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