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 -Wno-unknown-pragmas \ 11 ${CWARNEXTRA} 12# 13# The following flags are next up for working on: 14# -Wextra 15 16# Disable a few warnings for clang, since there are several places in the 17# kernel where fixing them is more trouble than it is worth, or where there is 18# a false positive. 19.if ${COMPILER_TYPE} == "clang" 20NO_WCONSTANT_CONVERSION= -Wno-constant-conversion 21NO_WSHIFT_COUNT_NEGATIVE= -Wno-shift-count-negative 22NO_WSHIFT_COUNT_OVERFLOW= -Wno-shift-count-overflow 23NO_WSELF_ASSIGN= -Wno-self-assign 24NO_WUNNEEDED_INTERNAL_DECL= -Wno-unneeded-internal-declaration 25NO_WSOMETIMES_UNINITIALIZED= -Wno-error-sometimes-uninitialized 26# Several other warnings which might be useful in some cases, but not severe 27# enough to error out the whole kernel build. Display them anyway, so there is 28# some incentive to fix them eventually. 29CWARNEXTRA?= -Wno-error-tautological-compare -Wno-error-empty-body \ 30 -Wno-error-parentheses-equality -Wno-error-unused-function \ 31 -Wno-error-pointer-sign -Wno-error-format -Wno-error-parentheses 32.endif 33 34.if ${COMPILER_TYPE} == "gcc" 35.if ${COMPILER_VERSION} >= 40300 36# Catch-all for all the things that are in our tree, but for which we're 37# not yet ready for this compiler. Note: we likely only really "support" 38# building with gcc 4.8 and newer. Nothing older has been tested. 39CWARNEXTRA?= -Wno-error=inline -Wno-error=enum-compare -Wno-error=unused-but-set-variable \ 40 -Wno-error=aggressive-loop-optimizations -Wno-error=maybe-uninitialized \ 41 -Wno-error=array-bounds -Wno-error=address \ 42 -Wno-error=cast-qual -Wno-error=sequence-point -Wno-error=attributes \ 43 -Wno-error=strict-overflow -Wno-error=overflow 44.else 45# For gcc 4.2, eliminate the too-often-wrong warnings about uninitialized vars. 46CWARNEXTRA?= -Wno-uninitialized 47.endif 48.endif 49 50# External compilers may not support our format extensions. Allow them 51# to be disabled. WARNING: format checking is disabled in this case. 52.if ${MK_FORMAT_EXTENSIONS} == "no" 53FORMAT_EXTENSIONS= -Wno-format 54.else 55FORMAT_EXTENSIONS= -fformat-extensions 56.endif 57 58# 59# On i386, do not align the stack to 16-byte boundaries. Otherwise GCC 2.95 60# and above adds code to the entry and exit point of every function to align the 61# stack to 16-byte boundaries -- thus wasting approximately 12 bytes of stack 62# per function call. While the 16-byte alignment may benefit micro benchmarks, 63# it is probably an overall loss as it makes the code bigger (less efficient 64# use of code cache tag lines) and uses more stack (less efficient use of data 65# cache tag lines). Explicitly prohibit the use of FPU, SSE and other SIMD 66# operations inside the kernel itself. These operations are exclusively 67# reserved for user applications. 68# 69# gcc: 70# Setting -mno-mmx implies -mno-3dnow 71# Setting -mno-sse implies -mno-sse2, -mno-sse3 and -mno-ssse3 72# 73# clang: 74# Setting -mno-mmx implies -mno-3dnow and -mno-3dnowa 75# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3, -mno-sse41 and -mno-sse42 76# 77.if ${MACHINE_CPUARCH} == "i386" 78CFLAGS.gcc+= -mno-align-long-strings -mpreferred-stack-boundary=2 79CFLAGS.clang+= -mno-aes -mno-avx 80CFLAGS+= -mno-mmx -mno-sse -msoft-float 81INLINE_LIMIT?= 8000 82.endif 83 84.if ${MACHINE_CPUARCH} == "arm" 85INLINE_LIMIT?