cmd/ld: correct assignment of sizes to mach-o symbols

If you compute the size by subtraction from the address
of the next symbol, it helps to wait until the symbols have
been sorted by address.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/11143043

diff --git a/src/cmd/ld/ldmacho.c b/src/cmd/ld/ldmacho.c
index d384a5094b1351a286915f5244ca4c86d1561c18..98a4eeac3ca07b73ac6d04e4c6bbf575899330a5 100644 (file)
--- a/src/cmd/ld/ldmacho.c
+++ b/src/cmd/ld/ldmacho.c
@@ -432,7 +432,7 @@ ldmacho(Biobuf *f, char *pkg, int64 len, char *pn)
        int64 base;
        MachoSect *sect;
        MachoRel *rel;
-       Sym *s, *outer;
+       Sym *s, *s1, *outer;
        MachoCmd *c;
        MachoSymtab *symtab;
        MachoDysymtab *dsymtab;
@@ -635,10 +635,6 @@ ldmacho(Biobuf *f, char *pkg, int64 len, char *pn)
                outer->sub = s;
                s->outer = outer;
                s->value = sym->value - sect->addr;
-               if(i+1 < symtab->nsym)
-                       s->size = (sym+1)->value - sym->value;
-               else
-                       s->size = sect->addr + sect->size - sym->value;
                if(!(s->cgoexport & CgoExportDynamic))
                        s->dynimplib = nil;     // satisfy dynimport
                if(outer->type == STEXT) {
@@ -668,17 +664,26 @@ ldmacho(Biobuf *f, char *pkg, int64 len, char *pn)
                sect = &c->seg.sect[i];
                if((s = sect->sym) == S)
                        continue;
-               if(s->sub)
+               if(s->sub) {
                        s->sub = listsort(s->sub, valuecmp, offsetof(Sym, sub));
+                       
+                       // assign sizes, now that we know symbols in sorted order.
+                       for(s1 = s->sub; s1 != S; s1 = s1->sub) {
+                               if(s1->sub)
+                                       s1->size = s1->sub->value - s1->value;
+                               else
+                                       s1->size = s->value + s->size - s1->value;
+                       }
+               }
                if(s->type == STEXT) {
                        if(etextp)
                                etextp->next = s;
                        else
                                textp = s;
                        etextp = s;
-                       for(s = s->sub; s != S; s = s->sub) {
-                               etextp->next = s;
-                               etextp = s;
+                       for(s1 = s->sub; s1 != S; s1 = s1->sub) {
+                               etextp->next = s1;
+                               etextp = s1;
                        }
                }
        }