20060303

1 files changed, 129 insertions, 0 deletions

diff --git a/utils/libmach/vobj.c b/utils/libmach/vobj.c
new file mode 100644
index 00000000..f676d219
--- /dev/null
+++ b/utils/libmach/vobj.c
@@ -0,0 +1,129 @@
+/*
+ * vobj.c - identify and parse a mips object file
+ */
+#include <lib9.h>
+#include <bio.h>
+#include "vc/v.out.h"
+#include "obj.h"
+
+typedef struct Addr	Addr;
+struct Addr
+{
+	char	type;
+	char	sym;
+	char	name;
+};
+static Addr addr(Biobuf*);
+static char type2char(int);
+static void skip(Biobuf*, int);
+
+int
+_isv(char *s)
+{
+	return  s[0] == ANAME				/* ANAME */
+		&& s[1] == D_FILE			/* type */
+		&& s[2] == 1				/* sym */
+		&& s[3] == '<';				/* name of file */
+}
+
+int
+_readv(Biobuf *bp, Prog *p)
+{
+	int as, n;
+	Addr a;
+
+	as = Bgetc(bp);			/* as */
+	if(as < 0)
+		return 0;
+	p->kind = aNone;
+	if(as == ANAME || as == ASIGNAME){
+		if(as == ASIGNAME)
+			skip(bp, 4);	/* signature */
+		p->kind = aName;
+		p->type = type2char(Bgetc(bp));		/* type */
+		p->sym = Bgetc(bp);			/* sym */
+		n = 0;
+		for(;;) {
+			as = Bgetc(bp);
+			if(as < 0)
+				return 0;
+			n++;
+			if(as == 0)
+				break;
+		}
+		p->id = malloc(n);
+		if(p->id == 0)
+			return 0;
+		Bseek(bp, -n, 1);
+		if(Bread(bp, p->id, n) != n)
+			return 0;
+		return 1;
+	}
+	if(as == ATEXT)
+		p->kind = aText;
+	else if(as == AGLOBL)
+		p->kind = aData;
+	skip(bp, 5);		/* reg(1), lineno(4) */
+	a = addr(bp);
+	addr(bp);
+	if(a.type != D_OREG || a.name != D_STATIC && a.name != D_EXTERN)
+		p->kind = aNone;
+	p->sym = a.sym;
+	return 1;
+}
+
+static Addr
+addr(Biobuf *bp)
+{
+	Addr a;
+	long off;
+
+	a.type = Bgetc(bp);	/* a.type */
+	skip(bp,1);		/* reg */
+	a.sym = Bgetc(bp);	/* sym index */
+	a.name = Bgetc(bp);	/* sym type */
+	switch(a.type){
+	default:
+	case D_NONE: case D_REG: case D_FREG: case D_MREG:
+	case D_FCREG: case D_LO: case D_HI:
+		break;
+	case D_OREG:
+	case D_CONST:
+	case D_BRANCH:
+		off = Bgetc(bp);
+		off |= Bgetc(bp) << 8;
+		off |= Bgetc(bp) << 16;
+		off |= Bgetc(bp) << 24;
+		if(off < 0)
+			off = -off;
+		if(a.sym && (a.name==D_PARAM || a.name==D_AUTO))
+			_offset(a.sym, off);
+		break;
+	case D_SCONST:
+		skip(bp, NSNAME);
+		break;
+	case D_FCONST:
+		skip(bp, 8);
+		break;
+	}
+	return a;
+}
+
+static char
+type2char(int t)
+{
+	switch(t){
+	case D_EXTERN:		return 'U';
+	case D_STATIC:		return 'b';
+	case D_AUTO:		return 'a';
+	case D_PARAM:		return 'p';
+	default:		return UNKNOWN;
+	}
+}
+
+static void
+skip(Biobuf *bp, int n)
+{
+	while (n-- > 0)
+		Bgetc(bp);
+}