var da_false = new DefiniteAssignmentBitSet (fc.DefiniteAssignmentOnFalse);
- fc.DefiniteAssignment = fc.DefiniteAssignmentOnTrue;
+ fc.BranchDefiniteAssignment (fc.DefiniteAssignmentOnTrue);
+ var labels = fc.CopyLabelStack ();
var res = TrueStatement.FlowAnalysis (fc);
+ fc.SetLabelStack (labels);
+
if (FalseStatement == null) {
+
var c = expr as Constant;
if (c != null && !c.IsDefaultValue)
return true_returns;
if (true_returns) {
fc.DefiniteAssignment = da_false;
- return FalseStatement.FlowAnalysis (fc);
+
+ res = FalseStatement.FlowAnalysis (fc);
+ fc.SetLabelStack (labels);
+ return res;
}
var da_true = fc.DefiniteAssignment;
fc.DefiniteAssignment = da_false;
+
res &= FalseStatement.FlowAnalysis (fc);
+ fc.SetLabelStack (labels);
+
if (!TrueStatement.IsUnreachable) {
if (false_returns || FalseStatement.IsUnreachable)
fc.DefiniteAssignment = da_true;
ec.Emit (OpCodes.Br, ec.LoopBegin);
ec.MarkLabel (while_loop);
+ expr.EmitPrepare (ec);
+
Statement.Emit (ec);
ec.MarkLabel (ec.LoopBegin);
{
expr.FlowAnalysisConditional (fc);
- fc.DefiniteAssignment = fc.DefiniteAssignmentOnTrue;
var da_false = new DefiniteAssignmentBitSet (fc.DefiniteAssignmentOnFalse);
+ fc.BranchDefiniteAssignment (fc.DefiniteAssignmentOnTrue);
+
Statement.FlowAnalysis (fc);
//
public class Return : ExitStatement
{
Expression expr;
+ bool expr_returns;
public Return (Expression expr, Location l)
{
if (expr == null)
return false;
+ if (expr is ReferenceExpression && block_return_type.Kind != MemberKind.ByRef) {
+ ec.Report.Error (8149, loc, "By-reference returns can only be used in methods that return by reference");
+ return false;
+ }
+
if (expr.Type != block_return_type && expr.Type != InternalType.ErrorType) {
- expr = Convert.ImplicitConversionRequired (ec, expr, block_return_type, loc);
+ if (block_return_type.Kind == MemberKind.ByRef) {
+ var ref_expr = Expr as ReferenceExpression;
+ if (ref_expr == null) {
+ ec.Report.Error (8150, loc, "By-reference return is required when method returns by reference");
+ return false;
+ }
+
+ var byref_return = (ReferenceContainer)block_return_type;
- if (expr == null) {
- if (am != null && block_return_type == ec.ReturnType) {
- ec.Report.Error (1662, loc,
- "Cannot convert `{0}' to delegate type `{1}' because some of the return types in the block are not implicitly convertible to the delegate return type",
- am.ContainerType, am.GetSignatureForError ());
+ if (expr.Type != byref_return.Element) {
+ ec.Report.Error (8151, loc, "The return by reference expression must be of type `{0}' because this method returns by reference",
+ byref_return.GetSignatureForError ());
+ return false;
+ }
+ } else {
+
+ expr = Convert.ImplicitConversionRequired (ec, expr, block_return_type, loc);
+
+ if (expr == null) {
+ if (am != null && block_return_type == ec.ReturnType) {
+ ec.Report.Error (1662, loc,
+ "Cannot convert `{0}' to delegate type `{1}' because some of the return types in the block are not implicitly convertible to the delegate return type",
+ am.ContainerType, am.GetSignatureForError ());
+ }
+ return false;
}
- return false;
}
}
// Special case hoisted return value (happens in try/finally scenario)
//
if (ec.TryFinallyUnwind != null) {
- exit_label = TryFinally.EmitRedirectedReturn (ec, async_body);
+ exit_label = TryFinally.EmitRedirectedReturn (ec, async_body, unwind_protect);
}
var async_return = (IAssignMethod)storey.HoistedReturnValue;
expr.Emit (ec);
if (ec.TryFinallyUnwind != null)
- exit_label = TryFinally.EmitRedirectedReturn (ec, async_body);
+ exit_label = TryFinally.EmitRedirectedReturn (ec, async_body, unwind_protect);
