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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 09:06:44 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 09:06:44 +0000
commited5640d8b587fbcfed7dd7967f3de04b37a76f26 (patch)
tree7a5f7c6c9d02226d7471cb3cc8fbbf631b415303 /compilerplugins/clang/constfields.cxx
parentInitial commit. (diff)
downloadlibreoffice-ed5640d8b587fbcfed7dd7967f3de04b37a76f26.tar.xz
libreoffice-ed5640d8b587fbcfed7dd7967f3de04b37a76f26.zip
Adding upstream version 4:7.4.7.upstream/4%7.4.7upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'compilerplugins/clang/constfields.cxx')
-rw-r--r--compilerplugins/clang/constfields.cxx596
1 files changed, 596 insertions, 0 deletions
diff --git a/compilerplugins/clang/constfields.cxx b/compilerplugins/clang/constfields.cxx
new file mode 100644
index 000000000..692c84dae
--- /dev/null
+++ b/compilerplugins/clang/constfields.cxx
@@ -0,0 +1,596 @@
+/* -*- 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/.
+ */
+
+#if !defined _WIN32 //TODO, #include <sys/file.h>
+
+#include <cassert>
+#include <string>
+#include <iostream>
+#include <fstream>
+#include <unordered_set>
+#include <vector>
+#include <algorithm>
+#include <sys/file.h>
+#include <unistd.h>
+
+#include "config_clang.h"
+
+#include "plugin.hxx"
+#include "check.hxx"
+
+#include "clang/AST/ParentMapContext.h"
+
+/**
+Look for fields that are only assigned to in the constructor using field-init, and can therefore be const.
+
+The process goes something like this:
+ $ make check
+ $ make FORCE_COMPILE=all COMPILER_PLUGIN_TOOL='constfields' check
+ $ ./compilerplugins/clang/constfields.py
+
+and then
+ $ for dir in *; do make $dir FORCE_COMPILE=all UPDATE_FILES=$dir COMPILER_PLUGIN_TOOL='constfieldsrewrite' $dir; done
+to auto-remove the method declarations
+
+*/
+
+namespace
+{
+struct MyFieldInfo
+{
+ const RecordDecl* parentRecord;
+ std::string parentClass;
+ std::string fieldName;
+ std::string fieldType;
+ std::string sourceLocation;
+ std::string access;
+};
+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> cannotBeConstSet;
+static std::set<MyFieldInfo> definitionSet;
+
+/**
+ * Wrap the different kinds of callable and callee objects in the clang AST so I can define methods that handle everything.
+ */
+class CallerWrapper
+{
+ const CallExpr* m_callExpr;
+ const CXXConstructExpr* m_cxxConstructExpr;
+
+public:
+ CallerWrapper(const CallExpr* callExpr)
+ : m_callExpr(callExpr)
+ , m_cxxConstructExpr(nullptr)
+ {
+ }
+ CallerWrapper(const CXXConstructExpr* cxxConstructExpr)
+ : m_callExpr(nullptr)
+ , m_cxxConstructExpr(cxxConstructExpr)
+ {
+ }
+ unsigned getNumArgs() const
+ {
+ return m_callExpr ? m_callExpr->getNumArgs() : m_cxxConstructExpr->getNumArgs();
+ }
+ const Expr* getArg(unsigned i) const
+ {
+ return m_callExpr ? m_callExpr->getArg(i) : m_cxxConstructExpr->getArg(i);
+ }
+};
+class CalleeWrapper
+{
+ const FunctionDecl* m_calleeFunctionDecl = nullptr;
+ const CXXConstructorDecl* m_cxxConstructorDecl = nullptr;
+ const FunctionProtoType* m_functionPrototype = nullptr;
+
+public:
+ explicit CalleeWrapper(const FunctionDecl* calleeFunctionDecl)
+ : m_calleeFunctionDecl(calleeFunctionDecl)
+ {
+ }
+ explicit CalleeWrapper(const CXXConstructExpr* cxxConstructExpr)
+ : m_cxxConstructorDecl(cxxConstructExpr->getConstructor())
+ {
+ }
+ explicit CalleeWrapper(const FunctionProtoType* functionPrototype)
+ : m_functionPrototype(functionPrototype)
+ {
+ }
+ unsigned getNumParams() const
+ {
+ if (m_calleeFunctionDecl)
