Branch: refs/heads/master
Home: https://github.com/mono/mono
Compare: https://github.com/mono/mono/compare/346b2ee26065...b055fa22dfaf
Commit: b055fa22dfaf8feb28c0ba4db9e5fb7c90b420b1
Author: Marek Safar <[email protected]> (marek-safar)
Date: 2013-10-16 17:17:25 GMT
URL: https://github.com/mono/mono/commit/b055fa22dfaf8feb28c0ba4db9e5fb7c90b420b1
Fixes too early optimization of binary &&/& bool constants. Fixes part of #15392
Changed paths:
M mcs/errors/known-issues-net_4_5
M mcs/mcs/ecore.cs
M mcs/mcs/expression.cs
M mcs/tests/ver-il-net_4_5.xml
Added paths:
A mcs/errors/cs0165-21.cs
A mcs/errors/cs0429-3.cs
A mcs/tests/test-871.cs
Added: mcs/errors/cs0165-21.cs
===================================================================
@@ -0,0 +1,19 @@
+// CS0165: Use of unassigned local variable `v'
+// Line: 17
+
+using System;
+
+class C
+{
+ void Test (int arg)
+ {
+ int v;
+ switch (arg) {
+ case 1:
+ v = 0;
+ break;
+ }
+
+ Console.WriteLine (v);
+ }
+}
\ No newline at end of file
Added: mcs/errors/cs0429-3.cs
===================================================================
@@ -0,0 +1,11 @@
+// CS0429: Unreachable expression code detected
+// Line: 9
+// Compiler options: -warn:4 -warnaserror
+
+class Main
+{
+ public void Method (int i)
+ {
+ var x = true ? 1 : i;
+ }
+}
Modified: mcs/errors/known-issues-net_4_5
===================================================================
@@ -15,6 +15,7 @@
cs0080.cs
cs0162-7.cs NO ERROR
+cs0165-3.cs
# Operators
cs0457-2.cs
Modified: mcs/mcs/ecore.cs
===================================================================
@@ -373,6 +373,11 @@ protected void Error_VoidPointerOperation (ResolveContext rc)
rc.Report.Error (242, loc, "The operation in question is undefined on void pointers");
}
+ public static void Warning_UnreachableExpression (ResolveContext rc, Location loc)
+ {
+ rc.Report.Warning (429, 4, loc, "Unreachable expression code detected");
+ }
+
public ResolveFlags ExprClassToResolveFlags {
get {
switch (eclass) {
Modified: mcs/mcs/expression.cs
===================================================================
@@ -2010,11 +2010,17 @@ public virtual Expression ConvertResult (ResolveContext rc, Binary b)
b.left = Convert.ImplicitConversion (rc, b.left, left, b.left.Location);
return ReducedExpression.Create (b.left, b).Resolve (rc);
}
- } else {
+
//
- // Optimizes
+ // Optimizes (value &/&& 0) to 0
+ //
+ if ((b.oper == Operator.BitwiseAnd || b.oper == Operator.LogicalAnd) && !IsLifted) {
+ Constant side_effect = new SideEffectConstant (c, b.left, c.Location);
+ return ReducedExpression.Create (side_effect, b);
+ }
+ } else {
//
- // (bool? & true) to bool?
+ // Optimizes (bool? & true) to bool?
//
if (IsLifted && left_unwrap.BuiltinType == BuiltinTypeSpec.Type.Bool && b.oper == Operator.BitwiseAnd) {
return ReducedExpression.Create (b.left, b).Resolve (rc);
@@ -2043,15 +2049,39 @@ public virtual Expression ConvertResult (ResolveContext rc, Binary b)
b.right = Convert.ImplicitConversion (rc, b.right, right, b.right.Location);
return ReducedExpression.Create (b.right, b).Resolve (rc);
}
- } else {
+
//
- // Optimizes
+ // Optimizes (false && expr) to false
+ //
+ if (b.oper == Operator.LogicalAnd && c.Type.BuiltinType == BuiltinTypeSpec.Type.Bool) {
+ // No rhs side-effects
+ Expression.Warning_UnreachableExpression (rc, b.right.StartLocation);
+ return ReducedExpression.Create (c, b);
+ }
+
+ //
+ // Optimizes (0 & value) to 0
+ //
+ if (b.oper == Operator.BitwiseAnd && !IsLifted) {
+ Constant side_effect = new SideEffectConstant (c, b.right, c.Location);
+ return ReducedExpression.Create (side_effect, b);
+ }
+ } else {
//
- // (true & bool?) to bool?
