Spelling suggestions for misspelled preprocessor directives

This patch allows the preprocessor to offer suggestions for misspelled
directives, taking us from e.g.:

test.c:5:2: error: invalid preprocessing directive #endfi
 #endfi
  ^~~~~

to:

test.c:5:2: error: invalid preprocessing directive #endfi; did you mean #endif?
 #endfi
  ^~~~~
  endif

gcc/c-family/ChangeLog:
	* c-common.c: Include "spellcheck.h".
	(cb_get_suggestion): New function.
	* c-common.h (cb_get_suggestion): New decl.
	* c-lex.c (init_c_lex): Initialize cb->get_suggestion to
	cb_get_suggestion.

gcc/testsuite/ChangeLog:
	* gcc.dg/cpp/misspelled-directive-1.c: New testcase.
	* gcc.dg/cpp/misspelled-directive-2.c: New testcase.

libcpp/ChangeLog:
	* directives.c (directive_names): New array.
	(_cpp_handle_directive): Offer spelling suggestions for misspelled
	directives.
	* errors.c (cpp_diagnostic_at_richloc): New function.
	(cpp_error_at_richloc): New function.
	* include/cpplib.h (struct cpp_callbacks): Add field
	"get_suggestion".
	(cpp_error_at_richloc): New decl.

From-SVN: r239585

1 files changed, 36 insertions, 0 deletions

diff --git a/libcpp/errors.c b/libcpp/errors.c
index f7d4112..3b0a0b4 100644
--- a/libcpp/errors.c
+++ b/libcpp/errors.c
@@ -31,6 +31,23 @@ along with this program; see the file COPYING3.  If not see
 
 ATTRIBUTE_FPTR_PRINTF(5,0)
 static bool
+cpp_diagnostic_at_richloc (cpp_reader * pfile, int level, int reason,
+			   rich_location *richloc,
+			   const char *msgid, va_list *ap)
+{
+  bool ret;
+
+  if (!pfile->cb.error)
+    abort ();
+  ret = pfile->cb.error (pfile, level, reason, richloc, _(msgid), ap);
+
+  return ret;
+}
+
+/* Print a diagnostic at the given location.  */
+
+ATTRIBUTE_FPTR_PRINTF(5,0)
+static bool
 cpp_diagnostic_at (cpp_reader * pfile, int level, int reason,
 		   source_location src_loc,
 		   const char *msgid, va_list *ap)
@@ -255,6 +272,25 @@ cpp_error_at (cpp_reader * pfile, int level, source_location src_loc,
   return ret;
 }
 
+/* As cpp_error, but use RICHLOC as the location of the error, without
+   a column override.  */
+
+bool
+cpp_error_at_richloc (cpp_reader * pfile, int level, rich_location *richloc,
+		      const char *msgid, ...)
+{
+  va_list ap;
+  bool ret;
+
+  va_start (ap, msgid);
+
+  ret = cpp_diagnostic_at_richloc (pfile, level, CPP_W_NONE, richloc,
+				   msgid, &ap);
+
+  va_end (ap);
+  return ret;
+}
+
 /* Print a warning or error, depending on the value of LEVEL.  Include
    information from errno.  */