+ return m_calleeFunctionDecl->getNumParams();
+ else if (m_cxxConstructorDecl)
+ return m_cxxConstructorDecl->getNumParams();
+ else if (m_functionPrototype->param_type_begin() == m_functionPrototype->param_type_end())
+ // FunctionProtoType will assert if we call getParamTypes() and it has no params
+ return 0;
+ else
+ return m_functionPrototype->getParamTypes().size();
+ }
+ const QualType getParamType(unsigned i) const
+ {
+ if (m_calleeFunctionDecl)
+ return m_calleeFunctionDecl->getParamDecl(i)->getType();
+ else if (m_cxxConstructorDecl)
+ return m_cxxConstructorDecl->getParamDecl(i)->getType();
+ else
+ return m_functionPrototype->getParamTypes()[i];
+ }
+ std::string getNameAsString() const
+ {
+ if (m_calleeFunctionDecl)
+ return m_calleeFunctionDecl->getNameAsString();
+ else if (m_cxxConstructorDecl)
+ return m_cxxConstructorDecl->getNameAsString();
+ else
+ return "";
+ }
+ CXXMethodDecl const* getAsCXXMethodDecl() const
+ {
+ if (m_calleeFunctionDecl)
+ return dyn_cast<CXXMethodDecl>(m_calleeFunctionDecl);
+ return nullptr;
+ }
+};
+
+class ConstFields : public RecursiveASTVisitor<ConstFields>, public loplugin::Plugin
+{
+public:
+ explicit ConstFields(loplugin::InstantiationData const& data)
+ : Plugin(data)
+ {
+ }
+
+ virtual void run() override;
+
+ bool shouldVisitTemplateInstantiations() const { return true; }
+ bool shouldVisitImplicitCode() const { return true; }
+
+ bool VisitFieldDecl(const FieldDecl*);
+ bool VisitMemberExpr(const MemberExpr*);
+ bool TraverseCXXConstructorDecl(CXXConstructorDecl*);
+ bool TraverseCXXMethodDecl(CXXMethodDecl*);
+ bool TraverseFunctionDecl(FunctionDecl*);
+ bool TraverseIfStmt(IfStmt*);
+
+private:
+ MyFieldInfo niceName(const FieldDecl*);
+ void check(const FieldDecl* fieldDecl, const Expr* memberExpr);
+ bool isSomeKindOfZero(const Expr* arg);
+ bool IsPassedByNonConst(const FieldDecl* fieldDecl, const Stmt* child, CallerWrapper callExpr,
+ CalleeWrapper calleeFunctionDecl);
+ llvm::Optional<CalleeWrapper> getCallee(CallExpr const*);
+
+ RecordDecl* insideMoveOrCopyDeclParent = nullptr;
+ // For reasons I do not understand, parentFunctionDecl() is not reliable, so
+ // we store the parent function on the way down the AST.
+ FunctionDecl* insideFunctionDecl = nullptr;
+ std::vector<FieldDecl const*> insideConditionalCheckOfMemberSet;
+};
+
+void ConstFields::run()
+{
+ 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 : cannotBeConstSet)
+ output += "write-outside-constructor:\t" + s.parentClass + "\t" + s.fieldName + "\n";
+ for (const MyFieldInfo& s : definitionSet)
+ output += "definition:\t" + s.access + "\t" + s.parentClass + "\t" + s.fieldName + "\t"
+ + s.fieldType + "\t" + s.sourceLocation + "\n";
+ std::ofstream myfile;
+ myfile.open(WORKDIR "/loplugin.constfields.log", std::ios::app | std::ios::out);
+ myfile << output;
+ myfile.close();
+ }
+ else
+ {
+ for (const MyFieldInfo& s : cannotBeConstSet)
+ report(DiagnosticsEngine::Warning, "notconst %0", s.parentRecord->getBeginLoc())
+ << s.fieldName;
+ }
+}
+
+MyFieldInfo ConstFields::niceName(const FieldDecl* fieldDecl)
+{
+ MyFieldInfo aInfo;
+
+ const RecordDecl* recordDecl = fieldDecl->getParent();
+
+ if (const CXXRecordDecl* cxxRecordDecl = dyn_cast<CXXRecordDecl>(recordDecl))
+ {
+ if (cxxRecordDecl->getTemplateInstantiationPattern())
+ cxxRecordDecl = cxxRecordDecl->getTemplateInstantiationPattern();
+ aInfo.parentRecord = cxxRecordDecl;
+ aInfo.parentClass = cxxRecordDecl->getQualifiedNameAsString();
+ }
+ else
+ {
