C++: Print handler parameters in PrintAST

cpp/ql/lib/semmle/code/cpp/PrintAST.qll

@@ -80,6 +80,8 @@ private Declaration getAnEnclosingDeclaration(Locatable ast) {
   or
   result = ast.(Parameter).getFunction()
   or
+  result = ast.(Parameter).getCatchBlock().getEnclosingFunction()
+  or
   result = ast.(Expr).getEnclosingDeclaration()
   or
   result = ast.(Initializer).getDeclaration()
@@ -510,6 +512,22 @@ class DeclStmtNode extends StmtNode {
   }
 }
 
+/**
+ * A node representing a `Handler`.
+ */
+class HandlerNode extends ChildStmtNode {
+  Handler handler;
+
+  HandlerNode() { handler = stmt }
+
+  override BaseAstNode getChildInternal(int childIndex) {
+    result = super.getChildInternal(childIndex)
+    or
+    childIndex = -1 and
+    result.getAst() = handler.getParameter()
+  }
+}
+
 /**
  * A node representing a `Parameter`.
  */
@@ -754,6 +772,8 @@ private predicate namedStmtChildPredicates(Locatable s, Element e, string pred)
     or
     s.(ConstexprIfStmt).getElse() = e and pred = "getElse()"
     or
+    s.(Handler).getParameter() = e and pred = "getParameter()"
+    or
     s.(IfStmt).getInitialization() = e and pred = "getInitialization()"
     or
     s.(IfStmt).getCondition() = e and pred = "getCondition()"

cpp/ql/test/examples/expressions/PrintAST.expected

@@ -870,6 +870,8 @@ Throw.cpp:
 #    8|               Type = [BoolType] bool
 #    8|               ValueCategory = prvalue
 #   12|       getChild(1): [Handler] <handler>
+#   12|         getParameter(): [Parameter] e
+#   12|             Type = [PointerType] E *
 #   12|         getBlock(): [CatchBlock] { ... }
 #   13|           getStmt(0): [ExprStmt] ExprStmt
 #   13|             getExpr(): [ReThrowExpr] re-throw exception 

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

@@ -9055,6 +9055,8 @@ ir.cpp:
 #  733|                 Value = [Literal] 7
 #  733|                 ValueCategory = prvalue
 #  735|       getChild(1): [Handler] <handler>
+#  735|         getParameter(): [Parameter] s
+#  735|             Type = [PointerType] const char *
 #  735|         getBlock(): [CatchBlock] { ... }
 #  736|           getStmt(0): [ExprStmt] ExprStmt
 #  736|             getExpr(): [ThrowExpr] throw ...
@@ -9067,6 +9069,8 @@ ir.cpp:
 #  736|                     Type = [PointerType] const char *
 #  736|                     ValueCategory = prvalue(load)
 #  738|       getChild(2): [Handler] <handler>
+#  738|         getParameter(): [Parameter] e
+#  738|             Type = [LValueReferenceType] const String &
 #  738|         getBlock(): [CatchBlock] { ... }
 #  740|       getChild(3): [Handler] <handler>
 #  740|         getBlock(): [CatchAnyBlock] { ... }
@@ -12852,6 +12856,8 @@ ir.cpp:
 # 1200|                 Value = [Literal] 7
 # 1200|                 ValueCategory = prvalue
 # 1202|       getChild(1): [Handler] <handler>
+# 1202|         getParameter(): [Parameter] s
+# 1202|             Type = [PointerType] const char *
 # 1202|         getBlock(): [CatchBlock] { ... }
 # 1203|           getStmt(0): [ExprStmt] ExprStmt
 # 1203|             getExpr(): [ThrowExpr] throw ...
@@ -12864,6 +12870,8 @@ ir.cpp:
 # 1203|                     Type = [PointerType] const char *
 # 1203|                     ValueCategory = prvalue(load)
 # 1205|       getChild(2): [Handler] <handler>
+# 1205|         getParameter(): [Parameter] e
+# 1205|             Type = [LValueReferenceType] const String &
 # 1205|         getBlock(): [CatchBlock] { ... }
 # 1207|     getStmt(1): [ReturnStmt] return ...
 # 1211| [TopLevelFunction] void VectorTypes(int)
@@ -20586,6 +20594,8 @@ ir.cpp:
 # 2281|               Type = [Struct] String
 # 2281|               ValueCategory = lvalue
 # 2282|       getChild(1): [Handler] <handler>
+# 2282|         getParameter(): [Parameter] s
+# 2282|             Type = [PointerType] const char *
 # 2282|         getBlock(): [CatchBlock] { ... }
 # 2283|           getStmt(0): [ExprStmt] ExprStmt
 # 2283|             getExpr(): [ThrowExpr] throw ...
@@ -20598,6 +20608,8 @@ ir.cpp:
 # 2283|                     Type = [PointerType] const char *
 # 2283|                     ValueCategory = prvalue(load)
 # 2285|       getChild(2): [Handler] <handler>
+# 2285|         getParameter(): [Parameter] e
+# 2285|             Type = [LValueReferenceType] const String &
 # 2285|         getBlock(): [CatchBlock] { ... }
 # 2287|       getChild(3): [Handler] <handler>
 # 2287|         getBlock(): [CatchAnyBlock] { ... }
@@ -22845,6 +22857,8 @@ ir.cpp:
 # 2537|                 Value = [Literal] 42
 # 2537|                 ValueCategory = prvalue
 # 2539|       getChild(1): [Handler] <handler>
+# 2539|         getParameter(): [Parameter] (unnamed parameter 0)
+# 2539|             Type = [PlainCharType] char
 # 2539|         getBlock(): [CatchBlock] { ... }
 # 2541|         getImplicitDestructorCall(0): [DestructorCall] call to ~ClassWithDestructor
 # 2541|             Type = [VoidType] void