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Diffstat (limited to 'build/moz.configure/warnings.configure')
| -rw-r--r-- | build/moz.configure/warnings.configure | 324 |
1 files changed, 324 insertions, 0 deletions
diff --git a/build/moz.configure/warnings.configure b/build/moz.configure/warnings.configure new file mode 100644 index 0000000000..9340c9e6ab --- /dev/null +++ b/build/moz.configure/warnings.configure @@ -0,0 +1,324 @@ +# -*- Mode: python; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 40 -*- +# vim: set filetype=python: +# This Source Code Form is subject to the terms of the Mozilla Public +# License, v. 2.0. If a copy of the MPL was not distributed with this +# file, You can obtain one at http://mozilla.org/MPL/2.0/. + +option( + "--enable-warnings-as-errors", + env="MOZ_ENABLE_WARNINGS_AS_ERRORS", + default=depends("MOZ_AUTOMATION")(lambda x: bool(x)), + help="{Enable|Disable} treating warnings as errors", +) + + +@depends("--enable-warnings-as-errors") +def warnings_as_errors(warnings_as_errors): + if not warnings_as_errors: + return "" + + return "-Werror" + + +set_config("WARNINGS_AS_ERRORS", warnings_as_errors) + +not_clang_cl = depends(c_compiler)(lambda c: c.type != "clang-cl") + +# GCC/Clang warnings: +# https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html +# https://clang.llvm.org/docs/DiagnosticsReference.html + +# Lots of useful warnings +add_warning("-Wall", when=not_clang_cl) +# In clang-cl, -Wall actually means -Weverything. -W3 does mean -Wall. +add_warning("-W3", when=depends(c_compiler)(lambda c: c.type == "clang-cl")) + +# catch implicit truncation of enum values assigned to smaller bit fields +check_and_add_warning("-Wbitfield-enum-conversion") + +# catches deprecated implicit capture of `this` in lambdas. +check_and_add_warning("-Wdeprecated-this-capture", cxx_compiler) + +# catches bugs, e.g. "if (c); foo();", few false positives +add_warning("-Wempty-body") + +# catches mismatched printf integer sizes. +check_and_add_warning("-Wformat-type-confusion") + +# catches return types with qualifiers like const +add_warning("-Wignored-qualifiers") + +# catches pointer arithmetic using NULL or sizeof(void) +add_warning("-Wpointer-arith") + +# catch modifying constructor parameter that shadows member variable +check_and_add_warning("-Wshadow-field-in-constructor-modified") + +# catches comparing signed/unsigned ints +add_warning("-Wsign-compare") + +# catches comparisons of values and sized types are always true or false +check_and_add_warning("-Wtautological-constant-in-range-compare") + +# catches overflow bugs, few false positives +add_warning("-Wtype-limits") + +# This can be triggered by certain patterns used deliberately in portable code +check_and_add_warning("-Wno-error=tautological-type-limit-compare") + +# catches some dead code +add_warning("-Wunreachable-code") +check_and_add_warning("-Wunreachable-code-return") + +# catches parameters that are set but not read +# Only enable on clang because gcc reports false positives. +check_and_add_warning( + "-Wunused-but-set-parameter", + when=depends(c_compiler)(lambda c: c.type in ("clang", "clang-cl")), +) + +# turned on by -Wall, but we use offsetof on non-POD types frequently +add_warning("-Wno-invalid-offsetof", cxx_compiler) + +# catches objects passed by value to variadic functions. +check_and_add_warning("-Wclass-varargs") + +# catches empty if/switch/for initialization statements that have no effect +check_and_add_warning("-Wempty-init-stmt", cxx_compiler) + +# catches some implicit conversion of floats to ints +check_and_add_warning("-Wfloat-overflow-conversion") +check_and_add_warning("-Wfloat-zero-conversion") + +# catches issues around loops +check_and_add_warning("-Wloop-analysis") +# But, disable range-loop-analysis because it can raise unhelpful false +# positives. +check_and_add_warning("-Wno-range-loop-analysis") + +# Enable some C++20 compat warnings. We can remove these flags after we compile +# as C++20 (bug 1768116), because they will be enabled by default: +check_and_add_warning("-Wc++2a-compat", cxx_compiler) +check_and_add_warning("-Wcomma-subscript", cxx_compiler) +check_and_add_warning("-Wenum-compare-conditional") +check_and_add_warning("-Wenum-float-conversion") +check_and_add_warning("-Wvolatile", cxx_compiler) + +# Downgrade some C++20 warnings-as-errors to warnings that we can fix after we +# compile as C++20 (bug 1768116). They don't need to block upgrading to C++20. +check_and_add_warning("-Wno-error=deprecated", cxx_compiler) +check_and_add_warning("-Wno-error=deprecated-anon-enum-enum-conversion", cxx_compiler) +check_and_add_warning("-Wno-error=deprecated-enum-enum-conversion", cxx_compiler) +check_and_add_warning("-Wno-error=deprecated-pragma", cxx_compiler) +check_and_add_warning("-Wno-error=deprecated-this-capture", cxx_compiler) + +# catches