Merge pull request github#5909 from tamasvajk/fix/foreach-ir-temp-var

C#: Fix type of temp foreach variable in IR

Author: tamasvajk

csharp/ql/src/experimental/ir/implementation/raw/internal/desugar/Common.qll

@@ -182,15 +182,21 @@ abstract class TranslatedCompilerGeneratedVariableAccess extends TranslatedCompi
 
   override Instruction getChildSuccessor(TranslatedElement child) { none() }
 
+  /**
+   * Returns the type of the accessed variable. Can be overriden when the return
+   * type is different than the type of the underlying variable.
+   */
+  Type getVariableType() { result = getResultType() }
+
   override predicate hasInstruction(Opcode opcode, InstructionTag tag, CSharpType resultType) {
     tag = AddressTag() and
     opcode instanceof Opcode::VariableAddress and
-    resultType = getTypeForGLValue(getResultType())
+    resultType = getTypeForGLValue(getVariableType())
     or
     needsLoad() and
     tag = LoadTag() and
     opcode instanceof Opcode::Load and
-    resultType = getTypeForPRValue(getResultType())
+    resultType = getTypeForPRValue(getVariableType())
   }
 
   override Instruction getInstructionSuccessor(InstructionTag tag, EdgeKind kind) {

csharp/ql/src/experimental/ir/implementation/raw/internal/desugar/Foreach.qll

@@ -359,9 +359,16 @@ private class TranslatedMoveNextEnumAcc extends TTranslatedCompilerGeneratedElem
 
   override Type getResultType() { result instanceof BoolType }
 
+  override Type getVariableType() {
+    exists(TranslatedForeachGetEnumerator ge |
+      ge.getAST() = generatedBy and
+      result = ge.getCallResultType()
+    )
+  }
+
   override predicate hasTempVariable(TempVariableTag tag, CSharpType type) {
     tag = ForeachEnumTempVar() and
-    type = getTypeForPRValue(getResultType())
+    type = getTypeForPRValue(getVariableType())
   }
 
   override IRVariable getInstructionVariable(InstructionTag tag) {
@@ -384,9 +391,16 @@ private class TranslatedForeachCurrentEnumAcc extends TTranslatedCompilerGenerat
 
   override Type getResultType() { result instanceof BoolType }
 
+  override Type getVariableType() {
+    exists(TranslatedForeachGetEnumerator ge |
+      ge.getAST() = generatedBy and
+      result = ge.getCallResultType()
+    )
+  }
+
   override predicate hasTempVariable(TempVariableTag tag, CSharpType type) {
     tag = ForeachEnumTempVar() and
-    type = getTypeForPRValue(getResultType())
+    type = getTypeForPRValue(getVariableType())
   }
 
   override IRVariable getInstructionVariable(InstructionTag tag) {
@@ -409,9 +423,16 @@ private class TranslatedForeachDisposeEnumAcc extends TTranslatedCompilerGenerat
 
   override Type getResultType() { result instanceof BoolType }
 
+  override Type getVariableType() {
+    exists(TranslatedForeachGetEnumerator ge |
+      ge.getAST() = generatedBy and
+      result = ge.getCallResultType()
+    )
+  }
+
   override predicate hasTempVariable(TempVariableTag tag, CSharpType type) {
     tag = ForeachEnumTempVar() and
-    type = getTypeForPRValue(getResultType())
+    type = getTypeForPRValue(getVariableType())
   }
 
   override IRVariable getInstructionVariable(InstructionTag tag) {

csharp/ql/test/experimental/ir/ir/raw_ir.expected

@@ -613,48 +613,48 @@ foreach.cs:
 #    5|     r5_28(glval<Int32>)      = PointerAdd[4]                  : r5_1, r5_27
 #    5|     r5_29(Int32)             = Constant[7]                    : 
 #    5|     mu5_30(Int32)            = Store[?]                       : &:r5_28, r5_29
-#    7|     r7_1(glval<Boolean>)     = VariableAddress[#temp7:9]      : 
+#    7|     r7_1(glval<IEnumerator>) = VariableAddress[#temp7:9]      : 
 #    7|     r7_2(glval<Int32[]>)     = VariableAddress[a_array]       : 
 #    7|     r7_3(Int32[])            = Load[a_array]                  : &:r7_2, ~m?
 #    7|     r7_4(<funcaddr>)         = FunctionAddress[GetEnumerator] : 
 #    7|     r7_5(IEnumerator)        = Call[GetEnumerator]            : func:r7_4, this:r7_3
 #    7|     mu7_6(<unknown>)         = ^CallSideEffect                : ~m?
-#    7|     mu7_7(Boolean)           = Store[#temp7:9]                : &:r7_1, r7_5
+#    7|     mu7_7(IEnumerator)       = Store[#temp7:9]                : &:r7_1, r7_5
 #-----|   Goto -> Block 1
 
