5l,6l,8l,kl,ql,vl: allow duplicate GLOBAL symbols (from Ori Bernstein)

The plan 9 assemblers support the DUPOK flag on text symbols. They parse and
ignore it on GLOBL symbols. This patch makes it work in the linkers.

The reason I ran into this is because my programming language (Myrddin) uses
data symbols to generate type information, and it's useful to avoid
duplicating all of the type info in every file that gets generated.

4 files changed, 6 insertions, 1 deletions

diff --git a/sys/src/cmd/8l/asm.c b/sys/src/cmd/8l/asm.c
index a1bb36ba6..129b3cd71 100644
--- a/sys/src/cmd/8l/asm.c
+++ b/sys/src/cmd/8l/asm.c
@@ -421,7 +421,7 @@ datblk(long s, long n)
 		}
 		if(l >= n)
 			continue;
-		if(p->as != AINIT && p->as != ADYNT) {
+		if(p->as != AINIT && p->as != ADYNT && !p->from.sym->dupok) {
 			for(j=l+(c-i)-1; j>=l; j--)
 				if(buf.dbuf[j]) {
 					print("%P\n", p);
diff --git a/sys/src/cmd/8l/l.h b/sys/src/cmd/8l/l.h
index fbb0a191b..2ca800342 100644
--- a/sys/src/cmd/8l/l.h
+++ b/sys/src/cmd/8l/l.h
@@ -80,6 +80,7 @@ struct	Sym
 	short	become;
 	short	frame;
 	uchar	subtype;
+	char	dupok;
 	ushort	file;
 	long	value;
 	long	sig;
diff --git a/sys/src/cmd/8l/list.c b/sys/src/cmd/8l/list.c
index 212b8ad3c..f6b1eda2e 100644
--- a/sys/src/cmd/8l/list.c
+++ b/sys/src/cmd/8l/list.c
@@ -23,6 +23,7 @@ Pconv(Fmt *fp)
 	bigP = p;
 	switch(p->as) {
 	case ATEXT:
+	case AGLOBL:
 		if(p->from.scale) {
 			snprint(str, sizeof(str), "(%ld)	%A	%D,%d,%D",
 				p->line, p->as, &p->from, p->from.scale, &p->to);
diff --git a/sys/src/cmd/8l/obj.c b/sys/src/cmd/8l/obj.c
index 2aeee6811..ba4571468 100644
--- a/sys/src/cmd/8l/obj.c
+++ b/sys/src/cmd/8l/obj.c
@@ -885,6 +885,8 @@ loop:
 
 	case AGLOBL:
 		s = p->from.sym;
+		if(p->from.scale & DUPOK)
+			s->dupok = 1;
 		if(s->type == 0 || s->type == SXREF) {
 			s->type = SBSS;
 			s->value = 0;
@@ -1134,6 +1136,7 @@ lookup(char *symb, int v)
 	s->version = v;
 	s->value = 0;
 	s->sig = 0;
+	s->dupok = 0;
 	hash[h] = s;
 	nsymbol++;
 	return s;