PR10828: Produce a warning when a no-arguments function is declared in block
scope, when no other indication is provided that the user intended to declare a
function rather than a variable.
Remove some false positives from the existing 'parentheses disambiguated as a
function' warning by suppressing it when the declaration is marked as 'typedef'
or 'extern'.
Add a new warning group -Wvexing-parse containing both of these warnings.
The new warning is enabled by default; despite a number of false positives (and
one bug) in clang's test-suite, I have only found genuine bugs with it when
running it over a significant quantity of real C++ code.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@147599 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Parse/ParseDecl.cpp b/lib/Parse/ParseDecl.cpp
index ee4a51e..d3c8211 100644
--- a/lib/Parse/ParseDecl.cpp
+++ b/lib/Parse/ParseDecl.cpp
@@ -1111,6 +1111,21 @@
if (FirstDecl)
DeclsInGroup.push_back(FirstDecl);
+ // In C++, "T var();" at block scope is probably an attempt to initialize a
+ // variable, not a function declaration. We don't catch this case earlier,
+ // since there is no ambiguity here.
+ if (getLang().CPlusPlus && Context != Declarator::FileContext &&
+ D.getNumTypeObjects() == 1 && D.isFunctionDeclarator() &&
+ D.getDeclSpec().getStorageClassSpecAsWritten()
+ == DeclSpec::SCS_unspecified &&
+ D.getDeclSpec().getTypeSpecType() != DeclSpec::TST_void) {
+ DeclaratorChunk &C = D.getTypeObject(0);
+ if (C.Fun.NumArgs == 0 && !C.Fun.isVariadic && !C.Fun.TrailingReturnType &&
+ C.Fun.getExceptionSpecType() == EST_None)
+ Diag(C.Loc, diag::warn_empty_parens_are_function_decl)
+ << SourceRange(C.Loc, C.EndLoc);
+ }
+
bool ExpectSemi = Context != Declarator::ForContext;
// If we don't have a comma, it is either the end of the list (a ';') or an