Move lib/va_list.c into include/tccdefs.h

This makes code with va_arg work with -nostdlib on x86_64.

Author: hermantb

include/tccdefs.h

@@ -191,7 +191,10 @@
 #if defined __x86_64__
 #if !defined _WIN32
     /* GCC compatible definition of va_list. */
-    /* This should be in sync with the declaration in our lib/libtcc1.c */
+
+    enum __va_arg_type {
+        __va_gen_reg, __va_float_reg, __va_stack
+    };
     typedef struct {
         unsigned gp_offset, fp_offset;
         union {
@@ -201,7 +204,43 @@
         char *reg_save_area;
     } __builtin_va_list[1];
 
-    void *__va_arg(__builtin_va_list ap, int arg_type, int size, int align);
+    static inline void *__va_arg(__builtin_va_list ap, int arg_type,
+                                 int size, int align)
+    {
+        size = (size + 7) & ~7;
+        align = (align + 7) & ~7;
+        switch ((enum __va_arg_type)arg_type) {
+        case __va_gen_reg:
+            if (ap->gp_offset + size <= 48) {
+                ap->gp_offset += size;
+                return ap->reg_save_area + ap->gp_offset - size;
+            }
+            goto use_overflow_area;
+        case __va_float_reg:
+            if (ap->fp_offset < 128 + 48) {
+                ap->fp_offset += 16;
+                if (size == 8)
+                    return ap->reg_save_area + ap->fp_offset - 16;
+                if (ap->fp_offset < 128 + 48) {
+                    double *p = (double *)(ap->reg_save_area + ap->fp_offset);
+                    p[-1] = p[0];
+                    ap->fp_offset += 16;
+                    return ap->reg_save_area + ap->fp_offset - 32;
+                }
+            }
+            goto use_overflow_area;
+        case __va_stack:
+        use_overflow_area:
+            ap->overflow_arg_area += size;
+            ap->overflow_arg_area =
+	      (char*)((long long)(ap->overflow_arg_area + align - 1) & -align);
+            return ap->overflow_arg_area - size;
+        default: /* should never happen */
+            char *a = (char *)0; *a = 0; // abort
+            return 0;
+        }
+    }
+
     #define __builtin_va_start(ap, last) \
        (*(ap) = *(__builtin_va_list)((char*)__builtin_frame_address(0) - 24))
     #define __builtin_va_arg(ap, t)   \

lib/Makefile

@@ -59,8 +59,8 @@ $(Cbc)COMMON_O += bcheck.o
 EXTRA_O = runmain.o bt-exe.o bt-dll.o bt-log.o bcheck.o
 
 OBJ-i386 = $(I386_O) $(LIN_O)
-OBJ-x86_64 = $(X86_64_O) va_list.o $(LIN_O)
-OBJ-x86_64-osx = $(X86_64_O) va_list.o $(OSX_O)
+OBJ-x86_64 = $(X86_64_O) $(LIN_O)
+OBJ-x86_64-osx = $(X86_64_O) $(OSX_O)
 OBJ-i386-win32 = $(I386_O) chkstk.o $(WIN_O)
 OBJ-x86_64-win32 = $(X86_64_O) chkstk.o $(WIN_O)
 OBJ-arm64 = $(ARM64_O) $(LIN_O)