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 ${NO_WFORMAT} 34.endif 35 36.if ${COMPILER_TYPE} == "gcc" 37# For gcc 4.2, eliminate the too-often-wrong warnings about uninitialized vars. 38CWARNEXTRA?= -Wno-uninitialized 39.endif 40 41# External compilers may not support our format extensions. Allow them 42# to be disabled. WARNING: format checking is disabled in this case. 43.if ${MK_FORMAT_EXTENSIONS} == "no" 44NO_WFORMAT= -Wno-format 45.else 46FORMAT_EXTENSIONS= -fformat-extensions 47.endif 48 49# 50# On i386, do not align the stack to 16-byte boundaries. Otherwise GCC 2.95 51# and above adds code to the entry and exit point of every function to align the 52# stack to 16-byte boundaries -- thus wasting approximately 12 bytes of stack 53# per function call. While the 16-byte alignment may benefit micro benchmarks, 54# it is probably an overall loss as it makes the code bigger (less efficient 55# use of code cache tag lines) and uses more stack (less efficient use of data 56# cache tag lines). Explicitly prohibit the use of FPU, SSE and other SIMD 57# operations inside the kernel itself. These operations are exclusively 58# reserved for user applications. 59# 60# gcc: 61# Setting -mno-mmx implies -mno-3dnow 62# Setting -mno-sse implies -mno-sse2, -mno-sse3 and -mno-ssse3 63# 64# clang: 65# Setting -mno-mmx implies -mno-3dnow and -mno-3dnowa 66# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3, -mno-sse41 and -mno-sse42 67# 68.if ${MACHINE_CPUARCH} == "i386" 69.if ${COMPILER_TYPE} != "clang" 70CFLAGS+= -mno-align-long-strings -mpreferred-stack-boundary=2 71.else 72CFLAGS+= -mno-aes -mno-avx 73.endif 74CFLAGS+= -mno-mmx -mno-sse -msoft-float 75INLINE_LIMIT?= 8000 76.endif 77 78.if ${MACHINE_CPUARCH} == "arm" 79INLINE_LIMIT?= 8000 80.endif 81 82# 83# For IA-64, we use r13 for the kernel globals pointer and we only use 84# a very small subset of float registers for integer divides. 85# 86.if ${MACHINE_CPUARCH} == "ia64" 87CFLAGS+= -ffixed-r13 -mfixed-range=f32-f127 -fpic #-mno-sdata 88INLINE_LIMIT?= 15000 89.endif 90 91# 92# For sparc64 we want the medany code model so modules may be located 93# anywhere in the 64-bit address space. We also tell GCC to use floating 94# point emulation. This avoids using floating point registers for integer 95# operations which it has a tendency to do. 96# 97.if ${MACHINE_CPUARCH} == "sparc64" 98.if ${COMPILER_TYPE} == "clang" 99CFLAGS+= -mcmodel=large -fno-dwarf2-cfi-asm 100.else 101CFLAGS+= -mcmodel=medany -msoft-float 102.endif 103INLINE_LIMIT?= 15000 104.endif 105 106# 107# For AMD64, we explicitly prohibit the use of FPU, SSE and other SIMD 108# operations inside the kernel itself. These operations are exclusively 109# reserved for user applications. 110# 111# gcc: 112# Setting -mno-mmx implies -mno-3dnow 113# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3 and -mfpmath=387 114# 115# clang: 116# Setting -mno-mmx implies -mno-3dnow and -mno-3dnowa 117# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3, -mno-sse41 and -mno-sse42 118# (-mfpmath= is not supported) 119# 120.if ${MACHINE_CPUARCH} == "amd64" 121.if ${COMPILER_TYPE} == "clang" 122CFLAGS+= -mno-aes -mno-avx 123.endif 124CFLAGS+= -mcmodel=kernel -mno-red-zone -mno-mmx -mno-sse -msoft-float \ 125 -fno-asynchronous-unwind-tables 126INLINE_LIMIT?= 8000 127.endif 128 129# 130# For PowerPC we tell gcc to use floating point emulation. This avoids using 131# floating point registers for integer operations which it has a tendency to do. 132# Also explicitly disable Altivec instructions inside the kernel. 133# 134.if ${MACHINE_CPUARCH} == "powerpc" 135CFLAGS+= -msoft-float -mno-altivec 136INLINE_LIMIT?= 15000 137.endif 138 139# 140# Use dot symbols on powerpc64 to make ddb happy 141# 142.if ${MACHINE_ARCH} == "powerpc64" 143CFLAGS+= -mcall-aixdesc 144.endif 145 146# 147# For MIPS we also tell gcc to use floating point emulation 148# 149.if ${MACHINE_CPUARCH} == "mips" 150CFLAGS+= -msoft-float 151INLINE_LIMIT?= 8000 152.endif 153 154# 155# GCC 3.0 and above like to do certain optimizations based on the 156# assumption that the program is linked against libc. Stop this. 157# 158CFLAGS+= -ffreestanding 159 160# 161# GCC SSP support 162# 163.if ${MK_SSP} != "no" && ${MACHINE_CPUARCH} != "ia64" && \ 164 ${MACHINE_CPUARCH} != "arm" && ${MACHINE_CPUARCH} != "mips" 165CFLAGS+= -fstack-protector 166.endif 167 168# 169# Add -gdwarf-2 when compiling -g 170# 171.if ${COMPILER_TYPE} == "clang" && ${CFLAGS:M-g} != "" && ${CFLAGS:M-gdwarf} == "" 172CFLAGS+= -gdwarf-2 173.endif 174