Adding upstream version 4:7.4.7.upstream/4%7.4.7upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 301 insertions, 0 deletions

diff --git a/compilerplugins/clang/unusedenumconstants.cxx b/compilerplugins/clang/unusedenumconstants.cxx
new file mode 100644
index 000000000..a04117343
--- /dev/null
+++ b/compilerplugins/clang/unusedenumconstants.cxx
@@ -0,0 +1,301 @@
+/* -*- 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 "config_clang.h"
+#include "plugin.hxx"
+
+/**
+This looks for unused enum constants
+
+We search for 3 things
+(a) constants that are declared but never used
+(b) constants only used in a "read" fashion i.e. we compare stuff against them, but we never store a value anywhere
+(c) constants only used in a "write" fashion i.e. we store a value, but never check for that value
+
+(a) is fairly reliable but (b) and (c) will need some checking before acting on.
+
+Be warned that it produces around 5G of log file.
+
+The process goes something like this:
+  $ make check
+  $ make FORCE_COMPILE=all COMPILER_PLUGIN_TOOL='unusedenumconstants' check
+  $ ./compilerplugins/clang/unusedenumconstants.py
+
+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;
+    SourceLocation loc;
+};
+bool operator < (const MyFieldInfo &lhs, const MyFieldInfo &rhs)
+{
+    return std::tie(lhs.parentClass, lhs.fieldName)
+         < std::tie(rhs.parentClass, rhs.fieldName);
+}
+
+
+// try to limit the voluminous output a little
+static std::set<MyFieldInfo> definitionSet;
+static std::set<MyFieldInfo> writeSet;
+static std::set<MyFieldInfo> readSet;
+
+
+class UnusedEnumConstants:
+    public loplugin::FilteringPlugin<UnusedEnumConstants>
+{
+public:
+    explicit UnusedEnumConstants(loplugin::InstantiationData const & data): FilteringPlugin(data) {}
+
+    virtual void run() override
+    {
+        TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
+
+        if (!isUnitTestMode())
+        {
+            // 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 : definitionSet)
+                output += "definition:\t" + s.parentClass + "\t" + s.fieldName + "\t" + s.sourceLocation + "\n";
+            for (const MyFieldInfo & s : writeSet)
+                output += "write:\t" + s.parentClass + "\t" + s.fieldName + "\n";
+            for (const MyFieldInfo & s : readSet)
+                output += "read:\t" + s.parentClass + "\t" + s.fieldName + "\n";
+            std::ofstream myfile;
+            myfile.open( WORKDIR "/loplugin.unusedenumconstants.log", std::ios::app | std::ios::out);
+            myfile << output;
+            myfile.close();
+        }
+        else
+        {
+            for (const MyFieldInfo& s : writeSet)
+                report(DiagnosticsEngine::Warning, "write %0", s.loc)
+                    << s.fieldName;
+            for (const MyFieldInfo& s : readSet)
+                report(DiagnosticsEngine::Warning, "read %0", s.loc)
+                    << s.fieldName;
+        }
+    }
+
+    bool shouldVisitTemplateInstantiations () const { return true; }
+    bool shouldVisitImplicitCode() const { return true; }
+
+    bool VisitEnumConstantDecl( const EnumConstantDecl * );
+    bool VisitDeclRefExpr( const DeclRefExpr * );
+private:
+    MyFieldInfo niceName(const EnumConstantDecl*);
+};
+
+MyFieldInfo UnusedEnumConstants::niceName(const EnumConstantDecl* enumConstantDecl)
+{
+    MyFieldInfo aInfo;
+
+    aInfo.parentClass = enumConstantDecl->getType().getAsString();
+    aInfo.fieldName = enumConstantDecl->getNameAsString();
+    // sometimes the name (if it's anonymous thing) contains the full path of the build folder, which we don't need
+    size_t idx = aInfo.fieldName.find(SRCDIR);
+    if (idx != std::string::npos) {
+        aInfo.fieldName = aInfo.fieldName.replace(idx, strlen(SRCDIR), "");
+    }
+
+    SourceLocation expansionLoc = compiler.getSourceManager().getExpansionLoc( enumConstantDecl->getLocation() );
+    StringRef name = getFilenameOfLocation(expansionLoc);
+    aInfo.loc = expansionLoc;
+    aInfo.sourceLocation = std::string(name.substr(strlen(SRCDIR)+1)) + ":" + std::to_string(compiler.getSourceManager().getSpellingLineNumber(expansionLoc));
+    loplugin::normalizeDotDotInFilePath(aInfo.sourceLocation);
+
+    return aInfo;
+}
+
+bool UnusedEnumConstants::VisitEnumConstantDecl( const EnumConstantDecl* enumConstantDecl )
+{
+    enumConstantDecl = enumConstantDecl->getCanonicalDecl();
+    if (ignoreLocation( enumConstantDecl )) {
+        return true;
+    }
+    // ignore stuff that forms part of the stable URE interface
+    if (isInUnoIncludeFile(compiler.getSourceManager().getSpellingLoc(enumConstantDecl->getLocation()))) {
+        return true;
+    }
+
+    definitionSet.insert(niceName(enumConstantDecl));
+    return true;
+}
+
+bool UnusedEnumConstants::VisitDeclRefExpr( const DeclRefExpr* declRefExpr )
+{
+    auto enumConstantDecl = dyn_cast<EnumConstantDecl>(declRefExpr->getDecl());
+    if (!enumConstantDecl) {
+        return true;
+    }
+    enumConstantDecl = enumConstantDecl->getCanonicalDecl();
+    if (ignoreLocation(enumConstantDecl)) {
+        return true;
+    }
+    // ignore stuff that forms part of the stable URE interface
+    if (isInUnoIncludeFile(compiler.getSourceManager().getSpellingLoc(enumConstantDecl->getLocation()))) {
+        return true;
+    }
+
+    const Stmt * parent = declRefExpr;
+    const Stmt * child = nullptr;
+
+walk_up:
+    child = parent;
+    parent = getParentStmt(parent);
+    bool bWrite = false;
+    bool bRead = false;
+    bool bDump = false;
+    if (!parent)
+    {
+        // Could probably do better here.
