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DenisGZMDenisGZM
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[Clang] Allow parsing arbitrary order of attributes for declarations (#133107)
Enable parsing alignas attribute after GNU attributes, before ParseDeclaration This might be useful for cuda code where __shared__ and other specificators may be mixed with align. I'd be glad to see if there are any better places or other technique to process this attribute without interrupting current flow of parsing.
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9 files changed

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‎clang/docs/ReleaseNotes.rst

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@@ -680,6 +680,7 @@ Bug Fixes to C++ Support
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- Improved parser recovery of invalid requirement expressions. In turn, this
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fixes crashes from follow-on processing of the invalid requirement. (#GH138820)
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- Fixed the handling of pack indexing types in the constraints of a member function redeclaration. (#GH138255)
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- Clang now correctly parses arbitrary order of ``[[]]``, ``__attribute__`` and ``alignas`` attributes for declarations (#GH133107)
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- Fixed a crash when forming an invalid function type in a dependent context. (#GH138657) (#GH115725) (#GH68852)
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Bug Fixes to AST Handling

‎clang/include/clang/Parse/Parser.h

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@@ -3081,13 +3081,16 @@ class Parser : public CodeCompletionHandler {
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bool CouldBeBitField = false);
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Decl *ParseHLSLBuffer(SourceLocation &DeclEnd);
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3084-
void MaybeParseMicrosoftAttributes(ParsedAttributes &Attrs) {
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bool MaybeParseMicrosoftAttributes(ParsedAttributes &Attrs) {
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bool AttrsParsed = false;
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if ((getLangOpts().MicrosoftExt || getLangOpts().HLSL) &&
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Tok.is(tok::l_square)) {
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ParsedAttributes AttrsWithRange(AttrFactory);
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ParseMicrosoftAttributes(AttrsWithRange);
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AttrsParsed = !AttrsWithRange.empty();
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Attrs.takeAllFrom(AttrsWithRange);
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}
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return AttrsParsed;
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}
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void ParseMicrosoftUuidAttributeArgs(ParsedAttributes &Attrs);
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void ParseMicrosoftAttributes(ParsedAttributes &Attrs);

‎clang/lib/Parse/ParseDeclCXX.cpp

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@@ -3096,11 +3096,24 @@ Parser::DeclGroupPtrTy Parser::ParseCXXClassMemberDeclaration(
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}
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ParsedAttributes DeclSpecAttrs(AttrFactory);
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MaybeParseMicrosoftAttributes(DeclSpecAttrs);
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// Hold late-parsed attributes so we can attach a Decl to them later.
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LateParsedAttrList CommonLateParsedAttrs;
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while (MaybeParseCXX11Attributes(DeclAttrs) ||
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MaybeParseGNUAttributes(DeclSpecAttrs, &CommonLateParsedAttrs) ||
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MaybeParseMicrosoftAttributes(DeclSpecAttrs))
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;
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SourceLocation DeclStart;
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if (DeclAttrs.Range.isValid()) {
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DeclStart = DeclSpecAttrs.Range.isInvalid()
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? DeclAttrs.Range.getBegin()
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: std::min(DeclAttrs.Range.getBegin(),
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DeclSpecAttrs.Range.getBegin());
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} else {
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DeclStart = DeclSpecAttrs.Range.getBegin();
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}
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// decl-specifier-seq:
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// Parse the common declaration-specifiers piece.
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ParsingDeclSpec DS(*this, TemplateDiags);
@@ -3128,6 +3141,9 @@ Parser::DeclGroupPtrTy Parser::ParseCXXClassMemberDeclaration(
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// Turn off colon protection that was set for declspec.
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X.restore();
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if (DeclStart.isValid())
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DS.SetRangeStart(DeclStart);
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// If we had a free-standing type definition with a missing semicolon, we
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// may get this far before the problem becomes obvious.
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if (DS.hasTagDefinition() &&

‎clang/lib/Parse/ParseStmt.cpp

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@@ -235,6 +235,9 @@ StmtResult Parser::ParseStatementOrDeclarationAfterAttributes(
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}
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default: {
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if (getLangOpts().CPlusPlus && MaybeParseCXX11Attributes(CXX11Attrs, true))
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goto Retry;
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bool HaveAttrs = !CXX11Attrs.empty() || !GNUAttrs.empty();
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auto IsStmtAttr = [](ParsedAttr &Attr) { return Attr.isStmtAttr(); };
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bool AllAttrsAreStmtAttrs = llvm::all_of(CXX11Attrs, IsStmtAttr) &&
@@ -260,11 +263,11 @@ StmtResult Parser::ParseStatementOrDeclarationAfterAttributes(
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GNUAttrs);
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}
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if (CXX11Attrs.Range.getBegin().isValid()) {
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// The caller must guarantee that the CXX11Attrs appear before the
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// GNUAttrs, and we rely on that here.
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assert(GNUAttrs.Range.getBegin().isInvalid() ||
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GNUAttrs.Range.getBegin() > CXX11Attrs.Range.getBegin());
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DeclStart = CXX11Attrs.Range.getBegin();
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// Order of C++11 and GNU attributes is may be arbitrary.
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DeclStart = GNUAttrs.Range.getBegin().isInvalid()
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? CXX11Attrs.Range.getBegin()
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: std::min(CXX11Attrs.Range.getBegin(),
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GNUAttrs.Range.getBegin());
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} else if (GNUAttrs.Range.getBegin().isValid())
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DeclStart = GNUAttrs.Range.getBegin();
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return Actions.ActOnDeclStmt(Decl, DeclStart, DeclEnd);