+ aInfo.parentRecord = recordDecl;
+ aInfo.parentClass = recordDecl->getQualifiedNameAsString();
+ }
+
+ aInfo.fieldName = fieldDecl->getNameAsString();
+ // sometimes the name (if it's an 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), "");
+ }
+ aInfo.fieldType = fieldDecl->getType().getAsString();
+
+ SourceLocation expansionLoc
+ = compiler.getSourceManager().getExpansionLoc(fieldDecl->getLocation());
+ StringRef name = getFilenameOfLocation(expansionLoc);
+ aInfo.sourceLocation
+ = std::string(name.substr(strlen(SRCDIR) + 1)) + ":"
+ + std::to_string(compiler.getSourceManager().getSpellingLineNumber(expansionLoc));
+ loplugin::normalizeDotDotInFilePath(aInfo.sourceLocation);
+
+ switch (fieldDecl->getAccess())
+ {
+ case AS_public:
+ aInfo.access = "public";
+ break;
+ case AS_private:
+ aInfo.access = "private";
+ break;
+ case AS_protected:
+ aInfo.access = "protected";
+ break;
+ default:
+ aInfo.access = "unknown";
+ break;
+ }
+
+ return aInfo;
+}
+
+bool ConstFields::VisitFieldDecl(const FieldDecl* fieldDecl)
+{
+ fieldDecl = fieldDecl->getCanonicalDecl();
+ if (ignoreLocation(fieldDecl))
+ {
+ return true;
+ }
+ // ignore stuff that forms part of the stable URE interface
+ if (isInUnoIncludeFile(compiler.getSourceManager().getSpellingLoc(fieldDecl->getLocation())))
+ {
+ return true;
+ }
+ definitionSet.insert(niceName(fieldDecl));
+ return true;
+}
+
+bool ConstFields::TraverseCXXConstructorDecl(CXXConstructorDecl* cxxConstructorDecl)
+{
+ auto copy = insideMoveOrCopyDeclParent;
+ if (!ignoreLocation(cxxConstructorDecl) && cxxConstructorDecl->isThisDeclarationADefinition())
+ {
+ if (cxxConstructorDecl->isCopyOrMoveConstructor())
+ insideMoveOrCopyDeclParent = cxxConstructorDecl->getParent();
+ }
+ bool ret = RecursiveASTVisitor::TraverseCXXConstructorDecl(cxxConstructorDecl);
+ insideMoveOrCopyDeclParent = copy;
+ return ret;
+}
+
+bool ConstFields::TraverseCXXMethodDecl(CXXMethodDecl* cxxMethodDecl)
+{
+ auto copy1 = insideMoveOrCopyDeclParent;
+ auto copy2 = insideFunctionDecl;
+ if (!ignoreLocation(cxxMethodDecl) && cxxMethodDecl->isThisDeclarationADefinition())
+ {
+ if (cxxMethodDecl->isCopyAssignmentOperator() || cxxMethodDecl->isMoveAssignmentOperator())
+ insideMoveOrCopyDeclParent = cxxMethodDecl->getParent();
+ }
+ insideFunctionDecl = cxxMethodDecl;
+ bool ret = RecursiveASTVisitor::TraverseCXXMethodDecl(cxxMethodDecl);
+ insideMoveOrCopyDeclParent = copy1;
+ insideFunctionDecl = copy2;
+ return ret;
+}
+
+bool ConstFields::TraverseFunctionDecl(FunctionDecl* functionDecl)
+{
+ auto copy2 = insideFunctionDecl;
+ insideFunctionDecl = functionDecl;
+ bool ret = RecursiveASTVisitor::TraverseFunctionDecl(functionDecl);
+ insideFunctionDecl = copy2;
+ return ret;
+}
+
+bool ConstFields::TraverseIfStmt(IfStmt* ifStmt)
+{
+ FieldDecl const* memberFieldDecl = nullptr;
+ if (Expr const* cond = ifStmt->getCond())
+ {
+ if (auto memberExpr = dyn_cast<MemberExpr>(cond->IgnoreParenImpCasts()))
+ {
+ if ((memberFieldDecl = dyn_cast<FieldDecl>(memberExpr->getMemberDecl())))
+ insideConditionalCheckOfMemberSet.push_back(memberFieldDecl);
+ }
+ }
+ bool ret = RecursiveASTVisitor::TraverseIfStmt(ifStmt);
+ if (memberFieldDecl)
+ insideConditionalCheckOfMemberSet.pop_back();
+ return ret;
+}
+
+bool ConstFields::VisitMemberExpr(const MemberExpr* memberExpr)
+{
+ const ValueDecl* decl = memberExpr->getMemberDecl();
+ const FieldDecl* fieldDecl = dyn_cast<FieldDecl>(decl);
+ if (!fieldDecl)
+ {
+ return true;
+ }
+ fieldDecl = fieldDecl->getCanonicalDecl();
