kern.mk revision 268813
1# $FreeBSD: stable/10/sys/conf/kern.mk 268813 2014-07-17 22:31:46Z imp $ 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-unused-function \ 33 ${NO_WFORMAT} 34.endif 35 36# External compilers may not support our format extensions. Allow them 37# to be disabled. WARNING: format checking is disabled in this case. 38.if ${MK_FORMAT_EXTENSIONS} == "no" 39NO_WFORMAT= -Wno-format 40.else 41FORMAT_EXTENSIONS= -fformat-extensions 42.endif 43 44# 45# On i386, do not align the stack to 16-byte boundaries. Otherwise GCC 2.95 46# and above adds code to the entry and exit point of every function to align the 47# stack to 16-byte boundaries -- thus wasting approximately 12 bytes of stack 48# per function call. While the 16-byte alignment may benefit micro benchmarks, 49# it is probably an overall loss as it makes the code bigger (less efficient 50# use of code cache tag lines) and uses more stack (less efficient use of data 51# cache tag lines). Explicitly prohibit the use of FPU, SSE and other SIMD 52# operations inside the kernel itself. These operations are exclusively 53# reserved for user applications. 54# 55# gcc: 56# Setting -mno-mmx implies -mno-3dnow 57# Setting -mno-sse implies -mno-sse2, -mno-sse3 and -mno-ssse3 58# 59# clang: 60# Setting -mno-mmx implies -mno-3dnow and -mno-3dnowa 61# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3, -mno-sse41 and -mno-sse42 62# 63.if ${MACHINE_CPUARCH} == "i386" 64.if ${COMPILER_TYPE} != "clang" 65CFLAGS+= -mno-align-long-strings -mpreferred-stack-boundary=2 66.else 67CFLAGS+= -mno-aes -mno-avx 68.endif 69CFLAGS+= -mno-mmx -mno-sse -msoft-float 70INLINE_LIMIT?= 8000 71.endif 72 73.if ${MACHINE_CPUARCH} == "arm" 74INLINE_LIMIT?= 8000 75.endif 76 77# 78# For IA-64, we use r13 for the kernel globals pointer and we only use 79# a very small subset of float registers for integer divides. 80# 81.if ${MACHINE_CPUARCH} == "ia64" 82CFLAGS+= -ffixed-r13 -mfixed-range=f32-f127 -fpic #-mno-sdata 83INLINE_LIMIT?= 15000 84.endif 85 86# 87# For sparc64 we want the medany code model so modules may be located 88# anywhere in the 64-bit address space. We also tell GCC to use floating 89# point emulation. This avoids using floating point registers for integer 90# operations which it has a tendency to do. 91# 92.if ${MACHINE_CPUARCH} == "sparc64" 93.if ${COMPILER_TYPE} == "clang" 94CFLAGS+= -mcmodel=large -fno-dwarf2-cfi-asm 95.else 96CFLAGS+= -mcmodel=medany -msoft-float 97.endif 98INLINE_LIMIT?= 15000 99.endif 100 101# 102# For AMD64, we explicitly prohibit the use of FPU, SSE and other SIMD 103# operations inside the kernel itself. These operations are exclusively 104# reserved for user applications. 105# 106# gcc: 107# Setting -mno-mmx implies -mno-3dnow 108# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3 and -mfpmath=387 109# 110# clang: 111# Setting -mno-mmx implies -mno-3dnow and -mno-3dnowa 112# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3, -mno-sse41 and -mno-sse42 113# (-mfpmath= is not supported) 114# 115.if ${MACHINE_CPUARCH} == "amd64" 116.if ${COMPILER_TYPE} == "clang" 117CFLAGS+= -mno-aes -mno-avx 118.endif 119CFLAGS+= -mcmodel=kernel -mno-red-zone -mno-mmx -mno-sse -msoft-float \ 120 -fno-asynchronous-unwind-tables 121INLINE_LIMIT?= 8000 122.endif 123 124# 125# For PowerPC we tell gcc to use floating point emulation. This avoids using 126# floating point registers for integer operations which it has a tendency to do. 127# Also explicitly disable Altivec instructions inside the kernel. 128# 129.if ${MACHINE_CPUARCH} == "powerpc" 130CFLAGS+= -msoft-float -mno-altivec 131INLINE_LIMIT?= 15000 132.endif 133 134# 135# Use dot symbols on powerpc64 to make ddb happy 136# 137.if ${MACHINE_ARCH} == "powerpc64" 138CFLAGS+= -mcall-aixdesc 139.endif 140 141# 142# For MIPS we also tell gcc to use floating point emulation 143# 144.if ${MACHINE_CPUARCH} == "mips" 145CFLAGS+= -msoft-float 146INLINE_LIMIT?= 8000 147.endif 148 149# 150# GCC 3.0 and above like to do certain optimizations based on the 151# assumption that the program is linked against libc. Stop this. 152# 153CFLAGS+= -ffreestanding 154 155# 156# GCC SSP support 157# 158.if ${MK_SSP} != "no" && ${MACHINE_CPUARCH} != "ia64" && \ 159 ${MACHINE_CPUARCH} != "arm" && ${MACHINE_CPUARCH} != "mips" 160CFLAGS+= -fstack-protector 161.endif 162 163# 164# Add -gdwarf-2 when compiling -g 165# 166.if ${COMPILER_TYPE} == "clang" && ${CFLAGS:M-g} != "" && ${CFLAGS:M-gdwarf} == "" 167CFLAGS+= -gdwarf-2 168.endif 169