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, 921 insertions, 0 deletions

diff --git a/compilerplugins/clang/implicitboolconversion.cxx b/compilerplugins/clang/implicitboolconversion.cxx
new file mode 100644
index 0000000000..64bc97ff49
--- /dev/null
+++ b/compilerplugins/clang/implicitboolconversion.cxx
@@ -0,0 +1,921 @@
+/* -*- 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 <algorithm>
+#include <cassert>
+#include <cstddef>
+#include <iterator>
+#include <stack>
+#include <string>
+#include <vector>
+
+#include "clang/Basic/Builtins.h"
+
+#include "check.hxx"
+#include "compat.hxx"
+#include "plugin.hxx"
+
+namespace {
+
+Expr const * ignoreParenAndTemporaryMaterialization(Expr const * expr) {
+    for (;;) {
+        expr = expr->IgnoreParens();
+        auto e = dyn_cast<MaterializeTemporaryExpr>(expr);
+        if (e == nullptr) {
+            return expr;
+        }
+        expr = e->getSubExpr();
+    }
+}
+
+Expr const * ignoreParenImpCastAndComma(Expr const * expr) {
+    for (;;) {
+        expr = expr->IgnoreParenImpCasts();
+        BinaryOperator const * op = dyn_cast<BinaryOperator>(expr);
+        if (op == nullptr || op->getOpcode() != BO_Comma) {
+            return expr;
+        }
+        expr = op->getRHS();
+    }
+}
+
+SubstTemplateTypeParmType const * getAsSubstTemplateTypeParmType(QualType type)
+{
+    //TODO: unwrap all kinds of (non-SubstTemplateTypeParmType) sugar, not only
+    // TypedefType sugar:
+    for (;;) {
+        TypedefType const * t = type->getAs<TypedefType>();
+        if (t == nullptr) {
+            return dyn_cast<SubstTemplateTypeParmType>(type);
+        }
+        type = t->desugar();
+    }
+}
+
+QualType reconstructTemplateArgumentType(
+    TemplateDecl const * decl, TemplateSpecializationType const * specializationType,
+    SubstTemplateTypeParmType const * parmType)
+{
+    TemplateParameterList const * ps = decl->getTemplateParameters();
+    auto i = std::find(ps->begin(), ps->end(), compat::getReplacedParameter(parmType));
+    if (i == ps->end()) {
+        return {};
+    }
+    auto const args = specializationType->template_arguments();
+    if (ps->size() != args.size()) { //TODO
+        return {};
+    }
+    TemplateArgument const & arg = args[i - ps->begin()];
+    if (arg.getKind() != TemplateArgument::Type) {
+        return {};
+    }
+    return arg.getAsType();
+}
+
+bool areSameTypedef(QualType type1, QualType type2) {
+    // type1.getTypePtr() == typ2.getTypePtr() fails for e.g. ::sal_Bool vs.
+    // sal_Bool:
+    auto t1 = type1->getAs<TypedefType>();
+    auto t2 = type2->getAs<TypedefType>();
+    return t1 != nullptr && t2 != nullptr && t1->getDecl() == t2->getDecl();
+}
+
+bool isBool(Expr const * expr, bool allowTypedefs = true) {
+    auto t = expr->getType();
+    return allowTypedefs
+        ? bool(loplugin::TypeCheck(t).AnyBoolean()) : t->isBooleanType();
+}
+
+bool isMatchingBool(Expr const * expr, Expr const * comparisonExpr) {
+    return isBool(expr, false)
+        || areSameTypedef(expr->getType(), comparisonExpr->getType());
+}
+
+bool isSalBool(QualType type) {
+    auto t = type->getAs<TypedefType>();
+    return t != nullptr && t->getDecl()->getName() == "sal_Bool";
+}
+
+bool isBoolExpr(Expr const * expr) {
+    if (isBool(expr)) {
+        return true;
+    }
+    expr = ignoreParenImpCastAndComma(expr);
+    ConditionalOperator const * co = dyn_cast<ConditionalOperator>(expr);
+    if (co != nullptr) {
+        ImplicitCastExpr const * ic1 = dyn_cast<ImplicitCastExpr>(
+            co->getTrueExpr()->IgnoreParens());
+        ImplicitCastExpr const * ic2 = dyn_cast<ImplicitCastExpr>(
+            co->getFalseExpr()->IgnoreParens());
+        if (ic1 != nullptr && ic2 != nullptr
+            && ic1->getType()->isSpecificBuiltinType(BuiltinType::Int)
+            && isBoolExpr(ic1->getSubExpr()->IgnoreParens())