+ if (ignoreLocation(fieldDecl))
+ {
+ return true;
+ }
+ // ignore stuff that forms part of the stable URE interface
+ if (isInUnoIncludeFile(compiler.getSourceManager().getSpellingLoc(fieldDecl->getLocation())))
+ {
+ return true;
+ }
+
+ check(fieldDecl, memberExpr);
+
+ return true;
+}
+
+void ConstFields::check(const FieldDecl* fieldDecl, const Expr* memberExpr)
+{
+ auto parentsRange = compiler.getASTContext().getParents(*memberExpr);
+ const Stmt* child = memberExpr;
+ const Stmt* parent
+ = parentsRange.begin() == parentsRange.end() ? nullptr : parentsRange.begin()->get<Stmt>();
+ // walk up the tree until we find something interesting
+ bool bCannotBeConst = false;
+ bool bDump = false;
+ auto walkUp = [&]() {
+ child = parent;
+ auto parentsRange = compiler.getASTContext().getParents(*parent);
+ parent = parentsRange.begin() == parentsRange.end() ? nullptr
+ : parentsRange.begin()->get<Stmt>();
+ };
+ do
+ {
+ if (!parent)
+ {
+ // check if we have an expression like
+ // int& r = m_field;
+ auto parentsRange = compiler.getASTContext().getParents(*child);
+ if (parentsRange.begin() != parentsRange.end())
+ {
+ auto varDecl = dyn_cast_or_null<VarDecl>(parentsRange.begin()->get<Decl>());
+ // The isImplicit() call is to avoid triggering when we see the vardecl which is part of a for-range statement,
+ // which is of type 'T&&' and also an l-value-ref ?
+ if (varDecl && !varDecl->isImplicit()
+ && loplugin::TypeCheck(varDecl->getType()).LvalueReference().NonConst())
+ {
+ bCannotBeConst = true;
+ }
+ }
+ break;
+ }
+ if (isa<CXXReinterpretCastExpr>(parent))
+ {
+ // once we see one of these, there is not much useful we can know
+ bCannotBeConst = true;
+ break;
+ }
+ else if (isa<CastExpr>(parent) || isa<MemberExpr>(parent) || isa<ParenExpr>(parent)
+ || isa<ParenListExpr>(parent) || isa<ArrayInitLoopExpr>(parent)
+ || isa<ExprWithCleanups>(parent))
+ {
+ walkUp();
+ }
+ else if (auto unaryOperator = dyn_cast<UnaryOperator>(parent))
+ {
+ UnaryOperator::Opcode op = unaryOperator->getOpcode();
+ if (op == UO_AddrOf || op == UO_PostInc || op == UO_PostDec || op == UO_PreInc
+ || op == UO_PreDec)
+ {
+ bCannotBeConst = true;
+ }
+ walkUp();
+ }
+ else if (auto operatorCallExpr = dyn_cast<CXXOperatorCallExpr>(parent))
+ {
+ auto callee = getCallee(operatorCallExpr);
+ if (callee)
+ {
+ // if calling a non-const operator on the field
+ auto calleeMethodDecl = callee->getAsCXXMethodDecl();
+ if (calleeMethodDecl && operatorCallExpr->getArg(0) == child
+ && !calleeMethodDecl->isConst())
+ {
+ bCannotBeConst = true;
+ }
+ else if (IsPassedByNonConst(fieldDecl, child, operatorCallExpr, *callee))
+ {
+ bCannotBeConst = true;
+ }
+ }
+ else
+ bCannotBeConst = true; // conservative, could improve
+ walkUp();
+ }
+ else if (auto cxxMemberCallExpr = dyn_cast<CXXMemberCallExpr>(parent))
+ {
+ const CXXMethodDecl* calleeMethodDecl = cxxMemberCallExpr->getMethodDecl();
+ if (calleeMethodDecl)
+ {
+ // if calling a non-const method on the field
+ const Expr* tmp = dyn_cast<Expr>(child);
+ if (tmp->isBoundMemberFunction(compiler.getASTContext()))
+ {
+ tmp = dyn_cast<MemberExpr>(tmp)->getBase();
+ }
+ if (cxxMemberCallExpr->getImplicitObjectArgument() == tmp
+ && !calleeMethodDecl->isConst())
+ {
+ bCannotBeConst = true;
+ break;
+ }
+ if (IsPassedByNonConst(fieldDecl, child, cxxMemberCallExpr,
+ CalleeWrapper(calleeMethodDecl)))
+ bCannotBeConst = true;
+ }
+ else
+ bCannotBeConst = true; // can happen in templates
+ walkUp();
+ }
+ else if (auto cxxConstructExpr = dyn_cast<CXXConstructExpr>(parent))
