Commit Graph

3 Commits

Author SHA1 Message Date
Richard Smith 943c440455 Improvements to vexing-parse warnings. Make the no-parameters case more
accurate by asking the parser whether there was an ambiguity rather than trying
to reverse-engineer it from the DeclSpec. Make the with-parameters case have
better diagnostics by using semantic information to drive the warning,
improving the diagnostics and adding a fixit.

Patch by Nikola Smiljanic. Some minor changes by me to suppress diagnostics for
declarations of the form 'T (*x)(...)', which seem to have a very high false
positive rate, and to reduce indentation in 'warnAboutAmbiguousFunction'.

llvm-svn: 160998
2012-07-30 21:30:52 +00:00
David Blaikie a90e86aa36 Use character literals for vexing initialization fixit hints.
Instead of suggesting " = 0" for "char c();", suggest " = '\0'", and similarly
for other char types (wide, 16, and 32). Add tests for all these, and since
this means testing such hints under C++0x, add tests for some untested C++0x
hint cases in the existing code, including suggesting nullptr for pointer
initialization.

This sets up the initialization helper to provide better type fidelity that
will be especially helpful for non-assignment cases (such as fixit-correcting
NULL usage in function calls (eg: foo(char) + foo(NULL) => foo('\0') instead
of the less informative foo(0)))

llvm-svn: 153008
2012-03-18 02:56:47 +00:00
Richard Smith 8d06f42448 Improve 0-argument -Wvexing-parse diagnostic by adding notes with fix-its:
- If the declarator is at the start of a line, and the previous line contained
   another declarator and ended with a comma, then that comma was probably a
   typo for a semicolon:

   int n = 0, m = 1, l = 2, // k = 5;
   myImportantFunctionCall(); // oops!

 - If removing the parentheses would correctly initialize the object, then
   produce a note suggesting that fix.

 - Otherwise, if there is a simple initializer we can suggest which performs
   value-initialization, then provide a note suggesting a correction to that
   initializer.

Sema::Declarator now tracks the location of the comma prior to the declarator in
the declaration, if there is one, to facilitate providing the note. The code to
determine an appropriate initializer from the -Wuninitialized warning has been
factored out to allow use in both that and -Wvexing-parse.

llvm-svn: 148072
2012-01-12 23:53:29 +00:00