6a9f79e102
See https://reviews.llvm.org/D130626 for motivation. Identifier in the grammar has different categories (type-name, template-name, namespace-name), they requires semantic information to resolve. This patch is to eliminate the "local" ambiguities in type-name, and namespace-name, which gives us a performance boost of the parser: - eliminate all different type rules (class-name, enum-name, typedef-name), and fold them into a unified type-name, this removes the #1 type-name ambiguity, and gives us a big performance boost; - remove the namespace-alis rules, as they're hard and uninteresting; Note that we could eliminate more and gain more performance (like fold template-name, type-name, namespace together), but at current stage, we'd like keep all existing categories of the identifier (as they might assist in correlated disambiguation & keep the representation of important concepts uniform). | file |ambiguous nodes | forest size | glrParse performance | |SemaCodeComplete.cpp| 11k -> 5.7K | 10.4MB -> 7.9MB | 7.1MB/s -> 9.98MB/s | | AST.cpp | 1.3k -> 0.73K | 0.99MB -> 0.77MB | 6.7MB/s -> 8.4MB/s | Differential Revision: https://reviews.llvm.org/D130747
31 lines
1.5 KiB
C++
31 lines
1.5 KiB
C++
// RUN: clang-pseudo -grammar=cxx -source=%s --print-forest -print-statistics | FileCheck %s
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void foo() {
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T* a; // a multiply expression or a pointer declaration?
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// CHECK: statement-seq~statement := <ambiguous>
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// CHECK-NEXT: ├─statement~expression-statement := expression ;
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// CHECK-NEXT: │ ├─expression~multiplicative-expression := multiplicative-expression * pm-expression
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// CHECK-NEXT: │ │ ├─multiplicative-expression~IDENTIFIER := tok[5]
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// CHECK-NEXT: │ │ ├─* := tok[6]
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// CHECK-NEXT: │ │ └─pm-expression~id-expression := unqualified-id #1
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// CHECK-NEXT: │ │ └─unqualified-id~IDENTIFIER := tok[7]
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// CHECK-NEXT: │ └─; := tok[8]
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// CHECK-NEXT: └─statement~simple-declaration := decl-specifier-seq init-declarator-list ;
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// CHECK-NEXT: ├─decl-specifier-seq~simple-type-specifier := <ambiguous>
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// CHECK-NEXT: │ ├─simple-type-specifier~IDENTIFIER := tok[5]
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// CHECK-NEXT: │ └─simple-type-specifier~IDENTIFIER := tok[5]
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// CHECK-NEXT: ├─init-declarator-list~ptr-declarator := ptr-operator ptr-declarator
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// CHECK-NEXT: │ ├─ptr-operator~* := tok[6]
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// CHECK-NEXT: │ └─ptr-declarator~id-expression =#1
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// CHECK-NEXT: └─; := tok[8]
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}
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// CHECK: 2 Ambiguous nodes:
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// CHECK-NEXT: 1 simple-type-specifier
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// CHECK-NEXT: 1 statement
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// CHECK-EMPTY:
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// CHECK-NEXT: 0 Opaque nodes:
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// CHECK-EMPTY:
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// CHECK-NEXT: Ambiguity: 0.20 misparses/token
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// CHECK-NEXT: Unparsed: 0.00%
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