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=unused-but-set-variable 62.if ${COMPILER_VERSION} >= 60100 63CWARNEXTRA+= -Wno-error=misleading-indentation \ 64 -Wno-error=nonnull-compare \ 65 -Wno-error=shift-overflow \ 66 -Wno-error=tautological-compare 67.endif 68.else 69# For gcc 4.2, eliminate the too-often-wrong warnings about uninitialized vars. 70CWARNEXTRA?= -Wno-uninitialized 71.endif 72.endif 73 74# External compilers may not support our format extensions. Allow them 75# to be disabled. WARNING: format checking is disabled in this case. 76.if ${MK_FORMAT_EXTENSIONS} == "no" 77FORMAT_EXTENSIONS= -Wno-format 78.elif ${COMPILER_TYPE} == "clang" && ${COMPILER_VERSION} >= 30600 79FORMAT_EXTENSIONS= -D__printf__=__freebsd_kprintf__ 80.else 81FORMAT_EXTENSIONS= -fformat-extensions 82.endif 83 84# 85# On i386, do not align the stack to 16-byte boundaries. Otherwise GCC 2.95 86# and above adds code to the entry and exit point of every function to align the 87# stack to 16-byte boundaries -- thus wasting approximately 12 bytes of stack 88# per function call. While the 16-byte alignment may benefit micro benchmarks, 89# it is probably an overall loss as it makes the code bigger (less efficient 90# use of code cache tag lines) and uses more stack (less efficient use of data 91# cache tag lines). Explicitly prohibit the use of FPU, SSE and other SIMD 92# operations inside the kernel itself. These operations are exclusively 93# reserved for user applications. 94# 95# gcc: 96# Setting -mno-mmx implies -mno-3dnow 97# Setting -mno-sse implies -mno-sse2, -mno-sse3 and -mno-ssse3 98# 99# clang: 100# Setting -mno-mmx implies -mno-3dnow and -mno-3dnowa 101# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3, -mno-sse41 and -mno-sse42 102# 103.if ${MACHINE_CPUARCH} == "i386" 104CFLAGS.gcc+= -mno-align-long-strings -mpreferred-stack-boundary=2 105CFLAGS.clang+= -mno-aes -mno-avx 106CFLAGS+= -mno-mmx -mno-sse -msoft-float 107INLINE_LIMIT?= 8000 108.endif 109 110.if ${MACHINE_CPUARCH} == "arm" 111INLINE_LIMIT?= 8000 112.endif 113 114.if ${MACHINE_CPUARCH} == "aarch64" 115# We generally don't want fpu instructions in the kernel. 116CFLAGS += -mgeneral-regs-only 117# Reserve x18 for pcpu data 118CFLAGS += -ffixed-x18 119INLINE_LIMIT?= 8000 120.endif 121 122.if ${MACHINE_CPUARCH} == "riscv" 123CFLAGS.gcc+= -mcmodel=medany -march=rv64imafdc -mabi=lp64 124INLINE_LIMIT?= 8000 125.endif 126 127# 128# For sparc64 we want the medany code model so modules may be located 129# anywhere in the 64-bit address space. We also tell GCC to use floating 130# point emulation. This avoids using floating point registers for integer 131# operations which it has a tendency to do. 132# 133.if ${MACHINE_CPUARCH} == "sparc64" 134CFLAGS.clang+= -mcmodel=large -fno-dwarf2-cfi-asm 135CFLAGS.gcc+= -mcmodel=medany -msoft-float 136INLINE_LIMIT?= 15000 137.endif 138 139# 140# For AMD64, we explicitly prohibit the use of FPU, SSE and other SIMD 141# operations inside the kernel itself. These operations are exclusively 142# reserved for user applications. 143# 144# gcc: 145# Setting -mno-mmx implies -mno-3dnow 146# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3 and -mfpmath=387 147# 148# clang: 149# Setting -mno-mmx implies -mno-3dnow and -mno-3dnowa 150# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3, -mno-sse41 and -mno-sse42 151# (-mfpmath= is not supported) 152# 153.if ${MACHINE_CPUARCH} == "amd64" 154CFLAGS.clang+= -mno-aes -mno-avx 155CFLAGS+= -mcmodel=kernel -mno-red-zone -mno-mmx -mno-sse -msoft-float \ 156 -fno-asynchronous-unwind-tables 157INLINE_LIMIT?= 8000 158.endif 159 160# 161# For PowerPC we tell gcc to use floating point emulation. This avoids using 162# floating point registers for integer operations which it has a tendency to do. 163# Also explicitly disable Altivec instructions inside the kernel. 