1# $FreeBSD: src/share/mk/bsd.kern.mk,v 1.17.2.1 2001/08/01 16:56:56 obrien Exp $ 2# $DragonFly: src/sys/conf/bsd.kern.mk,v 1.7 2006/03/24 18:35:28 dillon Exp $ 3 4# 5# Warning flags for compiling the kernel and components of the kernel. 6# 7# Note that the newly added -Wcast-qual is responsible for generating 8# most of the remaining warnings. Warnings introduced with -Wall will 9# also pop up, but are easier to fix. 10# 11.if ${CCVER} == "gcc2" 12CWARNFLAGS?= -Wall -Wredundant-decls -Wnested-externs -Wstrict-prototypes \ 13 -Wmissing-prototypes -Wpointer-arith -Winline -Wcast-qual \ 14 -fformat-extensions -ansi 15.else 16CWARNFLAGS?= -Wall -Wredundant-decls -Wnested-externs -Wstrict-prototypes \ 17 -Wmissing-prototypes -Wpointer-arith -Winline -Wcast-qual \ 18 -ansi 19.endif 20# 21# The following flags are next up for working on: 22# -W 23# 24# When working on removing warnings from code, the `-Werror' flag should be 25# of material assistance. 26# 27 28# 29# On the i386, do not align the stack to 16-byte boundaries. Otherwise GCC 30# 2.95 adds code to the entry and exit point of every function to align the 31# stack to 16-byte boundaries -- thus wasting approximately 12 bytes of stack 32# per function call. While the 16-byte alignment may benefit micro benchmarks, 33# it is probably an overall loss as it makes the code bigger (less efficient 34# use of code cache tag lines) and uses more stack (less efficient use of data 35# cache tag lines) 36# 37# Prohibit the use of FP registers in the kernel. The user FP state is 38# only saved and restored under strictly managed conditions and mainline 39# kernel code cannot safely use the FP system. 40# 41.if ${MACHINE_ARCH} == "i386" 42CFLAGS+= -mpreferred-stack-boundary=2 43CFLAGS+= -fno-stack-protector 44CFLAGS+= -mno-mmx -mno-3dnow -mno-sse -mno-sse2 -mno-sse3 45.endif 46 47# 48# On the alpha, make sure that we don't use floating-point registers and 49# allow the use of EV56 instructions (only needed for low-level i/o). 50# 51.if ${MACHINE_ARCH} == "alpha" 52CFLAGS+= -mno-fp-regs -Wa,-mev56 53.endif 54 55# Require the proper use of 'extern' for variables. -fno-common will 56# cause duplicate declarations to generate a link error. 57# 58CFLAGS+= -fno-common 59 60# Prevent GCC 3.x from making certain libc based inline optimizations 61# 62CFLAGS+= -ffreestanding 63