refs #9880 show index and bound in lots of index out of bounds errors

compiler/ccgexprs.nim

@@ -867,15 +867,15 @@ proc genArrayElem(p: BProc, n, x, y: PNode, d: var TLoc) =
       # semantic pass has already checked for const index expressions
       if firstOrd(p.config, ty) == 0:
         if (firstOrd(p.config, b.t) < firstOrd(p.config, ty)) or (lastOrd(p.config, b.t) > lastOrd(p.config, ty)):
-          linefmt(p, cpsStmts, "if ((NU)($1) > (NU)($2)) #raiseIndexError();$n",
+          linefmt(p, cpsStmts, "if ((NU)($1) > (NU)($2)) #raiseIndexError2($1, $2);$n",
                   rdCharLoc(b), intLiteral(lastOrd(p.config, ty)))
       else:
-        linefmt(p, cpsStmts, "if ($1 < $2 || $1 > $3) #raiseIndexError();$n",
+        linefmt(p, cpsStmts, "if ($1 < $2 || $1 > $3) #raiseIndexError3($1, $2, $3);$n",
                 rdCharLoc(b), first, intLiteral(lastOrd(p.config, ty)))
     else:
       let idx = getOrdValue(y)
       if idx < firstOrd(p.config, ty) or idx > lastOrd(p.config, ty):
-        localError(p.config, x.info, "index out of bounds")
+        localError(p.config, x.info, formatErrorIndexBound(idx, firstOrd(p.config, ty), lastOrd(p.config, ty)))
   d.inheritLocation(a)
   putIntoDest(p, d, n,
               ropecg(p.module, "$1[($2)- $3]", rdLoc(a), rdCharLoc(b), first), a.storage)
@@ -915,7 +915,7 @@ proc genOpenArrayElem(p: BProc, n, x, y: PNode, d: var TLoc) =
   initLocExpr(p, x, a)
   initLocExpr(p, y, b) # emit range check:
   if optBoundsCheck in p.options:
-    linefmt(p, cpsStmts, "if ((NU)($1) >= (NU)($2Len_0)) #raiseIndexError();$n",
+    linefmt(p, cpsStmts, "if ((NU)($1) >= (NU)($2Len_0)) #raiseIndexError2($1,$2Len_0-1);$n",
             rdLoc(b), rdLoc(a)) # BUGFIX: ``>=`` and not ``>``!
   inheritLocation(d, a)
   putIntoDest(p, d, n,
@@ -931,11 +931,11 @@ proc genSeqElem(p: BProc, n, x, y: PNode, d: var TLoc) =
   if optBoundsCheck in p.options:
     if ty.kind == tyString and (not defined(nimNoZeroTerminator) or optLaxStrings in p.options):
       linefmt(p, cpsStmts,
-              "if ((NU)($1) > (NU)$2) #raiseIndexError();$n",
+              "if ((NU)($1) > (NU)$2) #raiseIndexError2($1,$2);$n",
               rdLoc(b), lenExpr(p, a))
     else:
       linefmt(p, cpsStmts,
-              "if ((NU)($1) >= (NU)$2) #raiseIndexError();$n",
+              "if ((NU)($1) >= (NU)$2) #raiseIndexError2($1,$2-1);$n",
               rdLoc(b), lenExpr(p, a))
   if d.k == locNone: d.storage = OnHeap
   if skipTypes(a.t, abstractVar).kind in {tyRef, tyPtr}:

compiler/cgen.nim

@@ -16,6 +16,8 @@ import
   condsyms, rodutils, renderer, idgen, cgendata, ccgmerge, semfold, aliases,
   lowerings, tables, sets, ndi, lineinfos, pathutils, transf
 
+import system/helpers2
+
 when not defined(leanCompiler):
   import semparallel
 

compiler/semfold.nim

@@ -15,6 +15,8 @@ import
   nversion, platform, math, msgs, os, condsyms, idents, renderer, types,
   commands, magicsys, modulegraphs, strtabs, lineinfos
 
+import system/helpers2
+
 proc newIntNodeT*(intVal: BiggestInt, n: PNode; g: ModuleGraph): PNode =
   case skipTypes(n.typ, abstractVarRange).kind
   of tyInt:
@@ -489,11 +491,11 @@ proc foldArrayAccess(m: PSym, n: PNode; g: ModuleGraph): PNode =
       result = x.sons[int(idx)]
       if result.kind == nkExprColonExpr: result = result.sons[1]
     else:
-      localError(g.config, n.info, "index out of bounds: " & $n)
+      localError(g.config, n.info, formatErrorIndexBound(idx, sonsLen(x)+1) & $n)
   of nkBracket:
     idx = idx - firstOrd(g.config, x.typ)
     if idx >= 0 and idx < x.len: result = x.sons[int(idx)]
-    else: localError(g.config, n.info, "index out of bounds: " & $n)
+    else: localError(g.config, n.info, formatErrorIndexBound(idx, x.len+1) & $n)
   of nkStrLit..nkTripleStrLit:
     result = newNodeIT(nkCharLit, x.info, n.typ)
     if idx >= 0 and idx < len(x.strVal):
@@ -501,7 +503,7 @@ proc foldArrayAccess(m: PSym, n: PNode; g: ModuleGraph): PNode =
     elif idx == len(x.strVal) and optLaxStrings in g.config.options:
       discard
     else:
-      localError(g.config, n.info, "index out of bounds: " & $n)
+      localError(g.config, n.info, formatErrorIndexBound(idx, len(x.strVal)-1) & $n)
   else: discard
 
 proc foldFieldAccess(m: PSym, n: PNode; g: ModuleGraph): PNode =

lib/pure/collections/sharedstrings.nim

@@ -12,6 +12,8 @@
 type
   UncheckedCharArray = UncheckedArray[char]
 