+            && ic2->getType()->isSpecificBuiltinType(BuiltinType::Int)
+            && isBoolExpr(ic2->getSubExpr()->IgnoreParens()))
+        {
+            return true;
+        }
+    }
+    std::stack<Expr const *> stack;
+    Expr const * e = expr;
+    for (;;) {
+        e = ignoreParenImpCastAndComma(e);
+        MemberExpr const * me = dyn_cast<MemberExpr>(e);
+        if (me == nullptr) {
+            break;
+        }
+        stack.push(e);
+        e = me->getBase();
+    }
+    for (;;) {
+        e = ignoreParenImpCastAndComma(e);
+        CXXOperatorCallExpr const * op = dyn_cast<CXXOperatorCallExpr>(e);
+        if (op == nullptr || op->getOperator() != OO_Subscript) {
+            break;
+        }
+        stack.push(e);
+        e = op->getArg(0);
+    }
+    if (!stack.empty()) {
+        TemplateSpecializationType const * t
+            = e->getType()->getAs<TemplateSpecializationType>();
+        for (;;) {
+            if (t == nullptr) {
+                break;
+            }
+            QualType ty;
+            MemberExpr const * me = dyn_cast<MemberExpr>(stack.top());
+            if (me != nullptr) {
+                TemplateDecl const * td
+                    = t->getTemplateName().getAsTemplateDecl();
+                if (td == nullptr) {
+                    break;
+                }
+                SubstTemplateTypeParmType const * t2
+                    = getAsSubstTemplateTypeParmType(
+                        me->getMemberDecl()->getType());
+                if (t2 == nullptr) {
+                    break;
+                }
+                ty = reconstructTemplateArgumentType(td, t, t2);
+                if (ty.isNull()) {
+                    auto const canon = cast<TemplateDecl>(td->getCanonicalDecl());
+                    if (canon != td) {
+                        ty = reconstructTemplateArgumentType(canon, t, t2);
+                    }
+                }
+                if (ty.isNull()) {
+                    break;
+                }
+            } else {
+                CXXOperatorCallExpr const * op
+                    = dyn_cast<CXXOperatorCallExpr>(stack.top());
+                assert(op != nullptr);
+                (void)op;
+                TemplateDecl const * d
+                    = t->getTemplateName().getAsTemplateDecl();
+                if (d == nullptr) {
+                    break;
+                }
+                auto const dc = loplugin::DeclCheck(d->getTemplatedDecl());
+                auto const args = t->template_arguments();
+                if (dc.ClassOrStruct("array").StdNamespace() && args.size() >= 2
+                           && args[0].getKind() == TemplateArgument::Type)
+                {
+                    ty = args[0].getAsType();
+                } else if (dc.Class("Sequence").Namespace("uno").Namespace("star").Namespace("sun")
+                               .Namespace("com").GlobalNamespace()
+                           && args.size() == 1
+                           && args[0].getKind() == TemplateArgument::Type)
+                {
+                    ty = args[0].getAsType();
+                } else {
+                    break;
+                }
+            }
+            stack.pop();
+            if (stack.empty()) {
+                if (loplugin::TypeCheck(ty).AnyBoolean()) {
+                    return true;
+                }
+                break;
+            }
+            t = ty->getAs<TemplateSpecializationType>();
+        }
+    }
+    return false;
+}
+
+// It appears that, given a function declaration, there is no way to determine
+// the language linkage of the function's type, only of the function's name
+// (via FunctionDecl::isExternC); however, in a case like
+//
+//   extern "C" { static void f(); }
+//
+// the function's name does not have C language linkage while the function's
+// type does (as clarified in C++11 [decl.link]); cf. <http://clang-developers.
