allow forward declaration of struct in another file

(in the same package).

allow forward method declaration to be satisfied
by implementation in another file (in the same package).
all methods must be declared in the same file
as the receiver type.

R=ken
OCL=30864
CL=30869

1 files changed, 39 insertions, 35 deletions

diff --git a/src/cmd/ld/go.c b/src/cmd/ld/go.c
index 6990d73292..54a8e48d1d 100644
--- a/src/cmd/ld/go.c
+++ b/src/cmd/ld/go.c
@@ -22,7 +22,6 @@ typedef struct Import Import;
 struct Import
 {
 	Import *hash;	// next in hash table
-	int export;	// marked as export?
 	char *prefix;	// "type", "var", "func", "const"
 	char *name;
 	char *def;
@@ -89,7 +88,7 @@ gotypefor(char *name)
 
 static void loadpkgdata(char*, char*, int);
 static int parsemethod(char**, char*, char**);
-static int parsepkgdata(char*, char**, char*, int*, char**, char**, char**);
+static int parsepkgdata(char*, char**, char*, char**, char**, char**);
 
 void
 ldpkg(Biobuf *f, int64 len, char *filename)
@@ -154,47 +153,63 @@ ldpkg(Biobuf *f, int64 len, char *filename)
 	loadpkgdata(filename, p0, p1 - p0);
 }
 
+/*
+ * a and b don't match.
+ * is one a forward declaration and the other a valid completion?
+ * if so, return the one to keep.
+ */
+char*
+forwardfix(char *a, char *b)
+{
+	char *t;
+
+	if(strlen(a) > strlen(b)) {
+		t = a;
+		a = b;
+		b = t;
+	}
+	if(strcmp(a, "struct") == 0 && strncmp(b, "struct ", 7) == 0)
+		return b;
+	if(strcmp(a, "interface") == 0 && strncmp(b, "interface ", 10) == 0)
+		return b;
+	return nil;
+}
+
 static void
 loadpkgdata(char *file, char *data, int len)
 {
-	int export;
-	char *p, *ep, *prefix, *name, *def;
+	char *p, *ep, *prefix, *name, *def, *ndef;
 	Import *x;
 
 	file = strdup(file);
 	p = data;
 	ep = data + len;
-	while(parsepkgdata(file, &p, ep, &export, &prefix, &name, &def) > 0) {
+	while(parsepkgdata(file, &p, ep, &prefix, &name, &def) > 0) {
 		x = ilookup(name);
 		if(x->prefix == nil) {
 			x->prefix = prefix;
 			x->def = def;
 			x->file = file;
-			x->export = export;
+		} else if(strcmp(x->prefix, prefix) != 0) {
+			fprint(2, "%s: conflicting definitions for %s\n", argv0, name);
+			fprint(2, "%s:\t%s %s ...\n", x->file, x->prefix, name);
+			fprint(2, "%s:\t%s %s ...\n", file, prefix, name);
+			nerrors++;
+		} else if(strcmp(x->def, def) == 0) {
+			// fine
+		} else if((ndef = forwardfix(x->def, def)) != nil) {
+			x->def = ndef;
 		} else {
-			if(strcmp(x->prefix, prefix) != 0) {
-				fprint(2, "%s: conflicting definitions for %s\n", argv0, name);
-				fprint(2, "%s:\t%s %s ...\n", x->file, x->prefix, name);
-				fprint(2, "%s:\t%s %s ...\n", file, prefix, name);
-				nerrors++;
-			}
-			else if(strcmp(x->def, def) != 0) {
-				fprint(2, "%s: conflicting definitions for %s\n", argv0, name);
-				fprint(2, "%s:\t%s %s %s\n", x->file, x->prefix, name, x->def);
-				fprint(2, "%s:\t%s %s %s\n", file, prefix, name, def);
-				nerrors++;
-			}
-
-			// okay if some .6 say export and others don't.
-			// all it takes is one.
-			if(export)
-				x->export = 1;
+			fprint(2, "%d: conflicting definitions for %s\n", argv0, name);
+			fprint(2, "%s:\t%s %s %s\n", x->file, x->prefix, name, x->def);
+			fprint(2, "%s:\t%s %s %s\n", file, prefix, name, def);
+			nerrors++;
 		}
 	}
 }
 
 static int
-parsepkgdata(char *file, char **pp, char *ep, int *exportp, char **prefixp, char **namep, char **defp)
+parsepkgdata(char *file, char **pp, char *ep, char **prefixp, char **namep, char **defp)
 {
 	char *p, *prefix, *name, *def, *edef, *meth;
 	int n;
@@ -206,17 +221,6 @@ parsepkgdata(char *file, char **pp, char *ep, int *exportp, char **prefixp, char
 	if(p == ep || strncmp(p, "$$\n", 3) == 0)
 		return 0;
 
-	// [export|package ]
-	*exportp = 0;
-	if(p + 7 <= ep && strncmp(p, "export ", 7) == 0) {
-		*exportp = 1;
-		p += 7;
-	}
-	else if(p + 8 <= ep && strncmp(p, "package ", 8) == 0) {
-		*exportp = 2;
-		p += 8;
-	}
-
 	// prefix: (var|type|func|const)
 	prefix = p;