+ // Optimizes (true & bool?) to bool?
//
if (IsLifted && left_unwrap.BuiltinType == BuiltinTypeSpec.Type.Bool && b.oper == Operator.BitwiseAnd) {
return ReducedExpression.Create (b.right, b).Resolve (rc);
}
+
+ //
+ // Optimizes (true || expr) to true
+ //
+ if (b.oper == Operator.LogicalOr && c.Type.BuiltinType == BuiltinTypeSpec.Type.Bool) {
+ // No rhs side-effects
+ Expression.Warning_UnreachableExpression (rc, b.right.StartLocation);
+ return ReducedExpression.Create (c, b);
+ }
}
if (b.oper == Operator.Multiply && c.IsOneInteger)
@@ -3233,23 +3263,11 @@ protected override Expression DoResolve (ResolveContext ec)
if (left == null)
return null;
- Constant lc = left as Constant;
-
- if (lc != null && lc.Type.BuiltinType == BuiltinTypeSpec.Type.Bool &&
- ((oper == Operator.LogicalAnd && lc.IsDefaultValue) ||
- (oper == Operator.LogicalOr && !lc.IsDefaultValue))) {
-
- // FIXME: resolve right expression as unreachable
- // right.Resolve (ec);
-
- ec.Report.Warning (429, 4, right.StartLocation, "Unreachable expression code detected");
- return left;
- }
-
right = right.Resolve (ec);
if (right == null)
return null;
+ Constant lc = left as Constant;
Constant rc = right as Constant;
// The conversion rules are ignored in enum context but why
@@ -4029,17 +4047,11 @@ Expression ResolveOperatorPredefined (ResolveContext ec, PredefinedOperator [] o
if (best_operator == null)
return null;
- var expr = best_operator.ConvertResult (ec, this);
-
- if ((oper == Operator.BitwiseAnd || oper == Operator.LogicalAnd) && !best_operator.IsLifted) {
- expr = OptimizeAndOperation (expr);
- }
-
- return expr;
+ return best_operator.ConvertResult (ec, this);
}
//
- // Optimize &/&& constant expressions with 0 value
+ // Optimize & constant expressions with 0 value
//
Expression OptimizeAndOperation (Expression expr)
{
@@ -5342,8 +5354,8 @@ protected override Expression DoResolve (ResolveContext ec)
// Don't issue the warning for constant expressions
//
if (!(is_false ? true_expr is Constant : false_expr is Constant)) {
- ec.Report.Warning (429, 4, is_false ? true_expr.Location : false_expr.Location,
- "Unreachable expression code detected");
+ // CSC: Missing warning
+ Warning_UnreachableExpression (ec, is_false ? true_expr.Location : false_expr.Location);
}
return ReducedExpression.Create (
Added: mcs/tests/test-871.cs
===================================================================
@@ -0,0 +1,42 @@
+using System;
+
+class D
+{
+ int arg;
+
+ public D (int arg)
+ {
+ this.arg = arg;
+ }
+
+ public static D operator & (D x, D y)
+ {
+ return new D (100);
+ }
+
+ public static bool operator false (D d)
+ {
+ return false;
+ }
+
+ public static bool operator true (D d)
+ {
+ return true;
+ }
+
+ public static implicit operator D(bool b)
+ {
+ return new D (5);
+ }
+
+ static int Main ()
+ {
+ D d = false && new D (1);
+ Console.WriteLine (d.arg);
+ if (d.arg != 100)
+ return 1;
+
+ Console.WriteLine ("ok");
+ return 0;
+ }
+}
\ No newline at end of file
Modified: mcs/tests/ver-il-net_4_5.xml
===================================================================
@@ -48214,6 +48214,28 @@
</method>
</type>
</test>
+ <test name="test-871.cs">
+ <type name="D">
+ <method name="D op_BitwiseAnd(D, D)" attrs="2198">
+ <size>16</size>
+ </method>
+ <method name="Boolean op_False(D)" attrs="2198">
+ <size>10</size>
+ </method>
+ <method name="Boolean op_True(D)" attrs="2198">
+ <size>10</size>
+ </method>
+ <method name="D op_Implicit(Boolean)" attrs="2198">
+ <size>15</size>
+ </method>
+ <method name="Int32 Main()" attrs="145">
+ <size>80</size>
+ </method>
+ <method name="Void .ctor(Int32)" attrs="6278">
+ <size>15</size>
+ </method>
+ </type>
+ </test>
<test name="test-88.cs">
<type name="X">
<method name="Void f(System.String)" attrs="145">
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