Improve the diagnostic when a comma ends up at the end of a declarator group
instead of a semicolon (as sometimes happens during refactorings). When such a
comma is seen at the end of a line, and is followed by something which can't
possibly be a declarator (or even something which might be a plausible typo for
a declarator), suggest that a semicolon was intended.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@142544 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Parse/ParseDecl.cpp b/lib/Parse/ParseDecl.cpp
index 57766f9..8ce3bc1 100644
--- a/lib/Parse/ParseDecl.cpp
+++ b/lib/Parse/ParseDecl.cpp
@@ -965,6 +965,61 @@
return ParseDeclGroup(DS, Context, /*FunctionDefs=*/ false, &DeclEnd, FRI);
}
+/// Returns true if this might be the start of a declarator, or a common typo
+/// for a declarator.
+bool Parser::MightBeDeclarator(unsigned Context) {
+ switch (Tok.getKind()) {
+ case tok::annot_cxxscope:
+ case tok::annot_template_id:
+ case tok::caret:
+ case tok::code_completion:
+ case tok::coloncolon:
+ case tok::ellipsis:
+ case tok::kw___attribute:
+ case tok::kw_operator:
+ case tok::l_paren:
+ case tok::star:
+ return true;
+
+ case tok::amp:
+ case tok::ampamp:
+ case tok::colon: // Might be a typo for '::'.
+ return getLang().CPlusPlus;
+
+ case tok::identifier:
+ switch (NextToken().getKind()) {
+ case tok::code_completion:
+ case tok::coloncolon:
+ case tok::comma:
+ case tok::equal:
+ case tok::equalequal: // Might be a typo for '='.
+ case tok::kw_alignas:
+ case tok::kw_asm:
+ case tok::kw___attribute:
+ case tok::l_brace:
+ case tok::l_paren:
+ case tok::l_square:
+ case tok::less:
+ case tok::r_brace:
+ case tok::r_paren:
+ case tok::r_square:
+ case tok::semi:
+ return true;
+
+ case tok::colon:
+ // At namespace scope, 'identifier:' is probably a typo for 'identifier::'
+ // and in block scope it's probably a label.
+ return getLang().CPlusPlus && Context == Declarator::FileContext;
+
+ default:
+ return false;
+ }
+
+ default:
+ return false;
+ }
+}
+
/// ParseDeclGroup - Having concluded that this is either a function
/// definition or a group of object declarations, actually parse the
/// result.
@@ -1042,11 +1097,22 @@
if (FirstDecl)
DeclsInGroup.push_back(FirstDecl);
+ bool ExpectSemi = Context != Declarator::ForContext;
+
// If we don't have a comma, it is either the end of the list (a ';') or an
// error, bail out.
while (Tok.is(tok::comma)) {
- // Consume the comma.
- ConsumeToken();
+ SourceLocation CommaLoc = ConsumeToken();
+
+ if (Tok.isAtStartOfLine() && ExpectSemi && !MightBeDeclarator(Context)) {
+ // This comma was followed by a line-break and something which can't be
+ // the start of a declarator. The comma was probably a typo for a
+ // semicolon.
+ Diag(CommaLoc, diag::err_expected_semi_declaration)
+ << FixItHint::CreateReplacement(CommaLoc, ";");
+ ExpectSemi = false;
+ break;
+ }
// Parse the next declarator.
D.clear();
@@ -1071,7 +1137,7 @@
if (DeclEnd)
*DeclEnd = Tok.getLocation();
- if (Context != Declarator::ForContext &&
+ if (ExpectSemi &&
ExpectAndConsume(tok::semi,
Context == Declarator::FileContext
? diag::err_invalid_token_after_toplevel_declarator
@@ -3571,6 +3637,9 @@
/// isn't parsed at all, making this function effectively parse the C++
/// ptr-operator production.
///
+/// If the grammar of this construct is extended, matching changes must also be
+/// made to TryParseDeclarator and MightBeDeclarator.
+///
/// declarator: [C99 6.7.5] [C++ 8p4, dcl.decl]
/// [C] pointer[opt] direct-declarator
/// [C++] direct-declarator