[PATCH] D132260: [pseudo] Eliminate a false parse of structured binding declaration.
This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
Closed by commit rGf7dc91ad5609: [pseudo] Eliminate a false parse of structured
binding declaration. (authored by hokein).
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D132260/new/
https://reviews.llvm.org/D132260
Files:
clang-tools-extra/pseudo/lib/cxx/CXX.cpp
clang-tools-extra/pseudo/lib/cxx/cxx.bnf
clang-tools-extra/pseudo/test/cxx/structured-binding.cpp
Index: clang-tools-extra/pseudo/test/cxx/structured-binding.cpp
===
--- /dev/null
+++ clang-tools-extra/pseudo/test/cxx/structured-binding.cpp
@@ -0,0 +1,6 @@
+// RUN: clang-pseudo -grammar=cxx -source=%s --start-symbol=statement-seq
--print-forest | FileCheck %s
+
+// Verify there is no false parse of the structured binding declaration.
+ABC[post] = abc;
+// CHECK: statement-seq~expression-statement := expression ;
+// CHECK: postfix-expression [ expr-or-braced-init-list ]
Index: clang-tools-extra/pseudo/lib/cxx/cxx.bnf
===
--- clang-tools-extra/pseudo/lib/cxx/cxx.bnf
+++ clang-tools-extra/pseudo/lib/cxx/cxx.bnf
@@ -330,7 +330,7 @@
nodeclspec-function-declaration := function-declarator ;
alias-declaration := USING IDENTIFIER = defining-type-id ;
simple-declaration := decl-specifier-seq init-declarator-list_opt ;
-simple-declaration := decl-specifier-seq ref-qualifier_opt [ identifier-list ]
initializer ;
+simple-declaration := decl-specifier-seq ref-qualifier_opt [ identifier-list ]
initializer ; [guard]
static_assert-declaration := STATIC_ASSERT ( constant-expression ) ;
static_assert-declaration := STATIC_ASSERT ( constant-expression ,
string-literal ) ;
empty-declaration := ;
Index: clang-tools-extra/pseudo/lib/cxx/CXX.cpp
===
--- clang-tools-extra/pseudo/lib/cxx/CXX.cpp
+++ clang-tools-extra/pseudo/lib/cxx/CXX.cpp
@@ -161,6 +161,27 @@
return symbolToToken(P.Lookahead) != tok::kw_else;
}
+bool specifiesStructuredBinding(const GuardParams ) {
+ const auto DSS = P.RHS[0];
+ assert(DSS->symbol() == Symbol::decl_specifier_seq);
+
+ auto Length = P.RHS[1]->startTokenIndex() - DSS->startTokenIndex();
+ for (const auto :
+ P.Tokens.tokens().slice(DSS->startTokenIndex(), Length)) {
+switch (T.Kind) {
+case clang::tok::kw_static:
+case clang::tok::kw_thread_local:
+case clang::tok::kw_auto:
+case clang::tok::kw_const:
+case clang::tok::kw_volatile:
+ break;
+default:
+ return false;
+}
+ }
+ return true;
+}
+
// Whether this e.g. decl-specifier contains an "exclusive" type such as a
class
// name, and thus can't combine with a second exclusive type.
//
@@ -320,6 +341,18 @@
{rule::nested_name_specifier::COLONCOLON,
TOKEN_GUARD(coloncolon, Tok.prev().Kind != tok::identifier)},
+ // Implement C++ [dcl.pre#6]:
+ // A simple-declaration with an identifier-list is called a structured
+ // binding declaration ([dcl.struct.bind]). If the decl-specifier-seq
+ // contains any decl-specifier other than static, thread_local, auto,
+ // or cv-qualifiers, the program is ill-formed.
+ {rule::simple_declaration::
+
decl_specifier_seq__ref_qualifier__L_SQUARE__identifier_list__R_SQUARE__initializer__SEMI,
+ specifiesStructuredBinding},
+ {rule::simple_declaration::
+
decl_specifier_seq__L_SQUARE__identifier_list__R_SQUARE__initializer__SEMI,
+ specifiesStructuredBinding},
+
// The grammar distinguishes (only) user-defined vs plain string
literals,
// where the clang lexer distinguishes (only) encoding types.
