mirror of
https://github.com/RIOT-OS/RIOT.git
synced 2024-12-29 04:50:03 +01:00
95f814b5da
The standard is 9 years old now, it is well supported in all mayor compilers. In fact, features of the 'new' standard are already used in RIOT (std_atomic). Let's make it the default and adapt the Makefiles accordingly.
84 lines
3.4 KiB
Makefile
84 lines
3.4 KiB
Makefile
# Test if the input language was specified externally.
|
|
# Otherwise test if the compiler unterstands the "-std=c11" flag, and use it if so.
|
|
ifeq ($(filter -std=%,$(CFLAGS)),)
|
|
ifeq ($(shell $(CC) -std=c11 -E - 2>/dev/null >/dev/null </dev/null ; echo $$?),0)
|
|
CFLAGS += -std=c11
|
|
endif
|
|
endif
|
|
|
|
# Add `-fno-delete-null-pointer-checks` flag iff the compiler supports it.
|
|
# GCC removes moves tests whether `x == NULL`, if previously `x` or even `x->y` was accessed.
|
|
# 0x0 might be a sane memory location for embedded systems, so the test must not be removed.
|
|
# Right now clang does not use the *delete-null-pointer* optimization, and does not understand the parameter.
|
|
# Related issues: #628, #664.
|
|
OPTIONAL_CFLAGS += -fno-delete-null-pointer-checks
|
|
|
|
# Use colored compiler output if the compiler supports this and if this is not
|
|
# disabled by the user
|
|
ifneq ($(CC_NOCOLOR),1)
|
|
OPTIONAL_CFLAGS += -fdiagnostics-color
|
|
endif
|
|
|
|
# Force the C compiler to not ignore signed integer overflows
|
|
# Background: In practise signed integers overflow consistently and wrap
|
|
# around to the lowest number. But this is undefined behaviour.
|
|
# Branches that rely on this undefined behaviour will be silently
|
|
# optimized out. For details, have a look at
|
|
# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=30475
|
|
# Note: Please do not add new code that relies on this undefined
|
|
# behaviour, even though this flag makes your code work. There are
|
|
# safe ways to check for signed integer overflow.
|
|
CFLAGS += -fwrapv
|
|
# Enable warnings for code relying on signed integers to overflow correctly
|
|
# (see above for details).
|
|
# Note: This warning is sadly not reliable, thus -fwrapv cannot be
|
|
# dropped in favor of this
|
|
CFLAGS += -Wstrict-overflow
|
|
|
|
# Fast-out on old style function definitions.
|
|
# They cause unreadable error compiler errors on missing semicolons.
|
|
# Worse yet they hide errors by accepting wildcard argument types.
|
|
OPTIONAL_CFLAGS += -Wstrict-prototypes
|
|
OPTIONAL_CFLAGS += -Wold-style-definition
|
|
|
|
# Unwanted flags for c++
|
|
CXXUWFLAGS += -std=%
|
|
CXXUWFLAGS += -Wstrict-prototypes -Wold-style-definition
|
|
|
|
ifeq ($(LTO),1)
|
|
$(warning Building with Link-Time-Optimizations is currently an experimental feature. Expect broken binaries.)
|
|
LTOFLAGS = -flto
|
|
LINKFLAGS += $(LTOFLAGS)
|
|
endif
|
|
|
|
# Forbid common symbols to prevent accidental aliasing.
|
|
CFLAGS += -fno-common
|
|
|
|
# Place data and functions into their own sections. This helps the linker
|
|
# garbage collection to remove unused symbols when linking statically.
|
|
CFLAGS += -ffunction-sections -fdata-sections
|
|
|
|
# Compress debug info. This saves approximately 50% of disk usage.
|
|
# It has no effect if debugging information is not emitted, so it can be left
|
|
# on unconditionally.
|
|
OPTIONAL_CFLAGS += -gz
|
|
|
|
# Enable all default warnings and all extra warnings
|
|
CFLAGS += -Wall -Wextra
|
|
# Enable additional checks for printf/scanf format strings
|
|
OPTIONAL_CFLAGS += -Wformat=2
|
|
OPTIONAL_CFLAGS += -Wformat-overflow
|
|
OPTIONAL_CFLAGS += -Wformat-truncation
|
|
|
|
# Warn if a user-supplied include directory does not exist.
|
|
CFLAGS += -Wmissing-include-dirs
|
|
|
|
ifeq (,$(filter -DDEVELHELP,$(CFLAGS)))
|
|
ifneq (1,$(FORCE_ASSERTS))
|
|
CFLAGS += -DNDEBUG
|
|
endif
|
|
endif
|
|
|
|
# Add the optional flags that are not architecture/toolchain blacklisted
|
|
CFLAGS += $(filter-out $(OPTIONAL_CFLAGS_BLACKLIST),$(OPTIONAL_CFLAGS))
|