164# 165.if ${MACHINE_CPUARCH} == "powerpc" 166CFLAGS+= -mno-altivec -msoft-float 167INLINE_LIMIT?= 15000 168.endif 169 170.if ${MACHINE_ARCH} == "powerpcspe" 171CFLAGS.gcc+= -mno-spe 172.endif 173 174# 175# Use dot symbols (or, better, the V2 ELF ABI) on powerpc64 to make 176# DDB happy. ELFv2, if available, has some other efficiency benefits. 177# 178.if ${MACHINE_ARCH} == "powerpc64" 179.if ${COMPILER_VERSION} >= 40900 180CFLAGS.gcc+= -mabi=elfv2 181.else 182CFLAGS.gcc+= -mcall-aixdesc 183.endif 184CFLAGS.clang+= -mabi=elfv2 185.endif 186 187# 188# For MIPS we also tell gcc to use floating point emulation 189# 190.if ${MACHINE_CPUARCH} == "mips" 191CFLAGS+= -msoft-float 192INLINE_LIMIT?= 8000 193.endif 194 195# 196# GCC 3.0 and above like to do certain optimizations based on the 197# assumption that the program is linked against libc. Stop this. 198# 199CFLAGS+= -ffreestanding 200 201# 202# The C standard leaves signed integer overflow behavior undefined. 203# gcc and clang opimizers take advantage of this. The kernel makes 204# use of signed integer wraparound mechanics so we need the compiler 205# to treat it as a wraparound and not take shortcuts. 206# 207CFLAGS+= -fwrapv 208 209# 210# GCC SSP support 211# 212.if ${MK_SSP} != "no" && \ 213 ${MACHINE_CPUARCH} != "arm" && ${MACHINE_CPUARCH} != "mips" 214CFLAGS+= -fstack-protector 215.endif 216 217# 218# Add -gdwarf-2 when compiling -g. The default starting in clang v3.4 219# and gcc 4.8 is to generate DWARF version 4. However, our tools don't 220# cope well with DWARF 4, so force it to genereate DWARF2, which they 221# understand. Do this unconditionally as it is harmless when not needed, 222# but critical for these newer versions. 223# 224.if ${CFLAGS:M-g} != "" && ${CFLAGS:M-gdwarf*} == "" 225CFLAGS+= -gdwarf-2 226.endif 227 228CFLAGS+= ${CWARNFLAGS:M*} ${CWARNFLAGS.${.IMPSRC:T}} 229CFLAGS+= ${CFLAGS.${COMPILER_TYPE}} ${CFLAGS.${.IMPSRC:T}} 230 231# Tell bmake not to mistake standard targets for things to be searched for 232# or expect to ever be up-to-date. 233PHONY_NOTMAIN = afterdepend afterinstall all beforedepend beforeinstall \ 234 beforelinking build build-tools buildfiles buildincludes \ 235 checkdpadd clean cleandepend cleandir cleanobj configure \ 236 depend distclean distribute exe \ 237 html includes install installfiles installincludes \ 238 obj objlink objs objwarn \ 239 realinstall regress \ 240 tags whereobj 241 242.PHONY: ${PHONY_NOTMAIN} 243.NOTMAIN: ${PHONY_NOTMAIN} 244 245CSTD= c99 246 247.if ${CSTD} == "k&r" 248CFLAGS+= -traditional 249.elif ${CSTD} == "c89" || ${CSTD} == "c90" 250CFLAGS+= -std=iso9899:1990 251.elif ${CSTD} == "c94" || ${CSTD} == "c95" 252CFLAGS+= -std=iso9899:199409 253.elif ${CSTD} == "c99" 254CFLAGS+= -std=iso9899:1999 255.else # CSTD 256CFLAGS+= -std=${CSTD} 257.endif # CSTD 258 259# Set target-specific linker emulation name. 260LD_EMULATION_aarch64=aarch64elf 261LD_EMULATION_amd64=elf_x86_64_fbsd 262LD_EMULATION_arm=armelf_fbsd 263LD_EMULATION_armeb=armelfb_fbsd 264LD_EMULATION_armv6=armelf_fbsd 265LD_EMULATION_armv7=armelf_fbsd 266LD_EMULATION_i386=elf_i386_fbsd 267LD_EMULATION_mips= elf32btsmip_fbsd 268LD_EMULATION_mips64= elf64btsmip_fbsd 269LD_EMULATION_mipsel= elf32ltsmip_fbsd 270LD_EMULATION_mips64el= elf64ltsmip_fbsd 271LD_EMULATION_mipsn32= elf32btsmipn32_fbsd 272LD_EMULATION_mipsn32el= elf32btsmipn32_fbsd # I don't think this is a thing that works 273LD_EMULATION_powerpc= elf32ppc_fbsd 274LD_EMULATION_powerpcspe= elf32ppc_fbsd 275LD_EMULATION_powerpc64= elf64ppc_fbsd 276LD_EMULATION_riscv64= elf64lriscv 277LD_EMULATION_sparc64= elf64_sparc_fbsd 278LD_EMULATION=${LD_EMULATION_${MACHINE_ARCH}} 279