[clang-tools-extra] a1a1a78 - [pseudo] Eliminate an ambiguity for the empty member declaration.

[Haojian Wu via cfe-commits]

Author: Haojian Wu
Date: 2022-08-12T13:46:26+02:00
New Revision: a1a1a78ac8cf837e4c05152c9715f399b33bfb59

URL: https://github.com/llvm/llvm-project/commit/a1a1a78ac8cf837e4c05152c9715f399b33bfb59
DIFF: https://github.com/llvm/llvm-project/commit/a1a1a78ac8cf837e4c05152c9715f399b33bfb59.diff

LOG: [pseudo] Eliminate an ambiguity for the empty member declaration.

We happened to introduce a `member-declaration := ;` rule
when inlining the `member-declaration := decl-specifier-seq_opt
member-declarator-list_opt ;`.
And with the `member-declaration := empty-declaration` rule, we had two parses of `;`.

This patch is to restrict the grammar to eliminate the
`member-declaration := ;` rule.

Differential Revision: https://reviews.llvm.org/D131724

Added: 
    clang-tools-extra/pseudo/test/cxx/empty-member-declaration.cpp

Modified: 
    clang-tools-extra/pseudo/lib/cxx/cxx.bnf

Removed: 
    


################################################################################
diff  --git a/clang-tools-extra/pseudo/lib/cxx/cxx.bnf b/clang-tools-extra/pseudo/lib/cxx/cxx.bnf
index 5f1cba4503948..d5cc0a9d2c857 100644
--- a/clang-tools-extra/pseudo/lib/cxx/cxx.bnf
+++ b/clang-tools-extra/pseudo/lib/cxx/cxx.bnf
@@ -557,7 +557,8 @@ class-key := STRUCT
 class-key := UNION
 member-specification := member-declaration member-specification_opt
 member-specification := access-specifier : member-specification_opt
-member-declaration := decl-specifier-seq_opt member-declarator-list_opt ;
+member-declaration := decl-specifier-seq member-declarator-list_opt ;
+member-declaration := member-declarator-list ;
 member-declaration := function-definition
 member-declaration := using-declaration
 member-declaration := using-enum-declaration

diff  --git a/clang-tools-extra/pseudo/test/cxx/empty-member-declaration.cpp b/clang-tools-extra/pseudo/test/cxx/empty-member-declaration.cpp
new file mode 100644
index 0000000000000..2540dd010fcef
--- /dev/null
+++ b/clang-tools-extra/pseudo/test/cxx/empty-member-declaration.cpp
@@ -0,0 +1,7 @@
+// RUN: clang-pseudo -grammar=cxx -source=%s --print-forest --forest-abbrev=false | FileCheck %s
+class A {
+    ;
+// CHECK-NOT: member-declaration := ;
+// CHECK: member-declaration := empty-declaration
+// CHECK-NOT: member-declaration := ;
+};