1# $FreeBSD$ 2 3# 4# Warning flags for compiling the kernel and components of the kernel. 5# 6# Note that the newly added -Wcast-qual is responsible for generating 7# most of the remaining warnings. Warnings introduced with -Wall will 8# also pop up, but are easier to fix. 9# 10# XXX FIXME - revert when there is a gcc3 with -fformat-extensions 11.ifndef GCC3 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 -Wno-format -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.if ${MACHINE_ARCH} == "i386" 38CFLAGS+= -mpreferred-stack-boundary=2 39.endif 40 41# 42# On the alpha, make sure that we don't use floating-point registers and 43# allow the use of EV56 instructions (only needed for low-level i/o). 44# Also, reserve register t7 to point at per-cpu global variables. 45# 46.if ${MACHINE_ARCH} == "alpha" 47CFLAGS+= -mno-fp-regs -ffixed-8 -Wa,-mev56 48.endif 49 50# 51# For IA-64, we use r13 for the kernel globals pointer and we only use 52# a very small subset of float registers for integer divides. 53# 54.if ${MACHINE_ARCH} == "ia64" 55CFLAGS+= -ffixed-r13 -mfixed-range=f32-f127 56.endif 57 58# 59# GCC 3.0 and above like to do certain optimizations based on the 60# assumption that the program is linked against libc. Stop this. 61# 62.ifdef GCC3 63CFLAGS+= -ffreestanding 64.endif 65