+// 42468.n3.nabble.com/Language-linkage-of-function-type-tt4037248.html>
+// "Language linkage of function type":
+bool hasCLanguageLinkageType(FunctionDecl const * decl) {
+    assert(decl != nullptr);
+    if (decl->isExternC()) {
+        return true;
+    }
+    if (decl->isInExternCContext()) {
+        return true;
+    }
+    return false;
+}
+
+class ImplicitBoolConversion:
+    public loplugin::FilteringPlugin<ImplicitBoolConversion>
+{
+public:
+    explicit ImplicitBoolConversion(loplugin::InstantiationData const & data):
+        FilteringPlugin(data) {}
+
+    virtual void run() override
+    { TraverseDecl(compiler.getASTContext().getTranslationUnitDecl()); }
+
+    bool TraverseCallExpr(CallExpr * expr);
+
+    bool TraverseCXXMemberCallExpr(CXXMemberCallExpr * expr);
+
+    bool TraverseCXXConstructExpr(CXXConstructExpr * expr);
+
+    bool TraverseCXXTemporaryObjectExpr(CXXTemporaryObjectExpr * expr);
+
+    bool TraverseCStyleCastExpr(CStyleCastExpr * expr);
+
+    bool TraverseCXXStaticCastExpr(CXXStaticCastExpr * expr);
+
+    bool TraverseCXXFunctionalCastExpr(CXXFunctionalCastExpr * expr);
+
+    bool TraverseConditionalOperator(ConditionalOperator * expr);
+
+    bool TraverseBinaryOperator(BinaryOperator * expr);
+
+    bool TraverseCompoundAssignOperator(CompoundAssignOperator * expr);
+
+    bool TraverseInitListExpr(InitListExpr * expr);
+
+    bool TraverseReturnStmt(ReturnStmt * stmt);
+
+    bool TraverseFunctionDecl(FunctionDecl * decl);
+
+    bool VisitImplicitCastExpr(ImplicitCastExpr const * expr);
+
+    bool VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr const * expr);
+
+private:
+    bool isExternCFunctionCall(
+        CallExpr const * expr, FunctionProtoType const ** functionType);
+
+    bool isExternCFunctionCallReturningInt(Expr const * expr);
+
+    void checkCXXConstructExpr(CXXConstructExpr const * expr);
+
+    void reportWarning(ImplicitCastExpr const * expr);
+
+    std::stack<std::vector<ImplicitCastExpr const *>> nested;
+    std::stack<CallExpr const *> calls;
+    bool bExternCIntFunctionDefinition = false;
+};
+
+bool ImplicitBoolConversion::TraverseCallExpr(CallExpr * expr) {
+    nested.push(std::vector<ImplicitCastExpr const *>());
+    calls.push(expr);
+    bool bRet = RecursiveASTVisitor::TraverseCallExpr(expr);
+    FunctionProtoType const * t;
+    bool bExt = isExternCFunctionCall(expr, &t);
+    assert(!nested.empty());
+    for (auto i: nested.top()) {
+        auto j = std::find_if(
+            expr->arg_begin(), expr->arg_end(),
+            [&i](Expr * e) {
+                return i == ignoreParenAndTemporaryMaterialization(e);
+            });
+        if (j == expr->arg_end()) {
+            reportWarning(i);
+        } else {
+            std::ptrdiff_t n = j - expr->arg_begin();
+            assert(n >= 0);
+            if (t != nullptr
+                && static_cast<std::size_t>(n) >= t->getNumParams())
+            {
+                assert(t->isVariadic());
+                // ignore bool to int promotions of variadic arguments
+            } else if (bExt) {
+                if (t != nullptr) {
+                    assert(
+                        static_cast<std::size_t>(n) < t->getNumParams());
+                    if (!(t->getParamType(n)->isSpecificBuiltinType(
+                              BuiltinType::Int)
+                          || t->getParamType(n)->isSpecificBuiltinType(
+                              BuiltinType::UInt)
+                          || t->getParamType(n)->isSpecificBuiltinType(
+                              BuiltinType::Long)))
+                    {
+                        reportWarning(i);
+                    }
+                } else {
+                    reportWarning(i);
+                }
+            } else {
+                // Filter out
+                //
+                //   template<typename T> void f(T);
+                //   f<sal_Bool>(true);
+                //
+                DeclRefExpr const * dr = dyn_cast<DeclRefExpr>(
+                    expr->getCallee()->IgnoreParenImpCasts());
+                if (dr != nullptr && dr->hasExplicitTemplateArgs()) {
+                    FunctionDecl const * fd
+                        = dyn_cast<FunctionDecl>(dr->getDecl());
+                    if (fd != nullptr
+                        && static_cast<std::size_t>(n) < fd->getNumParams())
+                    {
+                        SubstTemplateTypeParmType const * t2