 #    7|   Block 1
-#    7|     r7_8(glval<Boolean>) = VariableAddress[#temp7:9] : 
-#    7|     r7_9(Boolean)        = Load[#temp7:9]            : &:r7_8, ~m?
-#    7|     r7_10(<funcaddr>)    = FunctionAddress[MoveNext] : 
-#    7|     r7_11(Boolean)       = Call[MoveNext]            : func:r7_10, this:r7_9
-#    7|     mu7_12(<unknown>)    = ^CallSideEffect           : ~m?
-#    7|     v7_13(Void)          = ConditionalBranch         : r7_11
+#    7|     r7_8(glval<IEnumerator>) = VariableAddress[#temp7:9] : 
+#    7|     r7_9(IEnumerator)        = Load[#temp7:9]            : &:r7_8, ~m?
+#    7|     r7_10(<funcaddr>)        = FunctionAddress[MoveNext] : 
+#    7|     r7_11(Boolean)           = Call[MoveNext]            : func:r7_10, this:r7_9
+#    7|     mu7_12(<unknown>)        = ^CallSideEffect           : ~m?
+#    7|     v7_13(Void)              = ConditionalBranch         : r7_11
 #-----|   False -> Block 3
 #-----|   True -> Block 2
 
 #    7|   Block 2
-#    7|     r7_14(glval<Int32>)   = VariableAddress[items]       : 
-#    7|     r7_15(glval<Boolean>) = VariableAddress[#temp7:9]    : 
-#    7|     r7_16(Boolean)        = Load[#temp7:9]               : &:r7_15, ~m?
-#    7|     r7_17(<funcaddr>)     = FunctionAddress[get_Current] : 
-#    7|     r7_18(Int32)          = Call[get_Current]            : func:r7_17, this:r7_16
-#    7|     mu7_19(<unknown>)     = ^CallSideEffect              : ~m?
-#    7|     mu7_20(Int32)         = Store[items]                 : &:r7_14, r7_18
-#    9|     r9_1(glval<Int32>)    = VariableAddress[x]           : 
-#    9|     r9_2(glval<Int32>)    = VariableAddress[items]       : 
-#    9|     r9_3(Int32)           = Load[items]                  : &:r9_2, ~m?
-#    9|     mu9_4(Int32)          = Store[x]                     : &:r9_1, r9_3
+#    7|     r7_14(glval<Int32>)       = VariableAddress[items]       : 
+#    7|     r7_15(glval<IEnumerator>) = VariableAddress[#temp7:9]    : 
+#    7|     r7_16(IEnumerator)        = Load[#temp7:9]               : &:r7_15, ~m?
+#    7|     r7_17(<funcaddr>)         = FunctionAddress[get_Current] : 
+#    7|     r7_18(Int32)              = Call[get_Current]            : func:r7_17, this:r7_16
+#    7|     mu7_19(<unknown>)         = ^CallSideEffect              : ~m?
+#    7|     mu7_20(Int32)             = Store[items]                 : &:r7_14, r7_18
+#    9|     r9_1(glval<Int32>)        = VariableAddress[x]           : 
+#    9|     r9_2(glval<Int32>)        = VariableAddress[items]       : 
+#    9|     r9_3(Int32)               = Load[items]                  : &:r9_2, ~m?
+#    9|     mu9_4(Int32)              = Store[x]                     : &:r9_1, r9_3
 #-----|   Goto (back edge) -> Block 1
 
 #    7|   Block 3
-#    7|     r7_21(glval<Boolean>) = VariableAddress[#temp7:9] : 
-#    7|     r7_22(Boolean)        = Load[#temp7:9]            : &:r7_21, ~m?
-#    7|     r7_23(<funcaddr>)     = FunctionAddress[Dispose]  : 
-#    7|     v7_24(Void)           = Call[Dispose]             : func:r7_23, this:r7_22
-#    7|     mu7_25(<unknown>)     = ^CallSideEffect           : ~m?
-#    4|     v4_3(Void)            = ReturnVoid                : 
-#    4|     v4_4(Void)            = AliasedUse                : ~m?
-#    4|     v4_5(Void)            = ExitFunction              : 
+#    7|     r7_21(glval<IEnumerator>) = VariableAddress[#temp7:9] : 
+#    7|     r7_22(IEnumerator)        = Load[#temp7:9]            : &:r7_21, ~m?
+#    7|     r7_23(<funcaddr>)         = FunctionAddress[Dispose]  : 
+#    7|     v7_24(Void)               = Call[Dispose]             : func:r7_23, this:r7_22
+#    7|     mu7_25(<unknown>)         = ^CallSideEffect           : ~m?
+#    4|     v4_3(Void)                = ReturnVoid                : 
+#    4|     v4_4(Void)                = AliasedUse                : ~m?
+#    4|     v4_5(Void)                = ExitFunction              : 
 
 func_with_param_call.cs:
 #    5| System.Int32 test_call_with_param.f(System.Int32,System.Int32)

