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