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[clang] Heuristic resolution for explicit object parameter #155143

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Merged
merged 8 commits into from
Aug 27, 2025
Merged

[clang] Heuristic resolution for explicit object parameter #155143

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c1cdb39
[clang] Heuristic resolution for explicit object parameter
MythreyaK Aug 24, 2025
0d48289
code review
MythreyaK Aug 24, 2025
cd3601a
remove cxxdecl check
MythreyaK Aug 24, 2025
ea15161
code review
MythreyaK Aug 24, 2025
c2b8ac4
add null-check
MythreyaK Aug 24, 2025
bf73e27
code review
MythreyaK Aug 26, 2025
b48fa0e
code review + misc cleanup
MythreyaK Aug 27, 2025
466efd8
fix error
MythreyaK Aug 27, 2025
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1 change: 1 addition & 0 deletions clang-tools-extra/clangd/unittests/RenameTests.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -2488,6 +2488,7 @@ TEST(CrossFileRenameTests, adjustmentCost) {
T.ExpectedCost);
}
}

} // namespace
} // namespace clangd
} // namespace clang
21 changes: 6 additions & 15 deletions clang/lib/Sema/HeuristicResolver.cpp
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Expand Up @@ -14,7 +14,6 @@
#include "clang/AST/TemplateBase.h"
#include "clang/AST/Type.h"
#include "llvm/ADT/identity.h"
#include <optional>

namespace clang {

Expand Down Expand Up @@ -256,17 +255,17 @@ QualType HeuristicResolverImpl::simplifyType(QualType Type, const Expr *E,
}
}
}
// check if member expr is in the context of an explicit object method
// Check if the expression refers to an explicit object parameter of
// templated type. If so, heuristically treat it as having the type of the
// enclosing class.
if (!T.Type.isNull() &&
(T.Type->isUndeducedAutoType() || T.Type->isTemplateTypeParmType())) {
if (auto *DRE = dyn_cast_if_present<DeclRefExpr>(T.E)) {
auto *PrDecl = dyn_cast_if_present<ParmVarDecl>(DRE->getDecl());
// Then the type of 'this' should be type of the record the method is
// defined in
auto *PrDecl = dyn_cast<ParmVarDecl>(DRE->getDecl());
if (PrDecl && PrDecl->isExplicitObjectParameter()) {
const auto *Parent =
dyn_cast<TypeDecl>(PrDecl->getDeclContext()->getParent());
return {Ctx.getTypeDeclType(Parent)};
dyn_cast<TagDecl>(PrDecl->getDeclContext()->getParent());
return {Ctx.getCanonicalTagType(Parent)};
}
}
}
Expand Down Expand Up @@ -321,14 +320,6 @@ std::vector<const NamedDecl *> HeuristicResolverImpl::resolveMemberExpr(
Expr *Base = ME->isImplicitAccess() ? nullptr : ME->getBase();
QualType BaseType = ME->getBaseType();
BaseType = simplifyType(BaseType, Base, ME->isArrow());

// fflush(stdout);
// fflush(stderr);
// std::flush(std::cout);
// std::flush(std::cerr);
// using namespace std::chrono_literals;
// std::this_thread::sleep_for(10ms);

return resolveDependentMember(BaseType, ME->getMember(), NoFilter);
}

Expand Down
2 changes: 1 addition & 1 deletion clang/unittests/Sema/HeuristicResolverTest.cpp
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Expand Up @@ -41,7 +41,7 @@ template <typename InputNode, typename ParamT, typename InputMatcher,
typename... OutputMatchers>
void expectResolution(llvm::StringRef Code, ResolveFnT<ParamT> ResolveFn,
const InputMatcher &IM, const OutputMatchers &...OMS) {
auto TU = tooling::buildASTFromCodeWithArgs(Code, {"-std=c++23"});
auto TU = tooling::buildASTFromCodeWithArgs(Code, {"-std=c++20"});
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@HighCommander4 HighCommander4 Aug 27, 2025

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This change (from c++20 to c++23) should be kept.

(It looks like the this auto test case manages to pass even without it, but that looks like a bug in the test suite; code with error diagnostics should cause the test to fail.)

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@MythreyaK MythreyaK Aug 27, 2025

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oh whoops, done

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@HighCommander4 HighCommander4 Aug 27, 2025

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(It looks like the this auto test case manages to pass even without it, but that looks like a bug in the test suite; code with error diagnostics should cause the test to fail.)

(Filed #155545 for this.)

auto &Ctx = TU->getASTContext();
auto InputMatches = match(IM, Ctx);
ASSERT_EQ(1u, InputMatches.size());
Expand Down