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 ${NO_WFORMAT} 33.endif 34 35# External compilers may not support our format extensions. Allow them 36# to be disabled. WARNING: format checking is disabled in this case. 37.if ${MK_FORMAT_EXTENSIONS} == "no" 38NO_WFORMAT= -Wno-format 39.else 40FORMAT_EXTENSIONS= -fformat-extensions 41.endif 42 43# 44# On i386, do not align the stack to 16-byte boundaries. Otherwise GCC 2.95 45# and above adds code to the entry and exit point of every function to align the 46# stack to 16-byte boundaries -- thus wasting approximately 12 bytes of stack 47# per function call. While the 16-byte alignment may benefit micro benchmarks, 48# it is probably an overall loss as it makes the code bigger (less efficient 49# use of code cache tag lines) and uses more stack (less efficient use of data 50# cache tag lines). Explicitly prohibit the use of FPU, SSE and other SIMD 51# operations inside the kernel itself. These operations are exclusively 52# reserved for user applications. 53# 54# gcc: 55# Setting -mno-mmx implies -mno-3dnow 56# Setting -mno-sse implies -mno-sse2, -mno-sse3 and -mno-ssse3 57# 58# clang: 59# Setting -mno-mmx implies -mno-3dnow and -mno-3dnowa 60# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3, -mno-sse41 and -mno-sse42 61# 62.if ${MACHINE_CPUARCH} == "i386" 63.if ${COMPILER_TYPE} != "clang" 64CFLAGS+= -mno-align-long-strings -mpreferred-stack-boundary=2 65.else 66CFLAGS+= -mno-aes -mno-avx 67.endif 68CFLAGS+= -mno-mmx -mno-sse -msoft-float 69INLINE_LIMIT?= 8000 70.endif 71 72.if ${MACHINE_CPUARCH} == "arm" 73INLINE_LIMIT?= 8000 74.endif 75 76# 77# For IA-64, we use r13 for the kernel globals pointer and we only use 78# a very small subset of float registers for integer divides. 79# 80.if ${MACHINE_CPUARCH} == "ia64" 81CFLAGS+= -ffixed-r13 -mfixed-range=f32-f127 -fpic #-mno-sdata 82INLINE_LIMIT?= 15000 83.endif 84 85# 86# For sparc64 we want the medany code model so modules may be located 87# anywhere in the 64-bit address space. We also tell GCC to use floating 88# point emulation. This avoids using floating point registers for integer 89# operations which it has a tendency to do. 90# 91.if ${MACHINE_CPUARCH} == "sparc64" 92CFLAGS+= -mcmodel=medany -msoft-float 93INLINE_LIMIT?= 15000 94.endif 95 96# 97# For AMD64, we explicitly prohibit the use of FPU, SSE and other SIMD 98# operations inside the kernel itself. These operations are exclusively 99# reserved for user applications. 100# 101# gcc: 102# Setting -mno-mmx implies -mno-3dnow 103# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3 and -mfpmath=387 104# 105# clang: 106# Setting -mno-mmx implies -mno-3dnow and -mno-3dnowa 107# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3, -mno-sse41 and -mno-sse42 108# (-mfpmath= is not supported) 109# 110.if ${MACHINE_CPUARCH} == "amd64" 111.if ${COMPILER_TYPE} == "clang" 112CFLAGS+= -mno-aes -mno-avx 113.endif 114CFLAGS+= -mcmodel=kernel -mno-red-zone -mno-mmx -mno-sse -msoft-float \ 115 -fno-asynchronous-unwind-tables 116INLINE_LIMIT?= 8000 117.endif 118 119# 120# For PowerPC we tell gcc to use floating point emulation. This avoids using 121# floating point registers for integer operations which it has a tendency to do. 122# Also explicitly disable Altivec instructions inside the kernel. 123# 124.if ${MACHINE_CPUARCH} == "powerpc" 125CFLAGS+= -msoft-float -mno-altivec 126INLINE_LIMIT?= 15000 127.endif 128 129# 130# Use dot symbols on powerpc64 to make ddb happy 131# 132.if ${MACHINE_ARCH} == "powerpc64" 133CFLAGS+= -mcall-aixdesc 134.endif 135 136# 137# For MIPS we also tell gcc to use floating point emulation 138# 139.if ${MACHINE_CPUARCH} == "mips" 140CFLAGS+= -msoft-float 141INLINE_LIMIT?= 8000 142.endif 143 144# 145# GCC 3.0 and above like to do certain optimizations based on the 146# assumption that the program is linked against libc. Stop this. 147# 148CFLAGS+= -ffreestanding 149 150# 151# GCC SSP support 152# 153.if ${MK_SSP} != "no" && ${MACHINE_CPUARCH} != "ia64" && \ 154 ${MACHINE_CPUARCH} != "arm" && ${MACHINE_CPUARCH} != "mips" 155CFLAGS+= -fstack-protector 156.endif 157