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-error-constant-conversion 21NO_WSHIFT_COUNT_NEGATIVE= -Wno-error-shift-count-negative 22NO_WSHIFT_COUNT_OVERFLOW= -Wno-error-shift-count-overflow 23NO_WSELF_ASSIGN= -Wno-error-self-assign 24NO_WUNNEEDED_INTERNAL_DECL= -Wno-error-unneeded-internal-declaration 25NO_WSOMETIMES_UNINITIALIZED= -Wno-error-sometimes-uninitialized 26NO_WCAST_QUAL= -Wno-error-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.if ${COMPILER_VERSION} >= 30700 34CWARNEXTRA+= -Wno-error-shift-negative-value 35.endif 36.if ${COMPILER_VERSION} >= 40000 37CWARNEXTRA+= -Wno-error-address-of-packed-member 38.endif 39 40CLANG_NO_IAS= -no-integrated-as 41.if ${COMPILER_VERSION} < 30500 42# XXX: clang < 3.5 integrated-as doesn't grok .codeNN directives 43CLANG_NO_IAS34= -no-integrated-as 44.endif 45.endif 46 47.if ${COMPILER_TYPE} == "gcc" 48.if ${COMPILER_VERSION} >= 40800 49# Catch-all for all the things that are in our tree, but for which we're 50# not yet ready for this compiler. 51CWARNEXTRA?= -Wno-error=address \ 52 -Wno-error=aggressive-loop-optimizations \ 53 -Wno-error=array-bounds \ 54 -Wno-error=attributes \ 55 -Wno-error=cast-qual \ 56 -Wno-error=enum-compare \ 57 -Wno-error=inline \ 58 -Wno-error=maybe-uninitialized \ 59 -Wno-error=overflow \ 60 -Wno-error=sequence-point \ 61 -Wno-error=strict-overflow \ 62 -Wno-error=unused-but-set-variable 63.if ${COMPILER_VERSION} >= 60100 64CWARNEXTRA+= -Wno-error=misleading-indentation \ 65 -Wno-error=nonnull-compare \ 66 -Wno-error=shift-overflow \ 67 -Wno-error=tautological-compare 68.endif 69.else 70# For gcc 4.2, eliminate the too-often-wrong warnings about uninitialized vars. 71CWARNEXTRA?= -Wno-uninitialized 72.endif 73.endif 74 75# External compilers may not support our format extensions. Allow them 76# to be disabled. WARNING: format checking is disabled in this case. 77.if ${MK_FORMAT_EXTENSIONS} == "no" 78FORMAT_EXTENSIONS= -Wno-format 79.elif ${COMPILER_TYPE} == "clang" && ${COMPILER_VERSION} >= 30600 80FORMAT_EXTENSIONS= -D__printf__=__freebsd_kprintf__ 81.else 82FORMAT_EXTENSIONS= -fformat-extensions 83.endif 84 85# 86# On i386, do not align the stack to 16-byte boundaries. Otherwise GCC 2.95 87# and above adds code to the entry and exit point of every function to align the 88# stack to 16-byte boundaries -- thus wasting approximately 12 bytes of stack 89# per function call. While the 16-byte alignment may benefit micro benchmarks, 90# it is probably an overall loss as it makes the code bigger (less efficient 91# use of code cache tag lines) and uses more stack (less efficient use of data 92# cache tag lines). Explicitly prohibit the use of FPU, SSE and other SIMD 93# operations inside the kernel itself. These operations are exclusively 94# reserved for user applications. 95# 96# gcc: 97# Setting -mno-mmx implies -mno-3dnow 98# Setting -mno-sse implies -mno-sse2, -mno-sse3 and -mno-ssse3 99# 100# clang: 101# Setting -mno-mmx implies -mno-3dnow and -mno-3dnowa 102# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3, -mno-sse41 and -mno-sse42 103# 104.if ${MACHINE_CPUARCH} == "i386" 105CFLAGS.gcc+= -mno-align-long-strings -mpreferred-stack-boundary=2 106CFLAGS.clang+= -mno-aes -mno-avx 107CFLAGS+= -mno-mmx -mno-sse -msoft-float 108INLINE_LIMIT?= 8000 109.endif 110 111.if ${MACHINE_CPUARCH} == "arm" 112INLINE_LIMIT?= 8000 113.endif 114 115.if ${MACHINE_CPUARCH} == "aarch64" 116# We generally don't want fpu instructions in the kernel. 117CFLAGS += -mgeneral-regs-only 118# Reserve x18 for pcpu data 119CFLAGS += -ffixed-x18 120INLINE_LIMIT?= 8000 121.endif 122 123.if ${MACHINE_CPUARCH} == "riscv" 124CFLAGS.gcc+= -mcmodel=medany 125INLINE_LIMIT?= 8000 126.endif 127 128# 129# For sparc64 we want the medany code model so modules may be located 130# anywhere in the 64-bit address space. We also tell GCC to use floating 131# point emulation. This avoids using floating point registers for integer 132# operations which it has a tendency to do. 133# 134.if ${MACHINE_CPUARCH} == "sparc64" 135CFLAGS.clang+= -mcmodel=large -fno-dwarf2-cfi-asm 136CFLAGS.gcc+= -mcmodel=medany -msoft-float 137INLINE_LIMIT?= 15000 138.endif 139 140# 141# For AMD64, we explicitly prohibit the use of FPU, SSE and other SIMD 142# operations inside the kernel itself. These operations are exclusively 143# reserved for user applications. 