1# $FreeBSD$ 2 3# 4# Warning flags for compiling the kernel and components of the kernel: 5# 6CWARNFLAGS?= -Wall -Wredundant-decls -Wnested-externs -Wstrict-prototypes \ 7 -Wmissing-prototypes -Wpointer-arith -Winline -Wcast-qual \ 8 -Wundef -Wno-pointer-sign ${FORMAT_EXTENSIONS} \ 9 -Wmissing-include-dirs -fdiagnostics-show-option \ 10 ${CWARNEXTRA} 11# 12# The following flags are next up for working on: 13# -Wextra 14 15# Disable a few warnings for clang, since there are several places in the 16# kernel where fixing them is more trouble than it is worth, or where there is 17# a false positive. 18.if ${COMPILER_TYPE} == "clang" 19NO_WCONSTANT_CONVERSION= -Wno-constant-conversion 20NO_WARRAY_BOUNDS= -Wno-array-bounds 21NO_WSHIFT_COUNT_NEGATIVE= -Wno-shift-count-negative 22NO_WSHIFT_COUNT_OVERFLOW= -Wno-shift-count-overflow 23NO_WUNUSED_VALUE= -Wno-unused-value 24NO_WSELF_ASSIGN= -Wno-self-assign 25NO_WFORMAT_SECURITY= -Wno-format-security 26NO_WUNNEEDED_INTERNAL_DECL= -Wno-unneeded-internal-declaration 27NO_WSOMETIMES_UNINITIALIZED= -Wno-error-sometimes-uninitialized 28# Several other warnings which might be useful in some cases, but not severe 29# enough to error out the whole kernel build. Display them anyway, so there is 30# some incentive to fix them eventually. 31CWARNEXTRA?= -Wno-error-tautological-compare -Wno-error-empty-body \ 32 -Wno-error-parentheses-equality -Wno-error-unused-function 33.endif 34 35.if ${COMPILER_TYPE} == "gcc" && ${COMPILER_VERSION} >= 40300 36CWARNEXTRA?= -Wno-inline 37.endif 38 39# External compilers may not support our format extensions. Allow them 40# to be disabled. WARNING: format checking is disabled in this case. 41.if ${MK_FORMAT_EXTENSIONS} == "no" 42FORMAT_EXTENSIONS= -Wno-format 43.else 44FORMAT_EXTENSIONS= -fformat-extensions 45.endif 46 47# 48# On i386, do not align the stack to 16-byte boundaries. Otherwise GCC 2.95 49# and above adds code to the entry and exit point of every function to align the 50# stack to 16-byte boundaries -- thus wasting approximately 12 bytes of stack 51# per function call. While the 16-byte alignment may benefit micro benchmarks, 52# it is probably an overall loss as it makes the code bigger (less efficient 53# use of code cache tag lines) and uses more stack (less efficient use of data 54# cache tag lines). Explicitly prohibit the use of FPU, SSE and other SIMD 55# operations inside the kernel itself. These operations are exclusively 56# reserved for user applications. 57# 58# gcc: 59# Setting -mno-mmx implies -mno-3dnow 60# Setting -mno-sse implies -mno-sse2, -mno-sse3 and -mno-ssse3 61# 62# clang: 63# Setting -mno-mmx implies -mno-3dnow and -mno-3dnowa 64# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3, -mno-sse41 and -mno-sse42 65# 66.if ${MACHINE_CPUARCH} == "i386" 67CFLAGS.gcc+= -mno-align-long-strings -mpreferred-stack-boundary=2 68CFLAGS.clang+= -mno-aes -mno-avx 69CFLAGS+= -mno-mmx -mno-sse -msoft-float 70INLINE_LIMIT?= 8000 71.endif 72 73.if ${MACHINE_CPUARCH} == "arm" 74INLINE_LIMIT?= 8000 75.endif 76 77# 78# For sparc64 we want the medany code model so modules may be located 79# anywhere in the 64-bit address space. We also tell GCC to use floating 80# point emulation. This avoids using floating point registers for integer 81# operations which it has a tendency to do. 82# 83.if ${MACHINE_CPUARCH} == "sparc64" 84CFLAGS.clang+= -mcmodel=large -fno-dwarf2-cfi-asm 85CFLAGS.gcc+= -mcmodel=medany -msoft-float 86INLINE_LIMIT?= 15000 87.endif 88 89# 90# For AMD64, we explicitly prohibit the use of FPU, SSE and other SIMD 91# operations inside the kernel itself. These operations are exclusively 92# reserved for user applications. 93# 94# gcc: 95# Setting -mno-mmx implies -mno-3dnow 96# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3 and -mfpmath=387 97# 98# clang: 99# Setting -mno-mmx implies -mno-3dnow and -mno-3dnowa 100# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3, -mno-sse41 and -mno-sse42 101# (-mfpmath= is not supported) 102# 103.if ${MACHINE_CPUARCH} == "amd64" 104CFLAGS.clang+= -mno-aes -mno-avx 105CFLAGS+= -mcmodel=kernel -mno-red-zone -mno-mmx -mno-sse -msoft-float \ 106 -fno-asynchronous-unwind-tables 107INLINE_LIMIT?= 8000 108.endif 109 110# 111# For PowerPC we tell gcc to use floating point emulation. This avoids using 112# floating point registers for integer operations which it has a tendency to do. 113# Also explicitly disable Altivec instructions inside the kernel. 114# 115.if ${MACHINE_CPUARCH} == "powerpc" 116CFLAGS+= -msoft-float -mno-altivec 117INLINE_LIMIT?= 15000 118.endif 119 120# 121# Use dot symbols on powerpc64 to make ddb happy 122# 123.if ${MACHINE_ARCH} == "powerpc64" 124CFLAGS+= -mcall-aixdesc 125.endif 126 127# 128# For MIPS we also tell gcc to use floating point emulation 129# 130.if ${MACHINE_CPUARCH} == "mips" 131CFLAGS+= -msoft-float 132INLINE_LIMIT?= 8000 133.endif 134 135# 136# GCC 3.0 and above like to do certain optimizations based on the 137# assumption that the program is linked against libc. Stop this. 138# 139CFLAGS+= -ffreestanding 140 141# 142# GCC SSP support 143# 144.if ${MK_SSP} != "no" && \ 145 ${MACHINE_CPUARCH} != "arm" && ${MACHINE_CPUARCH} != "mips" 146CFLAGS+= -fstack-protector 147.endif 148 149# 150# Add -gdwarf-2 when compiling -g. The default starting in clang v3.4 151# and gcc 4.8 is to generate DWARF version 4. However, our tools don't 152# cope well with DWARF 4, so force it to genereate DWARF2, which they 153# understand. Do this unconditionally as it is harmless when not needed, 154# but critical for these newer versions. 155# 156.if ${CFLAGS:M-g} != "" && ${CFLAGS:M-gdwarf*} == "" 157CFLAGS+= -gdwarf-2 158.endif 159 160CFLAGS+= ${CFLAGS.${COMPILER_TYPE}} 161