switch $(DEFAULT_SANITIZE_FLAGS)
GLOBAL_LDFLAGS += $(DEFAULT_SANITIZE_FLAGS)
# Allow switch-enum to be overridden for files that do not support it, usually because of dependency headers.
ERROR_SWITCH_ENUM = -Werror=switch-enum

17
meson.build
View file

@ -305,6 +305,23 @@ add_project_arguments(
language : 'cpp',
)
if cxx.get_id() in ['gcc', 'clang']
# 2024-03-24: jade benchmarked the default sanitize reporting in clang and got
# a regression of about 10% on hackage-packages.nix with clang. So we are trapping instead.
#
# This has an overhead of 0-4% on gcc and unmeasurably little on clang, in
# Nix evaluation benchmarks.
#
# N.B. Meson generates a completely nonsense warning here:
# https://github.com/mesonbuild/meson/issues/9822
# Both of these args cannot be written in the default meson configuration.
# b_sanitize=signed-integer-overflow is ignored, and
# -fsanitize-undefined-trap-on-error is not representable.
sanitize_args = ['-fsanitize=signed-integer-overflow', '-fsanitize-undefined-trap-on-error']
add_project_arguments(sanitize_args, language: 'cpp')
add_project_link_arguments(sanitize_args, language: 'cpp')
endif
add_project_link_arguments('-pthread', language : 'cpp')
if cxx.get_linker_id() in ['ld.bfd', 'ld.gold']
add_project_link_arguments('-Wl,--no-copy-dt-needed-entries', language : 'cpp')

6
mk/libraries.mk
View file

@ -78,11 +78,7 @@ define build-library
$(1)_LDFLAGS += -undefined suppress -flat_namespace
endif
else
ifndef HOST_DARWIN
ifndef HOST_CYGWIN
$(1)_LDFLAGS += -Wl,-z,defs
endif
endif
# -Wl,-z,defs is broken with sanitizers on Linux/clang at least.
endif
ifndef HOST_DARWIN

4
package.nix
View file

@ -297,7 +297,9 @@ in stdenv.mkDerivation (finalAttrs: {
strictDeps = true;
hardeningDisable = lib.optional stdenv.hostPlatform.isStatic "pie";
# strictoverflow is disabled because we trap on signed overflow instead
hardeningDisable = [ "strictoverflow" ]
++ lib.optional stdenv.hostPlatform.isStatic "pie";
meta.platforms = lib.platforms.unix;