cmd/nm: make -S listing a bit more accurate

Hide container symbols like text and etext so that
the individual pieces inside are shown instead.
For example, if text and main.init have the same
address, it was a toss-up which name was printed.

R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/13722046

diff --git a/src/cmd/nm/nm.c b/src/cmd/nm/nm.c
index b5e1ca0b6b7adbec73659cf12efdfc3de57c54e8..8209424269e6d301e9738f2e786b4ce64b2e85f9 100644 (file)
--- a/src/cmd/nm/nm.c
+++ b/src/cmd/nm/nm.c
@@ -299,6 +299,37 @@ psym(Sym *s, void* p)
        symptr[nsym++] = s;
 }
 
+const char *skipnames[] = {
+       "bss",
+       "data",
+       "ebss",
+       "edata",
+       "egcbss",
+       "egcdata",
+       "enoptrbss",
+       "enoptrdata",
+       "epclntab",
+       "erodata",
+       "esymtab",
+       "etext",
+       "etypelink",
+       "noptrbss",
+       "noptrdata",
+       "rodata",
+       "text",
+};
+
+int
+skipsize(char *name)
+{
+       int i;
+       
+       for(i=0; i<nelem(skipnames); i++)
+               if(strcmp(skipnames[i], name) == 0)
+                       return 1;
+       return 0;
+}
+
 void
 printsyms(Sym **symptr, long nsym)
 {
@@ -332,12 +363,12 @@ printsyms(Sym **symptr, long nsym)
                        Bprint(&bout, "%*llux ", wid, s->value);
                else
                        Bprint(&bout, "%*s ", wid, "");
-               if(Sflag) {
+               if(Sflag && !skipsize(cp)) {
                        vlong siz;
 
                        siz = 0;
                        for(j=i+1; j<nsym; j++) {
-                               if(symptr[j]->type != 'a' && symptr[j]->type != 'p') {
+                               if(!skipsize(symptr[j]->name) && symptr[j]->type != 'a' && symptr[j]->type != 'p') {
                                        siz = symptr[j]->value - s->value;
                                        break;
                                }