1 files changed, 15 insertions, 13 deletions
diff --git a/compiler/ccgexprs.nim b/compiler/ccgexprs.nim
index dde3d6e70..96f9265f1 100644
--- a/compiler/ccgexprs.nim
+++ b/compiler/ccgexprs.nim
@@ -63,6 +63,10 @@ proc genLiteral(p: BProc, n: PNode, ty: PType): Rope =
     of tyNil:
       result = genNilStringLiteral(p.module, n.info)
     of tyString:
+      # with the new semantics for 'nil' strings, we can map "" to nil and
+      # save tons of allocations:
+      #if n.strVal.len == 0: result = genNilStringLiteral(p.module, n.info)
+      #else:
       result = genStringLiteral(p.module, n)
     else:
       if n.strVal.isNil: result = rope("NIM_NIL")
@@ -905,14 +909,14 @@ proc genSeqElem(p: BProc, n, x, y: PNode, d: var TLoc) =
   if ty.kind in {tyRef, tyPtr}:
     ty = skipTypes(ty.lastSon, abstractVarRange) # emit range check:
   if optBoundsCheck in p.options:
-    if ty.kind == tyString:
+    if ty.kind == tyString and (not defined(nimNoZeroTerminator) or optLaxStrings in p.options):
       linefmt(p, cpsStmts,
-           "if (!$2 || (NU)($1) > (NU)($2->$3)) #raiseIndexError();$n",
-           rdLoc(b), rdLoc(a), lenField(p))
+              "if (!$2 || (NU)($1) > (NU)($2->$3)) #raiseIndexError();$n",
+              rdLoc(b), rdLoc(a), lenField(p))
     else:
       linefmt(p, cpsStmts,
-           "if (!$2 || (NU)($1) >= (NU)($2->$3)) #raiseIndexError();$n",
-           rdLoc(b), rdLoc(a), lenField(p))
+              "if (!$2 || (NU)($1) >= (NU)($2->$3)) #raiseIndexError();$n",
+              rdLoc(b), rdLoc(a), lenField(p))
   if d.k == locNone: d.storage = OnHeap
   if skipTypes(a.t, abstractVar).kind in {tyRef, tyPtr}:
     a.r = rfmt(nil, "(*$1)", a.r)
@@ -980,10 +984,10 @@ proc genEcho(p: BProc, n: PNode) =
     var a: TLoc
     for it in n.sons:
       if it.skipConv.kind == nkNilLit:
-        add(args, ", \"nil\"")
+        add(args, ", \"\"")
       else:
         initLocExpr(p, it, a)
-        addf(args, ", $1? ($1)->data:\"nil\"", [rdLoc(a)])
+        addf(args, ", $1? ($1)->data:\"\"", [rdLoc(a)])
     p.module.includeHeader("<base/log.h>")
     linefmt(p, cpsStmts, """Genode::log(""$1);$n""", args)
   else:
@@ -1755,16 +1759,14 @@ proc genStrEquals(p: BProc, e: PNode, d: var TLoc) =
   var x: TLoc
   var a = e.sons[1]
   var b = e.sons[2]
-  if (a.kind == nkNilLit) or (b.kind == nkNilLit):
-    binaryExpr(p, e, d, "($1 == $2)")
-  elif (a.kind in {nkStrLit..nkTripleStrLit}) and (a.strVal == ""):
+  if a.kind in {nkStrLit..nkTripleStrLit} and a.strVal == "":
     initLocExpr(p, e.sons[2], x)
     putIntoDest(p, d, e,
-      rfmt(nil, "(($1) && ($1)->$2 == 0)", rdLoc(x), lenField(p)))
-  elif (b.kind in {nkStrLit..nkTripleStrLit}) and (b.strVal == ""):
+      rfmt(nil, "(!($1) || ($1)->$2 == 0)", rdLoc(x), lenField(p)))
+  elif b.kind in {nkStrLit..nkTripleStrLit} and b.strVal == "":
     initLocExpr(p, e.sons[1], x)
     putIntoDest(p, d, e,
-      rfmt(nil, "(($1) && ($1)->$2 == 0)", rdLoc(x), lenField(p)))
+      rfmt(nil, "(!($1) || ($1)->$2 == 0)", rdLoc(x), lenField(p)))
   else:
     binaryExpr(p, e, d, "#eqStrings($1, $2)")