git/config.mak.dev
Jeff Hostetler 54795d37d9 config.mak.dev: disable suggest braces error on old clang versions
Add the "-Wno-missing-braces" option when building with an old version
of clang to suppress the "suggest braces around initialization" error
in developer mode.

For example, using an old version of clang gives the following errors
(when in DEVELOPER=1 mode):

$ make builtin/merge-file.o
    CC builtin/merge-file.o
builtin/merge-file.c:29:23: error: suggest braces around initialization \
			    of subobject [-Werror,-Wmissing-braces]
        mmfile_t mmfs[3] = { 0 };
                             ^
                             {}
builtin/merge-file.c:31:20: error: suggest braces around initialization \
			    of subobject [-Werror,-Wmissing-braces]
        xmparam_t xmp = { 0 };
                          ^
                          {}
2 errors generated.

This example compiles without error/warning with updated versions of
clang.  Since this is an obsolete error, use the -Wno-missing-braces
option to silence the warning when using an older compiler.  This
avoids the need to update the code to use "{{0}}" style
initializations.

Upstream clang version 8 has the problem.  It was fixed in version 9.

The version of clang distributed by Apple with XCode has its own
unique set of version numbers.  Apple clang version 11 has the
problem.  It was fixed in version 12.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-10-10 11:15:31 -07:00

103 lines
3.4 KiB
Plaintext

ifndef COMPILER_FEATURES
COMPILER_FEATURES := $(shell ./detect-compiler $(CC))
endif
ifeq ($(filter no-error,$(DEVOPTS)),)
DEVELOPER_CFLAGS += -Werror
SPARSE_FLAGS += -Wsparse-error
endif
DEVELOPER_CFLAGS += -Wall
ifeq ($(filter no-pedantic,$(DEVOPTS)),)
DEVELOPER_CFLAGS += -pedantic
ifneq (($or $(filter gcc5,$(COMPILER_FEATURES)),$(filter clang4,$(COMPILER_FEATURES))),)
DEVELOPER_CFLAGS += -Wpedantic
ifneq ($(filter gcc10,$(COMPILER_FEATURES)),)
ifeq ($(uname_S),MINGW)
DEVELOPER_CFLAGS += -Wno-pedantic-ms-format
endif
endif
endif
endif
ifneq ($(uname_S),FreeBSD)
ifneq ($(or $(filter gcc6,$(COMPILER_FEATURES)),$(filter clang7,$(COMPILER_FEATURES))),)
DEVELOPER_CFLAGS += -std=gnu99
endif
else
# FreeBSD cannot limit to C99 because its system headers unconditionally
# rely on C11 features.
endif
DEVELOPER_CFLAGS += -Wdeclaration-after-statement
DEVELOPER_CFLAGS += -Wformat-security
DEVELOPER_CFLAGS += -Wold-style-definition
DEVELOPER_CFLAGS += -Woverflow
DEVELOPER_CFLAGS += -Wpointer-arith
DEVELOPER_CFLAGS += -Wstrict-prototypes
DEVELOPER_CFLAGS += -Wunused
DEVELOPER_CFLAGS += -Wvla
DEVELOPER_CFLAGS += -fno-common
ifneq ($(filter clang4,$(COMPILER_FEATURES)),)
DEVELOPER_CFLAGS += -Wtautological-constant-out-of-range-compare
endif
ifneq ($(or $(filter gcc6,$(COMPILER_FEATURES)),$(filter clang4,$(COMPILER_FEATURES))),)
DEVELOPER_CFLAGS += -Wextra
# if a function is public, there should be a prototype and the right
# header file should be included. If not, it should be static.
DEVELOPER_CFLAGS += -Wmissing-prototypes
ifeq ($(filter extra-all,$(DEVOPTS)),)
# These are disabled because we have these all over the place.
DEVELOPER_CFLAGS += -Wno-empty-body
DEVELOPER_CFLAGS += -Wno-missing-field-initializers
DEVELOPER_CFLAGS += -Wno-sign-compare
DEVELOPER_CFLAGS += -Wno-unused-parameter
endif
endif
# uninitialized warnings on gcc 4.9.2 in xdiff/xdiffi.c and config.c
# not worth fixing since newer compilers correctly stop complaining
#
# Likewise, gcc older than 4.9 complains about initializing a
# struct-within-a-struct using just "{ 0 }"
ifneq ($(filter gcc4,$(COMPILER_FEATURES)),)
ifeq ($(filter gcc5,$(COMPILER_FEATURES)),)
DEVELOPER_CFLAGS += -Wno-uninitialized
DEVELOPER_CFLAGS += -Wno-missing-braces
endif
endif
# Old versions of clang complain about initializaing a
# struct-within-a-struct using just "{0}" rather than "{{0}}". This
# error is considered a false-positive and not worth fixing, because
# new clang versions do not, so just disable it.
#
# The "bug" was fixed in upstream clang 9.
#
# Complicating this is that versions of clang released by Apple have
# their own version numbers (associated with the corresponding version
# of XCode) unrelated to the official clang version numbers.
#
# The bug was fixed in Apple clang 12.
#
ifneq ($(filter clang1,$(COMPILER_FEATURES)),) # if we are using clang
ifeq ($(uname_S),Darwin) # if we are on darwin
ifeq ($(filter clang12,$(COMPILER_FEATURES)),) # if version < 12
DEVELOPER_CFLAGS += -Wno-missing-braces
endif
else # not darwin
ifeq ($(filter clang9,$(COMPILER_FEATURES)),) # if version < 9
DEVELOPER_CFLAGS += -Wno-missing-braces
endif
endif
endif
# https://bugzilla.redhat.com/show_bug.cgi?id=2075786
ifneq ($(filter gcc12,$(COMPILER_FEATURES)),)
DEVELOPER_CFLAGS += -Wno-error=stringop-overread
endif
GIT_TEST_PERL_FATAL_WARNINGS = YesPlease