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 26NO_WCAST_QUAL= -Wno-cast-qual 27# Several other warnings which might be useful in some cases, but not severe 28# enough to error out the whole kernel build. Display them anyway, so there is 29# some incentive to fix them eventually. 30CWARNEXTRA?= -Wno-error-tautological-compare -Wno-error-empty-body \ 31 -Wno-error-parentheses-equality -Wno-error-unused-function \ 32 -Wno-error-pointer-sign 33 34CLANG_NO_IAS= -no-integrated-as 35.if ${COMPILER_VERSION} < 30500 36# XXX: clang < 3.5 integrated-as doesn't grok .codeNN directives 37CLANG_NO_IAS34= -no-integrated-as 38.endif 39.endif 40 41.if ${COMPILER_TYPE} == "gcc" 42.if ${COMPILER_VERSION} >= 40300 43# Catch-all for all the things that are in our tree, but for which we're 44# not yet ready for this compiler. Note: we likely only really "support" 45# building with gcc 4.8 and newer. Nothing older has been tested. 46CWARNEXTRA?= -Wno-error=inline -Wno-error=enum-compare -Wno-error=unused-but-set-variable \ 47 -Wno-error=aggressive-loop-optimizations -Wno-error=maybe-uninitialized \ 48 -Wno-error=array-bounds -Wno-error=address \ 49 -Wno-error=cast-qual -Wno-error=sequence-point -Wno-error=attributes \ 50 -Wno-error=strict-overflow -Wno-error=overflow 51.else 52# For gcc 4.2, eliminate the too-often-wrong warnings about uninitialized vars. 53CWARNEXTRA?= -Wno-uninitialized 54.endif 55.endif 56 57# External compilers may not support our format extensions. Allow them 58# to be disabled. WARNING: format checking is disabled in this case. 59.if ${MK_FORMAT_EXTENSIONS} == "no" 60FORMAT_EXTENSIONS= -Wno-format 61.elif ${COMPILER_TYPE} == "clang" && ${COMPILER_VERSION} >= 30600 62FORMAT_EXTENSIONS= -D__printf__=__freebsd_kprintf__ 63.else 64FORMAT_EXTENSIONS= -fformat-extensions 65.endif 66 67# 68# On i386, do not align the stack to 16-byte boundaries. Otherwise GCC 2.95 69# and above adds code to the entry and exit point of every function to align the 70# stack to 16-byte boundaries -- thus wasting approximately 12 bytes of stack 71# per function call. While the 16-byte alignment may benefit micro benchmarks, 72# it is probably an overall loss as it makes the code bigger (less efficient 73# use of code cache tag lines) and uses more stack (less efficient use of data 74# cache tag lines). Explicitly prohibit the use of FPU, SSE and other SIMD 75# operations inside the kernel itself. These operations are exclusively 76# reserved for user applications. 77# 78# gcc: 79# Setting -mno-mmx implies -mno-3dnow 80# Setting -mno-sse implies -mno-sse2, -mno-sse3 and -mno-ssse3 81# 82# clang: 83# Setting -mno-mmx implies -mno-3dnow and -mno-3dnowa 84# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3, -mno-sse41 and -mno-sse42 85# 86.if ${MACHINE_CPUARCH} == "i386" 87CFLAGS.gcc+= -mno-align-long-strings -mpreferred-stack-boundary=2 88CFLAGS.clang+= -mno-aes -mno-avx 89CFLAGS+= -mno-mmx -mno-sse -msoft-float 90INLINE_LIMIT?= 8000 91.endif 92 93.if ${MACHINE_CPUARCH} == "arm" 94INLINE_LIMIT?= 8000 95.endif 96 97# 98# For sparc64 we want the medany code model so modules may be located 99# anywhere in the 64-bit address space. We also tell GCC to use floating 100# point emulation. This avoids using floating point registers for integer 101# operations which it has a tendency to do. 102# 103.if ${MACHINE_CPUARCH} == "sparc64" 104CFLAGS.clang+= -mcmodel=large -fno-dwarf2-cfi-asm 105CFLAGS.gcc+= -mcmodel=medany -msoft-float 106INLINE_LIMIT?= 15000 107.endif 108 109# 110# For AMD64, we explicitly prohibit the use of FPU, SSE and other SIMD 111# operations inside the kernel itself. These operations are exclusively 112# reserved for user applications. 