improve loplugin:pointerbool

to look through template instantiations involving std::forward

motivated by
commit b1617acde182d1683bdfb529794d7456f8b4bf6d
drop RadioButton arg defaults
the nBits arg in builder.cxx was in the wrong place

Change-Id: I222ea2aeea6f44ae54839e824a247a8105392c2d
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/109789
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

2 files changed, 51 insertions, 0 deletions

diff --git a/compilerplugins/clang/pointerbool.cxx b/compilerplugins/clang/pointerbool.cxx
index 66c6a04b3697..6886e1fac63f 100644
--- a/compilerplugins/clang/pointerbool.cxx
+++ b/compilerplugins/clang/pointerbool.cxx
@@ -38,12 +38,42 @@ public:
             TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
     }
 
+    bool shouldVisitTemplateInstantiations() const { return true; }
+
+    bool PreTraverseFunctionDecl(FunctionDecl* decl);
+    bool PostTraverseFunctionDecl(FunctionDecl* decl, bool);
+    bool TraverseFunctionDecl(FunctionDecl* decl);
     bool VisitCallExpr(CallExpr const*);
 
 private:
     llvm::Optional<APSInt> getCallValue(const Expr* arg);
+    std::vector<FunctionDecl*> functions_;
 };
 
+bool PointerBool::PreTraverseFunctionDecl(FunctionDecl* decl)
+{
+    functions_.push_back(decl);
+    return true;
+}
+
+bool PointerBool::PostTraverseFunctionDecl(FunctionDecl*, bool)
+{
+    assert(!functions_.empty());
+    functions_.pop_back();
+    return true;
+}
+
+bool PointerBool::TraverseFunctionDecl(FunctionDecl* decl)
+{
+    bool ret = true;
+    if (PreTraverseFunctionDecl(decl))
+    {
+        ret = FilteringPlugin::TraverseFunctionDecl(decl);
+        PostTraverseFunctionDecl(decl, ret);
+    }
+    return ret;
+}
+
 bool PointerBool::VisitCallExpr(CallExpr const* callExpr)
 {
     if (ignoreLocation(callExpr))
@@ -98,6 +128,13 @@ bool PointerBool::VisitCallExpr(CallExpr const* callExpr)
             << arg->getSourceRange();
         report(DiagnosticsEngine::Note, "method here", param->getLocation())
             << param->getSourceRange();
+        if (!functions_.empty())
+        {
+            auto callerFD = functions_.back();
+            if (callerFD->isTemplateInstantiation())
+                report(DiagnosticsEngine::Note, "instantiated from here",
+                       callerFD->getPointOfInstantiation());
+        }
     }
     return true;
 }
diff --git a/compilerplugins/clang/test/pointerbool.cxx b/compilerplugins/clang/test/pointerbool.cxx
index 276a95ae1e00..fcb4a9a31b57 100644
--- a/compilerplugins/clang/test/pointerbool.cxx
+++ b/compilerplugins/clang/test/pointerbool.cxx
@@ -29,4 +29,18 @@ void test1(int* p1)
     func_bool(aSeq[0]);
 }
 
+void func_bool2(bool); // expected-note {{method here [loplugin:pointerbool]}}
+
+template <typename... Args> void func_bool_via_forward_template(Args&&... args)
+{
+    // expected-error@+1 {{possibly unwanted implicit conversion when calling bool param [loplugin:pointerbool]}}
+    func_bool2(std::forward<Args>(args)...);
+}
+
+void test2(int p1)
+{
+    // expected-note@+1 {{instantiated from here [loplugin:pointerbool]}}
+    func_bool_via_forward_template(p1);
+}
+
 /* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */