libclang: expose diagnostic formatting to Python bindings

[osandov]

Summary

This makes it easier for tools using the Python libclang bindings to
display diagnostics in a manner consistent with clang.

[compnerd]

bindings/python/clang/cindex.py

314

Alignment.

413

Can we use * instead of Foo?

419

Lets promote this to be run always, even if the options is queried from clang_defaultDiagnosticDisplayoptions. If those change, we should ensure that we update these anyways.

[osandov]

Thanks for getting around to this, @compnerd, this should take care of your comments.

[compnerd]

Do you have commit access or would you like me to commit this on your behalf?

[osandov]

I don't have commit access, please commit this on my behalf. Thank you!

[compnerd]

SVN r278315.

bindings/python/clang/cindex.py

class Diagnostic(object):
     """
 
     Ignored = 0
     Note    = 1
     Warning = 2
     Error   = 3
     Fatal   = 4
 
+    DisplaySourceLocation = 0x01
+    DisplayColumn         = 0x02
+    DisplaySourceRanges   = 0x04
+    DisplayOption         = 0x08
+    DisplayCategoryId     = 0x10
+    DisplayCategoryName   = 0x20
+    _FormatOptionsMask    = 0x3f
+
     def __init__(self, ptr):
         self.ptr = ptr
 
     def __del__(self):
         conf.lib.clang_disposeDiagnostic(self)
 
     @property
     def severity(self):
class Diagnostic(object):
     @property
     def disable_option(self):
         """The command-line option that disables this diagnostic."""
         disable = _CXString()
         conf.lib.clang_getDiagnosticOption(self, byref(disable))
 
         return conf.lib.clang_getCString(disable)
 
+    def format(self, options=None):
+        """
+        Format this diagnostic for display. The options argument takes
+        Diagnostic.Display* flags, which can be combined using bitwise OR. If
+        the options argument is not provided, the default display options will
+        be used.
+        """
+        if options is None:
+            options = conf.lib.clang_defaultDiagnosticDisplayOptions()
+        if options & ~Diagnostic._FormatOptionsMask:
+            raise ValueError('Invalid format options')
+        formatted = conf.lib.clang_formatDiagnostic(self, options)
+        return conf.lib.clang_getCString(formatted)
+
     def __repr__(self):
         return "<Diagnostic severity %r, location %r, spelling %r>" % (
             self.severity, self.location, self.spelling)
 
+    def __str__(self):
+        return self.format()
+
     def from_param(self):
       return self.ptr
 
 class FixIt(object):
     """
     A FixIt represents a transformation to be applied to the source to
     "fix-it". The fix-it shouldbe applied by replacing the given source range
     with the given value.
functionList = [
   ("clang_CXXMethod_isStatic",
    [Cursor],
    bool),
 
   ("clang_CXXMethod_isVirtual",
    [Cursor],
    bool),
 
+  ("clang_defaultDiagnosticDisplayOptions",
+   [],
+   c_uint),
+
   ("clang_defaultSaveOptions",
    [TranslationUnit],
    c_uint),
 
   ("clang_disposeCodeCompleteResults",
    [CodeCompletionResults]),
 
 # ("clang_disposeCXTUResourceUsage",
#  [CXTUResourceUsage]),
   ("clang_equalRanges",
    [SourceRange, SourceRange],
    bool),
 
   ("clang_equalTypes",
    [Type, Type],
    bool),
 
+  ("clang_formatDiagnostic",
+   [Diagnostic, c_uint],
+   _CXString),
+
   ("clang_getArgType",
    [Type, c_uint],
    Type,
    Type.from_result),
 
   ("clang_getArrayElementType",
    [Type],
    Type,