C++: fix for constructor init without constructor

Author: Robert Marsh

cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/internal/TranslatedElement.qll

@@ -567,6 +567,13 @@ newtype TTranslatedElement =
   } or
   // The initialization of a base class from within a constructor.
   TTranslatedConstructorBaseInit(ConstructorBaseInit init) { not ignoreExpr(init) } or
+  // Workaround for a case where no base constructor is generated but a targetless base
+  // constructor call is present.
+  TTranslatedConstructorBareInit(ConstructorInit init) {
+    not ignoreExpr(init) and
+    not init instanceof ConstructorBaseInit and
+    not init instanceof ConstructorFieldInit
+  } or
   // The destruction of a base class from within a destructor.
   TTranslatedDestructorBaseDestruction(DestructorBaseDestruction destruction) {
     not ignoreExpr(destruction)

cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/internal/TranslatedFunction.qll

@@ -573,6 +573,11 @@ class TranslatedConstructorInitList extends TranslatedElement, InitializationCon
       baseInit = func.(Constructor).getInitializer(id) and
       result = getTranslatedConstructorBaseInit(baseInit)
     )
+    or
+    exists(ConstructorInit bareInit |
+      bareInit = func.(Constructor).getInitializer(id) and
+      result = getTranslatedConstructorBareInit(bareInit)
+    )
   }
 
   override Instruction getFirstInstruction() {

cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/internal/TranslatedInitialization.qll

@@ -917,3 +917,36 @@ class TranslatedDestructorBaseDestruction extends TranslatedBaseStructorCall,
 
   final override string toString() { result = "destroy base: " + call.toString() }
 }
+
+/**
+ * A constructor base init call where no base constructor has been generated.
+ *
+ * Workaround for an extractor issue.
+ */
+class TranslatedConstructorBareInit extends TranslatedElement, TTranslatedConstructorBareInit {
+  ConstructorInit init;
+
+  TranslatedConstructorBareInit() { this = TTranslatedConstructorBareInit(init) }
+
+  override Locatable getAST() { result = init }
+
+  final override string toString() { result = "construct base (no constructor)" }
+
+  override Instruction getFirstInstruction() { result = getParent().getChildSuccessor(this) }
+
+  override predicate hasInstruction(Opcode opcode, InstructionTag tag, CppType resultType) {
+    none()
+  }
+
+  override TranslatedElement getChild(int id) { none() }
+
+  override Function getFunction() { result = getParent().getFunction() }
+
+  override Instruction getInstructionSuccessor(InstructionTag tag, EdgeKind kind) { none() }
+
+  override Instruction getChildSuccessor(TranslatedElement child) { none() }
+}
+
+TranslatedConstructorBareInit getTranslatedConstructorBareInit(ConstructorInit init) {
+  result.getAST() = init
+}

cpp/ql/test/library-tests/ir/ir/operand_locations.expected

@@ -6644,12 +6644,17 @@
 | ir.cpp:1457:3:1457:20 | Load | m1457_6 |
 | ir.cpp:1457:3:1457:20 | SideEffect | m1457_3 |
 | ir.cpp:1457:3:1457:20 | SideEffect | m1458_6 |
+| ir.cpp:1457:3:1457:20 | Unary | m1457_6 |
+| ir.cpp:1457:26:1457:30 | Address | &:r1457_9 |
+| ir.cpp:1457:26:1457:30 | ChiPartial | partial:m1457_11 |
+| ir.cpp:1457:26:1457:30 | ChiTotal | total:m1457_8 |
+| ir.cpp:1457:26:1457:30 | StoreValue | r1457_10 |
 | ir.cpp:1458:5:1458:5 | Address | &:r1458_2 |
 | ir.cpp:1458:5:1458:5 | Address | &:r1458_4 |
 | ir.cpp:1458:5:1458:5 | Load | m1457_6 |
 | ir.cpp:1458:5:1458:5 | Unary | r1458_3 |
 | ir.cpp:1458:5:1458:9 | ChiPartial | partial:m1458_5 |
-| ir.cpp:1458:5:1458:9 | ChiTotal | total:m1457_8 |
+| ir.cpp:1458:5:1458:9 | ChiTotal | total:m1457_12 |
 | ir.cpp:1458:9:1458:9 | StoreValue | r1458_1 |
 | perf-regression.cpp:6:3:6:5 | Address | &:r6_5 |
 | perf-regression.cpp:6:3:6:5 | Address | &:r6_5 |

cpp/ql/test/library-tests/ir/ir/raw_consistency.expected

@@ -17,7 +17,6 @@ containsLoopOfForwardEdges
 lostReachability
 backEdgeCountMismatch
 useNotDominatedByDefinition
-| ir.cpp:1457:3:1457:20 | Unary | Operand 'Unary' is not dominated by its definition in function '$@'. | ir.cpp:1457:3:1457:20 | void Inheritance_Test_A::Inheritance_Test_A() | void Inheritance_Test_A::Inheritance_Test_A() |
 switchInstructionWithoutDefaultEdge
 notMarkedAsConflated
 wronglyMarkedAsConflated

cpp/ql/test/library-tests/ir/ir/raw_ir.expected

@@ -7882,25 +7882,19 @@ ir.cpp:
 # 1457|     mu1457_5(glval<Inheritance_Test_A>) = InitializeParameter[#this]   : &:r1457_4
 # 1457|     r1457_6(glval<Inheritance_Test_A>)  = Load[#this]                  : &:r1457_4, ~m?
 # 1457|     mu1457_7(Inheritance_Test_A)        = InitializeIndirection[#this] : &:r1457_6
-#-----|   Goto -> Block 2
-
-# 1457|   Block 1
-# 1457|     r1457_8(glval<int>) = FieldAddress[x] : mu1457_5
-# 1457|     r1457_9(int)        = Constant[42]    : 
-# 1457|     mu1457_10(int)      = Store[?]        : &:r1457_8, r1457_9
-#-----|   Goto -> Block 2
-
-# 1458|   Block 2
-# 1458|     r1458_1(int)                  = Constant[3]              : 
-# 1458|     r1458_2(glval<unknown>)       = VariableAddress[#this]   : 
-# 1458|     r1458_3(Inheritance_Test_A *) = Load[#this]              : &:r1458_2, ~m?
-# 1458|     r1458_4(glval<int>)           = FieldAddress[y]          : r1458_3
-# 1458|     mu1458_5(int)                 = Store[?]                 : &:r1458_4, r1458_1
-# 1459|     v1459_1(void)                 = NoOp                     : 
-# 1457|     v1457_11(void)                = ReturnIndirection[#this] : &:r1457_6, ~m?
-# 1457|     v1457_12(void)                = ReturnVoid               : 
-# 1457|     v1457_13(void)                = AliasedUse               : ~m?
-# 1457|     v1457_14(void)                = ExitFunction             : 
+# 1457|     r1457_8(glval<int>)                 = FieldAddress[x]              : mu1457_5
+# 1457|     r1457_9(int)                        = Constant[42]                 : 
+# 1457|     mu1457_10(int)                      = Store[?]                     : &:r1457_8, r1457_9
+# 1458|     r1458_1(int)                        = Constant[3]                  : 
+# 1458|     r1458_2(glval<unknown>)             = VariableAddress[#this]       : 
+# 1458|     r1458_3(Inheritance_Test_A *)       = Load[#this]                  : &:r1458_2, ~m?
+# 1458|     r1458_4(glval<int>)                 = FieldAddress[y]              : r1458_3
+# 1458|     mu1458_5(int)                       = Store[?]                     : &:r1458_4, r1458_1
+# 1459|     v1459_1(void)                       = NoOp                         : 
+# 1457|     v1457_11(void)                      = ReturnIndirection[#this]     : &:r1457_6, ~m?
+# 1457|     v1457_12(void)                      = ReturnVoid                   : 
+# 1457|     v1457_13(void)                      = AliasedUse                   : ~m?
+# 1457|     v1457_14(void)                      = ExitFunction                 : 
 
 perf-regression.cpp:
 #    6| void Big::Big()