= 8000 86.endif 87 88# 89# For sparc64 we want the medany code model so modules may be located 90# anywhere in the 64-bit address space. We also tell GCC to use floating 91# point emulation. This avoids using floating point registers for integer 92# operations which it has a tendency to do. 93# 94.if ${MACHINE_CPUARCH} == "sparc64" 95CFLAGS.clang+= -mcmodel=large -fno-dwarf2-cfi-asm 96CFLAGS.gcc+= -mcmodel=medany -msoft-float 97INLINE_LIMIT?= 15000 98.endif 99 100# 101# For AMD64, we explicitly prohibit the use of FPU, SSE and other SIMD 102# operations inside the kernel itself. These operations are exclusively 103# reserved for user applications. 104# 105# gcc: 106# Setting -mno-mmx implies -mno-3dnow 107# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3 and -mfpmath=387 108# 109# clang: 110# Setting -mno-mmx implies -mno-3dnow and -mno-3dnowa 111# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3, -mno-sse41 and -mno-sse42 112# (-mfpmath= is not supported) 113# 114.if ${MACHINE_CPUARCH} == "amd64" 115CFLAGS.clang+= -mno-aes -mno-avx 116CFLAGS+= -mcmodel=kernel -mno-red-zone -mno-mmx -mno-sse -msoft-float \ 117 -fno-asynchronous-unwind-tables 118INLINE_LIMIT?= 8000 119.endif 120 121# 122# For PowerPC we tell gcc to use floating point emulation. This avoids using 123# floating point registers for integer operations which it has a tendency to do. 124# Also explicitly disable Altivec instructions inside the kernel. 125# 126.if ${MACHINE_CPUARCH} == "powerpc" 127CFLAGS+= -msoft-float -mno-altivec 128INLINE_LIMIT?= 15000 129.endif 130 131# 132# Use dot symbols on powerpc64 to make ddb happy 133# 134.if ${MACHINE_ARCH} == "powerpc64" 135CFLAGS+= -mcall-aixdesc 136.endif 137 138# 139# For MIPS we also tell gcc to use floating point emulation 140# 141.if ${MACHINE_CPUARCH} == "mips" 142CFLAGS+= -msoft-float 143INLINE_LIMIT?= 8000 144.endif 145 146# 147# GCC 3.0 and above like to do certain optimizations based on the 148# assumption that the program is linked against libc. Stop this. 149# 150CFLAGS+= -ffreestanding 151 152# 153# GCC SSP support 154# 155.if ${MK_SSP} != "no" && \ 156 ${MACHINE_CPUARCH} != "arm" && ${MACHINE_CPUARCH} != "mips" 157CFLAGS+= -fstack-protector 158.endif 159 160# 161# Add -gdwarf-2 when compiling -g. The default starting in clang v3.4 162# and gcc 4.8 is to generate DWARF version 4. However, our tools don't 163# cope well with DWARF 4, so force it to genereate DWARF2, which they 164# understand. Do this unconditionally as it is harmless when not needed, 165# but critical for these newer versions. 166# 167.if ${CFLAGS:M-g} != "" && ${CFLAGS:M-gdwarf*} == "" 168CFLAGS+= -gdwarf-2 169.endif 170 171CFLAGS+= ${CWARNEXTRA} 172 173CFLAGS+= ${CFLAGS.${COMPILER_TYPE}} 174 175# Tell bmake not to mistake standard targets for things to be searched for 176# or expect to ever be up-to-date. 177PHONY_NOTMAIN = afterdepend afterinstall all beforedepend beforeinstall \ 178 beforelinking build build-tools buildfiles buildincludes \ 179 checkdpadd clean cleandepend cleandir cleanobj configure \ 180 depend dependall distclean distribute exe \ 181 html includes install installfiles installincludes lint \ 182 obj objlink objs objwarn realall realdepend \ 183 realinstall regress subdir-all subdir-depend subdir-install \ 184 tags whereobj 185 186.PHONY: ${PHONY_NOTMAIN} 187.NOTMAIN: ${PHONY_NOTMAIN} 188 189CSTD= c99 190 191.if ${CSTD} == "k&r" 192CFLAGS+= -traditional 193.elif ${CSTD} == "c89" || ${CSTD} == "c90" 194CFLAGS+= -std=iso9899:1990 195.elif ${CSTD} == "c94" || ${CSTD} == "c95" 196CFLAGS+= -std=iso9899:199409 197.elif ${CSTD} == "c99" 198CFLAGS+= -std=iso9899:1999 199.else # CSTD 200CFLAGS+= -std=${CSTD} 201.endif # CSTD 202 203# Pull in any CWARNFLAGS the modules have added. 204CFLAGS+= ${CWARNFLAGS} ${CWARNFLAGS.${.IMPSRC:T}} 205