{rule::user_defined_string_literal_chunk::STRING_LITERAL,
Index: clang-tools-extra/pseudo/test/cxx/structured-binding.cpp
===
--- /dev/null
+++ clang-tools-extra/pseudo/test/cxx/structured-binding.cpp
@@ -0,0 +1,6 @@
+// RUN: clang-pseudo -grammar=cxx -source=%s --start-symbol=statement-seq --print-forest | FileCheck %s
+
+// Verify there is no false parse of the structured binding declaration.
+ABC[post] = abc;
+// CHECK: statement-seq~expression-statement := expression ;
+// CHECK: postfix-expression [ expr-or-braced-init-list ]
Index: clang-tools-extra/pseudo/lib/cxx/cxx.bnf
===
--- clang-tools-extra/pseudo/lib/cxx/cxx.bnf
+++ clang-tools-extra/pseudo/lib/cxx/cxx.bnf
@@ -330,7 +330,7 @@
nodeclspec-function-declaration := function-declarator ;
alias-declaration := USING IDENTIFIER = defining-type-id ;
simple-declaration := decl-specifier-seq init-declarator-list_opt ;
-simple-declaration := decl-specifier-seq ref-qualifier_opt [ identifier-list ] initializer ;
[PATCH] D132260: [pseudo] Eliminate a false parse of structured binding declaration.
hokein updated this revision to Diff 454816.
hokein marked 3 inline comments as done.
hokein added a comment.
address comments
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D132260/new/
https://reviews.llvm.org/D132260
Files:
clang-tools-extra/pseudo/lib/cxx/CXX.cpp
clang-tools-extra/pseudo/lib/cxx/cxx.bnf
clang-tools-extra/pseudo/test/cxx/structured-binding.cpp
Index: clang-tools-extra/pseudo/test/cxx/structured-binding.cpp
===
--- /dev/null
+++ clang-tools-extra/pseudo/test/cxx/structured-binding.cpp
@@ -0,0 +1,6 @@
+// RUN: clang-pseudo -grammar=cxx -source=%s --start-symbol=statement-seq
--print-forest | FileCheck %s
+
+// Verify there is no false parse of the structured binding declaration.
+ABC[post] = abc;
+// CHECK: statement-seq~expression-statement := expression ;
+// CHECK: postfix-expression [ expr-or-braced-init-list ]
Index: clang-tools-extra/pseudo/lib/cxx/cxx.bnf
===
--- clang-tools-extra/pseudo/lib/cxx/cxx.bnf
+++ clang-tools-extra/pseudo/lib/cxx/cxx.bnf
@@ -330,7 +330,7 @@
nodeclspec-function-declaration := function-declarator ;
alias-declaration := USING IDENTIFIER = defining-type-id ;
simple-declaration := decl-specifier-seq init-declarator-list_opt ;
-simple-declaration := decl-specifier-seq ref-qualifier_opt [ identifier-list ]
initializer ;
+simple-declaration := decl-specifier-seq ref-qualifier_opt [ identifier-list ]
initializer ; [guard]
static_assert-declaration := STATIC_ASSERT ( constant-expression ) ;
static_assert-declaration := STATIC_ASSERT ( constant-expression ,
string-literal ) ;
empty-declaration := ;
Index: clang-tools-extra/pseudo/lib/cxx/CXX.cpp
===
--- clang-tools-extra/pseudo/lib/cxx/CXX.cpp
+++ clang-tools-extra/pseudo/lib/cxx/CXX.cpp
@@ -161,6 +161,27 @@
return symbolToToken(P.Lookahead) != tok::kw_else;
}
+bool specifiesStructuredBinding(const GuardParams ) {
+ const auto DSS = P.RHS[0];
+ assert(DSS->symbol() == Symbol::decl_specifier_seq);
+
+ auto Length = P.RHS[1]->startTokenIndex() - DSS->startTokenIndex();
+ for (const auto :
+ P.Tokens.tokens().slice(DSS->startTokenIndex(), Length)) {
+switch (T.Kind) {
+case clang::tok::kw_static:
+case clang::tok::kw_thread_local:
+case clang::tok::kw_auto:
+case clang::tok::kw_const:
+case clang::tok::kw_volatile:
+ break;
+default:
+ return false;
+}
+ }
+ return true;
+}
+
// Whether this e.g. decl-specifier contains an "exclusive" type such as a
class
// name, and thus can't combine with a second exclusive type.
//
@@ -320,6 +341,18 @@
{rule::nested_name_specifier::COLONCOLON,
TOKEN_GUARD(coloncolon, Tok.prev().Kind != tok::identifier)},
+ // Implement C++ [dcl.pre#6]:
+ // A simple-declaration with an identifier-list is called a structured
+ // binding declaration ([dcl.struct.bind]). If the decl-specifier-seq
+ // contains any decl-specifier other than static, thread_local, auto,
+ // or cv-qualifiers, the program is ill-formed.