+                            = getAsSubstTemplateTypeParmType(
+                                fd->getParamDecl(n)->getType()
+                                .getNonReferenceType());
+                        if (t2 != nullptr) {
+                            //TODO: fix this superficial nonsense check:
+                            if (dr->getNumTemplateArgs() == 1) {
+                                auto const ta = dr->getTemplateArgs();
+                                if ((ta[0].getArgument().getKind()
+                                     == TemplateArgument::Type)
+                                    && (loplugin::TypeCheck(
+                                            ta[0].getTypeSourceInfo()
+                                            ->getType())
+                                        .AnyBoolean()))
+                                {
+                                    continue;
+                                }
+                            }
+                        }
+                    }
+                }
+                reportWarning(i);
+            }
+        }
+    }
+    calls.pop();
+    nested.pop();
+    return bRet;
+}
+
+bool ImplicitBoolConversion::TraverseCXXMemberCallExpr(CXXMemberCallExpr * expr)
+{
+    nested.push(std::vector<ImplicitCastExpr const *>());
+    bool bRet = RecursiveASTVisitor::TraverseCXXMemberCallExpr(expr);
+    assert(!nested.empty());
+    for (auto i: nested.top()) {
+        auto j = std::find_if(
+            expr->arg_begin(), expr->arg_end(),
+            [&i](Expr * e) {
+                return i == ignoreParenAndTemporaryMaterialization(e);
+            });
+        if (j != expr->arg_end()) {
+            // Filter out
+            //
+            //  template<typename T> struct S { void f(T); };
+            //  S<sal_Bool> s;
+            //  s.f(true);
+            //
+            std::ptrdiff_t n = j - expr->arg_begin();
+            assert(n >= 0);
+            CXXMethodDecl const * d = expr->getMethodDecl();
+            if (static_cast<std::size_t>(n) >= d->getNumParams()) {
+                // Ignore bool to int promotions of variadic arguments:
+                assert(d->isVariadic());
+                continue;
+            }
+            QualType ty
+                = ignoreParenImpCastAndComma(expr->getImplicitObjectArgument())
+                ->getType();
+            if (dyn_cast<MemberExpr>(expr->getCallee())->isArrow()) {
+                ty = ty->getAs<clang::PointerType>()->getPointeeType();
+            }
+            TemplateSpecializationType const * ct
+                = ty->getAs<TemplateSpecializationType>();
+            if (ct != nullptr) {
+                SubstTemplateTypeParmType const * pt
+                    = getAsSubstTemplateTypeParmType(
+                        d->getParamDecl(n)->getType().getNonReferenceType());
+                if (pt != nullptr) {
+                    TemplateDecl const * td
+                        = ct->getTemplateName().getAsTemplateDecl();
+                    if (td != nullptr) {
+                        //TODO: fix this superficial nonsense check:
+                        auto const args = ct->template_arguments();
+                        if (args.size() >= 1
+                            && args[0].getKind() == TemplateArgument::Type
+                            && (loplugin::TypeCheck(args[0].getAsType())
+                                .AnyBoolean()))
+                        {
+                            continue;
+                        }
+                    }
+                }
+            }
+        }
+        reportWarning(i);
+    }
+    nested.pop();
+    return bRet;
+}
+
+bool ImplicitBoolConversion::TraverseCXXConstructExpr(CXXConstructExpr * expr) {
+    nested.push(std::vector<ImplicitCastExpr const *>());
+    bool bRet = RecursiveASTVisitor::TraverseCXXConstructExpr(expr);
+    checkCXXConstructExpr(expr);
+    nested.pop();
+    return bRet;
+}
+
+bool ImplicitBoolConversion::TraverseCXXTemporaryObjectExpr(
+    CXXTemporaryObjectExpr * expr)
+{
+    nested.push(std::vector<ImplicitCastExpr const *>());
+    bool bRet = RecursiveASTVisitor::TraverseCXXTemporaryObjectExpr(expr);
+    checkCXXConstructExpr(expr);
+    nested.pop();
+    return bRet;
+}
+
+bool ImplicitBoolConversion::TraverseCStyleCastExpr(CStyleCastExpr * expr) {
+    nested.push(std::vector<ImplicitCastExpr const *>());