144# 145# gcc: 146# Setting -mno-mmx implies -mno-3dnow 147# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3 and -mfpmath=387 148# 149# clang: 150# Setting -mno-mmx implies -mno-3dnow and -mno-3dnowa 151# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3, -mno-sse41 and -mno-sse42 152# (-mfpmath= is not supported) 153# 154.if ${MACHINE_CPUARCH} == "amd64" 155CFLAGS.clang+= -mno-aes -mno-avx 156CFLAGS+= -mcmodel=kernel -mno-red-zone -mno-mmx -mno-sse -msoft-float \ 157 -fno-asynchronous-unwind-tables 158INLINE_LIMIT?= 8000 159.endif 160 161# 162# For PowerPC we tell gcc to use floating point emulation. This avoids using 163# floating point registers for integer operations which it has a tendency to do. 164# Also explicitly disable Altivec instructions inside the kernel. 165# 166.if ${MACHINE_CPUARCH} == "powerpc" 167CFLAGS+= -mno-altivec -msoft-float 168INLINE_LIMIT?= 15000 169.endif 170 171.if ${MACHINE_ARCH} == "powerpcspe" 172CFLAGS.gcc+= -mno-spe 173.endif 174 175# 176# Use dot symbols on powerpc64 to make ddb happy 177# 178.if ${MACHINE_ARCH} == "powerpc64" 179CFLAGS.gcc+= -mcall-aixdesc 180.endif 181 182# 183# For MIPS we also tell gcc to use floating point emulation 184# 185.if ${MACHINE_CPUARCH} == "mips" 186CFLAGS+= -msoft-float 187INLINE_LIMIT?= 8000 188.if ${MACHINE_ARCH:Mmips*hf} != "" 189CFLAGS+= -DCPU_HAVEFPU 190.endif 191.endif 192 193# 194# GCC 3.0 and above like to do certain optimizations based on the 195# assumption that the program is linked against libc. Stop this. 196# 197CFLAGS+= -ffreestanding 198 199# 200# The C standard leaves signed integer overflow behavior undefined. 201# gcc and clang opimizers take advantage of this. The kernel makes 202# use of signed integer wraparound mechanics so we need the compiler 203# to treat it as a wraparound and not take shortcuts. 204# 205CFLAGS+= -fwrapv 206 207# 208# GCC SSP support 209# 210.if ${MK_SSP} != "no" && \ 211 ${MACHINE_CPUARCH} != "arm" && ${MACHINE_CPUARCH} != "mips" 212CFLAGS+= -fstack-protector 213.endif 214 215# 216# Add -gdwarf-2 when compiling -g. The default starting in clang v3.4 217# and gcc 4.8 is to generate DWARF version 4. However, our tools don't 218# cope well with DWARF 4, so force it to genereate DWARF2, which they 219# understand. Do this unconditionally as it is harmless when not needed, 220# but critical for these newer versions. 221# 222.if ${CFLAGS:M-g} != "" && ${CFLAGS:M-gdwarf*} == "" 223CFLAGS+= -gdwarf-2 224.endif 225 226CFLAGS+= ${CWARNFLAGS:M*} ${CWARNFLAGS.${.IMPSRC:T}} 227CFLAGS+= ${CFLAGS.${COMPILER_TYPE}} ${CFLAGS.${.IMPSRC:T}} 228 229# Tell bmake not to mistake standard targets for things to be searched for 230# or expect to ever be up-to-date. 231PHONY_NOTMAIN = afterdepend afterinstall all beforedepend beforeinstall \ 232 beforelinking build build-tools buildfiles buildincludes \ 233 checkdpadd clean cleandepend cleandir cleanobj configure \ 234 depend distclean distribute exe \ 235 html includes install installfiles installincludes lint \ 236 obj objlink objs objwarn \ 237 realinstall regress \ 238 tags whereobj 239 240.PHONY: ${PHONY_NOTMAIN} 241.NOTMAIN: ${PHONY_NOTMAIN} 242 243CSTD= c99 244 245.if ${CSTD} == "k&r" 246CFLAGS+= -traditional 247.elif ${CSTD} == "c89" || ${CSTD} == "c90" 248CFLAGS+= -std=iso9899:1990 249.elif ${CSTD} == "c94" || ${CSTD} == "c95" 250CFLAGS+= -std=iso9899:199409 251.elif ${CSTD} == "c99" 252CFLAGS+= -std=iso9899:1999 253.else # CSTD 254CFLAGS+= -std=${CSTD} 255.endif # CSTD 256 257# Set target-specific linker emulation name. Used by ld -b binary to convert 258# binary files into ELF objects. 259LD_EMULATION_aarch64=aarch64elf 260LD_EMULATION_amd64=elf_x86_64_fbsd 261LD_EMULATION_arm=armelf_fbsd 262LD_EMULATION_armeb=armelf_fbsd 263LD_EMULATION_armv6=armelf_fbsd 264LD_EMULATION_i386=elf_i386_fbsd 265LD_EMULATION_mips= elf32btsmip_fbsd 266LD_EMULATION_mips64= elf64btsmip_fbsd 267LD_EMULATION_mipsel= elf32ltsmip_fbsd 268LD_EMULATION_mips64el= elf64ltsmip_fbsd 269LD_EMULATION_mipsn32= elf32btsmipn32_fbsd 270LD_EMULATION_mipsn32el= elf32btsmipn32_fbsd # I don't think this is a thing that works 271LD_EMULATION_powerpc= elf32ppc_fbsd 272LD_EMULATION_powerpcspe= elf32ppc_fbsd 273LD_EMULATION_powerpc64= elf64ppc_fbsd 274LD_EMULATION_riscv= elf64riscv 275LD_EMULATION_sparc64= elf64_sparc_fbsd 276LD_EMULATION=${LD_EMULATION_${MACHINE_ARCH}} 277