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 -fformat-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 ${CC:T:Mclang} == "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 23# Several other warnings which might be useful in some cases, but not severe 24# enough to error out the whole kernel build. Display them anyway, so there is 25# some incentive to fix them eventually. 26CWARNEXTRA+= -Wno-error-tautological-compare 27.endif 28 29# 30# On i386, do not align the stack to 16-byte boundaries. Otherwise GCC 2.95 31# and above adds code to the entry and exit point of every function to align the 32# stack to 16-byte boundaries -- thus wasting approximately 12 bytes of stack 33# per function call. While the 16-byte alignment may benefit micro benchmarks, 34# it is probably an overall loss as it makes the code bigger (less efficient 35# use of code cache tag lines) and uses more stack (less efficient use of data 36# cache tag lines). Explicitly prohibit the use of FPU, SSE and other SIMD 37# operations inside the kernel itself. These operations are exclusively 38# reserved for user applications. 39# 40# gcc: 41# Setting -mno-mmx implies -mno-3dnow 42# Setting -mno-sse implies -mno-sse2, -mno-sse3 and -mno-ssse3 43# 44# clang: 45# Setting -mno-mmx implies -mno-3dnow, -mno-3dnowa, -mno-sse, -mno-sse2, 46# -mno-sse3, -mno-ssse3, -mno-sse41 and -mno-sse42 47# 48.if ${MACHINE_CPUARCH} == "i386" 49.if ${CC:T:Mclang} != "clang" 50CFLAGS+= -mno-align-long-strings -mpreferred-stack-boundary=2 -mno-sse 51.else 52CFLAGS+= -mno-aes -mno-avx 53.endif 54CFLAGS+= -mno-mmx -msoft-float 55INLINE_LIMIT?= 8000 56.endif 57 58.if ${MACHINE_CPUARCH} == "arm" 59INLINE_LIMIT?= 8000 60.endif 61 62# 63# For IA-64, we use r13 for the kernel globals pointer and we only use 64# a very small subset of float registers for integer divides. 65# 66.if ${MACHINE_CPUARCH} == "ia64" 67CFLAGS+= -ffixed-r13 -mfixed-range=f32-f127 -fpic #-mno-sdata 68INLINE_LIMIT?= 15000 69.endif 70 71# 72# For sparc64 we want medlow code model, and we tell gcc to use floating 73# point emulation. This avoids using floating point registers for integer 74# operations which it has a tendency to do. 75# 76.if ${MACHINE_CPUARCH} == "sparc64" 77CFLAGS+= -mcmodel=medany -msoft-float 78INLINE_LIMIT?= 15000 79.endif 80 81# 82# For AMD64, we explicitly prohibit the use of FPU, SSE and other SIMD 83# operations inside the kernel itself. These operations are exclusively 84# reserved for user applications. 85# 86# gcc: 87# Setting -mno-mmx implies -mno-3dnow 88# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3 and -mfpmath=387 89# 90# clang: 91# Setting -mno-mmx implies -mno-3dnow, -mno-3dnowa, -mno-sse, -mno-sse2, 92# -mno-sse3, -mno-ssse3, -mno-sse41 and -mno-sse42 93# (-mfpmath= is not supported) 94# 95.if ${MACHINE_CPUARCH} == "amd64" 96.if ${CC:T:Mclang} != "clang" 97CFLAGS+= -mno-sse 98.else 99CFLAGS+= -mno-aes -mno-avx 100.endif 101CFLAGS+= -mcmodel=kernel -mno-red-zone -mno-mmx -msoft-float \ 102 -fno-asynchronous-unwind-tables 103INLINE_LIMIT?= 8000 104.endif 105 106# 107# For PowerPC we tell gcc to use floating point emulation. This avoids using 108# floating point registers for integer operations which it has a tendency to do. 109# Also explicitly disable Altivec instructions inside the kernel. 110# 111.if ${MACHINE_CPUARCH} == "powerpc" 112CFLAGS+= -msoft-float -mno-altivec 113INLINE_LIMIT?= 15000 114.endif 115 116# 117# Use dot symbols on powerpc64 to make ddb happy 118# 119.if ${MACHINE_ARCH} == "powerpc64" 120CFLAGS+= -mcall-aixdesc 121.endif 122 123# 124# For MIPS we also tell gcc to use floating point emulation 125# 126.if ${MACHINE_CPUARCH} == "mips" 127CFLAGS+= -msoft-float 128INLINE_LIMIT?= 8000 129.endif 130 131# 132# GCC 3.0 and above like to do certain optimizations based on the 133# assumption that the program is linked against libc. Stop this. 134# 135CFLAGS+= -ffreestanding 136 137# 138# GCC SSP support 139# 140.if ${MK_SSP} != "no" && ${MACHINE_CPUARCH} != "ia64" && \ 141 ${MACHINE_CPUARCH} != "arm" && ${MACHINE_CPUARCH} != "mips" 142CFLAGS+= -fstack-protector 143.endif 144