+    bool bRet = RecursiveASTVisitor::TraverseCStyleCastExpr(expr);
+    assert(!nested.empty());
+    for (auto i: nested.top()) {
+        if (i != expr->getSubExpr()->IgnoreParens()) {
+            reportWarning(i);
+        }
+    }
+    nested.pop();
+    return bRet;
+}
+
+bool ImplicitBoolConversion::TraverseCXXStaticCastExpr(CXXStaticCastExpr * expr)
+{
+    nested.push(std::vector<ImplicitCastExpr const *>());
+    bool bRet = RecursiveASTVisitor::TraverseCXXStaticCastExpr(expr);
+    assert(!nested.empty());
+    for (auto i: nested.top()) {
+        if (i != expr->getSubExpr()->IgnoreParens()) {
+            reportWarning(i);
+        }
+    }
+    nested.pop();
+    return bRet;
+}
+
+bool ImplicitBoolConversion::TraverseCXXFunctionalCastExpr(
+    CXXFunctionalCastExpr * expr)
+{
+    nested.push(std::vector<ImplicitCastExpr const *>());
+    bool bRet = RecursiveASTVisitor::TraverseCXXFunctionalCastExpr(expr);
+    assert(!nested.empty());
+    for (auto i: nested.top()) {
+        if (i != expr->getSubExpr()->IgnoreParens()) {
+            reportWarning(i);
+        }
+    }
+    nested.pop();
+    return bRet;
+}
+
+bool ImplicitBoolConversion::TraverseConditionalOperator(
+    ConditionalOperator * expr)
+{
+    nested.push(std::vector<ImplicitCastExpr const *>());
+    bool bRet = RecursiveASTVisitor::TraverseConditionalOperator(expr);
+    assert(!nested.empty());
+    for (auto i: nested.top()) {
+        if (!((i == expr->getTrueExpr()->IgnoreParens()
+               && (isBoolExpr(expr->getFalseExpr()->IgnoreParenImpCasts())
+                   || isExternCFunctionCallReturningInt(expr->getFalseExpr())))
+              || (i == expr->getFalseExpr()->IgnoreParens()
+                  && (isBoolExpr(expr->getTrueExpr()->IgnoreParenImpCasts())
+                      || isExternCFunctionCallReturningInt(
+                          expr->getTrueExpr())))
+              || (!compiler.getLangOpts().CPlusPlus
+                  && i == expr->getCond()->IgnoreParens())))
+        {
+            reportWarning(i);
+        }
+    }
+    nested.pop();
+    return bRet;
+}
+
+bool ImplicitBoolConversion::TraverseBinaryOperator(BinaryOperator * expr) {
+    switch (expr->getOpcode()) {
+    case BO_LT:
+    case BO_LE:
+    case BO_GT:
+    case BO_GE:
+    case BO_EQ:
+    case BO_NE:
+        {
+            nested.push(std::vector<ImplicitCastExpr const *>());
+            bool bRet = RecursiveASTVisitor::TraverseBinaryOperator(expr);
+            assert(!nested.empty());
+            for (auto i: nested.top()) {
+                if (!((i == expr->getLHS()->IgnoreParens()
+                       && isMatchingBool(
+                           expr->getRHS()->IgnoreImpCasts(), i->getSubExprAsWritten()))
+                      || (i == expr->getRHS()->IgnoreParens()
+                          && isMatchingBool(
+                              expr->getLHS()->IgnoreImpCasts(),
+                              i->getSubExprAsWritten()))))
+                {
+                    reportWarning(i);
+                }
+            }
+            nested.pop();
+            return bRet;
+        }
+    case BO_Assign:
+        {
+            nested.push(std::vector<ImplicitCastExpr const *>());
+            bool bRet = RecursiveASTVisitor::TraverseBinaryOperator(expr);
+            // gtk-2.0/gtk/gtktogglebutton.h: struct _GtkToggleButton:
+            //  guint GSEAL (active) : 1;
+            // even though <http://www.gtk.org/api/2.6/gtk/GtkToggleButton.html>:
+            //  "active"               gboolean              : Read / Write
+            // qt5/QtGui/qaccessible.h: struct State:
+            //  quint64 disabled : 1;
+            bool bExt = false;
+            MemberExpr const * me = dyn_cast<MemberExpr>(expr->getLHS());
+            if (me != nullptr) {
+                FieldDecl const * fd = dyn_cast<FieldDecl>(me->getMemberDecl());
+                if (fd != nullptr && fd->isBitField()
+                    && fd->getBitWidthValue(compiler.getASTContext()) == 1)
+                {
+                    auto const check = loplugin::TypeCheck(fd->getType());
+                    bExt = check.Typedef("guint").GlobalNamespace()
+                        || check.Typedef("quint64").GlobalNamespace();
+                }
+            }
+            assert(!nested.empty());
+            for (auto i: nested.top()) {
+                if (i != expr->getRHS()->IgnoreParens()
