hohn/codeql
1
0
Fork 0
mirror of https://github.com/github/codeql.git synced 2026-05-02 20:25:13 +02:00
Code Issues Packages Projects Releases Wiki Activity

Merge pull request #1375 from hvitved/csharp/switch-expr-guard

Browse Source 
C#: Switch expression guards
This commit is contained in:
Calum Grant
2019-06-03 11:15:10 +01:00
committed by GitHub
parent 79406f8387 c68dfb9d68
commit 032a6b1c7c
8 changed files with 151 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files

20
csharp/ql/src/semmle/code/csharp/controlflow/Guards.qll
View File

@@ -70,13 +70,13 @@ module AbstractValues {
}
/** An integer value. */
class IntergerValue extends AbstractValue, TIntegerValue {
class IntegerValue extends AbstractValue, TIntegerValue {
/** Gets the underlying integer value. */
int getValue() { this = TIntegerValue(result) }
override predicate branch(ControlFlowElement cfe, ConditionalSuccessor s, Expr e) { none() }
override BooleanValue getDualValue() { none() }
override IntegerValue getDualValue() { none() }
override Expr getAnExpr() {
result.getValue().toInt() = this.getValue() and
@@ -199,7 +199,9 @@ class DereferenceableExpr extends Expr {
// incorrectly `int`, while it should have been `int?`. We apply
// `getNullEquivParent()` as a workaround
this = getNullEquivParent*(e) and
t = e.getType()
t = e.getType() and
not this instanceof SwitchCaseExpr and
not this instanceof PatternExpr
|
t instanceof NullableType and
isNullableType = true
@@ -734,6 +736,8 @@ module Internal {
Guard() {
this.getType() instanceof BoolType and
not this instanceof BoolLiteral and
not this instanceof SwitchCaseExpr and
not this instanceof PatternExpr and
val = TBooleanValue(_)
or
this instanceof DereferenceableExpr and
@@ -1037,9 +1041,9 @@ module Internal {
ck.isInequality() and branch = false
)
or
result = any(PatternMatch pm |
pm.getExpr() = e1 and
e2 = pm.getPattern().(ConstantPatternExpr) and
result = any(IsExpr ie |
ie.getExpr() = e1 and
e2 = ie.getPattern().(ConstantPatternExpr) and
branch = true
)
)
@@ -1068,11 +1072,11 @@ module Internal {
* then `o` is guaranteed to be equal to `""`.
*/
private Expr getAMatchingEqualityCheck(Expr e1, MatchValue v, Expr e2) {
exists(Switch s, ConstCase case | case = v.getCase() |
exists(Switch s, Case case | case = v.getCase() |
e1 = s.getExpr() and
result = e1 and
case = s.getACase() and
e2 = case.getPattern() and
e2 = case.getPattern().(ConstantPatternExpr) and
v.isMatch()
)
}

2
csharp/ql/test/library-tests/controlflow/guards/ExtractorOptions.cs
View File

@@ -1 +1 @@
// semmle-extractor-options: --cil
// semmle-extractor-options: --cil /langversion:8.0

16
csharp/ql/test/library-tests/controlflow/guards/GuardedControlFlowNode.expected
View File

