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diff --git a/build/moz.configure/warnings.configure b/build/moz.configure/warnings.configure
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+# -*- 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")
+
+# 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)