Adding upstream version 4:24.2.0.upstream/4%24.2.0

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

1 files changed, 1111 insertions, 0 deletions

diff --git a/compilerplugins/clang/plugin.cxx b/compilerplugins/clang/plugin.cxx
new file mode 100644
index 0000000000..10102d4260
--- /dev/null
+++ b/compilerplugins/clang/plugin.cxx
@@ -0,0 +1,1111 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * Based on LLVM/Clang.
+ *
+ * This file is distributed under the University of Illinois Open Source
+ * License. See LICENSE.TXT for details.
+ *
+ */
+
+#include "plugin.hxx"
+
+#include <cassert>
+#include <cstddef>
+#include <string>
+
+#include <clang/AST/ParentMapContext.h>
+#include <clang/Basic/FileManager.h>
+#include <clang/Lex/Lexer.h>
+
+#include "config_clang.h"
+
+#include "compat.hxx"
+#include "pluginhandler.hxx"
+#include "check.hxx"
+
+/*
+Base classes for plugin actions.
+*/
+namespace loplugin
+{
+
+namespace {
+
+Expr const * skipImplicit(Expr const * expr) {
+    if (auto const e = dyn_cast<MaterializeTemporaryExpr>(expr)) {
+        expr = e->getSubExpr()->IgnoreImpCasts();
+    }
+    if (auto const e = dyn_cast<CXXBindTemporaryExpr>(expr)) {
+        expr = e->getSubExpr();
+    }
+    return expr;
+}
+
+bool structurallyIdentical(Stmt const * stmt1, Stmt const * stmt2) {
+    if (stmt1->getStmtClass() != stmt2->getStmtClass()) {
+        return false;
+    }
+    switch (stmt1->getStmtClass()) {
+    case Stmt::CXXConstructExprClass:
+        if (cast<CXXConstructExpr>(stmt1)->getConstructor()->getCanonicalDecl()
+            != cast<CXXConstructExpr>(stmt2)->getConstructor()->getCanonicalDecl())
+        {
+            return false;
+        }
+        break;
+    case Stmt::DeclRefExprClass:
+        if (cast<DeclRefExpr>(stmt1)->getDecl()->getCanonicalDecl()
+            != cast<DeclRefExpr>(stmt2)->getDecl()->getCanonicalDecl())
+        {
+            return false;
+        }
+        break;
+    case Stmt::ImplicitCastExprClass:
+        {
+            auto const e1 = cast<ImplicitCastExpr>(stmt1);
+            auto const e2 = cast<ImplicitCastExpr>(stmt2);
+            if (e1->getCastKind() != e2->getCastKind()
+                || e1->getType().getCanonicalType() != e2->getType().getCanonicalType())
+            {
+                return false;
+            }
+            break;
+        }
+    case Stmt::MemberExprClass:
+        {
+            auto const e1 = cast<MemberExpr>(stmt1);
+            auto const e2 = cast<MemberExpr>(stmt2);
+            if (e1->isArrow() != e2->isArrow()
+                || e1->getType().getCanonicalType() != e2->getType().getCanonicalType())
+            {
+                return false;
+            }
+            break;
+        }
+    case Stmt::CXXMemberCallExprClass:
+    case Stmt::CXXOperatorCallExprClass:
+        if (cast<Expr>(stmt1)->getType().getCanonicalType()
+            != cast<Expr>(stmt2)->getType().getCanonicalType())
+        {
+            return false;
+        }
+        break;
+    case Stmt::MaterializeTemporaryExprClass:
+    case Stmt::CXXBindTemporaryExprClass:
+    case Stmt::CXXDefaultArgExprClass:
+    case Stmt::ParenExprClass:
+        break;
+    case Stmt::CXXNullPtrLiteralExprClass:
+        return true;
+    case Stmt::StringLiteralClass:
+        return cast<clang::StringLiteral>(stmt1)->getBytes()
+            == cast<clang::StringLiteral>(stmt2)->getBytes();
+    default:
+        // Conservatively assume non-identical for expressions that don't happen for us in practice
+        // when compiling the LO code base (and for which the above set of supported classes would
+        // need to be extended):
+        return false;
+    }
+    auto i1 = stmt1->child_begin();
+    auto e1 = stmt1->child_end();
+    auto i2 = stmt2->child_begin();
+    auto e2 = stmt2->child_end();
+    for (; i1 != e1; ++i1, ++i2) {
+        if (i2 == e2 || !structurallyIdentical(*i1, *i2)) {
+            return false;
+        }
+    }
+    return i2 == e2;
+}
+
+}
+
+Plugin::Plugin( const InstantiationData& data )
+    : compiler( data.compiler ), handler( data.handler ), name( data.name )
+{
+}
+
+DiagnosticBuilder Plugin::report( DiagnosticsEngine::Level level, StringRef message, SourceLocation loc ) const
+{
+    return handler.report( level, name, message, compiler, loc );
+}
+
+bool Plugin::suppressWarningAt(SourceLocation location) const {
+    auto const start = compiler.getSourceManager().getSpellingLoc(location);
+    auto const startInfo = compiler.getSourceManager().getDecomposedLoc(start);
+    auto invalid = false;
+    auto const buf = compiler.getSourceManager().getBufferData(startInfo.first, &invalid);
+    if (invalid) {
+        if (isDebugMode()) {
+            report(DiagnosticsEngine::Fatal, "failed to getBufferData", start);
+        }
+        return false;
+    }
+    auto const label = std::string("[-loplugin:").append(name).append("]");
+    // Look back to the beginning of the previous line:
+    auto loc = start;
+    auto locInfo = startInfo;
+    auto cur = loc;
+    enum class State { Normal, Slash, Comment };
+    auto state = State::Normal;
+    auto newlines = 0;
+    for (auto prev = cur;;) {
+        auto prevInfo = compiler.getSourceManager().getDecomposedLoc(prev);
+        if (prev == compiler.getSourceManager().getLocForStartOfFile(prevInfo.first)) {
+            if (state == State::Comment && isDebugMode()) {
+                report(
+                    DiagnosticsEngine::Fatal,
+                    "beginning of file while looking for beginning of comment", prev);
+            }
+            break;
+        }
+        Token tok;
+        if (Lexer::getRawToken(
+                Lexer::GetBeginningOfToken(
+                    prev.getLocWithOffset(-1), compiler.getSourceManager(), compiler.getLangOpts()),
+                tok, compiler.getSourceManager(), compiler.getLangOpts(), true))
+        {
+            if (isDebugMode()) {
+                report(
+                    DiagnosticsEngine::Fatal, "failed to getRawToken",
+                    prev.getLocWithOffset(-1));
+            }