@@ -168,6 +168,22 @@
| Guards.cs:269:11:269:12 | access to parameter o1 | Guards.cs:268:13:268:41 | call to operator == | Guards.cs:268:13:268:14 | access to parameter o1 | true |
| Guards.cs:269:11:269:12 | access to parameter o1 | Guards.cs:268:16:268:25 | call to method GetType | Guards.cs:268:13:268:14 | access to parameter o1 | non-null |
| Guards.cs:271:11:271:12 | access to parameter o1 | Guards.cs:270:13:270:42 | call to operator == | Guards.cs:270:13:270:14 | access to parameter o1 | true |
| Guards.cs:279:17:279:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | match Action<Object> a |
| Guards.cs:279:17:279:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | non-null |
| Guards.cs:283:17:283:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | match "" |
| Guards.cs:283:17:283:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | non-match Action<Object> a |
| Guards.cs:283:17:283:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | non-match Action<String> a |
| Guards.cs:283:17:283:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | non-null |
| Guards.cs:285:17:285:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | match null |
| Guards.cs:285:17:285:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | non-match "" |
| Guards.cs:285:17:285:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | non-match Action<Object> a |
| Guards.cs:285:17:285:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | non-match Action<String> a |
| Guards.cs:285:17:285:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | null |
| Guards.cs:287:17:287:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | non-match "" |
| Guards.cs:287:17:287:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | non-match Action<Object> a |
| Guards.cs:287:17:287:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | non-match Action<String> a |
| Guards.cs:287:17:287:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | non-match null |
| Guards.cs:287:17:287:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | non-null |
| Splitting.cs:13:17:13:17 | [b (line 9): true] access to parameter o | Splitting.cs:12:17:12:17 | access to parameter o | Splitting.cs:12:17:12:17 | access to parameter o | non-null |
| Splitting.cs:13:17:13:17 | [b (line 9): true] access to parameter o | Splitting.cs:12:17:12:25 | ... != ... | Splitting.cs:12:17:12:17 | access to parameter o | true |
| Splitting.cs:14:13:14:13 | [b (line 9): false] access to parameter b | Splitting.cs:11:13:11:13 | access to parameter b | Splitting.cs:11:13:11:13 | access to parameter b | false |

16
csharp/ql/test/library-tests/controlflow/guards/GuardedExpr.expected
View File

@@ -168,6 +168,22 @@
| Guards.cs:269:11:269:12 | access to parameter o1 | Guards.cs:268:13:268:41 | call to operator == | Guards.cs:268:13:268:14 | access to parameter o1 | true |
| Guards.cs:269:11:269:12 | access to parameter o1 | Guards.cs:268:16:268:25 | call to method GetType | Guards.cs:268:13:268:14 | access to parameter o1 | non-null |
| Guards.cs:271:11:271:12 | access to parameter o1 | Guards.cs:270:13:270:42 | call to operator == | Guards.cs:270:13:270:14 | access to parameter o1 | true |
| Guards.cs:279:17:279:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | match Action<Object> a |
| Guards.cs:279:17:279:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | non-null |
| Guards.cs:283:17:283:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | match "" |
| Guards.cs:283:17:283:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | non-match Action<Object> a |
| Guards.cs:283:17:283:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | non-match Action<String> a |
| Guards.cs:283:17:283:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | non-null |
| Guards.cs:285:17:285:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | match null |
| Guards.cs:285:17:285:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | non-match "" |
| Guards.cs:285:17:285:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | non-match Action<Object> a |
| Guards.cs:285:17:285:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | non-match Action<String> a |
| Guards.cs:285:17:285:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | null |
| Guards.cs:287:17:287:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | non-match "" |
| Guards.cs:287:17:287:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | non-match Action<Object> a |
| Guards.cs:287:17:287:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | non-match Action<String> a |
| Guards.cs:287:17:287:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | non-match null |
| Guards.cs:287:17:287:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | non-null |
| Splitting.cs:13:17:13:17 | access to parameter o | Splitting.cs:12:17:12:17 | access to parameter o | Splitting.cs:12:17:12:17 | access to parameter o | non-null |
| Splitting.cs:13:17:13:17 | access to parameter o | Splitting.cs:12:17:12:25 | ... != ... | Splitting.cs:12:17:12:17 | access to parameter o | true |
| Splitting.cs:23:24:23:24 | access to parameter o | Splitting.cs:22:17:22:17 | access to parameter o | Splitting.cs:22:17:22:17 | access to parameter o | non-null |