+ {
+ if (IsPassedByNonConst(fieldDecl, child, cxxConstructExpr,
+ CalleeWrapper(cxxConstructExpr)))
+ bCannotBeConst = true;
+ walkUp();
+ }
+ else if (auto callExpr = dyn_cast<CallExpr>(parent))
+ {
+ auto callee = getCallee(callExpr);
+ if (callee)
+ {
+ if (IsPassedByNonConst(fieldDecl, child, callExpr, *callee))
+ bCannotBeConst = true;
+ }
+ else
+ bCannotBeConst = true; // conservative, could improve
+ walkUp();
+ }
+ else if (auto binaryOp = dyn_cast<BinaryOperator>(parent))
+ {
+ BinaryOperator::Opcode op = binaryOp->getOpcode();
+ const bool assignmentOp = op == BO_Assign || 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;
+ if (assignmentOp)
+ {
+ if (binaryOp->getLHS() == child)
+ bCannotBeConst = true;
+ else if (loplugin::TypeCheck(binaryOp->getLHS()->getType())
+ .LvalueReference()
+ .NonConst())
+ // if the LHS is a non-const reference, we could write to the field later on
+ bCannotBeConst = true;
+ }
+ walkUp();
+ }
+ else if (isa<ReturnStmt>(parent))
+ {
+ if (insideFunctionDecl)
+ {
+ auto tc = loplugin::TypeCheck(insideFunctionDecl->getReturnType());
+ if (tc.LvalueReference().NonConst())
+ bCannotBeConst = true;
+ }
+ break;
+ }
+ else if (isa<SwitchStmt>(parent) || isa<WhileStmt>(parent) || isa<ForStmt>(parent)
+ || isa<IfStmt>(parent) || isa<DoStmt>(parent) || isa<CXXForRangeStmt>(parent)
+ || isa<DefaultStmt>(parent))
+ {
+ break;
+ }
+ else
+ {
+ walkUp();
+ }
+ } while (true);
+
+ if (bDump)
+ {
+ report(DiagnosticsEngine::Warning, "oh dear, what can the matter be? writtenTo=%0",
+ memberExpr->getBeginLoc())
+ << bCannotBeConst << memberExpr->getSourceRange();
+ if (parent)
+ {
+ report(DiagnosticsEngine::Note, "parent over here", parent->getBeginLoc())
+ << parent->getSourceRange();
+ parent->dump();
+ }
+ memberExpr->dump();
+ fieldDecl->getType()->dump();
+ }
+
+ if (bCannotBeConst)
+ {
+ cannotBeConstSet.insert(niceName(fieldDecl));
+ }
+}
+
+bool ConstFields::IsPassedByNonConst(const FieldDecl* fieldDecl, const Stmt* child,
+ CallerWrapper callExpr, CalleeWrapper calleeFunctionDecl)
+{
+ unsigned len = std::min(callExpr.getNumArgs(), calleeFunctionDecl.getNumParams());
+ // if it's an array, passing it by value to a method typically means the
+ // callee takes a pointer and can modify the array
+ if (fieldDecl->getType()->isConstantArrayType())
+ {
+ for (unsigned i = 0; i < len; ++i)
+ if (callExpr.getArg(i) == child)
+ if (loplugin::TypeCheck(calleeFunctionDecl.getParamType(i)).Pointer().NonConst())
+ return true;
+ }
+ else
+ {
+ for (unsigned i = 0; i < len; ++i)
+ if (callExpr.getArg(i) == child)
+ if (loplugin::TypeCheck(calleeFunctionDecl.getParamType(i))
+ .LvalueReference()
+ .NonConst())
+ return true;
+ }
+ return false;
+}
+
+llvm::Optional<CalleeWrapper> ConstFields::getCallee(CallExpr const* callExpr)
+{
+ FunctionDecl const* functionDecl = callExpr->getDirectCallee();
+ if (functionDecl)
+ return CalleeWrapper(functionDecl);
+
+ // Extract the functionprototype from a type
+ clang::Type const* calleeType = callExpr->getCallee()->getType().getTypePtr();
+ if (auto pointerType = calleeType->getUnqualifiedDesugaredType()->getAs<clang::PointerType>())
+ {
+ if (auto prototype = pointerType->getPointeeType()
+ ->getUnqualifiedDesugaredType()
+ ->getAs<FunctionProtoType>())
+ {
+ return CalleeWrapper(prototype);
+ }
+ }
+
+ return llvm::Optional<CalleeWrapper>();
+}
+
+loplugin::Plugin::Registration<ConstFields> X("constfields", false);
+}
+
+#endif
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */