public void Generate(Rule rule)
{
CGH.BeginRule(rule);
_currentRule = rule;
_target = new WList<LNode>();
_laVarsNeeded = 0;
_separatedMatchCounter = _stopLabelCounter = 0;
_recognizerMode = rule.IsRecognizer;
_labelsInUse.Clear();
Visit(rule.Pred);
if (_laVarsNeeded != 0) {
LNode laVars = F.Call(S.Var, CGH.LAType());
for (int i = 0; _laVarsNeeded != 0; i++, _laVarsNeeded >>= 1)
if ((_laVarsNeeded & 1) != 0)
laVars = laVars.PlusArg(F.Id("la" + i.ToString()));
_target.Insert(0, laVars);
}
LNode method;
if (rule.TryWrapperName != null) {
Debug.Assert(rule.IsRecognizer);
method = F.OnNewLine(CGH.CreateTryWrapperForRecognizer(rule));
_classBody.SpliceAdd(method, S.Splice);
}
method = CGH.CreateRuleMethod(rule, _target.ToVList());
if (!rule.IsRecognizer)
method = F.OnNewLine(method);
_classBody.SpliceAdd(method, S.Splice);
}
private void AddUserAction(VList <LNode> actions)
{
int i = _target.Count;
_target.AddRange(actions);
if (actions.Any(stmt => stmt.Range.StartIndex > 0))
{
if (LLPG.AddCsLineDirectives)
{
// Remove folder name. This only makes sense if the output
// file and input file are in the same folder; sadly we have
// no access to the output file name, but as of 2015-05 it's
// always true that the output file will be in the same folder.
string filename = System.IO.Path.GetFileName(_target[i].Range.Source.FileName);
var newline = F.Id(S.TriviaNewline);
int line = 0;
for (; i < _target.Count; i++, line++)
{
var r = _target[i].Range;
if (line != r.Start.Line)
{
line = r.Start.Line;
if (line <= 0) // sometimes occurs for generated `return result` statement
{
_target.Insert(i++, F.Trivia(S.CsPPRawText, "#line default"));
}
else
{
_target.Insert(i++, F.Trivia(S.CsPPRawText, "#line " + line + " " + Ecs.EcsNodePrinter.PrintString(filename, '"')));
}
}
}
if (line > 1)
{
_target.Add(F.Trivia(S.CsPPRawText, "#line default"));
}
}
else
{
_target[i] = _target[i].PlusAttr(F.Trivia(S.TriviaSLComment,
string.Format(" line {0}", _target[i].Range.Start.Line)));
}
}
}
public static void SpliceInsert(this WList <LNode> list, int index, LNode node, Symbol listName = null)
{
if (node.Calls(listName ?? CodeSymbols.Splice))
{
list.InsertRange(index, node.Args);
}
else
{
list.Insert(index, node);
}
}
public void Generate(Rule rule)
{
CGH.BeginRule(rule);
_currentRule = rule;
_target = new WList <LNode>();
_laVarsNeeded = 0;
_separatedMatchCounter = _stopLabelCounter = 0;
_recognizerMode = rule.IsRecognizer;
_labelsInUse.Clear();
Visit(rule.Pred);
if (_laVarsNeeded != 0)
{
LNode laVars = F.Call(S.Var, CGH.LAType());
for (int i = 0; _laVarsNeeded != 0; i++, _laVarsNeeded >>= 1)
{
if ((_laVarsNeeded & 1) != 0)
{
laVars = laVars.PlusArg(F.Id("la" + i.ToString()));
}
}
_target.Insert(0, laVars);
}
LNode method;
if (rule.TryWrapperName != null)
{
Debug.Assert(rule.IsRecognizer);
method = F.OnNewLine(CGH.CreateTryWrapperForRecognizer(rule));
_classBody.SpliceAdd(method, S.Splice);
}
method = CGH.CreateRuleMethod(rule, _target.ToVList());
if (!rule.IsRecognizer)
{
method = F.OnNewLine(method);
}
_classBody.SpliceAdd(method, S.Splice);
}
Mode = MacroMode.ProcessChildrenBefore)] // post-normal-macro-expansion
public static LNode with(LNode fn, IMessageSink sink)
{
LNode braces;
if (fn.ArgCount != 2 || !(braces = fn.Args[1]).Calls(S.Braces))
{
return(null);
}
LNode tmp = F.Id(NextTempName());
WList <LNode> stmts = braces.Args.ToWList();
stmts = stmts.SmartSelect(stmt =>
stmt.ReplaceRecursive(expr => {
if (expr.Calls(S.Dot, 1))
{
return(expr.WithArgs(new VList <LNode>(tmp, expr.Args.Last)));
}
return(null);
}));
stmts.Insert(0, F.Var(null, tmp.Name, fn.Args[0]));
return(F.Braces(stmts.ToVList()));
}
Mode = MacroMode.ProcessChildrenBefore)] // post-normal-macro-expansion
public static LNode with(LNode fn, IMacroContext context)
{
LNode braces;
if (fn.ArgCount != 2 || !(braces = fn.Args[1]).Calls(S.Braces))
{
return(null);
}
LNode tmp = F.Id(NextTempName(context));
WList <LNode> stmts = braces.Args.ToWList();
stmts = stmts.SmartSelect(stmt =>
stmt.ReplaceRecursive(expr => {
if (expr.Calls(S.Dot, 1))
{
return(expr.WithArgs(new VList <LNode>(tmp, expr.Args.Last)));
}
else if (expr.IsIdNamed("#"))
{
return(tmp);
}
return(null);
}));
stmts.Insert(0, F.Var(null, tmp.Name, fn.Args[0]));
if (IsExpressionContext(context))
{
stmts.Add(tmp);
return(F.Call("#runSequence", stmts.ToVList()));
}
else
{
return(F.Braces(stmts.ToVList()));
}
}
protected LNode GeneratePredictionTreeCode(PredictionTree tree, Pair<LNode, string>[] matchingCode, ref Symbol haveLoop)
{
var braces = F.Braces();
Debug.Assert(tree.Children.Count >= 1);
var alts = (Alts)_currentPred;
if (tree.Children.Count == 1)
return GetPredictionSubtreeCode(tree.Children[0], matchingCode, ref haveLoop);
// From the prediction table, we can generate either an if-else chain:
//
// if (la0 >= '0' && la0 <= '7') sub_tree_1();
// else if (la0 == '-') sub_tree_2();
// else break;
//
// or a switch statement:
//
// switch(la0) {
// case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7':
// sub_tree_1();
// break;
// case '-':
// sub_tree_2();
// break;
// default:
// goto breakfor;
// }
//
// Assertion levels always need an if-else chain; lookahead levels
// consider the complexity of switch vs if and decide which is most
// appropriate. Generally "if" is slower, but a switch may require
// too many labels since it doesn't support ranges like "la0 >= 'a'
// && la0 <= 'z'".
//
// This class makes if-else chains directly (using IPGTerminalSet.
// GenerateTest() to generate the test expressions), but the code
// snippet generator (CSG) is used to generate switch statements
// because the required code may be more complex.
//
// We may or may not be generating code inside a for(;;) loop. If we
// decide to generate a switch() statement, one of the branches will
// usually need to break out of the for loop, but "break" can only
// break out of the switch(). In that case, add "stop:" after the
// switch() and use "goto stop" instead of "break".
WList<LNode> block = new WList<LNode>();
LNode laVar = null;
MSet<int> switchCases = new MSet<int>();
IPGTerminalSet[] branchSets = null;
bool should = false;
if (tree.UsesLA()) {
laVar = F.Id("la" + tree.Lookahead.ToString());
if (!tree.IsAssertionLevel) {
IPGTerminalSet covered = CGH.EmptySet;
branchSets = tree.Children.Select(branch => {
var set = branch.Set.Subtract(covered);
covered = covered.Union(branch.Set);
return set;
}).ToArray();
should = CGH.ShouldGenerateSwitch(branchSets, switchCases, tree.Children.Last.IsErrorBranch);
if (!should)
switchCases.Clear();
else if (should && haveLoop == S.For)
// Can't "break" out of the for-loop when there is a nested switch,
haveLoop = GSymbol.Get(NextStopLabel()); // so use "goto stop".
}
}
LNode[] branchCode = new LNode[tree.Children.Count];
for (int i = 0; i < tree.Children.Count; i++)
if (tree.Children[i].IsErrorBranch) {
if (alts.ErrorBranch != null && alts.ErrorBranch != DefaultErrorBranch.Value) {
Debug.Assert(matchingCode.Length == alts.Arms.Count + 1);
branchCode[i] = matchingCode[alts.Arms.Count].A;
} else
branchCode[i] = CGH.ErrorBranch(tree.TotalCoverage, tree.Lookahead);
} else
branchCode[i] = GetPredictionSubtreeCode(tree.Children[i], matchingCode, ref haveLoop);
var code = GenerateIfElseChain(tree, branchCode, ref laVar, switchCases);
if (laVar != null) {
block.Insert(0, F.Assign(laVar, CGH.LA(tree.Lookahead)));
_laVarsNeeded |= 1ul << tree.Lookahead;
} else if (should)
laVar = CGH.LA(tree.Lookahead);
if (should) {
Debug.Assert(switchCases.Count != 0);
code = CGH.GenerateSwitch(branchSets, switchCases, branchCode, code, laVar);
}
block.Add(code);
return F.Braces(block.ToVList());
}
protected LNode GeneratePredictionTreeCode(PredictionTree tree, Pair <LNode, string>[] matchingCode, ref Symbol haveLoop)
{
var braces = F.Braces();
Debug.Assert(tree.Children.Count >= 1);
var alts = (Alts)_currentPred;
if (tree.Children.Count == 1)
{
return(GetPredictionSubtreeCode(tree.Children[0], matchingCode, ref haveLoop));
}
// From the prediction table, we can generate either an if-else chain:
//
// if (la0 >= '0' && la0 <= '7') sub_tree_1();
// else if (la0 == '-') sub_tree_2();
// else break;
//
// or a switch statement:
//
// switch(la0) {
// case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7':
// sub_tree_1();
// break;
// case '-':
// sub_tree_2();
// break;
// default:
// goto breakfor;
// }
//
// Assertion levels always need an if-else chain; lookahead levels
// consider the complexity of switch vs if and decide which is most
// appropriate. Generally "if" is slower, but a switch may require
// too many labels since it doesn't support ranges like "la0 >= 'a'
// && la0 <= 'z'".
//
// This class makes if-else chains directly (using IPGTerminalSet.
// GenerateTest() to generate the test expressions), but the code
// generation helper (CGH) is used to generate switch statements
// because the required code may be more complex.
//
// We may or may not be generating code inside a for(;;) loop. If we
// decide to generate a switch() statement, one of the branches will
// usually need to break out of the for loop, but "break" can only
// break out of the switch(). In that case, add "stop:" after the
// switch() and use "goto stop" instead of "break".
WList <LNode> block = new WList <LNode>();
LNode laVar = null;
MSet <int> switchCases = new MSet <int>();
IPGTerminalSet[] branchSets = null;
bool should = false;
if (tree.UsesLA())
{
laVar = F.Id("la" + tree.Lookahead.ToString());
if (!tree.IsAssertionLevel)
{
IPGTerminalSet covered = CGH.EmptySet;
branchSets = tree.Children.Select(branch => {
var set = branch.Set.Subtract(covered);
covered = covered.Union(branch.Set);
return(set);
}).ToArray();
should = CGH.ShouldGenerateSwitch(branchSets, switchCases, tree.Children.Last.IsErrorBranch);
if (!should)
{
switchCases.Clear();
}
else if (should && haveLoop == S.For)
{
// Can't "break" out of the for-loop when there is a nested switch,
haveLoop = GSymbol.Get(NextStopLabel()); // so use "goto stop".
}
}
}
LNode[] branchCode = new LNode[tree.Children.Count];
for (int i = 0; i < tree.Children.Count; i++)
{
if (tree.Children[i].IsErrorBranch)
{
if (_recognizerMode)
{
branchCode[i] = F.Call(S.Return, F.False);
}
else if (alts.ErrorBranch != null && alts.ErrorBranch != DefaultErrorBranch.Value)
{
Debug.Assert(matchingCode.Length == alts.Arms.Count + 1);
branchCode[i] = matchingCode[alts.Arms.Count].A;
}
else
{
branchCode[i] = CGH.ErrorBranch(tree.TotalCoverage, tree.Lookahead);
}
}
else
{
branchCode[i] = GetPredictionSubtreeCode(tree.Children[i], matchingCode, ref haveLoop);
}
}
var code = GenerateIfElseChain(tree, branchCode, ref laVar, switchCases);
if (laVar != null)
{
block.Insert(0, F.Assign(laVar, CGH.LA(tree.Lookahead)));
_laVarsNeeded |= 1ul << tree.Lookahead;
}
else if (should)
{
laVar = CGH.LA(tree.Lookahead);
}
if (should)
{
Debug.Assert(switchCases.Count != 0);
code = CGH.GenerateSwitch(branchSets, branchCode, switchCases, code ?? F.Missing, laVar);
}
block.Add(code);
return(F.Braces(block.ToVList()));
}
public static LNode @try(LNode node, IMessageSink sink)
{
if (!node.IsCall)
return null;
// try(code, catch, Exception::e, handler, catch, ..., finally, handler)
// ...becomes...
// #try(#{ stmt1; stmt2; ... }, #catch(#var(Exception, e), handler), #finally(handler))
LNode finallyCode = null;
WList<LNode> clauses = new WList<LNode>();
var parts = node.Args;
for (int i = parts.Count-2; i >= 1; i -= 2)
{
var p = parts[i];
if (p.IsIdNamed(_finally)) {
if (clauses.Count != 0 || finallyCode != null)
sink.Write(Severity.Error, p, "The «finally» clause must come last, there can only be one of them.");
finallyCode = parts[i+1];
} else if (p.Name == _catch) {
if (p.ArgCount > 0) {
if (p.ArgCount > 1)
sink.Write(Severity.Error, p, "Expected catch() to take one argument.");
// This is a normal catch clause
clauses.Insert(0, F.Call(S.Catch, p.Args[0], F.Missing, parts[i + 1]));
} else {
// This is a catch-all clause (the type argument is missing)
if (clauses.Count != 0)
sink.Write(Severity.Error, p, "The catch-all clause must be the last «catch» clause.");
clauses.Add(F.Call(S.Catch, F.Missing, F.Missing, parts[i + 1]));
}
} else if (i > 1 && parts[i-1].IsIdNamed(_catch)) {
// This is a normal catch clause
clauses.Insert(0, F.Call(S.Catch, AutoRemoveParens(p), F.Missing, parts[i+1]));
i--;
} else {
return Reject(sink, p, "Expected «catch» or «finally» clause here. Clause is missing or malformed.");
}
if (i == 2)
return Reject(sink, parts[1], "Expected «catch» or «finally» clause here. Clause is missing or malformed.");
}
if (clauses.Count == 0 && finallyCode == null) {
Debug.Assert(node.ArgCount <= 1);
return Reject(sink, node, "Missing «catch, Type, Code» or «finally, Code» clause");
}
if (finallyCode != null)
clauses.Add(F.Call(S.Finally, finallyCode));
clauses.Insert(0, node.Args[0]);
return node.With(S.Try, clauses.ToVList());
}
public static LNode @try(LNode node, IMessageSink sink)
{
if (!node.IsCall)
{
return(null);
}
// try(code, catch, Exception::e, handler, catch, ..., finally, handler)
// ...becomes...
// #try(#{ stmt1; stmt2; ... }, #catch(#var(Exception, e), handler), #finally(handler))
LNode finallyCode = null;
WList <LNode> clauses = new WList <LNode>();
var parts = node.Args;
for (int i = parts.Count - 2; i >= 1; i -= 2)
{
var p = parts[i];
if (p.IsIdNamed(_finally))
{
if (clauses.Count != 0 || finallyCode != null)
{
sink.Write(Severity.Error, p, "The «finally» clause must come last, there can only be one of them.");
}
finallyCode = parts[i + 1];
}
else if (p.Name == _catch)
{
if (p.ArgCount > 0)
{
if (p.ArgCount > 1)
{
sink.Write(Severity.Error, p, "Expected catch() to take one argument.");
}
// This is a normal catch clause
clauses.Insert(0, F.Call(S.Catch, p.Args[0], F.Missing, parts[i + 1]));
}
else
{
// This is a catch-all clause (the type argument is missing)
if (clauses.Count != 0)
{
sink.Write(Severity.Error, p, "The catch-all clause must be the last «catch» clause.");
}
clauses.Add(F.Call(S.Catch, F.Missing, F.Missing, parts[i + 1]));
}
}
else if (i > 1 && parts[i - 1].IsIdNamed(_catch))
{
// This is a normal catch clause
clauses.Insert(0, F.Call(S.Catch, AutoRemoveParens(p), F.Missing, parts[i + 1]));
i--;
}
else
{
return(Reject(sink, p, "Expected «catch» or «finally» clause here. Clause is missing or malformed."));
}
if (i == 2)
{
return(Reject(sink, parts[1], "Expected «catch» or «finally» clause here. Clause is missing or malformed."));
}
}
if (clauses.Count == 0 && finallyCode == null)
{
Debug.Assert(node.ArgCount <= 1);
return(Reject(sink, node, "Missing «catch, Type, Code» or «finally, Code» clause"));
}
if (finallyCode != null)
{
clauses.Add(F.Call(S.Finally, finallyCode));
}
clauses.Insert(0, node.Args[0]);
return(node.With(S.Try, clauses.ToVList()));
}