65
csharp/ql/test/library-tests/controlflow/guards/Guards.cs
View File

@@ -270,4 +270,69 @@ public class Guards
if (o1?.GetType() == o2?.GetType())
o1.ToString(); // not null guarded
}
string M23(object o)
{
return o switch
{
Action<object> a =>
o.ToString(), // null guarded
Action<string> a =>
a.ToString(), // not null (but not a guard)
"" =>
o.ToString(), // null guarded
null =>
o.ToString(), // not null guarded
_ =>
o.ToString() // null guarded
};
}
int M24(bool b1)
{
var b2 = true;
if (b1)
b2 = false;
return b2 switch
{
true => 0,
_ => 1
};
}
int M25(bool b1)
{
var b2 = false;
if (b1)
b2 = true;
return b2 switch
{
true => 0,
_ => 1
};
}
int M26(bool b)
{
var i = 0;
if (b)
i = 1;
return i switch
{
1 => 0,
_ => 1
};
}
int M27(bool b)
{
var e = E.A;
if (b)
e = E.B;
return e switch
{
E.B => 0,
_ => 1
};
}
}

26
csharp/ql/test/library-tests/controlflow/guards/Implications.expected
View File

@@ -349,6 +349,32 @@
| Guards.cs:268:16:268:25 | call to method GetType | non-null | Guards.cs:268:13:268:14 | access to parameter o1 | non-null |
| Guards.cs:270:16:270:25 | call to method GetType | non-null | Guards.cs:270:13:270:14 | access to parameter o1 | non-null |
| Guards.cs:270:33:270:42 | call to method GetType | non-null | Guards.cs:270:30:270:31 | access to parameter o2 | non-null |
| Guards.cs:276:16:276:16 | access to parameter o | match "" | Guards.cs:276:16:276:16 | access to parameter o | non-null |
| Guards.cs:276:16:276:16 | access to parameter o | match Action<Object> a | Guards.cs:276:16:276:16 | access to parameter o | non-null |
| Guards.cs:276:16:276:16 | access to parameter o | match Action<String> a | Guards.cs:276:16:276:16 | access to parameter o | non-null |
| Guards.cs:276:16:276:16 | access to parameter o | match null | Guards.cs:276:16:276:16 | access to parameter o | null |
| Guards.cs:276:16:276:16 | access to parameter o | non-match null | Guards.cs:276:16:276:16 | access to parameter o | non-null |
| Guards.cs:281:17:281:17 | access to local variable a | non-null | Guards.cs:276:16:276:16 | access to parameter o | non-null |
| Guards.cs:281:17:281:17 | access to local variable a | null | Guards.cs:276:16:276:16 | access to parameter o | null |
| Guards.cs:293:13:293:21 | Boolean b2 = ... | false | Guards.cs:293:13:293:14 | access to local variable b2 | false |
| Guards.cs:293:13:293:21 | Boolean b2 = ... | true | Guards.cs:293:13:293:14 | access to local variable b2 | true |
| Guards.cs:295:13:295:22 | ... = ... | false | Guards.cs:295:13:295:14 | access to local variable b2 | false |
| Guards.cs:295:13:295:22 | ... = ... | true | Guards.cs:295:13:295:14 | access to local variable b2 | true |
| Guards.cs:296:16:296:17 | access to local variable b2 | match true | Guards.cs:294:13:294:14 | access to parameter b1 | false |
| Guards.cs:296:16:296:17 | access to local variable b2 | match true | Guards.cs:296:16:296:17 | access to local variable b2 | true |
| Guards.cs:305:13:305:22 | Boolean b2 = ... | false | Guards.cs:305:13:305:14 | access to local variable b2 | false |
| Guards.cs:305:13:305:22 | Boolean b2 = ... | true | Guards.cs:305:13:305:14 | access to local variable b2 | true |
| Guards.cs:307:13:307:21 | ... = ... | false | Guards.cs:307:13:307:14 | access to local variable b2 | false |
| Guards.cs:307:13:307:21 | ... = ... | true | Guards.cs:307:13:307:14 | access to local variable b2 | true |
| Guards.cs:308:16:308:17 | access to local variable b2 | match true | Guards.cs:306:13:306:14 | access to parameter b1 | true |
| Guards.cs:308:16:308:17 | access to local variable b2 | match true | Guards.cs:308:16:308:17 | access to local variable b2 | true |
| Guards.cs:308:16:308:17 | access to local variable b2 | non-match true | Guards.cs:306:13:306:14 | access to parameter b1 | false |
| Guards.cs:320:16:320:16 | access to local variable i | match 1 | Guards.cs:318:13:318:13 | access to parameter b | true |
| Guards.cs:320:16:320:16 | access to local variable i | match 1 | Guards.cs:320:16:320:16 | access to local variable i | 1 |
| Guards.cs:320:16:320:16 | access to local variable i | non-match 1 | Guards.cs:318:13:318:13 | access to parameter b | false |
| Guards.cs:332:16:332:16 | access to local variable e | match access to constant B | Guards.cs:330:13:330:13 | access to parameter b | true |
| Guards.cs:332:16:332:16 | access to local variable e | match access to constant B | Guards.cs:332:16:332:16 | access to local variable e | 1 |
| Guards.cs:332:16:332:16 | access to local variable e | non-match access to constant B | Guards.cs:330:13:330:13 | access to parameter b | false |
| Splitting.cs:12:17:12:25 | ... != ... | false | Splitting.cs:12:17:12:17 | access to parameter o | null |
| Splitting.cs:12:17:12:25 | ... != ... | true | Splitting.cs:12:17:12:17 | access to parameter o | non-null |
| Splitting.cs:22:17:22:25 | ... != ... | false | Splitting.cs:22:17:22:17 | access to parameter o | null |

