Merge pull request #3322 from yglukhov/fix-uint64-str-vm

Uint64 to string in pure nim. array[char] to string fixed in vm.

compiler/vm.nim

@@ -320,8 +320,19 @@ proc opConv*(dest: var TFullReg, src: TFullReg, desttyp, srctyp: PType): bool =
       dest.node.strVal = if src.intVal == 0: "false" else: "true"
     of tyFloat..tyFloat128:
       dest.node.strVal = $src.floatVal
-    of tyString, tyCString:
+    of tyString:
       dest.node.strVal = src.node.strVal
+    of tyCString:
+      if src.node.kind == nkBracket:
+        # Array of chars
+        var strVal = ""
+        for son in src.node.sons:
+          let c = char(son.intVal)
+          if c == '\0': break
+          strVal.add(c)
+        dest.node.strVal = strVal
+      else:
+        dest.node.strVal = src.node.strVal
     of tyChar:
       dest.node.strVal = $chr(src.intVal)
     else:

lib/system/repr.nim

@@ -21,9 +21,22 @@ proc reprPointer(x: pointer): string {.compilerproc.} =
   return $buf
 
 proc `$`(x: uint64): string =
-  var buf: array [0..59, char]
-  discard c_sprintf(buf, "%llu", x)
-  return $buf
+  if x == 0:
+    result = "0"
+  else:
+    var buf: array [60, char]
+    var i = 0
+    var n = x
+    while n != 0:
+      let nn = n div 10'u64
+      buf[i] = char(n - 10'u64 * nn + ord('0'))
+      inc i
+      n = nn
+
+    let half = i div 2
+    # Reverse
+    for t in 0 .. < half: swap(buf[t], buf[i-t-1])
+    result = $buf
 
 proc reprStrAux(result: var string, s: string) =
   if cast[pointer](s) == nil:
@@ -294,4 +307,3 @@ when not defined(useNimRtl):
       reprAux(result, addr(p), typ, cl)
     add result, "\n"
     deinitReprClosure(cl)
-