Hacks to #define PROC_KSTACK_OFFSET and TRAPFRAME_SIZE at build time..

..this turned out to be more complicated than I expected.

Hacks to #define PROC_KSTACK_OFFSET and TRAPFRAME_SIZE at build time..
883c29c6 · Silas Boyd-Wickizer · 829545bc · 883c29c6 · 883c29c6 · 883c29c6
--- a/Makefile
+++ b/Makefile
@@ -29,14 +29,14 @@ STRIP = $(TOOLPREFIX)strip
 # XXX(sbw)
 # -nostdinc -nostdinc++

-COMFLAGS  = -static -fno-builtin -fno-strict-aliasing -O2 -Wall \
-	    -g -MD -m64 -Werror -fms-extensions -mno-sse -mcx16 \
-	    -mno-red-zone -Iinclude -I$(QEMUSRC) -fno-omit-frame-pointer \
-	    -DHW_$(HW) -include param.h -include include/compiler.h -DXV6
+COMFLAGS  = -static -g -MD -m64 -O2 -Wall -Werror -DHW_$(HW) -DXV6 \
+	    -fno-builtin -fno-strict-aliasing -fno-omit-frame-pointer -fms-extensions \
+	    -mno-sse -mcx16 -mno-red-zone -Iinclude -I$(QEMUSRC) \
+	    -include param.h -include include/compiler.h
 COMFLAGS += $(shell $(CC) -fno-stack-protector -E -x c /dev/null >/dev/null 2>&1 && echo -fno-stack-protector)
 CFLAGS   := $(COMFLAGS) -std=c99 $(CFLAGS)
 CXXFLAGS := $(COMFLAGS) -std=c++0x -Wno-sign-compare -fno-exceptions -fno-rtti -fcheck-new $(CXXFLAGS)
-ASFLAGS   = -Iinclude -m64 -gdwarf-2 -MD -DHW_$(HW) -include param.h
+ASFLAGS   = -Iinclude -I$(O)/include -m64 -gdwarf-2 -MD -DHW_$(HW) -include param.h
 LDFLAGS   = -m elf_x86_64

 all:

--- a/include/mmu.h
+++ b/include/mmu.h
@@ -129,6 +129,3 @@ struct taskstate
 	(u16) ((rip)&0xffff), (cs), 0, bits, (u16) (((rip)>>16)&0xffff), \
 	(u32) ((u64)(rip)>>32), 0, \
 }
-
-#define PROC_KSTACK_OFFSET 48
-#define TRAPFRAME_SIZE     192
--- a/kernel/Makefrag
+++ b/kernel/Makefrag
@@ -79,5 +79,12 @@ $(O)/kernel/%: kernel/%.S
 	$(Q)$(LD) $(LDFLAGS) -N -e start -Ttext $(TTEXT) -o $@.out $@.o
 	$(Q)$(OBJCOPY) -S -O binary $@.out $@

+$(O)/include/asmdefines.h: kernel/asmdefines.c
+	@echo "  GEN    $@"
+	$(Q)mkdir -p $(@D)
+	$(Q)$(CXX) -S $(CXXFLAGS) -o $(O)/kernel/asmdefines.S kernel/asmdefines.c
+	$(Q)sed -n 's/remove\$$//p' $(O)/kernel/asmdefines.S > $@
+$(O)/kernel/trapasm.o: $(O)/include/asmdefines.h
+
 .PRECIOUS: $(O)/kernel/%.o
 -include $(O)/kernel/*.d
--- a/kernel/asmdefines.c
+++ b/kernel/asmdefines.c
+#include "types.h"
+#include "kernel.hh"
+#include "spinlock.h"
+#include "amd64.h"
+#include "condvar.h"
+#include "proc.hh"
+
+#define DEFINE(sym, val) \
+  asm volatile ("\n#define " #sym " remove%0 " : : "i" (val))
+
+void
+asmdefines(void)
+{
+  DEFINE(PROC_KSTACK_OFFSET, __offsetof(struct proc, kstack));
+  DEFINE(TRAPFRAME_SIZE, sizeof(trapframe));
+}
--- a/kernel/main.cc
+++ b/kernel/main.cc
@@ -105,13 +105,6 @@ cmain(u64 mbmagic, u64 mbaddr)
  kpml4.e[0] = 0;  // don't need 1 GB identity mapping anymore
  lcr3(rcr3());

-  if (PROC_KSTACK_OFFSET != __offsetof(struct proc, kstack))
-    panic("PROC_KSTACK_OFFSET mismatch: %d %ld\n",
-          PROC_KSTACK_OFFSET, __offsetof(struct proc, kstack));
-  if (TRAPFRAME_SIZE != sizeof(trapframe))
-    panic("TRAPFRAME_SIZE mismatch: %d %ld\n",
-          TRAPFRAME_SIZE, sizeof(trapframe));
-
  idleloop();

  panic("Unreachable");

--- a/kernel/trapasm.S
+++ b/kernel/trapasm.S
 #include "mmu.h"
+#include "asmdefines.h"

 #define NOEC pushq $0
 #define EC