12
csharp/ql/test/library-tests/controlflow/guards/MatchingGuardedExpr.expected
View File

@@ -10,3 +10,15 @@
| Guards.cs:162:24:162:24 | access to parameter o | Guards.cs:151:17:151:17 | access to parameter o | Guards.cs:155:13:155:34 | case ...: | non-match Action<String> a | false |
| Guards.cs:162:24:162:24 | access to parameter o | Guards.cs:151:17:151:17 | access to parameter o | Guards.cs:157:13:157:20 | case ...: | non-match "" | false |
| Guards.cs:162:24:162:24 | access to parameter o | Guards.cs:151:17:151:17 | access to parameter o | Guards.cs:159:13:159:22 | case ...: | non-match null | false |
| Guards.cs:279:17:279:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:278:13:279:28 | ... => ... | match Action<Object> a | true |
| Guards.cs:283:17:283:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:278:13:279:28 | ... => ... | non-match Action<Object> a | false |
| Guards.cs:283:17:283:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:280:13:281:28 | ... => ... | non-match Action<String> a | false |
| Guards.cs:283:17:283:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:282:13:283:28 | ... => ... | match "" | true |
| Guards.cs:285:17:285:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:278:13:279:28 | ... => ... | non-match Action<Object> a | false |
| Guards.cs:285:17:285:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:280:13:281:28 | ... => ... | non-match Action<String> a | false |
| Guards.cs:285:17:285:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:282:13:283:28 | ... => ... | non-match "" | false |
| Guards.cs:285:17:285:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:284:13:285:28 | ... => ... | match null | true |
| Guards.cs:287:17:287:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:278:13:279:28 | ... => ... | non-match Action<Object> a | false |
| Guards.cs:287:17:287:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:280:13:281:28 | ... => ... | non-match Action<String> a | false |
| Guards.cs:287:17:287:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:282:13:283:28 | ... => ... | non-match "" | false |
| Guards.cs:287:17:287:17 | access to parameter o | Guards.cs:276:16:276:16 | access to parameter o | Guards.cs:284:13:285:28 | ... => ... | non-match null | false |

3
csharp/ql/test/library-tests/controlflow/guards/NullGuardedExpr.expected
View File

@@ -42,6 +42,9 @@
| Guards.cs:205:13:205:13 | access to parameter o |
| Guards.cs:208:17:208:17 | access to parameter o |
| Guards.cs:269:11:269:12 | access to parameter o1 |
| Guards.cs:279:17:279:17 | access to parameter o |
| Guards.cs:283:17:283:17 | access to parameter o |
| Guards.cs:287:17:287:17 | access to parameter o |
| Splitting.cs:13:17:13:17 | access to parameter o |
| Splitting.cs:23:24:23:24 | access to parameter o |
| Splitting.cs:35:13:35:13 | access to parameter o |