+ {rule::simple_declaration::
+
decl_specifier_seq__ref_qualifier__L_SQUARE__identifier_list__R_SQUARE__initializer__SEMI,
+ specifiesStructuredBinding},
+ {rule::simple_declaration::
+
decl_specifier_seq__L_SQUARE__identifier_list__R_SQUARE__initializer__SEMI,
+ specifiesStructuredBinding},
+
// The grammar distinguishes (only) user-defined vs plain string
literals,
// where the clang lexer distinguishes (only) encoding types.
{rule::user_defined_string_literal_chunk::STRING_LITERAL,
Index: clang-tools-extra/pseudo/test/cxx/structured-binding.cpp
===
--- /dev/null
+++ clang-tools-extra/pseudo/test/cxx/structured-binding.cpp
@@ -0,0 +1,6 @@
+// RUN: clang-pseudo -grammar=cxx -source=%s --start-symbol=statement-seq --print-forest | FileCheck %s
+
+// Verify there is no false parse of the structured binding declaration.
+ABC[post] = abc;
+// CHECK: statement-seq~expression-statement := expression ;
+// CHECK: postfix-expression [ expr-or-braced-init-list ]
Index: clang-tools-extra/pseudo/lib/cxx/cxx.bnf
===
--- clang-tools-extra/pseudo/lib/cxx/cxx.bnf
+++ clang-tools-extra/pseudo/lib/cxx/cxx.bnf
@@ -330,7 +330,7 @@
nodeclspec-function-declaration := function-declarator ;
alias-declaration := USING IDENTIFIER = defining-type-id ;
simple-declaration := decl-specifier-seq init-declarator-list_opt ;
-simple-declaration := decl-specifier-seq ref-qualifier_opt [ identifier-list ] initializer ;
+simple-declaration := decl-specifier-seq ref-qualifier_opt [ identifier-list ] initializer ; [guard]
static_assert-declaration :=
[PATCH] D132260: [pseudo] Eliminate a false parse of structured binding declaration.
sammccall accepted this revision.
sammccall added inline comments.
This revision is now accepted and ready to land.
Comment at: clang-tools-extra/pseudo/lib/cxx/CXX.cpp:164
+bool isStructuredBinding(const ForestNode* N) {
+ assert(N->symbol() == Symbol::decl_specifier_seq);
nit: specifiesStructuredBinding?
(because the structured binding itself is something bigger)
Comment at: clang-tools-extra/pseudo/lib/cxx/CXX.cpp:166
+ assert(N->symbol() == Symbol::decl_specifier_seq);
+ for (const auto : N->descendants()) {
+if (Child.kind() == ForestNode::Terminal) {
If you're going to iterate over tokens, it seems more direct (and cheaper) to
do it directly:
`for (const Tok& : P.Tokens.tokens(RHS[0].startTokenIndex(),
RHS[1].startTokenIndex()))`
Comment at: clang-tools-extra/pseudo/test/cxx/structured-binding.cpp:1
+
+// RUN: clang-pseudo -grammar=cxx -source=%s --start-symbol=statement-seq
--print-forest | FileCheck %s
nit: drop blank line
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D132260/new/
https://reviews.llvm.org/D132260
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[PATCH] D132260: [pseudo] Eliminate a false parse of structured binding declaration.
hokein created this revision.
hokein added a reviewer: sammccall.
Herald added a project: All.
hokein requested review of this revision.
Herald added a subscriber: alextsao1999.
Herald added a project: clang-tools-extra.
Using the guard to implement part of the rule https://eel.is/c++draft/dcl.pre#6.
void foo() {
// can be parsed as
// - structured-binding declaration (a false parse)
// - assignment expression
array[index] = value;
}
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D132260
Files:
clang-tools-extra/pseudo/lib/cxx/CXX.cpp
clang-tools-extra/pseudo/lib/cxx/cxx.bnf
clang-tools-extra/pseudo/test/cxx/structured-binding.cpp
Index: clang-tools-extra/pseudo/test/cxx/structured-binding.cpp
===
--- /dev/null
+++ clang-tools-extra/pseudo/test/cxx/structured-binding.cpp
@@ -0,0 +1,7 @@
+
+// RUN: clang-pseudo -grammar=cxx -source=%s --start-symbol=statement-seq
--print-forest | FileCheck %s
+
+// Verify there is no false parse of the structured binding declaration.