113# 114# gcc: 115# Setting -mno-mmx implies -mno-3dnow 116# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3 and -mfpmath=387 117# 118# clang: 119# Setting -mno-mmx implies -mno-3dnow and -mno-3dnowa 120# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3, -mno-sse41 and -mno-sse42 121# (-mfpmath= is not supported) 122# 123.if ${MACHINE_CPUARCH} == "amd64" 124CFLAGS.clang+= -mno-aes -mno-avx 125CFLAGS+= -mcmodel=kernel -mno-red-zone -mno-mmx -mno-sse -msoft-float \ 126 -fno-asynchronous-unwind-tables 127INLINE_LIMIT?= 8000 128.endif 129 130# 131# For PowerPC we tell gcc to use floating point emulation. This avoids using 132# floating point registers for integer operations which it has a tendency to do. 133# Also explicitly disable Altivec instructions inside the kernel. 134# 135.if ${MACHINE_CPUARCH} == "powerpc" 136CFLAGS+= -mno-altivec 137CFLAGS.clang+= -mllvm -disable-ppc-float-in-variadic=true 138CFLAGS.gcc+= -msoft-float 139INLINE_LIMIT?= 15000 140.endif 141 142# 143# Use dot symbols on powerpc64 to make ddb happy 144# 145.if ${MACHINE_ARCH} == "powerpc64" 146CFLAGS.gcc+= -mcall-aixdesc 147.endif 148 149# 150# For MIPS we also tell gcc to use floating point emulation 151# 152.if ${MACHINE_CPUARCH} == "mips" 153CFLAGS+= -msoft-float 154INLINE_LIMIT?= 8000 155.endif 156 157# 158# GCC 3.0 and above like to do certain optimizations based on the 159# assumption that the program is linked against libc. Stop this. 160# 161CFLAGS+= -ffreestanding 162 163# 164# The C standard leaves signed integer overflow behavior undefined. 165# gcc and clang opimizers take advantage of this. The kernel makes 166# use of signed integer wraparound mechanics so we need the compiler 167# to treat it as a wraparound and not take shortcuts. 168# 169CFLAGS+= -fwrapv 170 171# 172# GCC SSP support 173# 174.if ${MK_SSP} != "no" && \ 175 ${MACHINE_CPUARCH} != "arm" && ${MACHINE_CPUARCH} != "mips" 176CFLAGS+= -fstack-protector 177.endif 178 179# 180# Add -gdwarf-2 when compiling -g. The default starting in clang v3.4 181# and gcc 4.8 is to generate DWARF version 4. However, our tools don't 182# cope well with DWARF 4, so force it to genereate DWARF2, which they 183# understand. Do this unconditionally as it is harmless when not needed, 184# but critical for these newer versions. 185# 186.if ${CFLAGS:M-g} != "" && ${CFLAGS:M-gdwarf*} == "" 187CFLAGS+= -gdwarf-2 188.endif 189 190CFLAGS+= ${CWARNEXTRA} ${CWARNFLAGS} ${CWARNFLAGS.${.IMPSRC:T}} 191CFLAGS+= ${CFLAGS.${COMPILER_TYPE}} ${CFLAGS.${.IMPSRC:T}} 192 193# Tell bmake not to mistake standard targets for things to be searched for 194# or expect to ever be up-to-date. 195PHONY_NOTMAIN = afterdepend afterinstall all beforedepend beforeinstall \ 196 beforelinking build build-tools buildfiles buildincludes \ 197 checkdpadd clean cleandepend cleandir cleanobj configure \ 198 depend dependall distclean distribute exe \ 199 html includes install installfiles installincludes lint \ 200 obj objlink objs objwarn realall realdepend \ 201 realinstall regress subdir-all subdir-depend subdir-install \ 202 tags whereobj 203 204.PHONY: ${PHONY_NOTMAIN} 205.NOTMAIN: ${PHONY_NOTMAIN} 206 207CSTD= c99 208 209.if ${CSTD} == "k&r" 210CFLAGS+= -traditional 211.elif ${CSTD} == "c89" || ${CSTD} == "c90" 212CFLAGS+= -std=iso9899:1990 213.elif ${CSTD} == "c94" || ${CSTD} == "c95" 214CFLAGS+= -std=iso9899:199409 215.elif ${CSTD} == "c99" 216CFLAGS+= -std=iso9899:1999 217.else # CSTD 218CFLAGS+= -std=${CSTD} 219.endif # CSTD 220