fixes #2287

compiler/guards.nim

@@ -194,8 +194,12 @@ proc lowBound*(x: PNode): PNode =
   result.info = x.info
 
 proc highBound*(x: PNode): PNode =
-  result = if x.typ.skipTypes(abstractInst).kind == tyArray:
+  let typ = x.typ.skipTypes(abstractInst)
-             nkIntLit.newIntNode(lastOrd(x.typ))
+  result = if typ.kind in {tyArrayConstr, tyArray}:
+             nkIntLit.newIntNode(lastOrd(typ))
+           elif typ.kind == tySequence and x.kind == nkSym and
+               x.sym.kind == skConst:
+             nkIntLit.newIntNode(x.sym.ast.len-1)
            else:
              opAdd.buildCall(opLen.buildCall(x), minusOne())
   result.info = x.info
@@ -214,12 +218,23 @@ proc reassociation(n: PNode): PNode =
       result = opAdd.buildCall(result[1][1], result[1][2] |*| result[2])
   else: discard
 
+proc pred(n: PNode): PNode =
+  if n.kind in {nkCharLit..nkUInt64Lit} and n.intVal != low(BiggestInt):
+    result = copyNode(n)
+    dec result.intVal
+  else:
+    result = n
+
 proc canon*(n: PNode): PNode =
   # XXX for now only the new code in 'semparallel' uses this
   if n.safeLen >= 1:
     result = shallowCopy(n)
     for i in 0 .. < n.len:
       result.sons[i] = canon(n.sons[i])
+  elif n.kind == nkSym and n.sym.kind == skLet and
+      n.sym.ast.getMagic in (someEq + someAdd + someMul + someMin +
+      someMax + someHigh + {mUnaryLt} + someSub + someLen):
+    result = n.sym.ast.copyTree
   else:
     result = n
   case result.getMagic
@@ -231,20 +246,26 @@ proc canon*(n: PNode): PNode =
   of someHigh:
     # high == len+(-1)
     result = opAdd.buildCall(opLen.buildCall(result[1]), minusOne())
-  of mUnaryMinusI, mUnaryMinusI64:
+  of mUnaryLt:
     result = buildCall(opAdd, result[1], newIntNode(nkIntLit, -1))
   of someSub:
     # x - 4  -->  x + (-4)
     result = negate(result[1], result[2], result)
   of someLen:
     result.sons[0] = opLen.newSymNode
+  of someLt:
+    # x < y  same as x <= y-1:
+    let y = n[2].canon
+    let p = pred(y)
+    let minus = if p != y: p else: opAdd.buildCall(y, minusOne()).canon
+    result = opLe.buildCall(n[1].canon, minus)
   else: discard
 
   result = skipConv(result)
   result = reassociation(result)
-  # most important rule: (x-4) < a.len -->  x < a.len+4
+  # most important rule: (x-4) <= a.len -->  x <= a.len+4
   case result.getMagic
-  of someLe, someLt:
+  of someLe:
     let x = result[1]
     let y = result[2]
     if x.kind in nkCallKinds and x.len == 3 and x[2].isValue and
@@ -402,13 +423,6 @@ proc valuesUnequal(a, b: PNode): bool =
   if a.isValue and b.isValue:
     result = not sameValue(a, b)
 
-proc pred(n: PNode): PNode =
-  if n.kind in {nkCharLit..nkUInt64Lit} and n.intVal != low(BiggestInt):
-    result = copyNode(n)
-    dec result.intVal
-  else:
-    result = n
-
 proc impliesEq(fact, eq: PNode): TImplication =
   let (loc, val) = if isLocation(eq.sons[1]): (1, 2) else: (2, 1)
 
@@ -671,6 +685,7 @@ proc pleViaModel(model: TModel; aa, bb: PNode): TImplication
 
 proc ple(m: TModel; a, b: PNode): TImplication =
   template `<=?`(a,b): expr = ple(m,a,b) == impYes
+
   #   0 <= 3
   if a.isValue and b.isValue:
     return if leValue(a, b): impYes else: impNo
@@ -744,16 +759,21 @@ proc pleViaModelRec(m: var TModel; a, b: PNode): TImplication =
       # mark as used:
       m[i] = nil
       if ple(m, a, x) == impYes:
-        if ple(m, y, b) == impYes: return impYes
+        if ple(m, y, b) == impYes:
+          return impYes
         #if pleViaModelRec(m, y, b): return impYes
       # fact:  16 <= i
       #         x    y
       # question: i <= 15? no!
       result = impliesLe(fact, a, b)
-      if result != impUnknown: return result
+      if result != impUnknown:
+        return result
+      when false:
+        # given: x <= y;  y==a;  x <= a this means: a <= b  if  x <= b
         if sameTree(y, a):
           result = ple(m, b, x)
-        if result != impUnknown: return result
+          if result != impUnknown:
+            return result
 
 proc pleViaModel(model: TModel; aa, bb: PNode): TImplication =
   # compute replacements:

compiler/renderer.nim

@@ -41,6 +41,8 @@ proc renderModule*(n: PNode, filename: string, renderFlags: TRenderFlags = {})
 proc renderTree*(n: PNode, renderFlags: TRenderFlags = {}): string
 proc initTokRender*(r: var TSrcGen, n: PNode, renderFlags: TRenderFlags = {})
 proc getNextTok*(r: var TSrcGen, kind: var TTokType, literal: var string)
+
+proc `$`*(n: PNode): string = n.renderTree
 # implementation
 # We render the source code in a two phases: The first
 # determines how long the subtree will likely be, the second

compiler/transf.nim

@@ -152,6 +152,7 @@ proc transformVarSection(c: PTransf, v: PNode): PTransNode =
       defs[0] = newSymNode(newVar).PTransNode
       defs[1] = it.sons[1].PTransNode
       defs[2] = transform(c, it.sons[2])
+      newVar.ast = defs[2].PNode
       result[i] = defs
     else:
       if it.kind != nkVarTuple:

tests/parallel/tsimple_array_checks.nim

@@ -0,0 +1,41 @@
+# bug #2287
+
+import threadPool
+
+# If `nums` is an array instead of seq,
+# NONE of the iteration ways below work (including high / len-1)
+let nums = @[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
+
+proc log(n:int) =
+  echo n
+
+proc main =
+  parallel:
+    for n in nums: # Error: cannot prove: i <= len(nums) + -1
+      spawn log(n)
+    #for i in 0 .. <nums.len: # Error: cannot prove: i <= len(nums) + -1
+    #for i in 0 .. nums.len-1: # WORKS!
+    #for i in 0 .. <nums.len: # WORKS!
+    #  spawn log(nums[i])
+
+# Array needs explicit size to work, probably related to issue #2287
+#const a: array[0..5, int] = [1,2,3,4,5,6]
+
+#const a = [1,2,3,4,5,6] # Doesn't work
+const a = @[1,2,3,4,5,6] # Doesn't work
+proc f(n: int) = echo "Hello ", n
+
+proc maino =
+  parallel:
+    # while loop doesn't work:
+    var i = 0
+    while i < a.high:
+      #for i in countup(0, a.high-1, 2):
+      spawn f(a[i])
+      spawn f(a[i+1])
+      i += 2
+
+maino() # Doesn't work outside a proc
+
+when isMainModule:
+  main()

todo.txt

@@ -54,6 +54,7 @@ Bugs
 - VM: ptr/ref T cannot work in general
 - scopes are still broken for generic instantiation!
 - blocks can "export" an identifier but the CCG generates {} for them ...
+- ConcreteTypes in a 'case' means we don't check for duplicated case branches
 
 
 version 0.9.x