+ABC[post] = abc;
+// CHECK: statement-seq~expression-statement := expression ;
+// CHECK: postfix-expression [ expr-or-braced-init-list ]
Index: clang-tools-extra/pseudo/lib/cxx/cxx.bnf
===
--- clang-tools-extra/pseudo/lib/cxx/cxx.bnf
+++ clang-tools-extra/pseudo/lib/cxx/cxx.bnf
@@ -330,7 +330,7 @@
nodeclspec-function-declaration := function-declarator ;
alias-declaration := USING IDENTIFIER = defining-type-id ;
simple-declaration := decl-specifier-seq init-declarator-list_opt ;
-simple-declaration := decl-specifier-seq ref-qualifier_opt [ identifier-list ]
initializer ;
+simple-declaration := decl-specifier-seq ref-qualifier_opt [ identifier-list ]
initializer ; [guard]
static_assert-declaration := STATIC_ASSERT ( constant-expression ) ;
static_assert-declaration := STATIC_ASSERT ( constant-expression ,
string-literal ) ;
empty-declaration := ;
Index: clang-tools-extra/pseudo/lib/cxx/CXX.cpp
===
--- clang-tools-extra/pseudo/lib/cxx/CXX.cpp
+++ clang-tools-extra/pseudo/lib/cxx/CXX.cpp
@@ -161,6 +161,26 @@
return symbolToToken(P.Lookahead) != tok::kw_else;
}
+bool isStructuredBinding(const ForestNode* N) {
+ assert(N->symbol() == Symbol::decl_specifier_seq);
+ for (const auto : N->descendants()) {
+if (Child.kind() == ForestNode::Terminal) {
+ auto Kind = symbolToToken(Child.symbol());
+ switch (Kind) {
+ case clang::tok::kw_static:
+ case clang::tok::kw_thread_local:
+ case clang::tok::kw_auto:
+ case clang::tok::kw_const:
+ case clang::tok::kw_volatile:
+break;
+ default:
+return false;
+ }
+}
+ }
+ return true;
+}
+
// Whether this e.g. decl-specifier contains an "exclusive" type such as a
class
// name, and thus can't combine with a second exclusive type.
//
@@ -320,6 +340,18 @@
{rule::nested_name_specifier::COLONCOLON,
TOKEN_GUARD(coloncolon, Tok.prev().Kind != tok::identifier)},
+ // Implement C++ [dcl.pre#6]:
+ // A simple-declaration with an identifier-list is called a structured
+ // binding declaration ([dcl.struct.bind]). If the decl-specifier-seq
+ // contains any decl-specifier other than static, thread_local, auto,
+ // or cv-qualifiers, the program is ill-formed.
+ {rule::simple_declaration::
+
decl_specifier_seq__ref_qualifier__L_SQUARE__identifier_list__R_SQUARE__initializer__SEMI,
+ GUARD(isStructuredBinding(P.RHS[0]))},
+ {rule::simple_declaration::
+
decl_specifier_seq__L_SQUARE__identifier_list__R_SQUARE__initializer__SEMI,
+ GUARD(isStructuredBinding(P.RHS[0]))},
+
// The grammar distinguishes (only) user-defined vs plain string
literals,
// where the clang lexer distinguishes (only) encoding types.
{rule::user_defined_string_literal_chunk::STRING_LITERAL,
Index: clang-tools-extra/pseudo/test/cxx/structured-binding.cpp
===
--- /dev/null
+++ clang-tools-extra/pseudo/test/cxx/structured-binding.cpp
@@ -0,0 +1,7 @@
+
+// RUN: clang-pseudo -grammar=cxx -source=%s --start-symbol=statement-seq --print-forest | FileCheck %s
+
+// Verify there is no false parse of the structured binding declaration.
+ABC[post] = abc;
+// CHECK: statement-seq~expression-statement := expression ;
+// CHECK: postfix-expression [ expr-or-braced-init-list ]
Index: clang-tools-extra/pseudo/lib/cxx/cxx.bnf
===
--- clang-tools-extra/pseudo/lib/cxx/cxx.bnf
+++ clang-tools-extra/pseudo/lib/cxx/cxx.bnf
@@ -330,7 +330,7 @@
nodeclspec-function-declaration := function-declarator ;
alias-declaration := USING IDENTIFIER = defining-type-id ;
simple-declaration := decl-specifier-seq
