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/* 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 "NonParamInsideFunctionDeclChecker.h"
#include "CustomMatchers.h"
class NonParamAnnotation : public CustomTypeAnnotation {
public:
NonParamAnnotation() : CustomTypeAnnotation(moz_non_param, "non-param"){};
protected:
// Adding alignas(_) on a struct implicitly marks it as MOZ_NON_PARAM, due to
// MSVC limitations which prevent passing explcitly aligned types by value as
// parameters. This overload of hasFakeAnnotation injects fake MOZ_NON_PARAM
// annotations onto these types.
std::string getImplicitReason(const TagDecl *D) const override {
// Check if the decl itself has an AlignedAttr on it.
for (const Attr *A : D->attrs()) {
if (isa<AlignedAttr>(A)) {
return "it has an alignas(_) annotation";
}
}
// Check if any of the decl's fields have an AlignedAttr on them.
if (auto RD = dyn_cast<RecordDecl>(D)) {
for (auto F : RD->fields()) {
for (auto A : F->attrs()) {
if (isa<AlignedAttr>(A)) {
return ("member '" + F->getName() +
"' has an alignas(_) annotation")
.str();
}
}
}
}
// We don't need to check the types of fields, as the CustomTypeAnnotation
// infrastructure will handle that for us.
return "";
}
};
NonParamAnnotation NonParam;
void NonParamInsideFunctionDeclChecker::registerMatchers(
MatchFinder *AstMatcher) {
AstMatcher->addMatcher(
functionDecl(
anyOf(allOf(isDefinition(),
hasAncestor(
classTemplateSpecializationDecl().bind("spec"))),
isDefinition()))
.bind("func"),
this);
AstMatcher->addMatcher(lambdaExpr().bind("lambda"), this);
}
void NonParamInsideFunctionDeclChecker::check(
const MatchFinder::MatchResult &Result) {
static DenseSet<const FunctionDecl *> CheckedFunctionDecls;
const FunctionDecl *func = Result.Nodes.getNodeAs<FunctionDecl>("func");
if (!func) {
const LambdaExpr *lambda = Result.Nodes.getNodeAs<LambdaExpr>("lambda");
if (lambda) {
func = lambda->getCallOperator();
}
}
if (!func) {
return;
}
if (func->isDeleted()) {
return;
}
// We need to skip decls which have these types as parameters in system
// headers, because presumably those headers act like an assertion that the
// alignment will be preserved in that situation.
if (getDeclarationNamespace(func) == "std") {
return;
}
if (inThirdPartyPath(func)) {
return;
}
// Don't report errors on the same declarations more than once.
if (CheckedFunctionDecls.count(func)) {
return;
}
CheckedFunctionDecls.insert(func);
const ClassTemplateSpecializationDecl *Spec =
Result.Nodes.getNodeAs<ClassTemplateSpecializationDecl>("spec");
for (ParmVarDecl *p : func->parameters()) {
QualType T = p->getType().withoutLocalFastQualifiers();
if (NonParam.hasEffectiveAnnotation(T)) {
diag(p->getLocation(), "Type %0 must not be used as parameter",
DiagnosticIDs::Error)
<< T;
diag(p->getLocation(),
"Please consider passing a const reference instead",
DiagnosticIDs::Note);
if (Spec) {
diag(Spec->getPointOfInstantiation(),
"The bad argument was passed to %0 here", DiagnosticIDs::Note)
<< Spec->getSpecializedTemplate();
}
NonParam.dumpAnnotationReason(*this, T, p->getLocation());
}
}
}