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[Clang] Improve type traits recognition in __has_builtin #111516

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Merged
merged 2 commits into from
Oct 8, 2024
Merged

[Clang] Improve type traits recognition in __has_builtin #111516

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94874b7
[Clang] Improve type traits recognition in `__has_builtin`
cor3ntin Oct 8, 2024
b684ba4
add test
cor3ntin Oct 8, 2024
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2 changes: 2 additions & 0 deletions clang/docs/ReleaseNotes.rst
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Original file line number Diff line number Diff line change
Expand Up @@ -408,6 +408,8 @@ Bug Fixes to Compiler Builtins

- ``__noop`` can now be used in a constant expression. (#GH102064)

- Fix ``__has_builtin`` incorrectly returning ``false`` for some C++ type traits. (#GH111477)

Bug Fixes to Attribute Support
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

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5 changes: 4 additions & 1 deletion clang/include/clang/Basic/TokenKinds.def
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Expand Up @@ -64,6 +64,10 @@
#ifndef EXPRESSION_TRAIT
#define EXPRESSION_TRAIT(I,E,K) KEYWORD(I,K)
#endif
#ifndef TRANSFORM_TYPE_TRAIT_DEF
#define TRANSFORM_TYPE_TRAIT_DEF(K, Trait) KEYWORD(__##Trait, KEYCXX)
#endif

#ifndef ALIAS
#define ALIAS(X,Y,Z)
#endif
Expand Down Expand Up @@ -534,7 +538,6 @@ TYPE_TRAIT_1(__has_unique_object_representations,
TYPE_TRAIT_2(__is_layout_compatible, IsLayoutCompatible, KEYCXX)
TYPE_TRAIT_2(__is_pointer_interconvertible_base_of, IsPointerInterconvertibleBaseOf, KEYCXX)

#define TRANSFORM_TYPE_TRAIT_DEF(_, Trait) KEYWORD(__##Trait, KEYCXX)
#include "clang/Basic/TransformTypeTraits.def"

// Clang-only C++ Type Traits
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52 changes: 33 additions & 19 deletions clang/lib/Lex/PPMacroExpansion.cpp
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Expand Up @@ -1616,6 +1616,34 @@ asm("_ZNKSt8time_putIcSt19ostreambuf_iteratorIcSt11char_traitsIcEEE3putES3_"
"RSt8ios_basecPK2tmPKcSB_");
#endif

static bool IsBuiltinTrait(Token &Tok) {

#define TYPE_TRAIT_1(Spelling, Name, Key) \
case tok::kw_##Spelling: \
return true;
#define TYPE_TRAIT_2(Spelling, Name, Key) \
case tok::kw_##Spelling: \
return true;
#define TYPE_TRAIT_N(Spelling, Name, Key) \
case tok::kw_##Spelling: \
return true;
#define ARRAY_TYPE_TRAIT(Spelling, Name, Key) \
case tok::kw_##Spelling: \
return true;
#define EXPRESSION_TRAIT(Spelling, Name, Key) \
case tok::kw_##Spelling: \
return true;
#define TRANSFORM_TYPE_TRAIT_DEF(K, Spelling) \
case tok::kw___##Spelling: \
return true;

switch (Tok.getKind()) {
default:
return false;
#include "clang/Basic/TokenKinds.def"
}
}

/// ExpandBuiltinMacro - If an identifier token is read that is to be expanded
/// as a builtin macro, handle it and return the next token as 'Tok'.
void Preprocessor::ExpandBuiltinMacro(Token &Tok) {
Expand Down Expand Up @@ -1814,25 +1842,11 @@ void Preprocessor::ExpandBuiltinMacro(Token &Tok) {
getTargetInfo().getTargetOpts().FeatureMap);
}
return true;
} else if (II->getTokenID() != tok::identifier ||
II->hasRevertedTokenIDToIdentifier()) {
// Treat all keywords that introduce a custom syntax of the form
//
// '__some_keyword' '(' [...] ')'
//
// as being "builtin functions", even if the syntax isn't a valid
// function call (for example, because the builtin takes a type
// argument).
if (II->getName().starts_with("__builtin_") ||
II->getName().starts_with("__is_") ||
II->getName().starts_with("__has_"))
return true;
return llvm::StringSwitch<bool>(II->getName())
.Case("__array_rank", true)
.Case("__array_extent", true)
#define TRANSFORM_TYPE_TRAIT_DEF(_, Trait) .Case("__" #Trait, true)
#include "clang/Basic/TransformTypeTraits.def"
.Default(false);
} else if (IsBuiltinTrait(Tok)) {
return true;
} else if (II->getTokenID() != tok::identifier &&
II->getName().starts_with("__builtin_")) {
return true;
} else {
return llvm::StringSwitch<bool>(II->getName())
// Report builtin templates as being builtins.
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6 changes: 5 additions & 1 deletion clang/test/Preprocessor/feature_tests.cpp
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Expand Up @@ -31,7 +31,11 @@
!__has_builtin(__underlying_type) || \
!__has_builtin(__is_trivial) || \
!__has_builtin(__is_same_as) || \
!__has_builtin(__has_unique_object_representations)
!__has_builtin(__has_unique_object_representations) || \
!__has_builtin(__is_trivially_equality_comparable) || \
!__has_builtin(__reference_constructs_from_temporary) || \
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__reference_converts_from_temporary too?

!__has_builtin(__reference_binds_to_temporary) || \
!__has_builtin(__reference_converts_from_temporary)
#error Clang should have these
#endif

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