csharp/ql/test/experimental/ir/ir/raw_ir_consistency.expected

@@ -26,9 +26,6 @@ fieldAddressOnNonPointer
 | inoutref.cs:19:13:19:17 | FieldAddress: access to field fld | FieldAddress instruction 'FieldAddress: access to field fld' has an object address operand that is not an address, in function '$@'. | inoutref.cs:16:17:16:17 | System.Void InOutRef.F(System.Int32,MyStruct,MyStruct,MyClass,MyClass) | System.Void InOutRef.F(System.Int32,MyStruct,MyStruct,MyClass,MyClass) |
 | pointers.cs:35:17:35:24 | FieldAddress: access to field fld | FieldAddress instruction 'FieldAddress: access to field fld' has an object address operand that is not an address, in function '$@'. | pointers.cs:25:17:25:20 | System.Void Pointers.Main() | System.Void Pointers.Main() |
 thisArgumentIsNonPointer
-| foreach.cs:7:9:10:9 | Call: foreach (... ... in ...) ... | Call instruction 'Call: foreach (... ... in ...) ...' has a `this` argument operand that is not an address, in function '$@'. | foreach.cs:4:24:4:27 | System.Void ForEach.Main() | System.Void ForEach.Main() |
-| foreach.cs:7:9:10:9 | Call: foreach (... ... in ...) ... | Call instruction 'Call: foreach (... ... in ...) ...' has a `this` argument operand that is not an address, in function '$@'. | foreach.cs:4:24:4:27 | System.Void ForEach.Main() | System.Void ForEach.Main() |
-| foreach.cs:7:9:10:9 | Call: foreach (... ... in ...) ... | Call instruction 'Call: foreach (... ... in ...) ...' has a `this` argument operand that is not an address, in function '$@'. | foreach.cs:4:24:4:27 | System.Void ForEach.Main() | System.Void ForEach.Main() |
 | inoutref.cs:32:22:32:35 | Call: object creation of type MyStruct | Call instruction 'Call: object creation of type MyStruct' has a `this` argument operand that is not an address, in function '$@'. | inoutref.cs:29:17:29:20 | System.Void InOutRef.Main() | System.Void InOutRef.Main() |
 | pointers.cs:27:22:27:35 | Call: object creation of type MyStruct | Call instruction 'Call: object creation of type MyStruct' has a `this` argument operand that is not an address, in function '$@'. | pointers.cs:25:17:25:20 | System.Void Pointers.Main() | System.Void Pointers.Main() |
 missingCanonicalLanguageType

csharp/ql/test/experimental/ir/ir/unaliased_ssa_consistency.expected

@@ -26,9 +26,6 @@ fieldAddressOnNonPointer
 | inoutref.cs:19:13:19:17 | FieldAddress: access to field fld | FieldAddress instruction 'FieldAddress: access to field fld' has an object address operand that is not an address, in function '$@'. | inoutref.cs:16:17:16:17 | System.Void InOutRef.F(System.Int32,MyStruct,MyStruct,MyClass,MyClass) | System.Void InOutRef.F(System.Int32,MyStruct,MyStruct,MyClass,MyClass) |
 | pointers.cs:35:17:35:24 | FieldAddress: access to field fld | FieldAddress instruction 'FieldAddress: access to field fld' has an object address operand that is not an address, in function '$@'. | pointers.cs:25:17:25:20 | System.Void Pointers.Main() | System.Void Pointers.Main() |
 thisArgumentIsNonPointer
-| foreach.cs:7:9:10:9 | Call: foreach (... ... in ...) ... | Call instruction 'Call: foreach (... ... in ...) ...' has a `this` argument operand that is not an address, in function '$@'. | foreach.cs:4:24:4:27 | System.Void ForEach.Main() | System.Void ForEach.Main() |
-| foreach.cs:7:9:10:9 | Call: foreach (... ... in ...) ... | Call instruction 'Call: foreach (... ... in ...) ...' has a `this` argument operand that is not an address, in function '$@'. | foreach.cs:4:24:4:27 | System.Void ForEach.Main() | System.Void ForEach.Main() |
-| foreach.cs:7:9:10:9 | Call: foreach (... ... in ...) ... | Call instruction 'Call: foreach (... ... in ...) ...' has a `this` argument operand that is not an address, in function '$@'. | foreach.cs:4:24:4:27 | System.Void ForEach.Main() | System.Void ForEach.Main() |
 | inoutref.cs:32:22:32:35 | Call: object creation of type MyStruct | Call instruction 'Call: object creation of type MyStruct' has a `this` argument operand that is not an address, in function '$@'. | inoutref.cs:29:17:29:20 | System.Void InOutRef.Main() | System.Void InOutRef.Main() |
 | pointers.cs:27:22:27:35 | Call: object creation of type MyStruct | Call instruction 'Call: object creation of type MyStruct' has a `this` argument operand that is not an address, in function '$@'. | pointers.cs:25:17:25:20 | System.Void Pointers.Main() | System.Void Pointers.Main() |
 missingCanonicalLanguageType