Merge branch 'devel' of gh:/Araq/Nimrod into devel

6 files changed, 45 insertions, 28 deletions

diff --git a/compiler/c2nim/cparse.nim b/compiler/c2nim/cparse.nim
index ffab05788..e4abe11a0 100644
--- a/compiler/c2nim/cparse.nim
+++ b/compiler/c2nim/cparse.nim
@@ -540,7 +540,7 @@ proc typeAtom(p: var TParser): PNode =
       if p.tok.s == "unsigned":
         isUnsigned = true
       elif p.tok.s == "signed" or p.tok.s == "int":
-        nil
+        discard
       else:
         add(x, p.tok.s)
       getTok(p, nil)
@@ -746,7 +746,7 @@ proc directDeclarator(p: var TParser, a: PNode, ident: ptr PNode): PNode =
       result = declarator(p, a, ident)
       eat(p, pxParRi, result)
   else:
-    nil
+    discard
   return parseTypeSuffix(p, a)
 
 proc declarator(p: var TParser, a: PNode, ident: ptr PNode): PNode =
@@ -1165,7 +1165,7 @@ proc enumSpecifier(p: var TParser): PNode =
 
 proc setBaseFlags(n: PNode, base: TNumericalBase) = 
   case base
-  of base10: nil
+  of base10: discard
   of base2: incl(n.flags, nfBase2)
   of base8: incl(n.flags, nfBase8)
   of base16: incl(n.flags, nfBase16)
@@ -1686,7 +1686,7 @@ proc switchStatement(p: var TParser): PNode =
       break
     of "case", "default":
       break
-    else: nil
+    else: discard
     addSon(result, statement(p))
   if sonsLen(result) == 0:
     # translate empty statement list to Nimrod's ``nil`` statement
diff --git a/compiler/c2nim/cpp.nim b/compiler/c2nim/cpp.nim
index 1707b75db..84b4c4dfb 100644
--- a/compiler/c2nim/cpp.nim
+++ b/compiler/c2nim/cpp.nim
@@ -103,7 +103,7 @@ proc parseDefBody(p: var TParser, m: var TMacro, params: seq[string]) =
       m.body.add(tok)
     of pxDirConc: 
       # just ignore this token: this implements token merging correctly
-      nil
+      discard
     else:
       m.body.add(p.tok)
     # we do not want macro expansion here:
@@ -166,7 +166,7 @@ proc parseStmtList(p: var TParser): PNode =
     of pxDirectiveParLe, pxDirective: 
       case p.tok.s
       of "else", "endif", "elif": break
-    else: nil
+    else: discard
     addSon(result, statement(p))
   
 proc eatEndif(p: var TParser) =
diff --git a/compiler/ccgstmts.nim b/compiler/ccgstmts.nim
index af0d657f1..443d845f6 100644
--- a/compiler/ccgstmts.nim
+++ b/compiler/ccgstmts.nim
@@ -65,6 +65,7 @@ proc startBlock(p: BProc, start: TFormatStr = "{$n",
   setLen(p.blocks, result + 1)
   p.blocks[result].id = p.labels
   p.blocks[result].nestedTryStmts = p.nestedTryStmts.len.int16
+  p.blocks[result].nestedExceptStmts = p.inExceptBlock.int16
 
 proc assignLabel(b: var TBlock): PRope {.inline.} =
   b.label = con("LA", b.id.toRope)
@@ -260,14 +261,22 @@ proc genIf(p: BProc, n: PNode, d: var TLoc) =
     else: internalError(n.info, "genIf()")
   if sonsLen(n) > 1: fixLabel(p, lend)
 
-proc blockLeaveActions(p: BProc, howMany: int) = 
-  var L = p.nestedTryStmts.len
+
+proc blockLeaveActions(p: BProc, howManyTrys, howManyExcepts: int) = 
+  # This is called by return and break stmts.
+  # When jumping out of try/except/finally stmts,
+  # we need to pop safe points from try statements,
+  # execute finally-stmts, and pop exceptions
+  # from except stmts
+
+  let L = p.nestedTryStmts.len
+
   # danger of endless recursion! we workaround this here by a temp stack
   var stack: seq[PNode]
-  newSeq(stack, howMany)
-  for i in countup(1, howMany): 
+  newSeq(stack, howManyTrys)
+  for i in countup(1, howManyTrys): 
     stack[i-1] = p.nestedTryStmts[L-i]
-  setLen(p.nestedTryStmts, L-howMany)
+  setLen(p.nestedTryStmts, L-howManyTrys)
   
   var alreadyPoppedCnt = p.inExceptBlock
   for tryStmt in items(stack):
@@ -276,21 +285,26 @@ proc blockLeaveActions(p: BProc, howMany: int) =
         dec alreadyPoppedCnt
       else:
         linefmt(p, cpsStmts, "#popSafePoint();$n")
+    # Find finally-stmts for this try-stmt
+    # and generate a copy of the finally stmts here
     var finallyStmt = lastSon(tryStmt)
     if finallyStmt.kind == nkFinally: 
       genStmts(p, finallyStmt.sons[0])
   # push old elements again:
-  for i in countdown(howMany-1, 0): 
+  for i in countdown(howManyTrys-1, 0): 
     p.nestedTryStmts.add(stack[i])
+
   if gCmd != cmdCompileToCpp:
-    for i in countdown(p.inExceptBlock-1, 0):
+    # Pop exceptions that was handled by the
+    # except-blocks we are in
+    for i in countdown(howManyExcepts-1, 0):
       linefmt(p, cpsStmts, "#popCurrentException();$n")
 
 proc genReturnStmt(p: BProc, t: PNode) =
   p.beforeRetNeeded = true
   genLineDir(p, t)
   if (t.sons[0].kind != nkEmpty): genStmts(p, t.sons[0])
-  blockLeaveActions(p, min(1, p.nestedTryStmts.len))
+  blockLeaveActions(p, min(1, p.nestedTryStmts.len), p.inExceptBlock)
   lineFF(p, cpsStmts, "goto BeforeRet;$n", "br label %BeforeRet$n", [])
 
 proc genComputedGoto(p: BProc; n: PNode) =
@@ -450,7 +464,9 @@ proc genBreakStmt(p: BProc, t: PNode) =
     if idx < 0 or not p.blocks[idx].isLoop:
       internalError(t.info, "no loop to break")
   let label = assignLabel(p.blocks[idx])
-  blockLeaveActions(p, p.nestedTryStmts.len - p.blocks[idx].nestedTryStmts)
+  blockLeaveActions(p, 
+    p.nestedTryStmts.len - p.blocks[idx].nestedTryStmts,
+    p.inExceptBlock - p.blocks[idx].nestedExceptStmts)
   genLineDir(p, t)
   lineF(p, cpsStmts, "goto $1;$n", [label])
 
diff --git a/compiler/cgendata.nim b/compiler/cgendata.nim
index 0e1148343..71479abdd 100644
--- a/compiler/cgendata.nim
+++ b/compiler/cgendata.nim
@@ -58,6 +58,7 @@ type
     sections*: TCProcSections # the code beloging
     isLoop*: bool             # whether block is a loop
     nestedTryStmts*: int16    # how many try statements is it nested into
+    nestedExceptStmts*: int16 # how many except statements is it nested into
     frameLen*: int16
   
   TCProc{.final.} = object    # represents C proc that is currently generated
diff --git a/compiler/pas2nim/paslex.nim b/compiler/pas2nim/paslex.nim
index 67473e71f..f24b0c420 100644
--- a/compiler/pas2nim/paslex.nim
+++ b/compiler/pas2nim/paslex.nim
@@ -342,7 +342,7 @@ proc getSymbol(L: var TLexer, tok: var TToken) =
       h = h +% ord(c)
       h = h +% h shl 10
       h = h xor (h shr 6)
-    of '_': nil
+    of '_': discard
     else: break
     inc(pos)
   h = h +% h shl 3
diff --git a/compiler/pas2nim/pasparse.nim b/compiler/pas2nim/pasparse.nim
index 928896338..a6f8363f6 100644
--- a/compiler/pas2nim/pasparse.nim
+++ b/compiler/pas2nim/pasparse.nim
@@ -335,7 +335,7 @@ proc exprColonEqExprList(p: var TParser, kind, elemKind: TNodeKind,
 