+import system/helpers2
+
 type
   Buffer = ptr object
     refcount: int
@@ -49,11 +51,11 @@ proc len*(s: SharedString): int = s.len
 
 proc `[]`*(s: SharedString; i: Natural): char =
   if i < s.len: result = s.buffer.data[i+s.first]
-  else: raise newException(IndexError, "index out of bounds")
+  else: raise newException(IndexError, formatErrorIndexBound(i, s.len-1))
 
 proc `[]=`*(s: var SharedString; i: Natural; value: char) =
   if i < s.len: s.buffer.data[i+s.first] = value
-  else: raise newException(IndexError, "index out of bounds")
+  else: raise newException(IndexError, formatErrorIndexBound(i, s.len-1))
 
 proc `[]`*(s: SharedString; ab: HSlice[int, int]): SharedString =
   #incRef(src.buffer)

lib/pure/subexes.nim

@@ -17,7 +17,7 @@
 
 from strutils import parseInt, cmpIgnoreStyle, Digits
 include "system/inclrtl"
-
+import system/helpers2
 
 proc findNormalized(x: string, inArray: openarray[string]): int =
   var i = 0
@@ -85,7 +85,7 @@ proc getFormatArg(p: var FormatParser, a: openArray[string]): int =
     result = parseInt(a[result])-1
   else:
     raiseInvalidFormat("'#', '$', number or identifier expected")
-  if result >=% a.len: raiseInvalidFormat("index out of bounds: " & $result)
+  if result >=% a.len: raiseInvalidFormat(formatErrorIndexBound(result, a.len))
   p.i = i
 
 proc scanDollar(p: var FormatParser, a: openarray[string], s: var string) {.

lib/system/chcks.nim

@@ -8,6 +8,7 @@
 #
 
 # Implementation of some runtime checks.
+import system/helpers2
 
 proc raiseRangeError(val: BiggestInt) {.compilerproc, noinline.} =
   when hostOS == "standalone":
@@ -15,6 +16,12 @@ proc raiseRangeError(val: BiggestInt) {.compilerproc, noinline.} =
   else:
     sysFatal(RangeError, "value out of range: ", $val)
 
+proc raiseIndexError3(i, a, b: int) {.compilerproc, noinline.} =
+  sysFatal(IndexError, formatErrorIndexBound(i, a, b))
+
+proc raiseIndexError2(i, n: int) {.compilerproc, noinline.} =
+  sysFatal(IndexError, formatErrorIndexBound(i, n))
+
 proc raiseIndexError() {.compilerproc, noinline.} =
   sysFatal(IndexError, "index out of bounds")
 
@@ -25,7 +32,7 @@ proc chckIndx(i, a, b: int): int =
   if i >= a and i <= b:
     return i
   else:
-    raiseIndexError()
+    raiseIndexError3(i, a, b)
 
 proc chckRange(i, a, b: int): int =
   if i >= a and i <= b:

lib/system/helpers2.nim

@@ -0,0 +1,5 @@
+template formatErrorIndexBound*[T](i, a, b: T): string =
+  "index out of bounds: (a:" & $a & ") <= (i:" & $i & ") <= (b:" & $b & ") "
+
+template formatErrorIndexBound*[T](i, n: T): string =
+  "index out of bounds: (i:" & $i & ") <= (n:" & $n & ") "

tests/misc/tinvalidarrayaccess.nim

@@ -1,14 +1,21 @@
 discard """
-  errormsg: "index out of bounds"
+  errormsg: "index out of bounds: (a:0) <= (i:2) <= (b:1) "
-  line: 11
+  line: 18
 """
 
+block:
+  try:
+    let a = @[1,2]
+    echo a[3]
+  except Exception as e:
+    doAssert e.msg == "index out of bounds: (i:3) <= (n:1) "
 
-type TTestArr = array[0..1, int16]
+block:
-var f: TTestArr
+  type TTestArr = array[0..1, int16]
-f[0] = 30
+  var f: TTestArr
-f[1] = 40
+  f[0] = 30
-f[2] = 50
+  f[1] = 40
-f[3] = 60
+  f[2] = 50
+  f[3] = 60
 
-echo(repr(f))
+  echo(repr(f))

tests/misc/tinvalidarrayaccess2.nim

@@ -0,0 +1,16 @@
+discard """
+  errormsg: "index out of bounds: (a:0) <= (i:3) <= (b:1) "
+  line: 9
+"""
+
+# Note: merge in tinvalidarrayaccess.nim pending https://github.com/nim-lang/Nim/issues/9906
+
+let a = [1,2]
+echo a[3]
+
+when false:
+  # TOOD: this case is not yet handled, giving: "index out of bounds"
+  proc fun()=
+    let a = @[1,2]
+    echo a[3]
+  static: fun()