Improve error recovery in C/ObjC when the first argument of a function
declarator is incorrect. Not being a typename causes the parser to
dive down into the K&R identifier list handling stuff, which is almost
never the right thing to do.
Before:
r.c:3:17: error: expected ')'
void bar(intptr y);
^
r.c:3:9: note: to match this '('
void bar(intptr y);
^
r.c:3:10: error: a parameter list without types is only allowed in a function definition
void bar(intptr y);
^
After:
r.c:3:10: error: unknown type name 'intptr'; did you mean 'intptr_t'?
void bar(intptr y);
^~~~~~
intptr_t
r.c:1:13: note: 'intptr_t' declared here
typedef int intptr_t;
^
This fixes rdar://7980651 - poor recovery for bad type in the first arg of a C function
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@103783 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Parse/ParseDecl.cpp b/lib/Parse/ParseDecl.cpp
index 9b4264d..28d9dd0 100644
--- a/lib/Parse/ParseDecl.cpp
+++ b/lib/Parse/ParseDecl.cpp
@@ -2941,12 +2941,29 @@
// Identifier list. Note that '(' identifier-list ')' is only allowed for
// normal declarators, not for abstract-declarators. Get the first
// identifier.
- IdentifierInfo *FirstIdent = Tok.getIdentifierInfo();
- SourceLocation FirstIdentLoc = Tok.getLocation();
+ Token FirstTok = Tok;
ConsumeToken(); // eat the first identifier.
-
- return ParseFunctionDeclaratorIdentifierList(LParenLoc, FirstIdent,
- FirstIdentLoc, D);
+
+ // Identifier lists follow a really simple grammar: the identifiers can
+ // be followed *only* by a ", moreidentifiers" or ")". However, K&R
+ // identifier lists are really rare in the brave new modern world, and it
+ // is very common for someone to typo a type in a non-k&r style list. If
+ // we are presented with something like: "void foo(intptr x, float y)",
+ // we don't want to start parsing the function declarator as though it is
+ // a K&R style declarator just because intptr is an invalid type.
+ //
+ // To handle this, we check to see if the token after the first identifier
+ // is a "," or ")". Only if so, do we parse it as an identifier list.
+ if (Tok.is(tok::comma) || Tok.is(tok::r_paren))
+ return ParseFunctionDeclaratorIdentifierList(LParenLoc,
+ FirstTok.getIdentifierInfo(),
+ FirstTok.getLocation(), D);
+
+ // If we get here, the code is invalid. Push the first identifier back
+ // into the token stream and parse the first argument as an (invalid)
+ // normal argument declarator.
+ PP.EnterToken(Tok);
+ Tok = FirstTok;
}
}