+        // Sometimes this is a constructor-initialiser-expression, so just make a pessimistic assumption.
+        bWrite = true;
+    }
+    else if (const CXXOperatorCallExpr * operatorCall = dyn_cast<CXXOperatorCallExpr>(parent))
+    {
+        auto oo = operatorCall->getOperator();
+        if (oo == OO_AmpEqual)
+        {
+            // Ignore a common pattern that does not introduce any new information, merely removes
+            // information:     foo &= ~Enum6::Top
+            bool found = false;
+            if (auto innerOperatorCall = dyn_cast<CXXOperatorCallExpr>(operatorCall->getArg(1)->IgnoreImplicit()->IgnoreParens()->IgnoreImplicit()))
+            {
+                found = innerOperatorCall->getOperator() == OO_Tilde;
+            }
+            if (!found)
+                bWrite = true;
+        }
+            // if assignment op
+        else if (oo == OO_Equal || oo == OO_StarEqual || oo == OO_SlashEqual || oo == OO_PercentEqual
+           || oo == OO_PlusEqual || oo == OO_MinusEqual || oo == OO_LessLessEqual
+           || oo == OO_CaretEqual || oo == OO_PipeEqual)
+            bWrite = true;
+            // else if comparison op
+        else if (oo == OO_AmpAmp || oo == OO_PipePipe || oo == OO_Subscript
+            || oo == OO_Less || oo == OO_Greater || oo == OO_LessEqual || oo == OO_GreaterEqual || oo == OO_EqualEqual || oo == OO_ExclaimEqual)
+            bRead = true;
+        else
+            goto walk_up;
+    }
+    else if (const CXXMemberCallExpr * memberCall = dyn_cast<CXXMemberCallExpr>(parent))
+    {
+        // happens a lot with o3tl::typed_flags
+        if (*memberCall->child_begin() == child)
+        {
+            if (auto conversionDecl = dyn_cast<CXXConversionDecl>(memberCall->getMethodDecl()))
+            {
+                if (conversionDecl->getConversionType()->isSpecificBuiltinType(clang::BuiltinType::Bool))
+                    bRead = true;
+                else
+                    goto walk_up;
+            }
+            else
+                goto walk_up;
+        }
+        else
+            bWrite = true;
+    }
+    else if (isa<CallExpr>(parent) || isa<InitListExpr>(parent) || isa<ArraySubscriptExpr>(parent)
+             || isa<ReturnStmt>(parent) || isa<DeclStmt>(parent)
+             || isa<CXXConstructExpr>(parent)
+             || isa<CXXThrowExpr>(parent))
+    {
+        bWrite = true;
+    }
+    else if (isa<CaseStmt>(parent) || isa<SwitchStmt>(parent) || isa<IfStmt>(parent)
+            || isa<WhileStmt>(parent) || isa<DoStmt>(parent) || isa<ForStmt>(parent) || isa<DefaultStmt>(parent))
+    {
+        bRead = true;
+    }
+    else if (const BinaryOperator * binaryOp = dyn_cast<BinaryOperator>(parent))
+    {
+        if (BinaryOperator::isAssignmentOp(binaryOp->getOpcode())) {
+            bWrite = true;
+        } else if (BinaryOperator::isComparisonOp(binaryOp->getOpcode())) {
+            bRead = true;
+        } else {
+            goto walk_up;
+        }
+    }
+    else if (isa<ConditionalOperator>(parent))
+    {
+        goto walk_up;
+    }
+    else if (isa<CastExpr>(parent) || isa<UnaryOperator>(parent)
+                || isa<ParenExpr>(parent)
+                || isa<MaterializeTemporaryExpr>(parent)
+                || isa<ExprWithCleanups>(parent)
+                || isa<ConstantExpr>(parent)
+                || isa<CXXBindTemporaryExpr>(parent))
+    {
+        goto walk_up;
+    }
+    else if (isa<CXXDefaultArgExpr>(parent))
+    {
+        // TODO this could be improved
+        bWrite = true;
+    }
+    else if (isa<DeclRefExpr>(parent))
+    {
+        // slightly weird case I saw in basegfx where the enum is being used as a template param
+        bWrite = true;
+    }
+    else if (isa<MemberExpr>(parent))
+    {
+        goto walk_up;
+    }
+    else if (isa<UnresolvedLookupExpr>(parent)
+            || isa<CompoundStmt>(parent))
+    {
+        bRead = true;
+        bWrite = true;
+    }
+    else
+    {
+        bDump = true;
+    }
+
+    // to let me know if I missed something
+    if (bDump) {
+        parent->dump();
+        declRefExpr->dump();
+        report( DiagnosticsEngine::Warning,
+                "unhandled clang AST node type",
+                parent->getBeginLoc());
+    }
+
+    if (bWrite) {
+        writeSet.insert(niceName(enumConstantDecl));
+    }
+    if (bRead) {
+        readSet.insert(niceName(enumConstantDecl));
+    }
+    return true;
+}
+
+loplugin::Plugin::Registration< UnusedEnumConstants > X("unusedenumconstants", false);
+
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */