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, 414 insertions, 0 deletions

diff --git a/compilerplugins/clang/oncevar.cxx b/compilerplugins/clang/oncevar.cxx
new file mode 100644
index 000000000..44fcfa950
--- /dev/null
+++ b/compilerplugins/clang/oncevar.cxx
@@ -0,0 +1,414 @@
+/* -*- 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 <unordered_map>
+#include <unordered_set>
+
+#include "plugin.hxx"
+#include "check.hxx"
+#include "config_clang.h"
+#include "clang/AST/CXXInheritance.h"
+#include "clang/AST/StmtVisitor.h"
+
+// Original idea from tml.
+// Look for variables that are (a) initialised from zero or one constants. (b) only used in one spot.
+// In which case, we might as well inline it.
+
+namespace
+{
+
+Expr const * lookThroughInitListExpr(Expr const * expr) {
+    if (auto const ile = dyn_cast<InitListExpr>(expr->IgnoreParenImpCasts())) {
+        if (ile->getNumInits() == 1) {
+            return ile->getInit(0);
+        }
+    }
+    return expr;
+}
+
+class ConstantValueDependentExpressionVisitor:
+    public ConstStmtVisitor<ConstantValueDependentExpressionVisitor, bool>
+{
+    ASTContext const & context_;
+
+public:
+    ConstantValueDependentExpressionVisitor(ASTContext const & context):
+        context_(context) {}
+
+    bool Visit(Stmt const * stmt) {
+        assert(isa<Expr>(stmt));
+        auto const expr = cast<Expr>(stmt);
+        if (!expr->isValueDependent()) {
+            return expr->isEvaluatable(context_);
+        }
+        return ConstStmtVisitor::Visit(stmt);
+    }
+
+    bool VisitParenExpr(ParenExpr const * expr)
+    { return Visit(expr->getSubExpr()); }
+
+    bool VisitCastExpr(CastExpr const * expr) {
+        return Visit(expr->getSubExpr());
+    }
+
+    bool VisitUnaryOperator(UnaryOperator const * expr)
+    { return Visit(expr->getSubExpr()); }
+
+    bool VisitBinaryOperator(BinaryOperator const * expr) {
+        return Visit(expr->getLHS()) && Visit(expr->getRHS());
+    }
+
+    bool VisitUnaryExprOrTypeTraitExpr(UnaryExprOrTypeTraitExpr const *) {
+        return true;
+    }
+};
+
+class OnceVar:
+    public loplugin::FilteringPlugin<OnceVar>
+{
+public:
+    explicit OnceVar(loplugin::InstantiationData const & data): FilteringPlugin(data) {}
+
+    virtual void run() override {
+        // ignore some files with problematic macros
+        std::string fn(handler.getMainFileName());
+        loplugin::normalizeDotDotInFilePath(fn);
+        // platform-specific stuff
+        if (fn == SRCDIR "/sal/osl/unx/thread.cxx"
+            || fn == SRCDIR "/sot/source/base/formats.cxx"
+            || fn == SRCDIR "/svl/source/config/languageoptions.cxx"
+            || fn == SRCDIR "/sfx2/source/appl/appdde.cxx"
+            || fn == SRCDIR "/configmgr/source/components.cxx"
+            || fn == SRCDIR "/embeddedobj/source/msole/oleembed.cxx")
+             return;
+        // some of this is necessary
+        if (loplugin::hasPathnamePrefix( fn, SRCDIR "/sal/qa/"))
+             return;
+        if (loplugin::hasPathnamePrefix( fn, SRCDIR "/comphelper/qa/"))
+             return;
+        // TODO need to check calls via function pointer
+        if (fn == SRCDIR "/i18npool/source/textconversion/textconversion_zh.cxx"
+            || fn == SRCDIR "/i18npool/source/localedata/localedata.cxx")
+             return;
+        // debugging stuff
+        if (fn == SRCDIR "/sc/source/core/data/dpcache.cxx"
+            || fn == SRCDIR "/sw/source/core/layout/dbg_lay.cxx"
+            || fn == SRCDIR "/sw/source/core/layout/ftnfrm.cxx")
+             return;
+        // TODO taking local reference to variable
+        if (fn == SRCDIR "/sc/source/filter/excel/xechart.cxx")
+             return;
+        // macros managing to generate to a valid warning
+        if (fn == SRCDIR "/solenv/bin/concat-deps.c")
+             return;
+        // TODO bug in the plugin
+        if (fn == SRCDIR "/vcl/unx/generic/app/saldisp.cxx")
+            return;
+
+        TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
+
+        for (auto const & varDecl : maVarDeclSet)
+        {
+            if (maVarDeclToIgnoreSet.find(varDecl) != maVarDeclToIgnoreSet.end())
+                continue;
+            int noUses = 0;
+            auto it = maVarUsesMap.find(varDecl);
+            if (it != maVarUsesMap.end())
+                noUses = it->second;
+            if (noUses > 1)
+                continue;
+            report(DiagnosticsEngine::Warning,
+                   "var used only once, should be inlined or declared const",
+                   varDecl->getLocation())
+                << varDecl->getSourceRange();
+            if (it != maVarUsesMap.end())
+                report(DiagnosticsEngine::Note,
+                       "used here",
+                       maVarUseSourceRangeMap[varDecl].getBegin())
+                    << maVarUseSourceRangeMap[varDecl];
+        }
+    }
+
+    bool VisitMemberExpr(MemberExpr const * expr) {
+        // ignore cases like:
+        //     const OUString("xxx") xxx;
+        //     rtl_something(xxx.pData);
+        // where we cannot inline the declaration.
+        if (isa<FieldDecl>(expr->getMemberDecl())) {
+            recordIgnore(expr);
+        }
+        return true;
+    }
+
+    bool VisitUnaryOperator(UnaryOperator const * expr) {
+        // if we take the address of it, or we modify it, ignore it
+        UnaryOperator::Opcode op = expr->getOpcode();
+        if (op == UO_AddrOf || op == UO_PreInc || op == UO_PostInc
+            || op == UO_PreDec || op == UO_PostDec)
+        {
+            recordIgnore(expr->getSubExpr());
+        }
+        return true;
+    }
+
+    bool VisitBinaryOperator(BinaryOperator const * expr) {
+        // if we assign it another value, or modify it, ignore it
+        BinaryOperator::Opcode op = expr->getOpcode();
+        if (op == BO_Assign || op == BO_PtrMemD || op == BO_PtrMemI || op == BO_MulAssign
+            || op == BO_DivAssign || op == BO_RemAssign || op == BO_AddAssign
+            || op == BO_SubAssign || op == BO_ShlAssign || op == BO_ShrAssign
+            || op == BO_AndAssign || op == BO_XorAssign || op == BO_OrAssign)
+        {
+            recordIgnore(expr->getLHS());
+        }
+        return true;
+    }
+
+    bool VisitCallExpr(CallExpr const * expr) {
+        unsigned firstArg = 0;
+        if (auto const cmce = dyn_cast<CXXMemberCallExpr>(expr)) {
+            if (auto const e1 = cmce->getMethodDecl()) {
+                if (!(e1->isConst() || e1->isStatic())) {
+                    recordIgnore(cmce->getImplicitObjectArgument());
+                }
+            } else if (auto const e2 = dyn_cast<BinaryOperator>(
+                           cmce->getCallee()->IgnoreParenImpCasts()))
+            {
+                switch (e2->getOpcode()) {
+                case BO_PtrMemD:
+                case BO_PtrMemI:
+                    if (!e2->getRHS()->getType()->getAs<MemberPointerType>()
+                        ->getPointeeType()->getAs<FunctionProtoType>()
+                        ->isConst())
+                    {
+                        recordIgnore(e2->getLHS());
+                    }
+                    break;
+                default:
+                    break;
+                }
+            }
+        } else if (auto const coce = dyn_cast<CXXOperatorCallExpr>(expr)) {
+            if (auto const cmd = dyn_cast_or_null<CXXMethodDecl>(
+                    coce->getDirectCallee()))
+            {
+                if (!cmd->isStatic()) {
+                    assert(coce->getNumArgs() != 0);
+                    if (!cmd->isConst()) {
+                        recordIgnore(coce->getArg(0));
+                    }
+                    firstArg = 1;
+                }
+            }
+        }
+        // ignore those ones we are passing by reference
+        const FunctionDecl* calleeFunctionDecl = expr->getDirectCallee();
+        if (calleeFunctionDecl) {
+            for (unsigned i = firstArg; i < expr->getNumArgs(); ++i) {
+                if (i < calleeFunctionDecl->getNumParams()) {
+                    QualType qt { calleeFunctionDecl->getParamDecl(i)->getType() };
+                    if (loplugin::TypeCheck(qt).LvalueReference().NonConst()) {
+                        recordIgnore(expr->getArg(i));
+                    }
+                    if (loplugin::TypeCheck(qt).Pointer().NonConst()) {
+                        recordIgnore(expr->getArg(i));
+                    }
+                }
+            }
+        }
+        return true;
+    }
+
+    bool VisitCXXConstructExpr(CXXConstructExpr const * expr) {
+        // ignore those ones we are passing by reference
+        const CXXConstructorDecl* cxxConstructorDecl = expr->getConstructor();
+        for (unsigned i = 0; i < expr->getNumArgs(); ++i) {
+            if (i < cxxConstructorDecl->getNumParams()) {
+                QualType qt { cxxConstructorDecl->getParamDecl(i)->getType() };
+                if (loplugin::TypeCheck(qt).LvalueReference().NonConst()) {
+                    recordIgnore(expr->getArg(i));
+                }
+                if (loplugin::TypeCheck(qt).Pointer().NonConst()) {
+                    recordIgnore(expr->getArg(i));
+                }
+            }
+        }
+        return true;
+    }
+
+    bool VisitDeclRefExpr( const DeclRefExpr* );
+    bool VisitVarDecl( const VarDecl* );
+    bool TraverseFunctionDecl( FunctionDecl* functionDecl );
+
+private:
+    std::unordered_set<VarDecl const *> maVarDeclSet;
+    std::unordered_set<VarDecl const *> maVarDeclToIgnoreSet;
+    std::unordered_map<VarDecl const *, int> maVarUsesMap;
+    std::unordered_map<VarDecl const *, SourceRange> maVarUseSourceRangeMap;
+
+    bool isConstantValueDependentExpression(Expr const * expr) {
+        return ConstantValueDependentExpressionVisitor(compiler.getASTContext())
+            .Visit(expr);
+    }
+
+    void recordIgnore(Expr const * expr) {
+        for (;;) {
+            expr = expr->IgnoreParenImpCasts();
+            if (auto const e = dyn_cast<MemberExpr>(expr)) {
+                if (isa<FieldDecl>(e->getMemberDecl())) {
+                    expr = e->getBase();
+                    continue;
+                }
+            }
+            if (auto const e = dyn_cast<ArraySubscriptExpr>(expr)) {
+                expr = e->getBase();
+                continue;
+            }
+            if (auto const e = dyn_cast<BinaryOperator>(expr)) {
+                if (e->getOpcode() == BO_PtrMemD) {
+                    expr = e->getLHS();
+                    continue;
+                }
+            }
+            break;
+        }
+        auto const dre = dyn_cast<DeclRefExpr>(expr);
+        if (dre == nullptr) {
+            return;
+        }
+        auto const var = dyn_cast<VarDecl>(dre->getDecl());
+        if (var == nullptr) {
+            return;
+        }
+        maVarDeclToIgnoreSet.insert(var);
+    }
+};
+
+bool OnceVar::TraverseFunctionDecl( FunctionDecl* functionDecl )
+{
+    // Ignore functions that contains #ifdef-ery, can be quite tricky
+    // to make useful changes when this plugin fires in such functions
+    if (containsPreprocessingConditionalInclusion(
+            functionDecl->getSourceRange()))
+        return true;
+    return RecursiveASTVisitor::TraverseFunctionDecl(functionDecl);
+}
+