}
ec.Emit (OpCodes.Leave, exit_label);
if (expr != null)
expr.FlowAnalysis (fc);
- base.DoFlowAnalysis (fc);
+ if (!expr_returns)
+ base.DoFlowAnalysis (fc);
+
return true;
}
public override Reachability MarkReachable (Reachability rc)
{
base.MarkReachable (rc);
+
+ if (Expr != null) {
+ rc = Expr.MarkReachable (rc);
+ expr_returns = rc.IsUnreachable;
+ }
+
return Reachability.CreateUnreachable ();
}
if (ec.TryFinallyUnwind != null && IsLeavingFinally (label.Block)) {
var async_body = (AsyncInitializer) ec.CurrentAnonymousMethod;
- l = TryFinally.EmitRedirectedJump (ec, async_body, l, label.Block);
+ l = TryFinally.EmitRedirectedJump (ec, async_body, l, label.Block, unwind_protect);
}
ec.Emit (unwind_protect ? OpCodes.Leave : OpCodes.Br, l);
}
}
+ public static Expression ConvertType (ResolveContext rc, Expression expr)
+ {
+ var et = rc.BuiltinTypes.Exception;
+ if (Convert.ImplicitConversionExists (rc, expr, et))
+ expr = Convert.ImplicitConversion (rc, expr, et, expr.Location);
+ else {
+ rc.Report.Error (155, expr.Location, "The type caught or thrown must be derived from System.Exception");
+ expr = EmptyCast.Create (expr, et);
+ }
+
+ return expr;
+ }
+
public override bool Resolve (BlockContext ec)
{
if (expr == null) {
if (expr == null)
return false;
- var et = ec.BuiltinTypes.Exception;
- if (Convert.ImplicitConversionExists (ec, expr, et))
- expr = Convert.ImplicitConversion (ec, expr, et, loc);
- else
- ec.Report.Error (155, expr.Location, "The type caught or thrown must be derived from System.Exception");
+ expr = ConvertType (ec, expr);
return true;
}
if (ec.TryFinallyUnwind != null) {
var async_body = (AsyncInitializer) ec.CurrentAnonymousMethod;
- l = TryFinally.EmitRedirectedJump (ec, async_body, l, enclosing_loop.Statement as Block);
+ l = TryFinally.EmitRedirectedJump (ec, async_body, l, enclosing_loop.Statement as Block, unwind_protect);
}
ec.Emit (unwind_protect ? OpCodes.Leave : OpCodes.Br, l);
if (ec.TryFinallyUnwind != null) {
var async_body = (AsyncInitializer) ec.CurrentAnonymousMethod;
- l = TryFinally.EmitRedirectedJump (ec, async_body, l, enclosing_loop.Statement as Block);
+ l = TryFinally.EmitRedirectedJump (ec, async_body, l, enclosing_loop.Statement as Block, unwind_protect);
}
ec.Emit (unwind_protect ? OpCodes.Leave : OpCodes.Br, l);
}
if (type == null) {
- type = type_expr.ResolveAsType (bc);
+ type = ResolveTypeExpression (bc);
if (type == null)
return false;
}
if (initializer != null) {
+ if (li.IsByRef) {
+ if (!(initializer is ReferenceExpression)) {
+ bc.Report.Error (8172, loc, "Cannot initialize a by-reference variable `{0}' with a value", li.Name);
+ return false;
+ }
+
+ if (bc.CurrentAnonymousMethod is AsyncInitializer) {
+ bc.Report.Error (8177, loc, "Async methods cannot use by-reference variables");
+ } else if (bc.CurrentIterator != null) {
+ bc.Report.Error (8176, loc, "Iterators cannot use by-reference variables");
+ }
+
+ } else {
+ if (initializer is ReferenceExpression) {
+ bc.Report.Error (8171, loc, "Cannot initialize a by-value variable `{0}' with a reference expression", li.Name);
+ return false;
+ }
+ }
+
initializer = ResolveInitializer (bc, li, initializer);
// li.Variable.DefinitelyAssigned
}
return a.ResolveStatement (bc);
}
+ protected virtual TypeSpec ResolveTypeExpression (BlockContext bc)
+ {
+ return type_expr.ResolveAsType (bc);
+ }
+
protected override void DoEmit (EmitContext ec)
{
li.CreateBuilder (ec);
public override Reachability MarkReachable (Reachability rc)
{
- var init = initializer as ExpressionStatement;