‎clang/test/AST/ast-dump-template-json-win32-mangler-crash.cpp

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@@ -670,9 +670,18 @@ int main()
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// CHECK-NEXT: },
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// CHECK-NEXT: "range": {
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// CHECK-NEXT: "begin": {
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// CHECK-NEXT: "offset": 404,
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// CHECK-NEXT: "col": 16,
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// CHECK-NEXT: "tokLen": 9
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// CHECK-NEXT: "spellingLoc": {
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// CHECK-NEXT: "offset": 123,
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// CHECK-NEXT: "line": 4,
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// CHECK-NEXT: "col": 20,
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// CHECK-NEXT: "tokLen": 1
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// CHECK-NEXT: },
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// CHECK-NEXT: "expansionLoc": {
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// CHECK-NEXT: "offset": 393,
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// CHECK-NEXT: "line": 17,
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// CHECK-NEXT: "col": 5,
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// CHECK-NEXT: "tokLen": 10
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// CHECK-NEXT: }
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// CHECK-NEXT: },
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// CHECK-NEXT: "end": {
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// CHECK-NEXT: "offset": 481,

‎clang/test/Parser/c2x-alignas.c

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@@ -2,3 +2,26 @@
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_Alignas(int) struct c1; // expected-warning {{'_Alignas' attribute ignored}}
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alignas(int) struct c1; // expected-warning {{'alignas' attribute ignored}}
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__attribute__(()) [[]] alignas(int) int a; // expected-none TODO: actually this line should be an error
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__attribute__(()) alignas(int) [[]] int b; // expected-error {{an attribute list cannot appear here}}
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__attribute__(()) alignas(int) int c; // expected-none
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[[]] __attribute__(()) alignas(int) int d; // expected-none
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alignas(int) [[]] __attribute__(()) int e; // expected-error {{an attribute list cannot appear here}}
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struct C1 {
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__attribute__(()) [[]] alignas(int) int a; // expected-error {{an attribute list cannot appear here}}
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__attribute__(()) alignas(int) [[]] int b; // expected-error {{an attribute list cannot appear here}}
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__attribute__(()) alignas(int) int c; // expected-none
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[[]] __attribute__(()) alignas(int) int d; // expected-none
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alignas(int) [[]] __attribute__(()) int e; // expected-error {{an attribute list cannot appear here}}
19+
};
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void fn_with_decl() {
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__attribute__(()) [[]] alignas(int) int a; // expected-error {{an attribute list cannot appear here}}
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__attribute__(()) alignas(int) [[]] int b; // expected-error {{an attribute list cannot appear here}}
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__attribute__(()) alignas(int) int c; // expected-none
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[[]] __attribute__(()) alignas(int) int d; // expected-none
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alignas(int) [[]] __attribute__(()) int e; // expected-error {{an attribute list cannot appear here}}
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}

‎clang/test/Parser/cxx0x-attributes.cpp

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@@ -72,6 +72,30 @@ namespace test_misplacement {
7272
[[]] enum E2 { }; //expected-error{{misplaced attributes}}
7373
}
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__attribute__(()) alignas(int) int xx; // expected-none
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__attribute__(()) alignas(int) [[]] int yy; // expected-none
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[[]] __attribute__(()) alignas(int) int zz; // expected-none
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alignas(int) [[]] __attribute__(()) int aa; // expected-none
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[[]] alignas(int) __attribute__(()) int bb; // expected-none
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__attribute__(()) [[]] alignas(int) int cc; // expected-none
81+
82+
class C1 {
83+
__attribute__(()) alignas(int) int x; // expected-none
84+
__attribute__(()) alignas(int) [[]] int y; // expected-none
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[[]] __attribute__(()) alignas(int) int z; // expected-none
86+
alignas(int) [[]] __attribute__(()) int a; // expected-none
87+
[[]] alignas(int) __attribute__(()) int b; // expected-none
88+
__attribute__(()) [[]] alignas(int) int c; // expected-none
89+
};
90+
91+
void fn_with_decl() {
92+
__attribute__(()) alignas(int) int x; // expected-none
93+
__attribute__(()) alignas(int) [[]] int y; // expected-none
94+
[[]] __attribute__(()) alignas(int) int z; // expected-none
95+
alignas(int) [[]] __attribute__(()) int a; // expected-none
96+
[[]] alignas(int) __attribute__(()) int b; // expected-none
97+
__attribute__(()) [[]] alignas(int) int c; // expected-none
98+
}
7599
// Checks attributes placed at wrong syntactic locations of class specifiers.
76100
class [[]] [[]]
77101
attr_after_class_name_decl [[]] [[]]; // expected-error {{an attribute list cannot appear here}}

‎clang/test/SemaCUDA/cuda-attr-order.cu

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@@ -0,0 +1,15 @@
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// Verify that we can parse a simple CUDA file with different attributes order.
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// RUN: %clang_cc1 "-triple" "nvptx-nvidia-cuda" -fsyntax-only -verify %s
3+
// expected-no-diagnostics
4+
#include "Inputs/cuda.h"
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6+
struct alignas(16) float4 {
7+
float x, y, z, w;
8+
};
9+
10+
__attribute__((device)) float func() {
11+
__shared__ alignas(alignof(float4)) float As[4][4]; // Both combinations
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alignas(alignof(float4)) __shared__ float Bs[4][4]; // must be legal
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14+
return As[0][0] + Bs[0][0];
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}

‎clang/test/SemaCXX/warn-thread-safety-analysis.cpp

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@@ -2464,6 +2464,7 @@ class Foo {
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// expected-warning {{declaration does not declare anything}}
24652465
exclusive_locks_required(a))); // \
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// expected-warning {{attribute exclusive_locks_required ignored}}
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24672468
};
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} // end namespace WarnNoDecl

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