Fix build on OSX, by deduping syms correctly.

    With macho, we need to set a different attribute for asm
    than we need on ELF targets.

4 files changed, 30 insertions, 7 deletions

diff --git a/6/asm.h b/6/asm.h
index ed75659..5b8f061 100644
--- a/6/asm.h
+++ b/6/asm.h
@@ -53,7 +53,8 @@ typedef enum {
 } Rclass;
 
 typedef enum {
-	Gnugas,
+	Gnugaself,
+	Gnugasmacho,
 	Plan9,
 } Asmsyntax;
 
diff --git a/6/gen.c b/6/gen.c
index a942b9e..1dd387a 100644
--- a/6/gen.c
+++ b/6/gen.c
@@ -152,8 +152,12 @@ char *tydescid(char *buf, size_t bufsz, Type *ty)
 void gen(Node *file, char *out)
 {
 	switch (asmsyntax) {
-	case Plan9:	genp9(file, out);	break;
-	case Gnugas:	gengas(file, out);	break;
-	default:	die("unknown target");  break;
+	case Plan9:
+		genp9(file, out);	break;
+	case Gnugaself:
+	case Gnugasmacho:
+		gengas(file, out);	break;
+	default:
+		die("unknown target");  break;
 	}
 }
diff --git a/6/gengas.c b/6/gengas.c
index 6008d82..d439141 100644
--- a/6/gengas.c
+++ b/6/gengas.c
@@ -297,6 +297,19 @@ static void encodemin(FILE *fd, uint64_t val)
 	}
 }
 
+static void emitonce(FILE *fd, Blob *b)
+{
+	if (asmsyntax == Gnugaself) {
+		fprintf(fd, ".section .text.%s%s,\"aG\",%s%s,comdat\n",
+			Symprefix, b->lbl, Symprefix, b->lbl);
+	} else if (asmsyntax == Gnugasmacho) {
+		if (b->isglobl)
+			fprintf(fd, ".weak_def_can_be_hidden %s%s\n", Symprefix, b->lbl);
+	} else {
+		die("Unknown asm flavor");
+	}
+}
+
 static void writeblob(FILE *fd, Blob *b)
 {
 	size_t i;
@@ -305,7 +318,7 @@ static void writeblob(FILE *fd, Blob *b)
 		return;
 	if (b->lbl) {
 		if (b->iscomdat)
-			fprintf(fd, ".section .text.%s%s,\"aG\",%s%s,comdat\n", Symprefix, b->lbl, Symprefix, b->lbl);
+			emitonce(fd, b);
 		if (b->isglobl)
 			fprintf(fd, ".globl %s%s\n", Symprefix, b->lbl);
 		fprintf(fd, "%s%s:\n", Symprefix, b->lbl);
diff --git a/6/main.c b/6/main.c
index d8ee23b..3315b40 100644
--- a/6/main.c
+++ b/6/main.c
@@ -165,7 +165,7 @@ int main(int argc, char **argv)
 
 	outfile = NULL;
 
-	optinit(&ctx, "cd:?hSo:I:9G", argv, argc);
+	optinit(&ctx, "cd:?hSo:I:9G:", argv, argc);
 	asmsyntax = Defaultasm;
 	while (!optdone(&ctx)) {
 		switch (optnext(&ctx)) {
@@ -191,7 +191,12 @@ int main(int argc, char **argv)
 			asmsyntax = Plan9;
 			break;
 		case 'G':
-			asmsyntax = Gnugas;
+			if (!strcmp(ctx.optarg, "e"))
+				asmsyntax = Gnugaself;
+			else if (!strcmp(ctx.optarg, "m"))
+				asmsyntax = Gnugasmacho;
+			else
+				die("unknown gnu syntax flavor");
 			break;
 		case 'I':
 			lappend(&incpaths, &nincpaths, ctx.optarg);