new loplugin:unusedfields

run it over the framework module

Change-Id: I1220a4be0936ba30136ce22ffd78633c8a7b9d35

compilerplugins/clang/unusedfields.cxx

@@ -0,0 +1,202 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <cassert>
+#include <string>
+#include <iostream>
+#include <fstream>
+#include <set>
+#include "plugin.hxx"
+#include "compat.hxx"
+
+/**
+Dump a list of calls to methods, and a list of field definitions.
+Then we will post-process the 2 lists and find the set of unused methods.
+
+Be warned that it produces around 5G of log file.
+
+The process goes something like this:
+  $ make check
+  $ make FORCE_COMPILE_ALL=1 COMPILER_PLUGIN_TOOL='unusedfields' check
+  $ ./compilerplugins/clang/unusedfields.py unusedfields.log > result.txt
+
+and then
+  $ for dir in *; do make FORCE_COMPILE_ALL=1 UPDATE_FILES=$dir COMPILER_PLUGIN_TOOL='unusedfieldsremove' $dir; done
+to auto-remove the method declarations
+
+Note that the actual process may involve a fair amount of undoing, hand editing, and general messing around
+to get it to work :-)
+
+*/
+
+namespace {
+
+struct MyFieldInfo
+{
+    std::string parentClass;
+    std::string fieldName;
+    std::string sourceLocation;
+
+    bool operator < (const MyFieldInfo &other) const
+    {
+        if (parentClass < other.parentClass)
+            return true;
+        else if (parentClass == other.parentClass)
+            return fieldName < other.fieldName;
+        else
+            return false;
+    }
+};
+
+
+// try to limit the voluminous output a little
+static std::set<MyFieldInfo> touchedSet;
+static std::set<MyFieldInfo> definitionSet;
+
+
+class UnusedFields:
+    public RecursiveASTVisitor<UnusedFields>, public loplugin::Plugin
+{
+public:
+    explicit UnusedFields(InstantiationData const & data): Plugin(data) {}
+
+    virtual void run() override
+    {
+        TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
+
+        // dump all our output in one write call - this is to try and limit IO "crosstalk" between multiple processes
+        // writing to the same logfile
+        std::string output;
+        for (const MyFieldInfo & s : touchedSet)
+            output += "touch:\t" + s.parentClass + "\t" + s.fieldName + "\n";
+        for (const MyFieldInfo & s : definitionSet)
+        {
+            output += "definition:\t" + s.parentClass + "\t" + s.fieldName + "\t" + s.sourceLocation + "\n";
+        }
+        ofstream myfile;
+        myfile.open( SRCDIR "/unusedfields.log", ios::app | ios::out);
+        myfile << output;
+        myfile.close();
+    }
+
+    bool shouldVisitTemplateInstantiations () const { return true; }
+
+    bool VisitCallExpr(CallExpr* );
+    bool VisitFieldDecl( const FieldDecl* );
+    bool VisitMemberExpr( const MemberExpr* );
+    bool VisitDeclRefExpr( const DeclRefExpr* );
+private:
+    MyFieldInfo niceName(const FieldDecl*);
+    std::string fullyQualifiedName(const FunctionDecl*);
+};
+
+MyFieldInfo UnusedFields::niceName(const FieldDecl* fieldDecl)
+{
+    MyFieldInfo aInfo;
+    aInfo.parentClass = fieldDecl->getParent()->getQualifiedNameAsString();
+    aInfo.fieldName = fieldDecl->getNameAsString();
+
+    SourceLocation expansionLoc = compiler.getSourceManager().getExpansionLoc( fieldDecl->getLocation() );
+    StringRef name = compiler.getSourceManager().getFilename(expansionLoc);
+    aInfo.sourceLocation = std::string(name.substr(strlen(SRCDIR)+1)) + ":" + std::to_string(compiler.getSourceManager().getSpellingLineNumber(expansionLoc));
+
+    return aInfo;
+}
+
+std::string UnusedFields::fullyQualifiedName(const FunctionDecl* functionDecl)
+{
+    std::string ret = compat::getReturnType(*functionDecl).getCanonicalType().getAsString();
+    ret += " ";
+    if (isa<CXXMethodDecl>(functionDecl)) {
+        const CXXRecordDecl* recordDecl = dyn_cast<CXXMethodDecl>(functionDecl)->getParent();
+        ret += recordDecl->getQualifiedNameAsString();
+        ret += "::";
+    }
+    ret += functionDecl->getNameAsString() + "(";
+    bool bFirst = true;
+    for (const ParmVarDecl *pParmVarDecl : functionDecl->params()) {
+        if (bFirst)
+            bFirst = false;
+        else
+            ret += ",";
+        ret += pParmVarDecl->getType().getCanonicalType().getAsString();
+    }
+    ret += ")";
+    if (isa<CXXMethodDecl>(functionDecl) && dyn_cast<CXXMethodDecl>(functionDecl)->isConst()) {
+        ret += " const";
+    }
+
+    return ret;
+}
+
+// prevent recursive templates from blowing up the stack
+static std::set<std::string> traversedFunctionSet;
+
+bool UnusedFields::VisitCallExpr(CallExpr* expr)
+{
+    // Note that I don't ignore ANYTHING here, because I want to get calls to my code that result
+    // from template instantiation deep inside the STL and other external code
+
+    FunctionDecl* calleeFunctionDecl = expr->getDirectCallee();
+    if (calleeFunctionDecl == nullptr) {
+        Expr* callee = expr->getCallee()->IgnoreParenImpCasts();
+        DeclRefExpr* dr = dyn_cast<DeclRefExpr>(callee);
+        if (dr) {
+            calleeFunctionDecl = dyn_cast<FunctionDecl>(dr->getDecl());
+            if (calleeFunctionDecl)
+                goto gotfunc;
+        }
+        return true;
+    }
+
+gotfunc:
+    // if we see a call to a function, it may effectively create new code,
+    // if the function is templated. However, if we are inside a template function,
+    // calling another function on the same template, the same problem occurs.
+    // Rather than tracking all of that, just traverse anything we have not already traversed.
+    if (traversedFunctionSet.insert(fullyQualifiedName(calleeFunctionDecl)).second)
+        TraverseFunctionDecl(calleeFunctionDecl);
+
+    return true;
+}
+
+bool UnusedFields::VisitFieldDecl( const FieldDecl* fieldDecl )
+{
+    fieldDecl = fieldDecl->getCanonicalDecl();
+
+    if( !ignoreLocation( fieldDecl ))
+        definitionSet.insert(niceName(fieldDecl));
+    return true;
+}
+
+bool UnusedFields::VisitMemberExpr( const MemberExpr* memberExpr )
+{
+    const ValueDecl* decl = memberExpr->getMemberDecl();
+    if (!isa<FieldDecl>(decl)) {
+        return true;
+    }
+    touchedSet.insert(niceName(dyn_cast<FieldDecl>(decl)));
+    return true;
+}
+
+bool UnusedFields::VisitDeclRefExpr( const DeclRefExpr* declRefExpr )
+{
+    const Decl* decl = declRefExpr->getDecl();
+    if (!isa<FieldDecl>(decl)) {
+        return true;
+    }
+    touchedSet.insert(niceName(dyn_cast<FieldDecl>(decl)));
+    return true;
+}
+
+loplugin::Plugin::Registration< UnusedFields > X("unusedfields", false);
+
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */