C++: Put in a better fix.

geoffw0 · geoffw0 · commit 2d7552358b0f · 2020-09-03T18:51:57.000+01:00
diff --git a/cpp/ql/src/Best Practices/Hiding/DeclarationHidesParameter.ql b/cpp/ql/src/Best Practices/Hiding/DeclarationHidesParameter.ql
@@ -11,6 +11,21 @@
 
 import cpp
 
+/**
+ * Gets the template that a function `f` is constructed from, or just `f` if it
+ * is not from a template instantiation.
+ */
+Function getConstructedFrom(Function f)
+{
+  exists(Function mid |
+    f.isConstructedFrom(mid) and
+    result = getConstructedFrom(mid)
+  ) or (
+    not f.isConstructedFrom(_) and
+    result = f
+  )
+}
+
 /**
  * Gets the parameter of `f` with name `name`, which has to come from the
  * _definition_ of `f` and not a prototype declaration.
@@ -22,7 +37,7 @@ import cpp
 ParameterDeclarationEntry functionParameterNames(Function f, string name) {
   exists(FunctionDeclarationEntry fe |
     result.getFunctionDeclarationEntry() = fe and
-    fe.getFunction() = f and
+    getConstructedFrom(f).getDefinition() = fe and
     fe.getLocation() = f.getDefinitionLocation() and
     strictcount(f.getDefinitionLocation()) = 1 and
     result.getName() = name
diff --git a/cpp/ql/test/query-tests/Best Practices/Hiding/DeclarationHidesParameter/DeclarationHidesParameter.expected b/cpp/ql/test/query-tests/Best Practices/Hiding/DeclarationHidesParameter/DeclarationHidesParameter.expected
@@ -1,10 +1,7 @@
 | hiding.cpp:4:17:4:18 | ii | Local variable 'ii' hides a $@. | hiding.cpp:2:12:2:13 | definition of ii | parameter of the same name |
 | hiding.cpp:15:15:15:16 | kk | Local variable 'kk' hides a $@. | hiding.cpp:12:25:12:26 | definition of kk | parameter of the same name |
 | hiding.cpp:28:7:28:7 | a | Local variable 'a' hides a $@. | hiding.cpp:26:21:26:21 | definition of a | parameter of the same name |
-| hiding.cpp:45:7:45:7 | a | Local variable 'a' hides a $@. | hiding.cpp:39:20:39:20 | definition of a | parameter of the same name |
-| hiding.cpp:47:7:47:7 | c | Local variable 'c' hides a $@. | hiding.cpp:39:34:39:34 | definition of c | parameter of the same name |
+| hiding.cpp:45:7:45:7 | a | Local variable 'a' hides a $@. | hiding.cpp:43:41:43:41 | definition of a | parameter of the same name |
 | hiding.cpp:64:11:64:11 | i | Local variable 'i' hides a $@. | hiding.cpp:61:20:61:20 | definition of i | parameter of the same name |
-| hiding.cpp:76:7:76:15 | protoArg1 | Local variable 'protoArg1' hides a $@. | hiding.h:5:21:5:29 | definition of protoArg1 | parameter of the same name |
-| hiding.cpp:77:5:77:13 | protoArg2 | Local variable 'protoArg2' hides a $@. | hiding.h:5:34:5:42 | definition of protoArg2 | parameter of the same name |
 | hiding.cpp:78:7:78:10 | arg1 | Local variable 'arg1' hides a $@. | hiding.cpp:74:28:74:31 | definition of arg1 | parameter of the same name |
 | hiding.cpp:79:5:79:8 | arg2 | Local variable 'arg2' hides a $@. | hiding.cpp:74:36:74:39 | definition of arg2 | parameter of the same name |
diff --git a/cpp/ql/test/query-tests/Best Practices/Hiding/DeclarationHidesParameter/hiding.cpp b/cpp/ql/test/query-tests/Best Practices/Hiding/DeclarationHidesParameter/hiding.cpp
@@ -44,7 +44,7 @@ void MyTemplateClass<T> :: myMethod(int a, int b, int _c) {
 	{
 		int a = a; // local variable hides global variable
 		int _b = b;
-		int c = _c; // [FALSE POSITIVE]
+		int c = _c;
 
 		// ...
 	}
@@ -73,8 +73,8 @@ void myClass::myCaller(void) {
 template <typename T>
 void myClass::myMethod(int arg1, T arg2) {
 	{
-		int protoArg1; // [FALSE POSITIVE]
-		T protoArg2; // [FALSE POSITIVE]
+		int protoArg1;
+		T protoArg2;
 		int arg1; // local variable hides global variable
 		T arg2; // local variable hides global variable
 	}

Original file line number	Diff line number	Diff line change
`@@ -44,7 +44,7 @@ void MyTemplateClass<T> :: myMethod(int a, int b, int _c) {`
`44`	`44`	`{`
`45`	`45`	`int a = a; // local variable hides global variable`
`46`	`46`	`int _b = b;`
`47`		`- int c = _c; // [FALSE POSITIVE]`
	`47`	`+ int c = _c;`
`48`	`48`
`49`	`49`	`// ...`
`50`	`50`	`}`
`@@ -73,8 +73,8 @@ void myClass::myCaller(void) {`
`73`	`73`	`template <typename T>`
`74`	`74`	`void myClass::myMethod(int arg1, T arg2) {`
`75`	`75`	`{`
`76`		`- int protoArg1; // [FALSE POSITIVE]`
`77`		`- T protoArg2; // [FALSE POSITIVE]`
	`76`	`+ int protoArg1;`
	`77`	`+ T protoArg2;`
`78`	`78`	`int arg1; // local variable hides global variable`
`79`	`79`	`T arg2; // local variable hides global variable`
`80`	`80`	`}`