+            break;
+        }
+        if (tok.getLocation() == cur) {
+            // Keep walking back, character by character, through whitespace preceding the current
+            // token, which Clang treats as nominally belonging to that token (so the above
+            // Lexer::getRawToken/Lexer::GetBeginningOfToken will have produced just the same tok
+            // again):
+            prev = prev.getLocWithOffset(-1);
+            continue;
+        }
+        cur = tok.getLocation();
+        prev = cur;
+        if (state == State::Comment) {
+            // Lexer::GetBeginningOfToken (at least towards Clang 15, still) only re-scans from the
+            // start of the current line, so if we saw the end of a multi-line /*...*/ comment, we
+            // saw that as individual '/' and '*' faux-tokens, at which point we must (hopefully?)
+            // actually be at the end of such a multi-line comment, so we keep walking back to the
+            // first '/*' we encounter (TODO: which still need not be the real start of the comment,
+            // if the comment contains embedded '/*', but we could determine that only if we
+            // re-scanned from the start of the file):
+            if (!tok.is(tok::comment)) {
+                continue;
+            }
+            SmallVector<char, 256> tmp;
+            bool invalid = false;
+            auto const spell = Lexer::getSpelling(
+                prev, tmp, compiler.getSourceManager(), compiler.getLangOpts(), &invalid);
+            if (invalid) {
+                if (isDebugMode()) {
+                    report(DiagnosticsEngine::Fatal, "failed to getSpelling", prev);
+                }
+            } else if (!spell.startswith("/*")) {
+                continue;
+            }
+        }
+        prevInfo = compiler.getSourceManager().getDecomposedLoc(prev);
+        auto const end = prev.getLocWithOffset(tok.getLength());
+        auto const endInfo = compiler.getSourceManager().getDecomposedLoc(end);
+        assert(prevInfo.first == endInfo .first);
+        assert(prevInfo.second <= endInfo.second);
+        assert(endInfo.first == locInfo.first);
+        // Whitespace between tokens is found at the end of prev, from end to loc (unless this is a
+        // multi-line comment, in which case the whitespace has already been inspected as the
+        // whitespace following the comment's final '/' faux-token):
+        StringRef ws;
+        if (state != State::Comment) {
+            assert(endInfo.second <= locInfo.second);
+            ws = buf.substr(endInfo.second, locInfo.second - endInfo.second);
+        }
+        for (std::size_t i = 0;;) {
+            auto const j = ws.find('\n', i);
+            if (j == StringRef::npos) {
+                break;
+            }
+            ++newlines;
+            if (newlines == 2) {
+                break;
+            }
+            i = j + 1;
+        }
+        if (newlines == 2) {
+            break;
+        }
+        auto str = buf.substr(prevInfo.second, endInfo.second - prevInfo.second);
+        if (tok.is(tok::comment) && str.contains(label)) {
+            return true;
+        }
+        for (std::size_t i = 0;;) {
+            auto const j = str.find('\n', i);
+            if (j == StringRef::npos) {
+                break;
+            }
+            ++newlines;
+            if (newlines == 2) {
+                break;
+            }
+            i = j + 1;
+        }
+        if (newlines == 2) {
+            break;
+        }
+        loc = prev;
+        locInfo = prevInfo;
+        switch (state) {
+        case State::Normal:
+            if (tok.is(tok::slash)) {
+                state = State::Slash;
+            }
+            break;
+        case State::Slash:
+            state = tok.is(tok::star) && ws.empty() ? State::Comment : State::Normal;
+                //TODO: check for "ws is only folding whitespace" rather than for `ws.empty()` (but
+                // then, we must not count newlines in that whitespace twice, first as part of the
+                // whitespace following the comment's semi-final '*' faux-token and then as part of
+                // the comment token's content)
+            break;
+        case State::Comment:
+            state = State::Normal;
+        }
+    }
+    // Look forward to the end of the current line:
+    loc = start;
+    locInfo = startInfo;
+    for (;;) {
+        Token tok;
+        if (Lexer::getRawToken(loc, tok, compiler.getSourceManager(), compiler.getLangOpts(), true))
+        {
+            if (isDebugMode()) {
+                report(DiagnosticsEngine::Fatal, "failed to getRawToken", loc);
+            }
+            break;
+        }
+        // Whitespace between tokens is found at the beginning, from loc to beg:
+        auto const beg = tok.getLocation();
+        auto const begInfo = compiler.getSourceManager().getDecomposedLoc(beg);
+        assert(begInfo.first == locInfo.first);
+        assert(begInfo.second >= locInfo.second);
+        if (buf.substr(locInfo.second, begInfo.second - locInfo.second).contains('\n')) {
+            break;
+        }
+        auto const next = beg.getLocWithOffset(tok.getLength());
+        auto const nextInfo = compiler.getSourceManager().getDecomposedLoc(next);
+        assert(nextInfo.first == begInfo.first);
+        assert(nextInfo.second >= begInfo.second);
+        auto const str = buf.substr(begInfo.second, nextInfo.second - begInfo.second);
+        if (tok.is(tok::comment) && str.contains(label)) {
+            return true;
+        }
+        if (tok.is(tok::eof) || str.contains('\n')) {
+            break;
+        }
+        loc = next;
+        locInfo = nextInfo;
+    }
+    return false;
+}
+
+void normalizeDotDotInFilePath( std::string & s )
+{
+    for (std::string::size_type i = 0;;)
+    {
+        i = s.find("/.", i);
+        if (i == std::string::npos) {
+            break;
+        }
+        if (i + 2 == s.length() || s[i + 2] == '/') {
+            s.erase(i, 2); // [AAA]/.[/CCC] -> [AAA][/CCC]
+        } else if (s[i + 2] == '.'
+                   && (i + 3 == s.length() || s[i + 3] == '/'))
+        {
+            if (i == 0) { // /..[/CCC] -> /..[/CCC]
+                break;
+            }
+            auto j = s.rfind('/', i - 1);
+            if (j == std::string::npos)
+            {
+                // BBB/..[/CCC] -> BBB/..[/CCC] (instead of BBB/../CCC ->
+                // CCC, to avoid wrong ../../CCC -> CCC; relative paths
+                // shouldn't happen anyway, and even if they did, wouldn't
+                // match against WORKDIR anyway, as WORKDIR should be
+                // absolute):
+                break;
+            }
+            s.erase(j, i + 3 - j); // AAA/BBB/..[/CCC] -> AAA[/CCC]
+            i = j;
+        } else {
+            i += 2;
+        }
+    }
+}
+
+void Plugin::registerPlugin( Plugin* (*create)( const InstantiationData& ), const char* optionName,
+    bool isPPCallback, bool isSharedPlugin, bool byDefault )
+{
+    PluginHandler::registerPlugin( create, optionName, isPPCallback, isSharedPlugin, byDefault );
+}
+
+bool Plugin::evaluate(const Expr* expr, APSInt& x)
+{
+    if (compat::EvaluateAsInt(expr, x, compiler.getASTContext()))
+    {
+        return true;
+    }
+    if (isa<CXXNullPtrLiteralExpr>(expr)) {
+        x = 0;
+        return true;
+    }
+    return false;
+}
+
+const Stmt* Plugin::getParentStmt( const Stmt* stmt )
+{
+    auto parentsRange = compiler.getASTContext().getParents(*stmt);
+    if ( parentsRange.begin() == parentsRange.end())
+        return nullptr;
+    return parentsRange.begin()->get<Stmt>();
+}
+
+Stmt* Plugin::getParentStmt( Stmt* stmt )
+{
+    auto parentsRange = compiler.getASTContext().getParents(*stmt);
+    if ( parentsRange.begin() == parentsRange.end())
+        return nullptr;
+    return const_cast<Stmt*>(parentsRange.begin()->get<Stmt>());
+}
+
+const Decl* getFunctionDeclContext(ASTContext& context, const Stmt* stmt)
+{
+    auto const parents = context.getParents(*stmt);
+    auto it = parents.begin();
+
+    if (it == parents.end())
+          return nullptr;
+
+    const Decl *decl = it->get<Decl>();
+    if (decl)
+    {
+        if (isa<VarDecl>(decl))
+            return dyn_cast<FunctionDecl>(decl->getDeclContext());
+        return decl;
+    }
+
+    stmt = it->get<Stmt>();
+    if (stmt)
+        return getFunctionDeclContext(context, stmt);
+
+    return nullptr;
+}
+
+const FunctionDecl* Plugin::getParentFunctionDecl( const Stmt* stmt )
+{
+    const Decl *decl = getFunctionDeclContext(compiler.getASTContext(), stmt);
+    if (decl)
+        return static_cast<const FunctionDecl*>(decl->getNonClosureContext());
+
+    return nullptr;
+}
+
+StringRef Plugin::getFilenameOfLocation(SourceLocation spellingLocation) const
+{
+    // prevent crashes when running the global-analysis plugins
+    if (!spellingLocation.isValid())
+        return "";
+
+    static enum { NOINIT, STDIN, GOOD } s_Mode(NOINIT);
+    if (s_Mode == GOOD)
+    {
+        return compiler.getSourceManager().getFilename(spellingLocation);
+    }
+    else if (s_Mode == STDIN
+             || !compiler.getSourceManager().isInMainFile(spellingLocation))
+    {
+        const char* bufferName = compiler.getSourceManager().getPresumedLoc(spellingLocation).getFilename();
+        return bufferName;
+    }
+    else
+    {
+        char const*const pCXX = getenv("CXX");
+        if (pCXX && strstr(pCXX, "sccache"))
+        {   // heuristic; sccache passes file with -frewrite-directives by name
+            s_Mode = STDIN;
+            return getFilenameOfLocation(spellingLocation);
+        }
+        auto const fn(compiler.getSourceManager().getFilename(spellingLocation));
+        if (!fn.data()) // wtf? happens in sot/source/sdstor/stg.cxx
+        {
+            return fn;
+        }
+#if !defined _WIN32
+        assert(fn.startswith("/") || fn == "<stdin>");
+#endif
+        s_Mode = fn == "<stdin>" ? STDIN : GOOD;
+        return getFilenameOfLocation(spellingLocation);
+    }
+}
+
+bool Plugin::isInUnoIncludeFile(SourceLocation spellingLocation) const
+{
+    StringRef name{ getFilenameOfLocation(spellingLocation) };
+    return compiler.getSourceManager().isInMainFile(spellingLocation)
+        ? (isSamePathname(name, SRCDIR "/cppu/source/cppu/compat.cxx")
+           || isSamePathname(name, SRCDIR "/cppuhelper/source/compat.cxx")
+           || isSamePathname(name, SRCDIR "/sal/osl/all/compat.cxx"))
+        : (hasPathnamePrefix(name, SRCDIR "/include/com/")
+           || hasPathnamePrefix(name, SRCDIR "/include/cppu/")
+           || hasPathnamePrefix(name, SRCDIR "/include/cppuhelper/")
+           || hasPathnamePrefix(name, SRCDIR "/include/osl/")
+           || hasPathnamePrefix(name, SRCDIR "/include/rtl/")
+           || hasPathnamePrefix(name, SRCDIR "/include/sal/")
+           || hasPathnamePrefix(name, SRCDIR "/include/salhelper/")
