diff options
| author |  qunyanm <unknown> | 2015-11-10 15:53:39 -0800 |
|---|---|---|
| committer | qunyanm <unknown> | 2015-11-10 15:53:39 -0800 |
| commit | 324c2f4bf8842cce7922e7ff7972216dfc06546f (patch) | |
| tree | 6554d1c5d1fbdab85af2a04e1d44ae709b41ac7f | |
| parent | 23067608f2d8855abd64982cabfe7f0c7f8e4f5a (diff) | |
Fix issue 101. Instead of swapping operands for Exp opcode in BinaryExpr,
swap them when the expr is first created in parser or for calcstmt. This
avoids problems of operands being swapped again when the expr is copied.
| -rw-r--r-- | Source/Dafny/Dafny.atg | 7 | ||||
| -rw-r--r-- | Source/Dafny/DafnyAst.cs | 17 | ||||
| -rw-r--r-- | Source/Dafny/Parser.cs | 5 | ||||
| -rw-r--r-- | Test/dafny4/Bug101.dfy | 19 | ||||
| -rw-r--r-- | Test/dafny4/Bug101.dfy.expect | 8 |
5 files changed, 43 insertions, 13 deletions
diff --git a/Source/Dafny/Dafny.atg b/Source/Dafny/Dafny.atg index 5fa1085d..ff3b75a3 100644 --- a/Source/Dafny/Dafny.atg +++ b/Source/Dafny/Dafny.atg @@ -2175,10 +2175,13 @@ ImpliesExpliesExpression<out Expression e0, bool allowSemi, bool allowLambda> ( ImpliesOp (. x = t; .)
ImpliesExpression<out e1, allowSemi, allowLambda> (. e0 = new BinaryExpr(x, BinaryExpr.Opcode.Imp, e0, e1); .)
| ExpliesOp (. x = t; .)
- LogicalExpression<out e1, allowSemi, allowLambda> (. e0 = new BinaryExpr(x, BinaryExpr.Opcode.Exp, e0, e1); .)
+ LogicalExpression<out e1, allowSemi, allowLambda> (. // The order of operands is reversed so that it can be turned into implication during resolution
+ e0 = new BinaryExpr(x, BinaryExpr.Opcode.Exp, e1, e0); .)
{ IF(IsExpliesOp()) /* read a reverse implication as far as possible */
ExpliesOp (. x = t; .)
- LogicalExpression<out e1, allowSemi, allowLambda> (. e0 = new BinaryExpr(x, BinaryExpr.Opcode.Exp, e0, e1); .)
+ LogicalExpression<out e1, allowSemi, allowLambda> (. //The order of operands is reversed so that it can be turned into implication during resolution
+ e0 = new BinaryExpr(x, BinaryExpr.Opcode.Exp, e1, e0);
+ .)
}
)
]
diff --git a/Source/Dafny/DafnyAst.cs b/Source/Dafny/DafnyAst.cs index fdbd484e..9ed3b7e0 100644 --- a/Source/Dafny/DafnyAst.cs +++ b/Source/Dafny/DafnyAst.cs @@ -4885,7 +4885,12 @@ namespace Microsoft.Dafny { public override Expression StepExpr(Expression line0, Expression line1)
{
- return new BinaryExpr(line0.tok, Op, line0, line1);
+ if (Op == BinaryExpr.Opcode.Exp) {
+ // The order of operands is reversed so that it can be turned into implication during resolution
+ return new BinaryExpr(line0.tok, Op, line1, line0);
+ } else {
+ return new BinaryExpr(line0.tok, Op, line0, line1);
+ }
}
public override string ToString()
@@ -6779,14 +6784,8 @@ namespace Microsoft.Dafny { Contract.Requires(e0 != null);
Contract.Requires(e1 != null);
this.Op = op;
- if (op == Opcode.Exp) {
- // The order of operands is reversed so that it can be turned into implication during resolution
- this.E0 = e1;
- this.E1 = e0;
- } else {
- this.E0 = e0;
- this.E1 = e1;
- }
+ this.E0 = e0;
+ this.E1 = e1;
}
/// <summary>
diff --git a/Source/Dafny/Parser.cs b/Source/Dafny/Parser.cs index 6a5f32ab..b6a59f4e 100644 --- a/Source/Dafny/Parser.cs +++ b/Source/Dafny/Parser.cs @@ -3267,12 +3267,13 @@ List<Expression/*!*/>/*!*/ decreases, ref Attributes decAttrs, ref Attributes mo ExpliesOp();
x = t;
LogicalExpression(out e1, allowSemi, allowLambda);
- e0 = new BinaryExpr(x, BinaryExpr.Opcode.Exp, e0, e1);
+ e0 = new BinaryExpr(x, BinaryExpr.Opcode.Exp, e1, e0);
while (IsExpliesOp()) {
ExpliesOp();
x = t;
LogicalExpression(out e1, allowSemi, allowLambda);
- e0 = new BinaryExpr(x, BinaryExpr.Opcode.Exp, e0, e1);
+ e0 = new BinaryExpr(x, BinaryExpr.Opcode.Exp, e1, e0);
+
}
} else SynErr(219);
}
diff --git a/Test/dafny4/Bug101.dfy b/Test/dafny4/Bug101.dfy new file mode 100644 index 00000000..878ed57a --- /dev/null +++ b/Test/dafny4/Bug101.dfy @@ -0,0 +1,19 @@ +// RUN: %dafny /compile:0 "%s" > "%t"
+// RUN: %diff "%s.expect" "%t"
+
+predicate P(i:int) { true }
+
+lemma Tester()
+{
+// forall i ensures false ==> P(i) {}
+ forall i ensures P(i) <== false {}
+ assert forall i :: P(i) ==> false;
+ assert P(0);
+ assert false;
+}
+
+
+
+
+
+
diff --git a/Test/dafny4/Bug101.dfy.expect b/Test/dafny4/Bug101.dfy.expect new file mode 100644 index 00000000..a4e5f4b3 --- /dev/null +++ b/Test/dafny4/Bug101.dfy.expect @@ -0,0 +1,8 @@ +Bug101.dfy(10,11): Error: assertion violation
+Execution trace:
+ (0,0): anon0
+ (0,0): anon6_Else
+ (0,0): anon7_Then
+ (0,0): anon5
+
+Dafny program verifier finished with 2 verified, 1 error
|