+                    || !(bExt || isBoolExpr(expr->getLHS())))
+                {
+                    reportWarning(i);
+                }
+            }
+            nested.pop();
+            return bRet;
+        }
+    default:
+        return RecursiveASTVisitor::TraverseBinaryOperator(expr);
+    }
+}
+
+bool ImplicitBoolConversion::TraverseCompoundAssignOperator(CompoundAssignOperator * expr) {
+    switch (expr->getOpcode()) {
+    case BO_AndAssign:
+    case BO_OrAssign:
+    case BO_XorAssign:
+        {
+            nested.push(std::vector<ImplicitCastExpr const *>());
+            bool bRet = RecursiveASTVisitor::TraverseCompoundAssignOperator(expr);
+            assert(!nested.empty());
+            for (auto i: nested.top()) {
+                if (i != expr->getRHS()->IgnoreParens()
+                    || !isBool(expr->getLHS()->IgnoreParens(), false))
+                {
+                    reportWarning(i);
+                }
+            }
+            nested.pop();
+            if (!ignoreLocation(expr) && isBool(expr->getLHS(), false)
+                && !isBool(expr->getRHS()->IgnoreParenImpCasts(), false))
+            {
+                report(
+                    DiagnosticsEngine::Warning, "mix of %0 and %1 in operator %2",
+                    expr->getRHS()->getBeginLoc())
+                    << expr->getLHS()->getType()
+                    << expr->getRHS()->IgnoreParenImpCasts()->getType()
+                    << expr->getOpcodeStr()
+                    << expr->getSourceRange();
+            }
+            return bRet;
+        }
+    default:
+        return RecursiveASTVisitor::TraverseCompoundAssignOperator(expr);
+    }
+}
+
+bool ImplicitBoolConversion::TraverseInitListExpr(InitListExpr * expr) {
+    nested.push(std::vector<ImplicitCastExpr const *>());
+    auto const e = expr->isSemanticForm() ? expr : expr->getSemanticForm();
+    auto const ret = TraverseSynOrSemInitListExpr(e, nullptr);
+    assert(!nested.empty());
+    for (auto i: nested.top()) {
+        if (std::find(e->begin(), e->end(), i) == e->end()
+            || !i->getType()->isSpecificBuiltinType(clang::BuiltinType::UChar))
+        {
+            reportWarning(i);
+        }
+    }
+    nested.pop();
+    return ret;
+}
+
+bool ImplicitBoolConversion::TraverseReturnStmt(ReturnStmt * stmt) {
+    nested.push(std::vector<ImplicitCastExpr const *>());
+    bool bRet = RecursiveASTVisitor::TraverseReturnStmt(stmt);
+    Expr const * expr = stmt->getRetValue();
+    if (expr != nullptr) {
+        ExprWithCleanups const * ec = dyn_cast<ExprWithCleanups>(expr);
+        if (ec != nullptr) {
+            expr = ec->getSubExpr();
+        }
+        expr = expr->IgnoreParens();
+    }
+    assert(!nested.empty());
+    for (auto i: nested.top()) {
+        if (i != expr || !bExternCIntFunctionDefinition) {
+            reportWarning(i);
+        }
+    }
+    nested.pop();
+    return bRet;
+}
+
+bool ImplicitBoolConversion::TraverseFunctionDecl(FunctionDecl * decl) {
+    bool bExt = false;
+    if (hasCLanguageLinkageType(decl) && decl->isThisDeclarationADefinition()) {
+        QualType t { decl->getReturnType() };
+        if (t->isSpecificBuiltinType(BuiltinType::Int)
+            || t->isSpecificBuiltinType(BuiltinType::UInt))
+        {
+            bExt = true;
+        } else {
+            TypedefType const * t2 = t->getAs<TypedefType>();
+            // cf. rtl_locale_equals (and sal_Int32 can be long):
+            if (t2 != nullptr
+                && t2->getDecl()->getNameAsString() == "sal_Int32")
+            {
+                bExt = true;
+            }
+        }
+    }
+    if (bExt) {
+        assert(!bExternCIntFunctionDefinition);
+        bExternCIntFunctionDefinition = true;
+    }
+    bool bRet = RecursiveASTVisitor::TraverseFunctionDecl(decl);
+    if (bExt) {
+        bExternCIntFunctionDefinition = false;
+    }
+    return bRet;
+}
+
+bool ImplicitBoolConversion::VisitImplicitCastExpr(
+    ImplicitCastExpr const * expr)
+{
+    if (ignoreLocation(expr)) {
+        return true;
+    }
+    if (isBool(compat::getSubExprAsWritten(expr)) && !isBool(expr)) {
+        // Ignore NoOp from 'sal_Bool' (aka 'unsigned char') to 'const unsigned
+        // char' in makeAny(b) with b of type sal_Bool:
+        if (expr->getCastKind() == CK_NoOp) {
+            return true;
+        }
+        // Ignore implicit conversions from bool to int in
+        //
+        //   #define _G_STR_NONNULL(x) (x + !x)
+        //
+        // from
+        // <https://gitlab.gnome.org/GNOME/glib/-/commit/48730d2b30473c5eeda2badf9a65d380304477c3>
+        // "gstrfuncs: Add back x + !x warning workaround":
+        if (auto const sub = dyn_cast<UnaryOperator>(compat::getSubExprAsWritten(expr))) {
+            if (sub->getOpcode() == UO_LNot) {
+                auto const l = expr->getBeginLoc();
+                if (compiler.getSourceManager().isMacroBodyExpansion(l)
+                    && Lexer::getImmediateMacroName(
+                            l, compiler.getSourceManager(), compiler.getLangOpts())
+                        == "_G_STR_NONNULL")
+                {
+                    return true;
+                }
+            }
+        }
+        if (nested.empty()) {
+            reportWarning(expr);
+        } else {
+            nested.top().push_back(expr);
+        }
+        return true;
+    }
+    if (auto const sub = dyn_cast<ExplicitCastExpr>(
+            compat::getSubExprAsWritten(expr)))
+    {
+        auto const subsub = compat::getSubExprAsWritten(sub);
+        if (subsub->getType().IgnoreParens() == expr->getType().IgnoreParens()
+            && isBool(subsub))
+        {
+            // Ignore "normalizing cast" bool(b) from sal_Bool b to bool, then
+            // implicitly cast back again to sal_Bool:
+            if (dyn_cast<CXXFunctionalCastExpr>(sub) != nullptr
+                && sub->getType()->isBooleanType() && isSalBool(expr->getType())
+                && isSalBool(subsub->getType()))
+            {
+                return true;
+            }
+            report(
+                DiagnosticsEngine::Warning,
+                ("explicit conversion (%0) from %1 to %2 implicitly cast back"
+                 " to %3"),
+                expr->getBeginLoc())
+                << sub->getCastKindName() << subsub->getType() << sub->getType()
+                << expr->getType() << expr->getSourceRange();
+            return true;
+        }
+    }
+    if (expr->getType()->isBooleanType() && !isBoolExpr(expr->getSubExpr())
+        && !calls.empty())
+    {
+        CallExpr const * call = calls.top();
+        if (std::any_of(
+                call->arg_begin(), call->arg_end(),
+                [expr](Expr const * e) { return expr == e->IgnoreParens(); }))
+        {
+            report(
+                DiagnosticsEngine::Warning,
+                "implicit conversion (%0) of call argument from %1 to %2",
+                expr->getBeginLoc())
+                << expr->getCastKindName() << expr->getSubExpr()->getType()
+                << expr->getType() << expr->getSourceRange();
+            return true;
+        }
+    }
+    return true;
+}
+
+bool ImplicitBoolConversion::VisitMaterializeTemporaryExpr(
+    MaterializeTemporaryExpr const * expr)
+{
+    if (ignoreLocation(expr)) {
+        return true;
+    }
+    if (auto const sub = dyn_cast<ExplicitCastExpr>(expr->getSubExpr())) {
+        auto const subsub = compat::getSubExprAsWritten(sub);
+        if (subsub->getType().IgnoreParens() == expr->getType().IgnoreParens()
+            && isBool(subsub))
+        {
+            report(
+                DiagnosticsEngine::Warning,
+                ("explicit conversion (%0) from %1 to %2 implicitly converted"
+                 " back to %3"),
+                expr->getBeginLoc())
+                << sub->getCastKindName() << subsub->getType() << sub->getType()
+                << expr->getType() << expr->getSourceRange();
+            return true;
+        }
+    }
+    return true;
+}
+
+bool ImplicitBoolConversion::isExternCFunctionCall(
+    CallExpr const * expr, FunctionProtoType const ** functionType)
+{
+    assert(functionType != nullptr);
+    *functionType = nullptr;
+    Decl const * d = expr->getCalleeDecl();
+    if (d != nullptr) {
+        FunctionDecl const * fd = dyn_cast<FunctionDecl>(d);
+        if (fd != nullptr) {
+            clang::PointerType const * pt = fd->getType()
+                ->getAs<clang::PointerType>();
+            QualType t2(pt == nullptr ? fd->getType() : pt->getPointeeType());
+            *functionType = t2->getAs<FunctionProtoType>();
+            assert(
+                *functionType != nullptr || !compiler.getLangOpts().CPlusPlus
+                || (fd->getBuiltinID() != Builtin::NotBuiltin
+                    && isa<FunctionNoProtoType>(t2)));
+                // __builtin_*s have no proto type?