+           || hasPathnamePrefix(name, SRCDIR "/include/typelib/")
+           || hasPathnamePrefix(name, SRCDIR "/include/uno/")
+           || hasPathnamePrefix(name, SDKDIR "/include/"));
+}
+
+bool Plugin::isInUnoIncludeFile(const FunctionDecl* functionDecl) const
+{
+    return isInUnoIncludeFile(compiler.getSourceManager().getSpellingLoc(
+             functionDecl->getCanonicalDecl()->getNameInfo().getLoc()));
+}
+
+SourceLocation Plugin::locationAfterToken( SourceLocation location )
+{
+    return Lexer::getLocForEndOfToken( location, 0, compiler.getSourceManager(), compiler.getLangOpts());
+}
+
+bool Plugin::isUnitTestMode()
+{
+    return PluginHandler::isUnitTestMode();
+}
+
+bool Plugin::containsPreprocessingConditionalInclusion(SourceRange range)
+{
+    // Preprocessing directives (other than _Pragma, which is not relevant here) cannot appear in
+    // macro expansions, so it is safe to just consider the range of expansion locations:
+    auto const begin = compiler.getSourceManager().getExpansionLoc(
+        range.getBegin());
+    auto const end = compiler.getSourceManager().getExpansionLoc(
+        range.getEnd());
+    assert(begin.isFileID() && end.isFileID());
+    if (!(begin == end
+          || compiler.getSourceManager().isBeforeInTranslationUnit(
+              begin, end)))
+    {
+        if (isDebugMode()) {
+            report(
+                DiagnosticsEngine::Fatal,
+                ("unexpected broken range for Plugin::containsPreprocessingConditionalInclusion,"
+                 " case 1"),
+                range.getBegin())
+                << range;
+        }
+        // Conservatively assume "yes" if lexing fails:
+        return true;
+    }
+    auto hash = false;
+    for (auto loc = begin;;) {
+        Token tok;
+        if (Lexer::getRawToken(
+                loc, tok, compiler.getSourceManager(),
+                compiler.getLangOpts(), true))
+        {
+            if (isDebugMode()) {
+                report(
+                    DiagnosticsEngine::Fatal,
+                    ("unexpected broken range for"
+                     " Plugin::containsPreprocessingConditionalInclusion, case 2"),
+                    loc)
+                    << range;
+            }
+            // Conservatively assume "yes" if lexing fails:
+            return true;
+        }
+        if (hash && tok.is(tok::raw_identifier)) {
+            auto const id = tok.getRawIdentifier();
+            if (id == "if" || id == "ifdef" || id == "ifndef"
+                || id == "elif" || id == "else" || id == "endif")
+            {
+                return true;
+            }
+        }
+        if (loc == end) {
+            break;
+        }
+        hash = tok.is(tok::hash) && tok.isAtStartOfLine();
+        loc = loc.getLocWithOffset(
+            std::max<unsigned>(
+                Lexer::MeasureTokenLength(
+                    loc, compiler.getSourceManager(),
+                    compiler.getLangOpts()),
+                1));
+    }
+    return false;
+}
+
+bool Plugin::containsComment(SourceRange range)
+{
+    SourceManager& SM = compiler.getSourceManager();
+    SourceLocation startLoc = range.getBegin();
+    SourceLocation endLoc = range.getEnd();
+    char const* p1 = SM.getCharacterData(startLoc);
+    char const* p2 = SM.getCharacterData(endLoc);
+    p2 += Lexer::MeasureTokenLength(endLoc, SM, compiler.getLangOpts());
+
+    // when doing 'make solenv.check' we don't want the special comments in the
+    // unit test files to trigger this check
+    constexpr char const comment0[] = "// expected-error";
+    if (std::search(p1, p2, comment0, comment0 + strlen(comment0)) != p2)
+        return false;
+
+    // check for comments
+    constexpr char const comment1[] = "/*";
+    constexpr char const comment2[] = "//";
+    if (std::search(p1, p2, comment1, comment1 + strlen(comment1)) != p2)
+        return true;
+    if (std::search(p1, p2, comment2, comment2 + strlen(comment2)) != p2)
+        return true;
+
+    return false;
+}
+
+Plugin::IdenticalDefaultArgumentsResult Plugin::checkIdenticalDefaultArguments(
+    Expr const * argument1, Expr const * argument2)
+{
+    if ((argument1 == nullptr) != (argument2 == nullptr)) {
+        return IdenticalDefaultArgumentsResult::No;
+    }
+    if (argument1 == nullptr) {
+        return IdenticalDefaultArgumentsResult::Yes;
+    }
+    if (argument1->isNullPointerConstant(compiler.getASTContext(), Expr::NPC_NeverValueDependent)
+        && argument2->isNullPointerConstant(compiler.getASTContext(), Expr::NPC_NeverValueDependent))
+    {
+        return IdenticalDefaultArgumentsResult::Yes;
+    }
+    APSInt x1, x2;
+    if (evaluate(argument1, x1) && evaluate(argument2, x2))
+    {
+        return x1 == x2
+            ? IdenticalDefaultArgumentsResult::Yes
+            : IdenticalDefaultArgumentsResult::No;
+    }
+    APFloat f1(0.0f), f2(0.0f);
+    if (argument1->EvaluateAsFloat(f1, compiler.getASTContext())
+        && argument2->EvaluateAsFloat(f2, compiler.getASTContext()))
+    {
+        return f1.bitwiseIsEqual(f2)
+            ? IdenticalDefaultArgumentsResult::Yes
+            : IdenticalDefaultArgumentsResult::No;
+    }
+    auto const desugared1 = argument1->IgnoreParenImpCasts();
+    auto const desugared2 = argument2->IgnoreParenImpCasts();
+    if (auto const lit1 = dyn_cast<clang::StringLiteral>(desugared1)) {
+        if (auto const lit2 = dyn_cast<clang::StringLiteral>(desugared2)) {
+            return lit1->getBytes() == lit2->getBytes()
+                ? IdenticalDefaultArgumentsResult::Yes
+                : IdenticalDefaultArgumentsResult::No;
+        }
+    }
+    // catch params with defaults like "= OUString()"
+    for (Expr const * e1 = desugared1, * e2 = desugared2;;) {
+        auto const ce1 = dyn_cast<CXXConstructExpr>(skipImplicit(e1));
+        auto const ce2 = dyn_cast<CXXConstructExpr>(skipImplicit(e2));
+        if (ce1 == nullptr || ce2 == nullptr) {
+            break;
+        }
+        if (ce1->getConstructor()->getCanonicalDecl() != ce2->getConstructor()->getCanonicalDecl())
+        {
+            return IdenticalDefaultArgumentsResult::No;
+        }
+        if (ce1->isElidable() && ce2->isElidable() && ce1->getNumArgs() == 1
+            && ce2->getNumArgs() == 1)
+        {
+            assert(ce1->getConstructor()->isCopyOrMoveConstructor());
+            e1 = ce1->getArg(0)->IgnoreImpCasts();
+            e2 = ce2->getArg(0)->IgnoreImpCasts();
+            continue;
+        }
+        if (ce1->getNumArgs() == 0 && ce2->getNumArgs() == 0) {
+            return IdenticalDefaultArgumentsResult::Yes;
+        }
+        break;
+    }
+    // If the EvaluateAsRValue derivatives above failed because the arguments use e.g. (constexpr)
+    // function template specializations that happen to not have been instantiated in this TU, try a
+    // structural comparison of the arguments:
+    if (structurallyIdentical(argument1, argument2)) {
+        return IdenticalDefaultArgumentsResult::Yes;
+    }
+    if (isDebugMode()) {
+        report(
+            DiagnosticsEngine::Fatal, "TODO: Unexpected 'IdenticalDefaultArgumentsResult::Maybe'",
+            argument1->getExprLoc())
+            << argument1->getSourceRange();
+        report(
+            DiagnosticsEngine::Note, "TODO: second argument is here", argument2->getExprLoc())
+            << argument2->getSourceRange();
+        argument1->dump();
+        argument2->dump();
+    }
+    return IdenticalDefaultArgumentsResult::Maybe;
+}
+
+RewritePlugin::RewritePlugin( const InstantiationData& data )
+    : Plugin( data )
+    , rewriter( data.rewriter )
+{
+}
+
+bool RewritePlugin::insertText( SourceLocation Loc, StringRef Str, bool InsertAfter, bool indentNewLines )
+{
+    assert( rewriter );
+    if (wouldRewriteWorkdir(Loc))
+        return false;
+    SourceRange Range(SourceRange(Loc, Loc.getLocWithOffset(Str.size())));
+    if( !handler.checkOverlap( Range ) )
+    {
+        report( DiagnosticsEngine::Warning, "double code removal, possible plugin error", Range.getBegin());
+        return false;
+    }
+    if( rewriter->InsertText( Loc, Str, InsertAfter, indentNewLines ))
+        return reportEditFailure( Loc );
+    handler.addSourceModification(Range);
+    return true;
+}
+
+bool RewritePlugin::insertTextAfter( SourceLocation Loc, StringRef Str )
+{
+    assert( rewriter );
+    if (wouldRewriteWorkdir(Loc))
+        return false;
+    SourceRange Range(SourceRange(Loc, Loc.getLocWithOffset(Str.size())));
+    if( !handler.checkOverlap( Range ) )
+    {
+        report( DiagnosticsEngine::Warning, "double code removal, possible plugin error", Range.getBegin());
+        return false;
+    }
+    if( rewriter->InsertTextAfter( Loc, Str ))
+        return reportEditFailure( Loc );
+    handler.addSourceModification(Range);
+    return true;
+}
+
+bool RewritePlugin::insertTextAfterToken( SourceLocation Loc, StringRef Str )
+{
+    assert( rewriter );
+    if (wouldRewriteWorkdir(Loc))
+        return false;
+    SourceRange Range(SourceRange(Loc, Loc.getLocWithOffset(Str.size())));
+    if( !handler.checkOverlap( Range ) )
+    {
+        report( DiagnosticsEngine::Warning, "double code removal, possible plugin error", Range.getBegin());
+        return false;
+    }
+    if( rewriter->InsertTextAfterToken( Loc, Str ))
+        return reportEditFailure( Loc );
+    handler.addSourceModification(Range);
+    return true;
+}
+
+bool RewritePlugin::insertTextBefore( SourceLocation Loc, StringRef Str )
+{
+    assert( rewriter );
+    if (wouldRewriteWorkdir(Loc))
+        return false;
