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freebsd/sys/conf/kern.mk
Alexander Leidinger 21edb039c6 WITH_CTF can now be specified in src.conf (not recommended, there
are some problems with static executables), make.conf (would also
affect ports which do not use GNU make and do not override the
compile targets) or in the kernel config (via "makeoptions
WITH_CTF=yes").

Additional (related) changes:
 - propagate WITH_CTF to module builds
 - do not add -g to the linker flags, it's a noop there anyway
   (at least according to the man page of ld)
 - do not add -g to CFLAGS unconditionally
   we need to have a look if it is really needed (IMO not) or if there
   is a way to add it only when WITH_CTF is used

Note: ctfconvert / ctfmerge lines will not appear in the build output,
to protect the innocent (those which do not build with WITH_CTF would
see the shell-test and may think WITH_CTF is used).

Reviewed by:	imp, jhb, scottl (earlier version)
Discussed on:	arch@
2010-04-02 06:55:31 +00:00

119 lines
3.4 KiB
Makefile

# $FreeBSD$
#
# Warning flags for compiling the kernel and components of the kernel.
#
# Note that the newly added -Wcast-qual is responsible for generating
# most of the remaining warnings. Warnings introduced with -Wall will
# also pop up, but are easier to fix.
.if ${CC} == "icc"
#CWARNFLAGS= -w2 # use this if you are terribly bored
CWARNFLAGS=
.else
CWARNFLAGS?= -Wall -Wredundant-decls -Wnested-externs -Wstrict-prototypes \
-Wmissing-prototypes -Wpointer-arith -Winline -Wcast-qual \
-Wundef -Wno-pointer-sign -fformat-extensions
.endif
#
# The following flags are next up for working on:
# -W
#
# On the i386, do not align the stack to 16-byte boundaries. Otherwise GCC
# 2.95 adds code to the entry and exit point of every function to align the
# stack to 16-byte boundaries -- thus wasting approximately 12 bytes of stack
# per function call. While the 16-byte alignment may benefit micro benchmarks,
# it is probably an overall loss as it makes the code bigger (less efficient
# use of code cache tag lines) and uses more stack (less efficient use of data
# cache tag lines). Explicitly prohibit the use of SSE and other SIMD
# operations inside the kernel itself. These operations are exclusively
# reserved for user applications.
#
.if ${MACHINE_ARCH} == "i386" && ${CC} != "icc"
CFLAGS+= -mno-align-long-strings -mpreferred-stack-boundary=2 \
-mno-mmx -mno-3dnow -mno-sse -mno-sse2 -mno-sse3
INLINE_LIMIT?= 8000
.endif
.if ${MACHINE_ARCH} == "arm"
INLINE_LIMIT?= 8000
.endif
#
# For IA-64, we use r13 for the kernel globals pointer and we only use
# a very small subset of float registers for integer divides.
#
.if ${MACHINE_ARCH} == "ia64"
CFLAGS+= -ffixed-r13 -mfixed-range=f32-f127 -fpic #-mno-sdata
INLINE_LIMIT?= 15000
.endif
#
# For sparc64 we want medlow code model, and we tell gcc to use floating
# point emulation. This avoids using floating point registers for integer
# operations which it has a tendency to do.
#
.if ${MACHINE_ARCH} == "sparc64"
CFLAGS+= -mcmodel=medany -msoft-float
INLINE_LIMIT?= 15000
.endif
#
# For AMD64, we explicitly prohibit the use of FPU, SSE and other SIMD
# operations inside the kernel itself. These operations are exclusively
# reserved for user applications.
#
.if ${MACHINE_ARCH} == "amd64"
CFLAGS+= -mcmodel=kernel -mno-red-zone \
-mfpmath=387 -mno-sse -mno-sse2 -mno-sse3 -mno-mmx -mno-3dnow \
-msoft-float -fno-asynchronous-unwind-tables
INLINE_LIMIT?= 8000
.endif
#
# For PowerPC we tell gcc to use floating point emulation. This avoids using
# floating point registers for integer operations which it has a tendency to do.
# Also explicitly disable Altivec instructions inside the kernel.
#
.if ${MACHINE_ARCH} == "powerpc"
CFLAGS+= -msoft-float -mno-altivec
INLINE_LIMIT?= 15000
.endif
#
# For MIPS we also tell gcc to use floating point emulation
#
.if ${MACHINE_ARCH} == "mips"
CFLAGS+= -msoft-float
INLINE_LIMIT?= 8000
.endif
#
# GCC 3.0 and above like to do certain optimizations based on the
# assumption that the program is linked against libc. Stop this.
#
.if ${CC} == "icc"
CFLAGS+= -nolib_inline
.else
CFLAGS+= -ffreestanding
.endif
.if ${CC} == "icc"
CFLAGS+= -restrict
.endif
#
# GCC SSP support.
#
.if ${MK_SSP} != "no" && ${CC} != "icc" && ${MACHINE_ARCH} != "ia64" && \
${MACHINE_ARCH} != "arm" && ${MACHINE_ARCH} != "mips"
CFLAGS+= -fstack-protector
.endif
#
# Enable CTF conversation on request.
#
.if defined(WITH_CTF)
.undef NO_CTF
.endif