+            return fd->isExternC()
+                || compiler.getSourceManager().isInExternCSystemHeader(
+                    fd->getLocation());
+        }
+        VarDecl const * vd = dyn_cast<VarDecl>(d);
+        if (vd != nullptr) {
+            clang::PointerType const * pt = vd->getType()
+                ->getAs<clang::PointerType>();
+            *functionType
+                = ((pt == nullptr ? vd->getType() : pt->getPointeeType())
+                   ->getAs<FunctionProtoType>());
+            return vd->isExternC();
+        }
+    }
+    return false;
+}
+
+bool ImplicitBoolConversion::isExternCFunctionCallReturningInt(
+    Expr const * expr)
+{
+    CallExpr const * e = dyn_cast<CallExpr>(expr->IgnoreParenImpCasts());
+    FunctionProtoType const * t;
+    return e != nullptr && e->getType()->isSpecificBuiltinType(BuiltinType::Int)
+        && isExternCFunctionCall(e, &t);
+}
+
+void ImplicitBoolConversion::checkCXXConstructExpr(
+    CXXConstructExpr const * expr)
+{
+    assert(!nested.empty());
+    for (auto i: nested.top()) {
+        auto j = std::find_if(
+            expr->arg_begin(), expr->arg_end(),
+            [&i](Expr const * e) {
+                return i == ignoreParenAndTemporaryMaterialization(e);
+            });
+        if (j != expr->arg_end()) {
+            TemplateSpecializationType const * t1 = expr->getType()->
+                getAs<TemplateSpecializationType>();
+            if (t1 == nullptr) {
+                //TODO:
+                if (i->getType()->isSpecificBuiltinType(clang::BuiltinType::UChar)) {
+                    continue;
+                }
+            } else {
+                SubstTemplateTypeParmType const * t2 = nullptr;
+                CXXConstructorDecl const * d = expr->getConstructor();
+                if (d->getNumParams() == expr->getNumArgs()) { //TODO: better check
+                    t2 = getAsSubstTemplateTypeParmType(
+                        d->getParamDecl(j - expr->arg_begin())->getType()
+                        .getNonReferenceType());
+                }
+                if (t2 != nullptr) {
+                    TemplateDecl const * td
+                        = t1->getTemplateName().getAsTemplateDecl();
+                    if (td != nullptr) {
+                        TemplateParameterList const * ps
+                            = td->getTemplateParameters();
+                        auto k = std::find(
+                            ps->begin(), ps->end(),
+                            compat::getReplacedParameter(t2));
+                        if (k != ps->end()) {
+                            auto const args = t1->template_arguments();
+                            if (ps->size() == args.size()) { //TODO
+                                TemplateArgument const & arg = args[
+                                    k - ps->begin()];
+                                if (arg.getKind() == TemplateArgument::Type
+                                    && (loplugin::TypeCheck(arg.getAsType())
+                                        .AnyBoolean()))
+                                {
+                                    continue;
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+        reportWarning(i);
+    }
+}
+
+void ImplicitBoolConversion::reportWarning(ImplicitCastExpr const * expr) {
+    if (compiler.getLangOpts().CPlusPlus) {
+        if (expr->getCastKind() == CK_ConstructorConversion) {
+            auto const t1 = expr->getType();
+            if (auto const t2 = t1->getAs<TemplateSpecializationType>()) {
+                auto const args = t2->template_arguments();
+                assert(args.size() >= 1);
+                auto const a = args[0];
+                if (a.getKind() == TemplateArgument::Type && a.getAsType()->isBooleanType()
+                    && (loplugin::TypeCheck(t1).TemplateSpecializationClass()
+                        .ClassOrStruct("atomic").StdNamespace()))
+                {
+                    return;
+                }
+            }
+        }
+        report(
+            DiagnosticsEngine::Warning,
+            "implicit conversion (%0) from %1 to %2", expr->getBeginLoc())
+            << expr->getCastKindName() << expr->getSubExprAsWritten()->getType()
+            << expr->getType() << expr->getSourceRange();
+    }
+}
+
+loplugin::Plugin::Registration<ImplicitBoolConversion> X(
+    "implicitboolconversion");
+
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */