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

diff --git a/src/cmd/ar/ar.c b/src/cmd/ar/ar.c
index 35a3eeccdb09fa5fcde326015068d2e2367d0d64..880f32986cb8525986a92f91d1fdc73524f22166 100644 (file)
--- a/src/cmd/ar/ar.c
+++ b/src/cmd/ar/ar.c
@@ -1216,7 +1216,7 @@ longt(Armember *bp)
        pmode(strtoul(bp->hdr.mode, 0, 8));
        Bprint(&bout, "%3ld/%1ld", strtol(bp->hdr.uid, 0, 0), strtol(bp->hdr.gid, 0, 0));
        Bprint(&bout, "%7ld", bp->size);
-       cp = ctime(bp->date);
+       cp = ctime(&bp->date);
        Bprint(&bout, " %-12.12s %-4.4s ", cp+4, cp+24);
 }
 
@@ -1455,7 +1455,6 @@ typedef struct Import Import;
 struct Import
 {
        Import *hash;   // next in hash table
-       char *export;   // marked as export or package?
        char *prefix;   // "type", "var", "func", "const"
        char *name;
        char *def;
@@ -1485,58 +1484,65 @@ ilookup(char *name)
        return x;
 }
 
+/*
+ * 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;
+}
+
 int parsemethod(char**, char*, char**);
-int parsepkgdata(char**, char*, char**, char**, char**, char**);
+int parsepkgdata(char**, char*, char**, char**, char**);
 
 void
 loadpkgdata(char *data, int len)
 {
-       char *export;
-       char *p, *ep, *prefix, *name, *def;
+       char *p, *ep, *prefix, *name, *def, *ndef;
        Import *x;
 
        p = data;
        ep = data + len;
-       while(parsepkgdata(&p, ep, &export, &prefix, &name, &def) > 0) {
+       while(parsepkgdata(&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, "ar: conflicting definitions for %s\n", name);
+                       fprint(2, "%s:\t%s %s ...\n", x->file, x->prefix, name);
+                       fprint(2, "%s:\t%s %s ...\n", file, prefix, name);
+                       errors++;
+               } 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, "ar: conflicting definitions for %s\n", name);
-                               fprint(2, "%s:\t%s %s ...\n", x->file, x->prefix, name);
-                               fprint(2, "%s:\t%s %s ...\n", file, prefix, name);
-                               errors++;
-                       }
-                       else if(strcmp(x->def, def) != 0) {
-                               fprint(2, "ar: conflicting definitions for %s\n", 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);
-                               errors++;
-                       }
-
-                       // okay if some .6 say export/package and others don't.
-                       // all it takes is one.  not okay if some say export
-                       // and others say package.
-                       if(export) {
-                               if(x->export == nil)
-                                       x->export = export;
-                               else if(strcmp(x->export, export) != 0) {
-                                       fprint(2, "ar: conflicting scopes for %s\n", name);
-                                       fprint(2, "%s:\t%s\n", x->file, x->export);
-                                       fprint(2, "%s:\t%s\n", file, export);
-                                       errors++;
-                               }
-                       }
+                       fprint(2, "ar: conflicting definitions for %s\n", 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);
+                       errors++;
                }
        }
 }
 
 int
-parsepkgdata(char **pp, char *ep, char **exportp, char **prefixp, char **namep, char **defp)
+parsepkgdata(char **pp, char *ep, char **prefixp, char **namep, char **defp)
 {
        char *p, *prefix, *name, *def, *edef, *meth;
        int n;
@@ -1548,16 +1554,6 @@ parsepkgdata(char **pp, char *ep, char **exportp, char **prefixp, char **namep,
        if(p == ep)
                return 0;
 
-       // [export|package ]
-       *exportp = 0;
-       if(p + 7 <= ep && strncmp(p, "export ", 7) == 0) {
-               *exportp = "export";
-               p += 7;
-       } else if(p + 8 <= ep && strncmp(p, "package ", 8) == 0) {
-               *exportp = "package";
-               p += 8;
-       }
-
        // prefix: (var|type|func|const)
        prefix = p;
 
@@ -1710,8 +1706,6 @@ getpkgdef(char **datap, int *lenp)
                        len += strlen(x->prefix) + 1
                                + strlen(x->name) + 1
                                + strlen(x->def) + 1;
-                       if(x->export)
-                               len += strlen(x->export) + 1;
                }
        }
        if(j != nimport) {
@@ -1735,11 +1729,7 @@ getpkgdef(char **datap, int *lenp)
        p = strappend(p, "\n");
        for(i=0; i<nimport; i++) {
                x = all[i];
-               // [export|package] prefix name def\n
-               if(x->export) {
-                       p = strappend(p, x->export);
-                       p = strappend(p, " ");
-               }
+               // prefix name def\n
                p = strappend(p, x->prefix);
                p = strappend(p, " ");
                p = strappend(p, x->name);

diff --git a/src/cmd/gc/dcl.c b/src/cmd/gc/dcl.c
index 38bc022d2889d026be81e8d3475c72ad6e7a5e36..0fe204d463a320d6f0e08c3a109af7020f69944c 100644 (file)
--- a/src/cmd/gc/dcl.c
+++ b/src/cmd/gc/dcl.c
@@ -93,12 +93,13 @@ updatetype(Type *n, Type *t)
 {
        Sym *s;
        int local;
-       int maplineno, lno;
+       int maplineno, lno, etype;
 
        s = n->sym;
        if(s == S || s->def == N || s->def->op != OTYPE || s->def->type != n)
                fatal("updatetype %T = %T", n, t);
 
+       etype = n->etype;
        switch(n->etype) {
        case TFORW:
                break;
@@ -144,7 +145,7 @@ updatetype(Type *n, Type *t)
        default:
                checkwidth(n);
        }
-       
+
        // double-check use of type as map key
        if(maplineno) {
                lno = lineno;
@@ -316,13 +317,7 @@ addmethod(Node *n, Type *t, int local)
        if(f == T)
                goto bad;
 
-       if(local && !f->local) {
-               yyerror("cannot define methods on non-local type %T", f);
-               return;
-       }
-
        pa = f;
-
        if(pkgimportname != S && !exportname(sf->name))
                sf = pkglookup(sf->name, pkgimportname->name);
 
@@ -331,13 +326,11 @@ addmethod(Node *n, Type *t, int local)
 
        d = T;  // last found
        for(f=pa->method; f!=T; f=f->down) {
+               d = f;
                if(f->etype != TFIELD)
                        fatal("addmethod: not TFIELD: %N", f);
-
-               if(strcmp(sf->name, f->sym->name) != 0) {
-                       d = f;
+               if(strcmp(sf->name, f->sym->name) != 0)
                        continue;
-               }
                if(!eqtype(t, f->type)) {
                        yyerror("method redeclared: %T.%S", pa, sf);
                        print("\t%T\n\t%T\n", f->type, t);
@@ -345,6 +338,14 @@ addmethod(Node *n, Type *t, int local)
                return;
        }
 
+       if(local && !pa->local) {
+               // defining method on non-local type.
+               // method must have been forward declared
+               // elsewhere, i.e. where the type was.
+               yyerror("cannot define new methods on non-local type %T", pa);
+               return;
+       }
+
        if(d == T)
                stotype(n, 0, &pa->method);
        else

diff --git a/src/cmd/gc/export.c b/src/cmd/gc/export.c
index 8653cb551189017e1ccb64adbbbeb4b355229721..fbe9cb202d809f85c8e6315c625784546436a8cf 100644 (file)
--- a/src/cmd/gc/export.c
+++ b/src/cmd/gc/export.c
@@ -168,9 +168,13 @@ dumpexporttype(Sym *s)
        Bprint(bout, "\t");
        switch (t->etype) {
        case TFORW:
+               yyerror("export of incomplete type %T", t);
+               return;
        case TFORWSTRUCT:
+               Bprint(bout, "type %#T struct\n", t);
+               return;
        case TFORWINTER:
-               yyerror("export of incomplete type %T", t);
+               Bprint(bout, "type %#T interface\n", t);
                return;
        }
        Bprint(bout, "type %#T %l#T\n",  t, t);
@@ -276,11 +280,15 @@ importsym(Sym *s, int op)
                else
                        yyerror("redeclaration of %lS during import", s, s->def->op, op);
        }
-       if(exportname(s->name))
-               s->export = 1;
-       else
-               s->export = 2;  // package scope
-       s->imported = 1;
+
+       // mark the symbol so it is not reexported
+       if(s->def == N) {
+               if(exportname(s->name))
+                       s->export = 1;
+               else
+                       s->export = 2;  // package scope
+               s->imported = 1;
+       }
        return s;
 }
 
@@ -359,9 +367,12 @@ importtype(Sym *s, Type *t)
        if(n != N && n->op == OTYPE) {
                if(cvttype(t, n->type))
                        return;
-               if(n->type->etype != TFORW) {
-                       warn("redeclare import type %S from %lT to %lT",
-                               s, n->type, t);
+               if(t->etype == TFORWSTRUCT && n->type->etype == TSTRUCT)
+                       return;
+               if(t->etype == TFORWINTER && n->type->etype == TINTER)
+                       return;
+               if(n->type->etype != TFORW && n->type->etype != TFORWSTRUCT && n->type->etype != TFORWINTER) {
+                       yyerror("redeclare import type %S from %lT to %lT", s, n->type, t);
                        n = s->def = typenod(typ(0));
                }
        }
@@ -376,7 +387,16 @@ importtype(Sym *s, Type *t)
        *n->type = *t;
        n->type->sym = s;
        n->type->nod = n;
-       checkwidth(n->type);
+       switch(n->type->etype) {
+       case TFORWINTER:
+       case TFORWSTRUCT:
+               // allow re-export in case it gets defined
+               s->export = 0;
+               s->imported = 0;
+               break;
+       default:
+               checkwidth(n->type);
+       }
 
        if(debug['E'])
                print("import type %S %lT\n", s, t);

diff --git a/src/cmd/gc/go.y b/src/cmd/gc/go.y
index ec5032e9ee6349a3d0ab590c8ce826ffca00ddd3..8e844e342d2613b2e30dc478ee8d2f781030a911 100644 (file)
--- a/src/cmd/gc/go.y
+++ b/src/cmd/gc/go.y
@@ -1700,6 +1700,14 @@ hidden_import:
        {
                importtype($2, $3);
        }
+|      LTYPE hidden_pkg_importsym LSTRUCT
+       {
+               importtype($2, typ(TFORWSTRUCT));
+       }
+|      LTYPE hidden_pkg_importsym LINTERFACE
+       {
+               importtype($2, typ(TFORWINTER));
+       }
 |      LFUNC hidden_pkg_importsym '(' ohidden_funarg_list ')' ohidden_funres
        {
                importvar($2, functype(N, $4, $6), PFUNC);

diff --git a/src/cmd/ld/go.c b/src/cmd/ld/go.c
index 6990d7329257a08e311e91766f3df84881b8f579..54a8e48d1d8f5760be871fde96c2903de158235b 100644 (file)
--- 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;