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 ${CWARNEXTRA} 11# 12# The following flags are next up for working on: 13# -Wextra 14 15# Disable a few warnings for clang, since there are several places in the 16# kernel where fixing them is more trouble than it is worth, or where there is 17# a false positive. 18.if ${COMPILER_TYPE} == "clang" 19NO_WCONSTANT_CONVERSION= -Wno-constant-conversion 20NO_WARRAY_BOUNDS= -Wno-array-bounds 21NO_WSHIFT_COUNT_NEGATIVE= -Wno-shift-count-negative 22NO_WSHIFT_COUNT_OVERFLOW= -Wno-shift-count-overflow 23NO_WUNUSED_VALUE= -Wno-unused-value 24NO_WSELF_ASSIGN= -Wno-self-assign 25NO_WFORMAT_SECURITY= -Wno-format-security 26NO_WUNNEEDED_INTERNAL_DECL= -Wno-unneeded-internal-declaration 27NO_WSOMETIMES_UNINITIALIZED= -Wno-error-sometimes-uninitialized 28# Several other warnings which might be useful in some cases, but not severe 29# enough to error out the whole kernel build. Display them anyway, so there is 30# some incentive to fix them eventually. 31CWARNEXTRA?= -Wno-error-tautological-compare -Wno-error-empty-body \ 32 -Wno-error-parentheses-equality -Wno-error-unused-function 33.endif 34 35.if ${COMPILER_TYPE} == "gcc" && ${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.endif 44 45# External compilers may not support our format extensions. Allow them 46# to be disabled. WARNING: format checking is disabled in this case. 47.if ${MK_FORMAT_EXTENSIONS} == "no" 48FORMAT_EXTENSIONS= -Wno-format 49.else 50FORMAT_EXTENSIONS= -fformat-extensions 51.endif 52 53# 54# On i386, do not align the stack to 16-byte boundaries. Otherwise GCC 2.95 55# and above adds code to the entry and exit point of every function to align the 56# stack to 16-byte boundaries -- thus wasting approximately 12 bytes of stack 57# per function call. While the 16-byte alignment may benefit micro benchmarks, 58# it is probably an overall loss as it makes the code bigger (less efficient 59# use of code cache tag lines) and uses more stack (less efficient use of data 60# cache tag lines). Explicitly prohibit the use of FPU, SSE and other SIMD 61# operations inside the kernel itself. These operations are exclusively 62# reserved for user applications. 63# 64# gcc: 65# Setting -mno-mmx implies -mno-3dnow 66# Setting -mno-sse implies -mno-sse2, -mno-sse3 and -mno-ssse3 67# 68# clang: 69# Setting -mno-mmx implies -mno-3dnow and -mno-3dnowa 70# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3, -mno-sse41 and -mno-sse42 71# 72.if ${MACHINE_CPUARCH} == "i386" 73CFLAGS.gcc+= -mno-align-long-strings -mpreferred-stack-boundary=2 74CFLAGS.clang+= -mno-aes -mno-avx 75CFLAGS+= -mno-mmx -mno-sse -msoft-float 76INLINE_LIMIT?= 8000 77.endif 78 79.if ${MACHINE_CPUARCH} == "arm" 80INLINE_LIMIT?= 8000 81.endif 82 83# 84# For sparc64 we want the medany code model so modules may be located 85# anywhere in the 64-bit address space. We also tell GCC to use floating 86# point emulation. This avoids using floating point registers for integer 87# operations which it has a tendency to do. 88# 89.if ${MACHINE_CPUARCH} == "sparc64" 90CFLAGS.clang+= -mcmodel=large -fno-dwarf2-cfi-asm 91CFLAGS.gcc+= -mcmodel=medany -msoft-float 92INLINE_LIMIT?= 15000 93.endif 94 95# 96# For AMD64, we explicitly prohibit the use of FPU, SSE and other SIMD 97# operations inside the kernel itself. These operations are exclusively 98# reserved for user applications. 99# 100# gcc: 101# Setting -mno-mmx implies -mno-3dnow 102# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3 and -mfpmath=387 103# 104# clang: 105# Setting -mno-mmx implies -mno-3dnow and -mno-3dnowa 106# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3, -mno-sse41 and -mno-sse42 107# (-mfpmath= is not supported) 108# 109.if ${MACHINE_CPUARCH} == "amd64" 110CFLAGS.clang+= -mno-aes -mno-avx 111CFLAGS+= -mcmodel=kernel -mno-red-zone -mno-mmx -mno-sse -msoft-float \ 112 -fno-asynchronous-unwind-tables 113INLINE_LIMIT?= 8000 114.endif 115 116# 117# For PowerPC we tell gcc to use floating point emulation. This avoids using 118# floating point registers for integer operations which it has a tendency to do. 119# Also explicitly disable Altivec instructions inside the kernel. 120# 121.if ${MACHINE_CPUARCH} == "powerpc" 122CFLAGS+= -msoft-float -mno-altivec 123INLINE_LIMIT?= 15000 124.endif 125 126# 127# Use dot symbols on powerpc64 to make ddb happy 128# 129.if ${MACHINE_ARCH} == "powerpc64" 130CFLAGS+= -mcall-aixdesc 131.endif 132 133# 134# For MIPS we also tell gcc to use floating point emulation 135# 136.if ${MACHINE_CPUARCH} == "mips" 137CFLAGS+= -msoft-float 138INLINE_LIMIT?= 8000 139.endif 140 141# 142# GCC 3.0 and above like to do certain optimizations based on the 143# assumption that the program is linked against libc. Stop this. 144# 145CFLAGS+= -ffreestanding 146 147# 148# GCC SSP support 149# 150.if ${MK_SSP} != "no" && \ 151 ${MACHINE_CPUARCH} != "arm" && ${MACHINE_CPUARCH} != "mips" 152CFLAGS+= -fstack-protector 153.endif 154 155# 156# Add -gdwarf-2 when compiling -g. The default starting in clang v3.4 157# and gcc 4.8 is to generate DWARF version 4. However, our tools don't 158# cope well with DWARF 4, so force it to genereate DWARF2, which they 159# understand. Do this unconditionally as it is harmless when not needed, 160# but critical for these newer versions. 161# 162.if ${CFLAGS:M-g} != "" && ${CFLAGS:M-gdwarf*} == "" 163CFLAGS+= -gdwarf-2 164.endif 165 166CFLAGS+= ${CFLAGS.${COMPILER_TYPE}} 167