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[cxx-interop] Avoid importing too complex specializations #59906

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Merged
merged 1 commit into from
Jul 6, 2022
Merged

[cxx-interop] Avoid importing too complex specializations #59906

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4 changes: 4 additions & 0 deletions include/swift/AST/DiagnosticsClangImporter.def
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Original file line number Diff line number Diff line change
Expand Up @@ -124,6 +124,10 @@ WARNING(libstdcxx_not_found, none,
"libstdc++ not found for '%0'; C++ stdlib may be unavailable",
(StringRef))

WARNING(too_many_class_template_instantiations, none,
"template instantiation for '%0' not imported: too many instantiations",
(StringRef))

NOTE(macro_not_imported_unsupported_operator, none, "operator not supported in macro arithmetic", ())
NOTE(macro_not_imported_unsupported_named_operator, none, "operator '%0' not supported in macro arithmetic", (StringRef))
NOTE(macro_not_imported_invalid_string_literal, none, "invalid string literal", ())
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10 changes: 9 additions & 1 deletion lib/ClangImporter/ImportDecl.cpp
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Expand Up @@ -2486,8 +2486,16 @@ namespace {
// deep/complex template, or we've run into an infinite loop. In either
// case, its not worth the compile time, so bail.
// TODO: this could be configurable at some point.
if (llvm::size(decl->getSpecializedTemplate()->specializations()) > 10000)
if (llvm::size(decl->getSpecializedTemplate()->specializations()) >
1000) {
std::string name;
llvm::raw_string_ostream os(name);
decl->printQualifiedName(os);
// Emit a warning if we haven't warned about this decl yet.
if (Impl.tooDeepTemplateSpecializations.insert(name).second)
Impl.diagnose({}, diag::too_many_class_template_instantiations, name);
return nullptr;
}

// `Sema::isCompleteType` will try to instantiate the class template as a
// side-effect and we rely on this here. `decl->getDefinition()` can
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4 changes: 4 additions & 0 deletions lib/ClangImporter/ImporterImpl.h
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Expand Up @@ -626,6 +626,10 @@ class LLVM_LIBRARY_VISIBILITY ClangImporter::Implementation
llvm::DenseMap<clang::FunctionDecl *, ValueDecl *>
specializedFunctionTemplates;

/// Stores qualified names of C++ template specializations that were too deep
/// to import into Swift.
llvm::StringSet<> tooDeepTemplateSpecializations;
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Seeing the following:

Assertion failed: (isHandleInSync() && "invalid iterator access!"), function operator++, file DenseMap.h, line 1263.

Pretty sure this is the cause.


/// Keeps track of the Clang functions that have been turned into
/// properties.
llvm::DenseMap<const clang::FunctionDecl *, VarDecl *> FunctionsAsProperties;
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