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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 16:51:28 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 16:51:28 +0000 |
commit | 940b4d1848e8c70ab7642901a68594e8016caffc (patch) | |
tree | eb72f344ee6c3d9b80a7ecc079ea79e9fba8676d /compilerplugins/clang/inlinesimplememberfunctions.cxx | |
parent | Initial commit. (diff) | |
download | libreoffice-upstream.tar.xz libreoffice-upstream.zip |
Adding upstream version 1:7.0.4.upstream/1%7.0.4upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'compilerplugins/clang/inlinesimplememberfunctions.cxx')
-rw-r--r-- | compilerplugins/clang/inlinesimplememberfunctions.cxx | 295 |
1 files changed, 295 insertions, 0 deletions
diff --git a/compilerplugins/clang/inlinesimplememberfunctions.cxx b/compilerplugins/clang/inlinesimplememberfunctions.cxx new file mode 100644 index 000000000..668e9f252 --- /dev/null +++ b/compilerplugins/clang/inlinesimplememberfunctions.cxx @@ -0,0 +1,295 @@ +/* -*- 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 <string> + +#include "plugin.hxx" +#include "compat.hxx" + +// Methods that purely return a local field should be declared in the header and be declared inline. +// So that the compiler can elide the function call and turn it into a simple fixed-offset-load instruction. + +namespace { + +class InlineSimpleMemberFunctions: + public loplugin::FilteringRewritePlugin<InlineSimpleMemberFunctions> +{ +public: + explicit InlineSimpleMemberFunctions(loplugin::InstantiationData const & data): FilteringRewritePlugin(data) {} + + virtual void run() override { TraverseDecl(compiler.getASTContext().getTranslationUnitDecl()); } + + bool VisitCXXMethodDecl(const CXXMethodDecl * decl); +private: + bool rewrite(const CXXMethodDecl * functionDecl); +}; + +static bool oneAndOnlyOne(clang::Stmt::const_child_range range) { + if (range.begin() == range.end()) { + return false; + } + if (++range.begin() != range.end()) { + return false; + } + return true; +} + + +bool InlineSimpleMemberFunctions::VisitCXXMethodDecl(const CXXMethodDecl * functionDecl) { + if (ignoreLocation(functionDecl)) { + return true; + } + // no point in doing virtual methods, the compiler always has to generate a vtable entry and a method + if (functionDecl->isVirtual()) { + return true; + } + if (functionDecl->getTemplatedKind() != FunctionDecl::TK_NonTemplate) { + return true; + } + if (!functionDecl->isInstance()) { + return true; + } + if (!functionDecl->isOutOfLine()) { + return true; + } + if( !functionDecl->hasBody()) { + return true; + } + if( functionDecl->isInlineSpecified()) { + return true; + } + if( functionDecl->getCanonicalDecl()->isInlineSpecified()) { + return true; + } + if( functionDecl->getNameAsString().find("Impl") != std::string::npos) { + return true; + } + // ignore stuff that forms part of the stable URE interface + if (isInUnoIncludeFile(functionDecl)) { + return true; + } + // ignore stuff like: + // template<class E> E * Sequence<E>::begin() { return getArray(); } + if( functionDecl->getParent()->getDescribedClassTemplate() != nullptr ) { + return true; + } + + /* + The chain here looks like + CompoundStmt + ReturnStmt + other stuff + CXXThisExpr + */ + + const CompoundStmt* compoundStmt = dyn_cast< CompoundStmt >( functionDecl->getBody() ); + if (compoundStmt == nullptr) { + return true; + } + if (compoundStmt->body_begin() == compoundStmt->body_end()) { + return true; + } + + + const Stmt* childStmt = *compoundStmt->child_begin(); + + if (dyn_cast<ReturnStmt>( childStmt ) == nullptr) { + return true; + } + if (!oneAndOnlyOne(childStmt->children())) { + return true; + } + + + /* Don't warn if we see a method definition like + X X::a() { + return *this; + } + which translates to: + CompoundStmt + ReturnStmt + ImplicitCastExpr + UnaryOperator + CXXThisExpr + or: + CompoundStmt + ReturnStmt + UnaryOperator + CXXThisExpr + */ + childStmt = *childStmt->child_begin(); + if (dyn_cast<ImplicitCastExpr>( childStmt ) != nullptr + && oneAndOnlyOne( childStmt->children() )) + { + const Stmt* childStmt2 = *childStmt->child_begin(); + if (dyn_cast<UnaryOperator>( childStmt2 ) != nullptr + && oneAndOnlyOne(childStmt2->children())) + { + childStmt2 = *childStmt2->child_begin(); + if (dyn_cast<CXXThisExpr>( childStmt2 ) != nullptr + && childStmt2->children().begin() == childStmt2->children().end()) + { + return true; + } + } + } + if (dyn_cast<UnaryOperator>( childStmt ) != nullptr + && oneAndOnlyOne( childStmt->children() )) + { + const Stmt* childStmt2 = *childStmt->child_begin(); + if (dyn_cast<CXXThisExpr>( childStmt2 ) != nullptr + && childStmt2->children().begin() == childStmt2->children().end()) + { + return true; + } + } + + /* look for a chains like: + CompoundStmt + ReturnStmt + stuff + CXXThisExpr + */ + childStmt = *(*compoundStmt->child_begin())->child_begin(); + while (1) { + if (dyn_cast<CallExpr>( childStmt ) != nullptr) + return true; + if (dyn_cast<CXXNewExpr>( childStmt ) != nullptr) + return true; + if (dyn_cast<CXXConstructExpr>( childStmt ) != nullptr) + return true; + if (dyn_cast<ConditionalOperator>( childStmt ) != nullptr) + return true; + if (dyn_cast<BinaryOperator>( childStmt ) != nullptr) + return true; + // exclude methods that return fields on incomplete types .e.g the pImpl pattern + const MemberExpr* memberExpr = dyn_cast<MemberExpr>( childStmt ); + if (memberExpr != nullptr && memberExpr->getMemberDecl()) { + const FieldDecl* fieldDecl = dyn_cast<FieldDecl>(memberExpr->getMemberDecl()); + if (fieldDecl != nullptr) + { + // yes, a little bit of a hack. However, it is quite hard to determine if the method + // in question is accessing a field via a pImpl pattern. + if (fieldDecl->getType()->isIncompleteType()) + return true; + if (fieldDecl->getNameAsString().find("Impl") != std::string::npos) + return true; + if (fieldDecl->getNameAsString().find("pImp") != std::string::npos) + return true; + // somewhere in VCL + if (fieldDecl->getNameAsString().find("mpGlobalSyncData") != std::string::npos) + return true; + std::string s = fieldDecl->getType().getAsString(); + if (s.find("Impl") != std::string::npos || s.find("pImp") != std::string::npos || s.find("Internal") != std::string::npos) + return true; + } + } + if (dyn_cast<CXXThisExpr>( childStmt ) != nullptr) { + if (!rewrite(functionDecl)) + { + report( + DiagnosticsEngine::Warning, + "inlinesimpleaccessmethods", + functionDecl->getSourceRange().getBegin()) + << functionDecl->getSourceRange(); + // display the location of the class member declaration so I don't have to search for it by hand + report( + DiagnosticsEngine::Note, + "inlinesimpleaccessmethods", + functionDecl->getCanonicalDecl()->getSourceRange().getBegin()) + << functionDecl->getCanonicalDecl()->getSourceRange(); + } + return true; + } + if ( childStmt->children().begin() == childStmt->children().end() ) + return true; + childStmt = *childStmt->child_begin(); + } + return true; +} + +static std::string ReplaceString(std::string subject, const std::string& search, + const std::string& replace) { + size_t pos = 0; + while ((pos = subject.find(search, pos)) != std::string::npos) { + subject.replace(pos, search.length(), replace); + pos += replace.length(); + } + return subject; +} + +bool InlineSimpleMemberFunctions::rewrite(const CXXMethodDecl * functionDecl) { + if (rewriter == nullptr) { + return false; + } + // Only rewrite declarations in include files if a + // definition is also seen, to avoid compilation of a + // definition (in a main file only processed later) to fail + // with a "mismatch" error before the rewriter had a chance + // to act upon the definition. + if (!compiler.getSourceManager().isInMainFile( + compiler.getSourceManager().getSpellingLoc( + functionDecl->getNameInfo().getLoc()))) + { + return false; + } + + const char *p1, *p2; + + // get the function body contents + p1 = compiler.getSourceManager().getCharacterData( compat::getBeginLoc(functionDecl->getBody()) ); + p2 = compiler.getSourceManager().getCharacterData( compat::getEndLoc(functionDecl->getBody()) ); + std::string s1( p1, p2 - p1 + 1); + + /* we can't safely move around stuff containing comments, we mess up the resulting code */ + if ( s1.find("/*") != std::string::npos || s1.find("//") != std::string::npos ) { + return false; + } + + // strip linefeeds and any double-spaces, so we have a max of one space between tokens + s1 = ReplaceString(s1, "\r", ""); + s1 = ReplaceString(s1, "\n", ""); + s1 = ReplaceString(s1, "\t", " "); + s1 = ReplaceString(s1, " ", " "); + s1 = ReplaceString(s1, " ", " "); + s1 = ReplaceString(s1, " ", " "); + s1 = " " + s1; + + // scan from the end of the function's body through the trailing whitespace, so we can do a nice clean remove +// commented out because for some reason it will sometimes chomp an extra token +// SourceLocation endOfRemoveLoc = functionDecl->getBody()->getLocEnd(); +// for (;;) { +// endOfRemoveLoc = endOfRemoveLoc.getLocWithOffset(1); +// p1 = compiler.getSourceManager().getCharacterData( endOfRemoveLoc ); +// if (*p1 != ' ' && *p1 != '\r' && *p1 != '\n' && *p1 != '\t') +// break; +// } + + // remove the function's out of line body and declaration + RewriteOptions opts; + opts.RemoveLineIfEmpty = true; + if (!removeText(SourceRange(compat::getBeginLoc(functionDecl), compat::getEndLoc(functionDecl->getBody())), opts)) { + return false; + } + + // scan forward until we find the semicolon + const FunctionDecl * canonicalDecl = functionDecl->getCanonicalDecl(); + p1 = compiler.getSourceManager().getCharacterData( compat::getEndLoc(canonicalDecl) ); + p2 = ++p1; + while (*p2 != 0 && *p2 != ';') p2++; + + // insert the function body into the inline function definition (i.e. the one inside the class definition) + return replaceText(compat::getEndLoc(canonicalDecl).getLocWithOffset(p2 - p1 + 1), 1, s1); +} + +loplugin::Plugin::Registration< InlineSimpleMemberFunctions > X("inlinesimplememberfunctions"); + +} + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |