# $FreeBSD$ # # 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. # # XXX FIXME - revert to -fformat-extensions when we've re-added it CWARNFLAGS?= -Wall -Wredundant-decls -Wnested-externs -Wstrict-prototypes \ -Wmissing-prototypes -Wpointer-arith -Winline -Wcast-qual \ -Wno-format -ansi # # The following flags are next up for working on: # -W # # When working on removing warnings from code, the `-Werror' flag should be # of material assistance. # # # 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) # .if ${MACHINE_ARCH} == "i386" CFLAGS+= -mpreferred-stack-boundary=2 .endif # # On the alpha, make sure that we don't use floating-point registers and # allow the use of EV56 instructions (only needed for low-level i/o). # Also, reserve register t7 to point at per-cpu global variables. # .if ${MACHINE_ARCH} == "alpha" CFLAGS+= -mno-fp-regs -ffixed-8 -Wa,-mev56 .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 .endif # # GCC 3.0 and above like to do certain optimizations based on the # assumption that the program is linked against libc. Stop this. # CFLAGS+= -ffreestanding