 proc setBaseFlags(n: PNode, base: TNumericalBase) = 
   case base
-  of base10: nil
+  of base10: discard
   of base2: incl(n.flags, nfBase2)
   of base8: incl(n.flags, nfBase8)
   of base16: incl(n.flags, nfBase16)
@@ -466,7 +466,7 @@ proc lowestExprAux(p: var TParser, v: var PNode, limit: int): TTokKind =
         eat(p, pxCurlyDirRi)
         opNode.ident = getIdent("&")
       else: 
-        nil
+        discard
     of pxMinus: 
       if p.tok.xkind == pxPer: 
         getTok(p)
@@ -477,7 +477,7 @@ proc lowestExprAux(p: var TParser, v: var PNode, limit: int): TTokKind =
     of pxNeq: 
       opNode.ident = getIdent("!=")
     else: 
-      nil
+      discard
     skipCom(p, opNode)        # read sub-expression with higher priority
     nextop = lowestExprAux(p, v2, opPred)
     addSon(node, opNode)
@@ -505,7 +505,7 @@ proc fixExpr(n: PNode): PNode =
             (n.sons[2].kind in {nkCharLit, nkStrLit}): 
           n.sons[0].ident = getIdent("&") # fix operator
   else: 
-    nil
+    discard
   if not (n.kind in {nkEmpty..nkNilLit}): 
     for i in countup(0, sonsLen(n) - 1): result.sons[i] = fixExpr(n.sons[i])
   
@@ -603,7 +603,7 @@ proc parseStmtList(p: var TParser): PNode =
     of pxCurlyDirLe, pxStarDirLe: 
       if not isHandledDirective(p): break 
     else: 
-      nil
+      discard
     addSon(result, parseStmt(p))
   if sonsLen(result) == 1: result = result.sons[0]
   
@@ -732,7 +732,7 @@ proc parseRepeat(p: var TParser): PNode =
   addSon(b, c)
   addSon(a, b)
   if b.sons[0].kind == nkIdent and b.sons[0].ident.id == getIdent("false").id: 
-    nil
+    discard
   else: 
     addSon(s, a)
   addSon(result, s)
@@ -840,7 +840,7 @@ proc parseParam(p: var TParser): PNode =
     getTok(p)
     v = newNodeP(nkVarTy, p)
   else: 
-    nil
+    discard
   while true: 
     case p.tok.xkind
     of pxSymbol: a = createIdentNodeP(p.tok.ident, p)
@@ -1133,7 +1133,7 @@ proc parseRecordPart(p: var TParser): PNode =
 proc exSymbol(n: var PNode) = 
   case n.kind
   of nkPostfix: 
-    nil
+    discard
   of nkPragmaExpr: 
     exSymbol(n.sons[0])
   of nkIdent, nkAccQuoted: 
@@ -1154,7 +1154,7 @@ proc fixRecordDef(n: var PNode) =
     for i in countup(0, sonsLen(n) - 1): fixRecordDef(n.sons[i])
   of nkIdentDefs: 
     for i in countup(0, sonsLen(n) - 3): exSymbol(n.sons[i])
-  of nkNilLit, nkEmpty: nil
+  of nkNilLit, nkEmpty: discard
   else: internalError(n.info, "fixRecordDef(): " & $n.kind)
   
 proc addPragmaToIdent(ident: var PNode, pragma: PNode) = 
@@ -1191,7 +1191,7 @@ proc parseRecordBody(p: var TParser, result, definition: PNode) =
     if definition != nil: addPragmaToIdent(definition.sons[0], parseCommand(p))
     else: internalError(result.info, "anonymous record is not supported")
   else: 
-    nil
+    discard
   opt(p, pxSemicolon)
   skipCom(p, result)
 
@@ -1399,7 +1399,7 @@ proc fixVarSection(p: var TParser, counter: PNode) =
 
 proc exSymbols(n: PNode) = 
   case n.kind
-  of nkEmpty..nkNilLit: nil
+  of nkEmpty..nkNilLit: discard
   of nkProcDef..nkIteratorDef: exSymbol(n.sons[namePos])
   of nkWhenStmt, nkStmtList: 
     for i in countup(0, sonsLen(n) - 1): exSymbols(n.sons[i])
@@ -1410,7 +1410,7 @@ proc exSymbols(n: PNode) =
       exSymbol(n.sons[i].sons[0])
       if n.sons[i].sons[2].kind == nkObjectTy: 
         fixRecordDef(n.sons[i].sons[2])
-  else: nil
+  else: discard
 
 proc parseBegin(p: var TParser, result: PNode) = 
   getTok(p)