possible misuse of the comma operator +check_and_add_warning("-Wcomma", cxx_compiler) + +# catches duplicated conditions in if-else-if chains +check_and_add_warning("-Wduplicated-cond") + +# catches unintentional switch case fallthroughs +check_and_add_warning("-Wimplicit-fallthrough", cxx_compiler) + +# Warn about suspicious uses of logical operators in expressions. +check_and_add_warning("-Wlogical-op") + +# Enable some ObjC diagnostics that are only relevant when targeting macOS: +with only_when(depends(target)(lambda t: t.kernel == "Darwin")): + # catch redeclaration of ObjC method parameter name + check_and_add_warning("-Wduplicate-method-arg") + + # catch multiple declarations of ObjC method found + check_and_add_warning("-Wduplicate-method-match") + + # catch ObjC method with no return type specified + check_and_add_warning("-Wmissing-method-return-type") + + # catch implicit conversions between ObjC BOOL and int + check_and_add_warning("-Wobjc-signed-char-bool") + + # catch semicolon before ObjC method body + check_and_add_warning("-Wsemicolon-before-method-body") + + # catch ObjC method parameter type not matching super class method + check_and_add_warning("-Wsuper-class-method-mismatch") + +# catches string literals used in boolean expressions +check_and_add_warning("-Wstring-conversion") + +# we inline 'new' and 'delete' in mozalloc +check_and_add_warning("-Wno-inline-new-delete", cxx_compiler) + +# Prevent the following GCC warnings from being treated as errors: +# too many false positives +check_and_add_warning("-Wno-error=maybe-uninitialized") + +# we don't want our builds held hostage when a platform-specific API +# becomes deprecated. +check_and_add_warning("-Wno-error=deprecated-declarations") + +# false positives depending on optimization +check_and_add_warning("-Wno-error=array-bounds") + +# false positives depending on optimizations +check_and_add_warning("-Wno-error=free-nonheap-object") + +# Would be a pain to fix all occurrences, for very little gain +check_and_add_warning("-Wno-multistatement-macros") + +# Disable the -Werror for -Wclass-memaccess as we have a long +# tail of issues to fix +check_and_add_warning("-Wno-error=class-memaccess") + +# -Watomic-alignment is a new warning in clang 7 that seems way too broad. +# https://bugs.llvm.org/show_bug.cgi?id=38593 +check_and_add_warning("-Wno-error=atomic-alignment") + +# New warning with clang 15. Catches uses of deprecated builtins in abseil-cpp. +# https://bugzilla.mozilla.org/show_bug.cgi?id=1779528 +check_and_add_warning("-Wno-error=deprecated-builtins") + +# catches format/argument mismatches with printf +c_format_warning, cxx_format_warning = check_and_add_warning( + "-Wformat", when=depends(target)(lambda t: t.kernel != "WINNT") +) + +# Add compile-time warnings for unprotected functions and format functions +# that represent possible security problems. Enable this only when -Wformat +# is enabled, otherwise it is an error +check_and_add_warning("-Wformat-security", when=c_format_warning & cxx_format_warning) +check_and_add_warning("-Wformat-overflow=2", when=c_format_warning & cxx_format_warning) + +# Other Windows specific things +with only_when(target_is_windows): + # When compiling for Windows with gcc, we encounter lots of "#pragma warning"'s + # which is an MSVC-only pragma that GCC does not recognize. + # With clang-cl, as it claims to be MSVC it would be difficult to add + # #if defined(_MSC_VER) && !defined(__clang__) everywhere we use such pragmas, + # so just ignore them. + check_and_add_warning("-Wno-unknown-pragmas") + + with only_when(depends(c_compiler)(lambda c: c.type == "clang-cl")): + # We get errors about various #pragma intrinsic directives from + # clang-cl, and we don't need to hear about those. + check_and_add_warning("-Wno-ignored-pragmas") + + # clang-cl's Intrin.h marks things like _ReadWriteBarrier as + # __attribute((__deprecated__)). This is nice to know, but since we don't + # get the equivalent warning from MSVC, let's just ignore it. + check_and_add_warning("-Wno-deprecated-declarations") + + # This warns for reasonable things like: + # enum { X = 0xffffffffU }; + # which is annoying for IDL headers. + check_and_add_warning("-Wno-microsoft-enum-value", cxx_compiler) + + # This warns for cases that would be reached by the Microsoft + # #include rules, but also currently warns on cases that would + # *also* be reached by standard C++ include rules. That + # behavior doesn't seem useful, so we turn