+    SourceRange Range(SourceRange(Loc, Loc.getLocWithOffset(Str.size())));
+    if( !handler.checkOverlap( Range ) )
+    {
+        report( DiagnosticsEngine::Warning, "double code removal, possible plugin error", Range.getBegin());
+        return false;
+    }
+    if( rewriter->InsertTextBefore( Loc, Str ))
+        return reportEditFailure( Loc );
+    handler.addSourceModification(Range);
+    return true;
+}
+
+bool RewritePlugin::removeText( SourceLocation Start, unsigned Length, RewriteOptions opts )
+{
+    CharSourceRange range( SourceRange( Start, Start.getLocWithOffset( Length )), false );
+    return removeText( range, opts );
+}
+
+bool RewritePlugin::removeText( SourceRange range, RewriteOptions opts )
+{
+    return removeText( CharSourceRange( range, true ), opts );
+}
+
+bool RewritePlugin::removeText( CharSourceRange range, RewriteOptions opts )
+{
+    assert( rewriter );
+    if (wouldRewriteWorkdir(range.getBegin()))
+        return false;
+    if( rewriter->getRangeSize( range, opts ) == -1 )
+        return reportEditFailure( range.getBegin());
+    if( !handler.checkOverlap( range.getAsRange() ) )
+    {
+        report( DiagnosticsEngine::Warning, "double code removal, possible plugin error", range.getBegin());
+        return false;
+    }
+    if( opts.flags & RemoveWholeStatement || opts.flags & RemoveAllWhitespace )
+    {
+        if( !adjustRangeForOptions( &range, opts ))
+            return reportEditFailure( range.getBegin());
+    }
+    if( rewriter->RemoveText( range, opts ))
+        return reportEditFailure( range.getBegin());
+    handler.addSourceModification(range.getAsRange());
+    return true;
+}
+
+bool RewritePlugin::adjustRangeForOptions( CharSourceRange* range, RewriteOptions opts )
+{
+    assert( rewriter );
+    SourceManager& SM = rewriter->getSourceMgr();
+    SourceLocation fileStartLoc = SM.getLocForStartOfFile( SM.getFileID( range->getBegin()));
+    if( fileStartLoc.isInvalid())
+        return false;
+    bool isInvalid = false;
+    const char* fileBuf = SM.getCharacterData( fileStartLoc, &isInvalid );
+    if( isInvalid )
+        return false;
+    const char* startBuf = SM.getCharacterData( range->getBegin(), &isInvalid );
+    if( isInvalid )
+        return false;
+    SourceLocation locationEnd = range->getEnd();
+    if( range->isTokenRange())
+        locationEnd = locationAfterToken( locationEnd );
+    const char* endBuf = SM.getCharacterData( locationEnd, &isInvalid );
+    if( isInvalid )
+        return false;
+    const char* startPos = startBuf;
+    --startPos;
+    while( startPos >= fileBuf && ( *startPos == ' ' || *startPos == '\t' ))
+        --startPos;
+    if( startPos >= fileBuf && *startPos == '\n' )
+        startPos = startBuf - 1; // do not remove indentation whitespace (RemoveLineIfEmpty can do that)
+    const char* endPos = endBuf;
+    while( *endPos == ' ' || *endPos == '\t' )
+        ++endPos;
+    if( opts.flags & RemoveWholeStatement )
+    {
+        if( *endPos == ';' )
+            ++endPos;
+        else
+            return false;
+    }
+    *range = CharSourceRange( SourceRange( range->getBegin().getLocWithOffset( startPos - startBuf + 1 ),
+        locationEnd.getLocWithOffset( endPos - endBuf )), false );
+    return true;
+}
+
+bool RewritePlugin::replaceText( SourceLocation Start, unsigned OrigLength, StringRef NewStr )
+{
+    assert( rewriter );
+    if (wouldRewriteWorkdir(Start))
+        return false;
+    SourceRange Range(Start, Start.getLocWithOffset(std::max<size_t>(OrigLength, NewStr.size())));
+    if( OrigLength != 0 && !handler.checkOverlap( Range ) )
+    {
+        report( DiagnosticsEngine::Warning, "overlapping code replacement, possible plugin error", Start );
+        return false;
+    }
+    if( rewriter->ReplaceText( Start, OrigLength, NewStr ))
+        return reportEditFailure( Start );
+    handler.addSourceModification(Range);
+    return true;
+}
+
+bool RewritePlugin::replaceText( SourceRange range, StringRef NewStr )
+{
+    assert( rewriter );
+    if (wouldRewriteWorkdir(range.getBegin()))
+        return false;
+    if( rewriter->getRangeSize( range ) == -1 )
+        return reportEditFailure( range.getBegin());
+    if( !handler.checkOverlap( range ) )
+    {
+        report( DiagnosticsEngine::Warning, "overlapping code replacement, possible plugin error", range.getBegin());
+        return false;
+    }
+    if( rewriter->ReplaceText( range, NewStr ))
+        return reportEditFailure( range.getBegin());
+    handler.addSourceModification(range);
+    return true;
+}
+
+bool RewritePlugin::replaceText( SourceRange range, SourceRange replacementRange )
+{
+    assert( rewriter );
+    if (wouldRewriteWorkdir(range.getBegin()))
+        return false;
+    if( rewriter->getRangeSize( range ) == -1 )
+        return reportEditFailure( range.getBegin());
+    if( !handler.checkOverlap( range ) )
+    {
+        report( DiagnosticsEngine::Warning, "overlapping code replacement, possible plugin error", range.getBegin());
+        return false;
+    }
+    if( rewriter->ReplaceText( range, replacementRange ))
+        return reportEditFailure( range.getBegin());
+    handler.addSourceModification(range);
+    return true;
+}
+
+bool RewritePlugin::wouldRewriteWorkdir(SourceLocation loc)
+{
+    if (loc.isInvalid() || loc.isMacroID()) {
+        return false;
+    }
+    return
+        getFilenameOfLocation(compiler.getSourceManager().getSpellingLoc(loc))
+        .startswith(WORKDIR "/");
+}
+
+bool RewritePlugin::reportEditFailure( SourceLocation loc )
+{
+    report( DiagnosticsEngine::Warning, "cannot perform source modification (macro expansion involved?)", loc );
+    return false;
+}
+
+namespace {
+
+template<typename Fn> bool checkPathname(
+    StringRef pathname, StringRef against, Fn check)
+{
+    if (check(pathname, against)) {
+        return true;
+    }
+#if defined _WIN32
+    for (std::size_t n = 0;;)
+    {
+        std::size_t n1 = pathname.find('\\', n);
+        std::size_t n2 = against.find('\\', n);
+        if (n1 <= n2) {
+            if (n1 >= against.size()) {
+                return check(pathname.substr(n), against.substr(n));
+            }
+            if ((against[n1] != '/' && against[n1] != '\\')
+                || pathname.substr(n, n1 - n) != against.substr(n, n1 - n))
+            {
+                break;
+            }
+            n = n1 + 1;
+        } else {
+            if (n2 >= pathname.size()) {
+                return check(pathname.substr(n), against.substr(n));
+            }
+            if (pathname[n2] != '/'
+                || pathname.substr(n, n2 - n) != against.substr(n, n2 - n))
+            {
+                break;
+            }
+            n = n2 + 1;
+        }
+    }
+#endif
+    return false;
+}
+
+}
+
+bool hasPathnamePrefix(StringRef pathname, StringRef prefix)
+{
+    return checkPathname(
+        pathname, prefix,
+        [](StringRef p, StringRef a) { return p.startswith(a); });
+}
+
+bool isSamePathname(StringRef pathname, StringRef other)
+{
+    return checkPathname(
+        pathname, other, [](StringRef p, StringRef a) { return p == a; });
+}
+
+bool isSameUnoIncludePathname(StringRef fullPathname, StringRef includePathname)
+{
+    llvm::SmallVector<char, 256> buf;
+    if (isSamePathname(fullPathname, (SRCDIR "/include/" + includePathname).toStringRef(buf))) {
+        return true;
+    }
+    buf.clear();
+    return isSamePathname(fullPathname, (SDKDIR "/include/" + includePathname).toStringRef(buf));
+}
+
+bool hasCLanguageLinkageType(FunctionDecl const * decl) {
+    assert(decl != nullptr);
+    if (decl->isExternC()) {
+        return true;
+    }
+    if (decl->isInExternCContext()) {
+        return true;
+    }
+    return false;
+}
+
+static const CXXRecordDecl* stripTypeSugar(QualType qt)
+{
+    const clang::Type* t = qt.getTypePtr();
+    do
+    {
+        if (auto elaboratedType = dyn_cast<ElaboratedType>(t))
+            t = elaboratedType->desugar().getTypePtr();
+        else if (auto tsType = dyn_cast<TemplateSpecializationType>(t))
+            t = tsType->desugar().getTypePtr();
+        else if (auto sttpType = dyn_cast<SubstTemplateTypeParmType>(t))
+            t = sttpType->desugar().getTypePtr();
+        else if (auto tdType = dyn_cast<TypedefType>(t))
+            t = tdType->desugar().getTypePtr();
+        else
+            break;
+    } while(true);
+    auto recordType = dyn_cast<RecordType>(t);
+    if (!recordType)
+        return nullptr;
+    return dyn_cast_or_null<CXXRecordDecl>(recordType->getDecl());
+}
+
+int derivedFromCount(const CXXRecordDecl* subclassRecordDecl, const CXXRecordDecl* baseclassRecordDecl)
+{
+    if (!subclassRecordDecl || !baseclassRecordDecl)
+        return 0;
+    int derivedCount = 0;
+    if (subclassRecordDecl == baseclassRecordDecl)
+        derivedCount++;
+    if (!subclassRecordDecl->hasDefinition())
+        return derivedCount;
+    for (auto it = subclassRecordDecl->bases_begin(); it != subclassRecordDecl->bases_end(); ++it)
+    {
+        derivedCount += derivedFromCount(stripTypeSugar(it->getType()), baseclassRecordDecl);
+        // short-circuit, we only care about 0,1,2
+        if (derivedCount > 1)
+            return derivedCount;
+    }
+    for (auto it = subclassRecordDecl->vbases_begin(); it != subclassRecordDecl->vbases_end(); ++it)
+    {
+        derivedCount += derivedFromCount(stripTypeSugar(it->getType()), baseclassRecordDecl);
+        // short-circuit, we only care about 0,1,2
+        if (derivedCount > 1)
+            return derivedCount;
+    }
+    return derivedCount;
+}
+
+int derivedFromCount(QualType subclassQt, QualType baseclassQt)
+{
+    auto baseclassRecordDecl = stripTypeSugar(baseclassQt);
+    if (!baseclassRecordDecl)
+        return 0;
+    auto subclassRecordDecl = stripTypeSugar(subclassQt);
+    if (!subclassRecordDecl)
+        return 0;
+
+    return derivedFromCount(subclassRecordDecl, baseclassRecordDecl);
+}
+
+// It looks like Clang wrongly implements DR 4
+// (<http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#4>) and treats
+// a variable declared in an 'extern "..." {...}'-style linkage-specification as
+// if it contained the 'extern' specifier:
+bool hasExternalLinkage(VarDecl const * decl) {
+    if (decl->getLinkageAndVisibility().getLinkage() != compat::Linkage::External) {
+        return false;
+    }
+    for (auto ctx = decl->getLexicalDeclContext();
+         ctx->getDeclKind() != Decl::TranslationUnit;
+         ctx = ctx->getLexicalParent())
+    {
+        if (auto ls = dyn_cast<LinkageSpecDecl>(ctx)) {
+            if (!ls->hasBraces()) {
+                return true;
+            }
+            if (auto prev = decl->getPreviousDecl()) {
+                return hasExternalLinkage(prev);
+            }
+            return !decl->isInAnonymousNamespace();
+        }
+    }
+    return true;
+}
+
+bool isSmartPointerType(QualType qt)
+{
+    // First check whether the object type as written is, or is derived from, std::unique_ptr or
+    // std::shared_ptr, in case the get member function is declared at a base class of that std
+    // type:
+    if (loplugin::isDerivedFrom(
+            qt->getAsCXXRecordDecl(),
+            [](Decl const * decl) {
+                auto const dc = loplugin::DeclCheck(decl);
+                return dc.ClassOrStruct("unique_ptr").StdNamespace()
+                    || dc.ClassOrStruct("shared_ptr").StdNamespace();
+            }))
+        return true;
+
+    // Then check the object type coerced to the type of the get member function, in
+    // case the type-as-written is derived from one of these types (tools::SvRef is
+    // final, but the rest are not):
+    auto const tc2 = loplugin::TypeCheck(qt);
+    if (tc2.ClassOrStruct("unique_ptr").StdNamespace()
+           || tc2.ClassOrStruct("shared_ptr").StdNamespace()
+           || tc2.Class("Reference").Namespace("uno").Namespace("star")
+                .Namespace("sun").Namespace("com").GlobalNamespace()
+           || tc2.Class("Reference").Namespace("rtl").GlobalNamespace()
+           || tc2.Class("SvRef").Namespace("tools").GlobalNamespace()
+           || tc2.Class("WeakReference").Namespace("tools").GlobalNamespace()
+           || tc2.Class("ScopedReadAccess").Namespace("Bitmap").GlobalNamespace()
+           || tc2.Class("ScopedVclPtrInstance").GlobalNamespace()
+           || tc2.Class("VclPtr").GlobalNamespace()
+           || tc2.Class("ScopedVclPtr").GlobalNamespace()
+           || tc2.Class("intrusive_ptr").Namespace("boost").GlobalNamespace())
+    {
+        return true;
+    }
+    return false;
+}
+
+bool isSmartPointerType(const Expr* e)
+{
+    // First check whether the object type as written is, or is derived from, std::unique_ptr or
+    // std::shared_ptr, in case the get member function is declared at a base class of that std
+    // type:
+    if (loplugin::isDerivedFrom(
+            e->IgnoreImpCasts()->getType()->getAsCXXRecordDecl(),
+            [](Decl const * decl) {
+                auto const dc = loplugin::DeclCheck(decl);
+                return dc.ClassOrStruct("unique_ptr").StdNamespace()
+                    || dc.ClassOrStruct("shared_ptr").StdNamespace();
+            }))
+        return true;
+
+    // Then check the object type coerced to the type of the get member function, in
+    // case the type-as-written is derived from one of these types (tools::SvRef is
+    // final, but the rest are not):
+    auto const tc2 = loplugin::TypeCheck(e->getType());
+    if (tc2.ClassOrStruct("unique_ptr").StdNamespace()
+           || tc2.ClassOrStruct("shared_ptr").StdNamespace()
+           || tc2.Class("Reference").Namespace("uno").Namespace("star")
+                .Namespace("sun").Namespace("com").GlobalNamespace()
+           || tc2.Class("Reference").Namespace("rtl").GlobalNamespace()
+           || tc2.Class("SvRef").Namespace("tools").GlobalNamespace()
+           || tc2.Class("WeakReference").Namespace("tools").GlobalNamespace()
+           || tc2.Class("ScopedReadAccess").Namespace("Bitmap").GlobalNamespace()
+           || tc2.Class("ScopedVclPtrInstance").GlobalNamespace()
+           || tc2.Class("VclPtr").GlobalNamespace()
+           || tc2.Class("ScopedVclPtr").GlobalNamespace()
+           || tc2.Class("intrusive_ptr").Namespace("boost").GlobalNamespace())
+    {
+        return true;
+    }
+    return false;
+}
+
+
+} // namespace
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */