code review 812043: gc: add panic and recover (still unimplemented in runtime)

src/pkg/runtime/print.c

 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 #include "runtime.h"
 #include "type.h"
 
 //static Lock debuglock;
 
 static void vprintf(int8*, byte*);
@@ skipping 331 matching lines @@
 {
         write(fd, " ", 1);
 }
 
 void
 ·printnl(void)
 {
         write(fd, "\n", 1);
 }
 
+// print an empty interface, for use by panic.
+// this could be arbitrarily complex in general,
+// so we pick off only a few important cases:
+// int, string, and values with a String() string method.
 void
 printany(Eface e)
 {
         int32 i;
         FuncType *ft;
         Method *m;
         String s;
         Type *rt;
         UncommonType *x;
 
@@ skipping 13 matching lines @@
                            (ft = (FuncType*)m->mtyp)->in.len == 0 &&
                            ft->out.len == 1 &&
                            // Found single output.  Is it string?
                            // Only base types have name != nil but pkgPath == nil.
                            (rt = *(Type**)ft->out.array)->kind == KindString &&
                            rt->x != nil &&
                            rt->x->name != nil && rt->x->pkgPath == nil) {
                                 // Found the method!
                                 // Have to use assembly to call it
                                 // and save the return value.
-                                callstring(m->ifn, e.data, &s);
+                                callString(m->ifn, e.data, &s);
                                 ·printstring(s);
                                 return;
                         }
                 }
         }
 
-        switch(e.type->kind) {
+        switch(e.type->kind & ~KindNoPointers) {
         case KindInt:
                 mcpy((byte*)&i, (byte*)&e.data, sizeof(i));
                 ·printint(i);
                 break;
 
         case KindString:
                 ·printstring(*(String*)e.data);
                 break;
 
         default:
                 // Could print the other numeric types,
                 // but that's overkill: good panics have
                 // a string method anyway.
                 ·printstring(*e.type->string);
                 write(fd, "(???)", 5);
                 break;
         }
 
 }