+bool OnceVar::VisitVarDecl( const VarDecl* varDecl )
+{
+    if (ignoreLocation(varDecl)) {
+        return true;
+    }
+    if (auto const init = varDecl->getInit()) {
+        recordIgnore(lookThroughInitListExpr(init));
+    }
+    if (varDecl->isExceptionVariable() || isa<ParmVarDecl>(varDecl)) {
+        return true;
+    }
+    // ignore stuff in header files (which should really not be there, but anyhow)
+    if (!compiler.getSourceManager().isInMainFile(varDecl->getLocation())) {
+        return true;
+    }
+    // Ignore macros like FD_ZERO
+    if (compiler.getSourceManager().isMacroBodyExpansion(varDecl->getBeginLoc())) {
+        return true;
+    }
+    if (varDecl->hasGlobalStorage()) {
+        return true;
+    }
+    auto const tc = loplugin::TypeCheck(varDecl->getType());
+    if (!varDecl->getType().isCXX11PODType(compiler.getASTContext())
+        && !tc.Class("OString").Namespace("rtl").GlobalNamespace()
+        && !tc.Class("OUString").Namespace("rtl").GlobalNamespace()
+        && !tc.Class("OStringBuffer").Namespace("rtl").GlobalNamespace()
+        && !tc.Class("OUStringBuffer").Namespace("rtl").GlobalNamespace()
+        && !tc.Class("Color").GlobalNamespace()
+        && !tc.Class("Pair").GlobalNamespace()
+        && !tc.Class("Point").GlobalNamespace()
+        && !tc.Class("Size").GlobalNamespace()
+        && !tc.Class("Range").GlobalNamespace()
+        && !tc.Class("Selection").GlobalNamespace()
+        && !tc.Class("Rectangle").Namespace("tools").GlobalNamespace())
+    {
+        return true;
+    }
+    if (varDecl->getType()->isPointerType())
+        return true;
+    // if it's declared const, ignore it, it's there to make the code easier to read
+    if (tc.Const())
+        return true;
+
+    if (!varDecl->hasInit())
+        return true;
+
+    // check for string or scalar literals
+    bool foundStringLiteral = false;
+    const Expr * initExpr = varDecl->getInit();
+    if (auto e = dyn_cast<ExprWithCleanups>(initExpr)) {
+        initExpr = e->getSubExpr();
+    }
+    if (isa<clang::StringLiteral>(initExpr)) {
+        foundStringLiteral = true;
+    } else if (auto constructExpr = dyn_cast<CXXConstructExpr>(initExpr)) {
+        if (constructExpr->getNumArgs() == 0) {
+            foundStringLiteral = true; // i.e., empty string
+        } else {
+            auto stringLit2 = dyn_cast<clang::StringLiteral>(constructExpr->getArg(0));
+            foundStringLiteral = stringLit2 != nullptr;
+        }
+    }
+    if (!foundStringLiteral) {
+        auto const init = varDecl->getInit();
+        if (!(init->isValueDependent()
+              ? isConstantValueDependentExpression(init)
+              : init->isConstantInitializer(
+                  compiler.getASTContext(), false/*ForRef*/)))
+        {
+            return true;
+        }
+    }
+
+    maVarDeclSet.insert(varDecl);
+
+    return true;
+}
+
+bool OnceVar::VisitDeclRefExpr( const DeclRefExpr* declRefExpr )
+{
+    if (ignoreLocation(declRefExpr)) {
+        return true;
+    }
+    const Decl* decl = declRefExpr->getDecl();
+    if (!isa<VarDecl>(decl) || isa<ParmVarDecl>(decl)) {
+        return true;
+    }
+    const VarDecl * varDecl = dyn_cast<VarDecl>(decl)->getCanonicalDecl();
+    // ignore stuff in header files (which should really not be there, but anyhow)
+    if (!compiler.getSourceManager().isInMainFile(varDecl->getLocation())) {
+        return true;
+    }
+
+    if (maVarUsesMap.find(varDecl) == maVarUsesMap.end()) {
+        maVarUsesMap[varDecl] = 1;
+        maVarUseSourceRangeMap[varDecl] = declRefExpr->getSourceRange();
+    } else {
+        maVarUsesMap[varDecl]++;
+    }
+
+    return true;
+}
+
+loplugin::Plugin::Registration< OnceVar > X("oncevar", false);
+
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */