commit 9fe55a32b717cc301d3707356f1e4b71b920a9e7
author Daniel Jasper <djasper@google.com> Mon Jul 27 13:46:37 2015 +0000
committer Daniel Jasper <djasper@google.com> Mon Jul 27 13:46:37 2015 +0000
tree 490c661285867fa7e3a00569789053a7ea2ef4e2
parent 5a4892b4faa6307aba79d15fee725bb8cc019e02

misc-unused-parameters: Don't warn on ParmVarDecls in the return type.

As there don't seem to be a good way of formulating a matcher that
finds all pairs of functions and their ParmVarDecls, just match on
functionDecls and iterate over their parameters. This should also be
more efficient as some checks are only performed once per function.

llvm-svn: 243267

clang-tools-extra/clang-tidy/misc/UnusedParametersCheck.cpp

diff --git a/clang-tools-extra/clang-tidy/misc/UnusedParametersCheck.cpp b/clang-tools-extra/clang-tidy/misc/UnusedParametersCheck.cpp
index df00c9f..02cb621 100644
--- a/clang-tools-extra/clang-tidy/misc/UnusedParametersCheck.cpp
+++ b/clang-tools-extra/clang-tidy/misc/UnusedParametersCheck.cpp
@@ -17,9 +17,7 @@
 namespace tidy {
 
 void UnusedParametersCheck::registerMatchers(MatchFinder *Finder) {
-  Finder->addMatcher(
-      parmVarDecl(hasParent(functionDecl().bind("function"))).bind("x"),
-      this);
+  Finder->addMatcher(functionDecl().bind("function"), this);
 }
 
 static FixItHint removeParameter(const FunctionDecl *Function, unsigned Index) {
@@ -54,15 +52,10 @@
   return FixItHint::CreateRemoval(RemovalRange);
 }
 
-void UnusedParametersCheck::check(const MatchFinder::MatchResult &Result) {
-  const auto *Function = Result.Nodes.getNodeAs<FunctionDecl>("function");
-  if (!Function->doesThisDeclarationHaveABody())
-    return;
-  const auto *Param = Result.Nodes.getNodeAs<ParmVarDecl>("x");
-  if (Param->isUsed() || Param->isReferenced() || !Param->getDeclName() ||
-      Param->hasAttr<UnusedAttr>())
-    return;
-
+void UnusedParametersCheck::warnOnUnusedParameter(
+    const MatchFinder::MatchResult &Result, const FunctionDecl *Function,
+    unsigned ParamIndex) {
+  const auto *Param = Function->getParamDecl(ParamIndex);
   auto MyDiag = diag(Param->getLocation(), "parameter '%0' is unused")
                 << Param->getName();
 
@@ -86,10 +79,6 @@
     return;
   }
 
-  // Handle local functions by deleting the parameters.
-  unsigned ParamIndex = Param->getFunctionScopeIndex();
-  assert(ParamIndex < Function->getNumParams());
-
   // Fix all redeclarations.
   for (const FunctionDecl *FD : Function->redecls())
     MyDiag << removeParameter(FD, ParamIndex);
@@ -103,5 +92,18 @@
     MyDiag << removeArgument(Match.getNodeAs<CallExpr>("x"), ParamIndex);
 }
 
+void UnusedParametersCheck::check(const MatchFinder::MatchResult &Result) {
+  const auto *Function = Result.Nodes.getNodeAs<FunctionDecl>("function");
+  if (!Function->doesThisDeclarationHaveABody())
+    return;
+  for (unsigned i = 0, e = Function->getNumParams(); i != e; ++i) {
+    const auto *Param = Function->getParamDecl(i);
+    if (Param->isUsed() || Param->isReferenced() || !Param->getDeclName() ||
+        Param->hasAttr<UnusedAttr>())
+      continue;
+    warnOnUnusedParameter(Result, Function, i);
+  }
+}
+
 } // namespace tidy
 } // namespace clang