- if (init != null)
- init.MarkReachable (rc);
-
- return base.MarkReachable (rc);
+ base.MarkReachable (rc);
+ return initializer == null ? rc : initializer.MarkReachable (rc);
}
protected override void CloneTo (CloneContext clonectx, Statement target)
public override void Emit (EmitContext ec)
{
+ if (!Variable.IsUsed)
+ ec.Report.Warning (219, 3, loc, "The constant `{0}' is never used", Variable.Name);
+
// Nothing to emit, not even sequence point
}
UsingVariable = 1 << 7,
IsLocked = 1 << 8,
SymbolFileHidden = 1 << 9,
+ ByRef = 1 << 10,
ReadonlyMask = ForeachVariable | FixedVariable | UsingVariable
}
}
}
+ public bool Created {
+ get {
+ return builder != null;
+ }
+ }
+
public bool IsDeclared {
get {
return type != null;
}
}
+ public bool IsByRef => (flags & Flags.ByRef) != 0;
+
public bool IsCompilerGenerated {
get {
return (flags & Flags.CompilerGenerated) != 0;
}
}
+ public bool IsUsed {
+ get {
+ return (flags & Flags.Used) != 0;
+ }
+ }
+
public bool IsFixed {
get {
return (flags & Flags.FixedVariable) != 0;
throw new InternalErrorException ("Already created variable `{0}'", name);
}
- //
- // All fixed variabled are pinned, a slot has to be alocated
- //
- builder = ec.DeclareLocal (Type, IsFixed);
+ if (IsByRef) {
+ builder = ec.DeclareLocal (ReferenceContainer.MakeType (ec.Module, Type), IsFixed);
+ } else {
+ //
+ // All fixed variabled are pinned, a slot has to be alocated
+ //
+ builder = ec.DeclareLocal(Type, IsFixed);
+ }
+
if ((flags & Flags.SymbolFileHidden) == 0)
ec.DefineLocalVariable (name, builder);
}
public Expression CreateReferenceExpression (ResolveContext rc, Location loc)
{
- if (IsConstant && const_value != null)
+ if (IsConstant && const_value != null) {
+ SetIsUsed ();
return Constant.CreateConstantFromValue (Type, const_value.GetValue (), loc);
+ }
return new LocalVariableReference (this, loc);
}
if ((flags & Flags.CompilerGenerated) != 0)
CreateBuilder (ec);
- ec.Emit (OpCodes.Ldloca, builder);
+ if (IsByRef)
+ ec.Emit (OpCodes.Ldloc, builder);
+ else
+ ec.Emit (OpCodes.Ldloca, builder);
}
public static string GetCompilerGeneratedName (Block block)
public override void Emit (EmitContext ec)
{
- if (Parent != null) {
- // TODO: It's needed only when scope has variable (normal or lifted)
- ec.BeginScope (GetDebugSymbolScopeIndex ());
+ // TODO: It's needed only when scope has variable (normal or lifted)
+ var scopeIndex = GetDebugSymbolScopeIndex ();
+ if (scopeIndex > 0) {
+ ec.BeginScope (scopeIndex);
}
EmitScopeInitialization (ec);
DoEmit (ec);
- if (Parent != null)
+ if (scopeIndex > 0)
ec.EndScope ();
if (ec.EmitAccurateDebugInfo && HasReachableClosingBrace && !(this is ParametersBlock) &&
storey.Parent.PartialContainer.AddCompilerGeneratedClass (storey);
}
- public int GetDebugSymbolScopeIndex ()
+ public void DisableDebugScopeIndex ()
+ {
+ debug_scope_index = -1;
+ }
+
+ public virtual int GetDebugSymbolScopeIndex ()
{
if (debug_scope_index == 0)
debug_scope_index = ++ParametersBlock.debug_scope_index;
return res;
}
+ public override int GetDebugSymbolScopeIndex ()
+ {
+ return 0;
+ }
+
public LabeledStatement GetLabel (string name, Block block)
{
//
public override bool Resolve (BlockContext ec)
{
if (ec.CurrentIterator != null)
- ec.Report.Error (1629, loc, "Unsafe code may not appear in iterators");
+ Expression.UnsafeInsideIteratorError (ec, loc);
using (ec.Set (ResolveContext.Options.UnsafeScope))
return Block.Resolve (ec);
{
ExplicitBlock fini;
List<DefiniteAssignmentBitSet> try_exit_dat;
- List<Label> redirected_jumps;
+ List<Tuple<Label, bool>> redirected_jumps;
Label? start_fin_label;
public TryFinally (Statement stmt, ExplicitBlock fini, Location loc)
return false;
}
- public static Label EmitRedirectedJump (EmitContext ec, AsyncInitializer initializer, Label label, Block labelBlock)
+ public static Label EmitRedirectedJump (EmitContext ec, AsyncInitializer initializer, Label label, Block labelBlock, bool unwindProtect)
{
int idx;
if (labelBlock != null) {
if (labelBlock != null && !fin.IsParentBlock (labelBlock))
break;
- fin.EmitRedirectedExit (ec, label, initializer, set_return_state);
+ fin.EmitRedirectedExit (ec, label, initializer, set_return_state, unwindProtect);
set_return_state = false;
if (fin.start_fin_label == null) {
return label;
}
- public static Label EmitRedirectedReturn (EmitContext ec, AsyncInitializer initializer)
+ public static Label EmitRedirectedReturn (EmitContext ec, AsyncInitializer initializer, bool unwindProtect)
{
- return EmitRedirectedJump (ec, initializer, initializer.BodyEnd, null);
+ return EmitRedirectedJump (ec, initializer, initializer.BodyEnd, null, unwindProtect);
}
- void EmitRedirectedExit (EmitContext ec, Label label, AsyncInitializer initializer, bool setReturnState)
+ void EmitRedirectedExit (EmitContext ec, Label label, AsyncInitializer initializer, bool setReturnState, bool unwindProtect)
{
if (redirected_jumps == null) {
- redirected_jumps = new List<Label> ();
+ redirected_jumps = new List<Tuple<Label, bool>> ();
// Add fallthrough label
- redirected_jumps.Add (ec.DefineLabel ());
+ redirected_jumps.Add (Tuple.Create (ec.DefineLabel (), false));
if (setReturnState)
initializer.HoistedReturnState = ec.GetTemporaryField (ec.Module.Compiler.BuiltinTypes.Int, true);
}
- int index = redirected_jumps.IndexOf (label);
+ int index = redirected_jumps.FindIndex (l => l.Item1 == label);
if (index < 0) {
- redirected_jumps.Add (label);
+ redirected_jumps.Add (Tuple.Create (label, unwindProtect));
index = redirected_jumps.Count - 1;
}
var initializer = (AsyncInitializer)ec.CurrentAnonymousMethod;
initializer.HoistedReturnState.EmitLoad (ec);
- ec.Emit (OpCodes.Switch, redirected_jumps.ToArray ());
+
+ var jumps_table = new Label [redirected_jumps.Count];
+ List<Tuple<Label, Label>> leave_redirect = null;
+ for (int i = 0; i < jumps_table.Length; ++i) {
+ var val = redirected_jumps [i];
+
+ if (val.Item2) {
+ if (leave_redirect == null)
+ leave_redirect = new List<Tuple<Label, Label>> ();
+ var label = ec.DefineLabel ();
+ leave_redirect.Add (Tuple.Create (label, val.Item1));
+ jumps_table [i] = label;
+ } else {
+ jumps_table [i] = val.Item1;
+ }
+ }
+
+ ec.Emit (OpCodes.Switch, jumps_table);
+
+ if (leave_redirect != null) {
+ foreach (var entry in leave_redirect) {
+ ec.MarkLabel (entry.Item1);
+ ec.Emit (OpCodes.Leave, entry.Item2);
+ }
+ }
// Mark fallthrough label
- ec.MarkLabel (redirected_jumps [0]);
+ ec.MarkLabel (jumps_table [0]);
}
protected override bool DoFlowAnalysis (FlowAnalysisContext fc)
ec.Emit (OpCodes.Br, end);
ec.MarkLabel (labels [i + 1]);
+
+ ec.EmitInt (0);
+ ec.Emit (OpCodes.Stloc, state_variable);
+
c = catch_sm [i];
ec.AsyncThrowVariable = c.Variable;
c.Block.Emit (ec);
ec.LoopBegin = ec.DefineLabel ();
ec.LoopEnd = ec.DefineLabel ();
- if (!(Statement is Block))
- ec.BeginCompilerScope (variable.Block.Explicit.GetDebugSymbolScopeIndex ());
+ ec.BeginCompilerScope (variable.Block.Explicit.GetDebugSymbolScopeIndex ());
+ body.Explicit.DisableDebugScopeIndex ();
variable.CreateBuilder (ec);
Statement.Emit (ec);
- if (!(Statement is Block))
- ec.EndScope ();
+ ec.EndScope ();
ec.LoopBegin = old_begin;
ec.LoopEnd = old_end;