6l/8l: generate dwarf variable names with disambiguating suffix.

R=rsc
CC=golang-dev
https://golang.org/cl/2733042

diff --git a/src/cmd/ld/dwarf.c b/src/cmd/ld/dwarf.c
index 7891f64c9a1d545108037b9dd6cf8f7cd7241f3a..4094b7e79f3a35fa0cd4ee4aceda66617009d2f8 100644 (file)
--- a/src/cmd/ld/dwarf.c
+++ b/src/cmd/ld/dwarf.c
@@ -783,7 +783,7 @@ decodetype_structfieldcount(Sym *s)
 }
 
 // Type.StructType.fields[]-> name, typ and offset. sizeof(structField) =  5*PtrSize
-static uchar*
+static char*
 decodetype_structfieldname(Sym *s, int i)
 {
        Sym *p;
@@ -793,7 +793,7 @@ decodetype_structfieldname(Sym *s, int i)
        p = decode_reloc(p, 0);                 // string."foo"
        if (p == nil)                           // shouldn't happen.
                return nil;
-       return p->p;                            // the c-string
+       return (char*)p->p;                     // the c-string
 }
 
 static Sym*
@@ -1328,6 +1328,18 @@ newcfaoffsetattr(DWDie *die, int32 offs)
        memmove(die->attr->data, block, i);
 }
 
+static char*
+mkvarname(char* name, int da)
+{
+       char buf[1024];
+       char *n;
+
+       snprint(buf, sizeof buf, "%s#%d", name, da);
+       n = mal(strlen(buf) + 1);
+       memmove(n, buf, strlen(buf));
+       return n;
+}
+
 /*
  * Walk prog table, emit line program and build DIE tree.
  */
@@ -1365,9 +1377,11 @@ writelines(void)
        vlong unitstart;
        vlong pc, epc, lc, llc, lline;
        int currfile;
-       int i, lang;
+       int i, lang, da, dt;
        Linehist *lh;
        DWDie *dwinfo, *dwfunc, *dwvar;
+       DWDie *varhash[HASHSIZE];
+       char *n;
 
        unitstart = -1;
        epc = pc = 0;
@@ -1483,20 +1497,34 @@ writelines(void)
                        llc = lline;
                }
 
+               da = 0;
+               dwfunc->hash = varhash;  // enable indexing of children by name
+               memset(varhash, 0, sizeof varhash);
+
                for(a = s->autom; a; a = a->link) {
                        switch (a->type) {
                        case D_AUTO:
-                               dwvar = newdie(dwfunc, DW_ABRV_AUTO, a->asym->name);
+                               dt = DW_ABRV_AUTO;
                                break;
                        case D_PARAM:
-                               dwvar = newdie(dwfunc, DW_ABRV_PARAM, a->asym->name);
+                               dt = DW_ABRV_PARAM;
                                break;
                        default:
                                continue;
                        }
+                       if (strstr(a->asym->name, ".autotmp_"))
+                               continue;
+                       if (find(dwfunc, a->asym->name) != nil)
+                               n = mkvarname(a->asym->name, da);
+                       else
+                               n = a->asym->name;
+                       dwvar = newdie(dwfunc, dt, n);
                        newcfaoffsetattr(dwvar, a->aoffset);
                        newrefattr(dwvar, DW_AT_type, defgotype(a->gotype));
+                       da++;
                }
+
+               dwfunc->hash = nil;
        }
 
        flushunit(dwinfo, epc, unitstart);