it off. + check_and_add_warning("-Wno-microsoft-include", cxx_compiler) + + # We use a function like: + # __declspec(noreturn) __inline void f() {} + # which -Winvalid-noreturn complains about. Again, MSVC seems + # OK with it, so let's silence the warning. + check_and_add_warning("-Wno-invalid-noreturn") + + # Missing |override| on virtual function declarations isn't + # something that MSVC currently warns about. + check_and_add_warning("-Wno-inconsistent-missing-override", cxx_compiler) + + # We use -DHAS_EXCEPTIONS=0, which removes the |throw()| + # declaration on |operator delete(void*)|. However, clang-cl + # must internally declare |operator delete(void*)| differently, + # which causes this warning for virtually every file in the + # tree. clang-cl doesn't support -fno-exceptions or equivalent, + # so there doesn't seem to be any way to convince clang-cl to + # declare |delete| differently. Therefore, suppress this + # warning. + check_and_add_warning("-Wno-implicit-exception-spec-mismatch", cxx_compiler) + + # Macros like STDMETHOD() and IFACEMETHOD() can declare + # __attribute__((nothrow)) on their respective method declarations, + # while the definitions are left without the matching attribute. + check_and_add_warning("-Wno-microsoft-exception-spec", cxx_compiler) + + # At least one MSVC header and several headers in-tree have + # unused typedefs, so turn this on. + check_and_add_warning("-Wno-unused-local-typedef", cxx_compiler) + + # jemalloc uses __declspec(allocator) as a profiler hint, + # which clang-cl doesn't understand. + check_and_add_warning("-Wno-ignored-attributes", cxx_compiler) + + # __attribute__((unused)) really means "might be unused" and + # we use it to avoid warnings about things that are unused + # in some compilation units, but used in many others. This + # warning insists on complaining about the latter case, which + # is annoying, and rather noisy. + check_and_add_warning("-Wno-used-but-marked-unused", cxx_compiler) + + with only_when(depends(c_compiler)(lambda c: c.type != "clang-cl")): + # When compiling for Windows with gcc, gcc throws false positives and true + # positives where the callsite is ifdef-ed out + check_and_add_warning("-Wno-unused-function") + + # When compiling for Windows with gcc, gcc cannot produce this warning + # correctly: it mistakes DWORD_PTR and ULONG_PTR as types you cannot + # give NULL to. (You can in fact do that.) + check_and_add_warning("-Wno-conversion-null") + + # Throughout the codebase we regularly have switch statements off of enums + # without covering every value in the enum. We don't care about these warnings. + check_and_add_warning("-Wno-switch") + + # Another code pattern we have is using start and end constants in enums of + # different types. We do this for safety, but then when comparing it throws + # an error, which we would like to ignore. This seems to only affect the MinGW + # build, but we're not sure why. + check_and_add_warning("-Wno-enum-compare") + +# Make it an error to be missing function declarations for C code. +check_and_add_warning("-Werror=implicit-function-declaration", c_compiler) + +# New in clang 11. We can't really do anything about this warning. +check_and_add_warning("-Wno-psabi") + +# Disable broken missing-braces warning on old clang versions +check_and_add_warning( + "-Wno-missing-braces", + when=depends(c_compiler)(lambda c: c.type == "clang" and c.version < "6.0"), +) + +# Turn on clang thread-safety analysis +# Older clangs don't support AutoUnlock, and have other issues +check_and_add_warning( + "-Wthread-safety", + when=depends(c_compiler)( + lambda c: c.type in ("clang", "clang-cl") and c.version >= "8.0" + ), +) + +# Warn if APIs are used without available() checks on macOS. +check_and_add_warning("-Werror=unguarded-availability-new", when=target_is_osx) + +# clang 17 warns about builtins being redefined and... well, we do that in +# multiple places, some of which are third-party. Until the situation is +# fixed, disable the new warning. +check_and_add_warning("-Wno-error=builtin-macro-redefined") + +# clang 18 has a new warning about VLAs being an extension in C++, but we +# have a number of them. +check_and_add_warning("-Wno-vla-cxx-extension", cxx_compiler) + +# Please keep the following last in this file + +# Avoid requiring complicated logic for extra warning flags in moz.build files. +check_and_add_warning("-Wno-unknown-warning-option") + +set_config("WARNINGS_CFLAGS", warnings_flags.cflags) +set_config("WARNINGS_CXXFLAGS", warnings_flags.cxxflags) +set_config("WARNINGS_HOST_CFLAGS", warnings_flags.host_cflags) +set_config("WARNINGS_HOST_CXXFLAGS", warnings_flags.host_cxxflags) |