spellcheck bugfixes: don't offer the goal string as a suggestion

gcc/cp/ChangeLog:
	PR c++/77922
	* name-lookup.c (lookup_name_fuzzy): Filter out reserved words
	that were filtered out by init_reswords.

gcc/ChangeLog:
	PR c++/72774
	PR c++/72786
	PR c++/77922
	PR c++/78313
	* spellcheck.c (selftest::test_find_closest_string): Verify that
	we don't offer the goal string as a suggestion.
	* spellcheck.h (best_match::get_best_meaningful_candidate): Don't
	offer the goal string as a suggestion.

gcc/testsuite/ChangeLog:
	PR c++/72774
	PR c++/72786
	PR c++/77922
	PR c++/78313
	* g++.dg/spellcheck-c++-11-keyword.C: New test case.
	* g++.dg/spellcheck-macro-ordering.C: New test case.
	* g++.dg/spellcheck-pr78313.C: New test case.

From-SVN: r242965

9 files changed, 90 insertions, 0 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 04d2030..92033ba 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,15 @@
+2016-11-29  David Malcolm  <dmalcolm@redhat.com>
+
+	PR c++/72774
+	PR c++/72786
+	PR c++/77922
+	PR c++/78313
+	* spellcheck.c (selftest::test_find_closest_string): Verify that
+	we don't offer the goal string as a suggestion.
+	* spellcheck.h (best_match::get_best_meaningful_candidate): Don't
+	offer the goal string as a suggestion.
+
+
 2016-11-29  Claudiu Zissulescu  <claziss@synopsys.com>
 
 	* config/arc/arc.c (arc_override_options): Avoid selection of
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 476ff654..35db0db 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2016-11-29  David Malcolm  <dmalcolm@redhat.com>
+
+	PR c++/77922
+	* name-lookup.c (lookup_name_fuzzy): Filter out reserved words
+	that were filtered out by init_reswords.
+
 2016-11-28  Jakub Jelinek  <jakub@redhat.com>
 	    Jason Merrill  <jason@redhat.com>
 
diff --git a/gcc/cp/name-lookup.c b/gcc/cp/name-lookup.c
index 4f80e8d..d80c031 100644
--- a/gcc/cp/name-lookup.c
+++ b/gcc/cp/name-lookup.c
@@ -4812,6 +4812,12 @@ lookup_name_fuzzy (tree name, enum lookup_name_fuzzy_kind kind)
       if (!resword_identifier)
 	continue;
       gcc_assert (TREE_CODE (resword_identifier) == IDENTIFIER_NODE);
+
+      /* Only consider reserved words that survived the
+	 filtering in init_reswords (e.g. for -std).  */
+      if (!C_IS_RESERVED_WORD (resword_identifier))
+	continue;
+
       bm.consider (resword_identifier);
     }
 
diff --git a/gcc/spellcheck.c b/gcc/spellcheck.c
index b37b1e4..86cdee1 100644
--- a/gcc/spellcheck.c
+++ b/gcc/spellcheck.c
@@ -210,6 +210,11 @@ test_find_closest_string ()
   ASSERT_STREQ ("banana", find_closest_string ("banyan", &candidates));
   ASSERT_STREQ ("cherry", find_closest_string ("berry", &candidates));
   ASSERT_EQ (NULL, find_closest_string ("not like the others", &candidates));
+
+  /* If the goal string somehow makes it into the candidate list, offering
+     it as a suggestion will be nonsensical.  Verify that we don't offer such
+     suggestions.  */
+  ASSERT_EQ (NULL, find_closest_string ("banana", &candidates));
 }
 
 /* Test data for test_metric_conditions.  */
diff --git a/gcc/spellcheck.h b/gcc/spellcheck.h
index b48cfbc..41c9308 100644
--- a/gcc/spellcheck.h
+++ b/gcc/spellcheck.h
@@ -165,6 +165,16 @@ class best_match
 	if (m_best_distance > cutoff)
 	  return NULL;
     }
+
+    /* If the goal string somehow makes it into the candidate list, offering
+       it as a suggestion will be nonsensical e.g.
+         'constexpr' does not name a type; did you mean 'constexpr'?
+       Ultimately such suggestions are due to bugs in constructing the
+       candidate list, but as a band-aid, do not offer suggestions for
+       distance == 0 (where candidate == goal).  */
+    if (m_best_distance == 0)
+      return NULL;
+
     return m_best_candidate;
   }
 
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 71b8684..2107f7e 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,13 @@
+2016-11-29  David Malcolm  <dmalcolm@redhat.com>
+
+	PR c++/72774
+	PR c++/72786
+	PR c++/77922
+	PR c++/78313
+	* g++.dg/spellcheck-c++-11-keyword.C: New test case.
+	* g++.dg/spellcheck-macro-ordering.C: New test case.
+	* g++.dg/spellcheck-pr78313.C: New test case.
+
 2016-11-29  Tamar Christina  <tamar.christina@arm.com>
 
 	* gcc.target/aarch64/advsimd-intrinsics/arm-neon-ref.h
diff --git a/gcc/testsuite/g++.dg/spellcheck-c++-11-keyword.C b/gcc/testsuite/g++.dg/spellcheck-c++-11-keyword.C
new file mode 100644
index 0000000..0984af9
--- /dev/null
+++ b/gcc/testsuite/g++.dg/spellcheck-c++-11-keyword.C
@@ -0,0 +1,15 @@
+/* c++/77922: "constexpr" is only available from C++11 onwards.
+   We shouldn't offer it as a spellcheck suggestion in C++98.  */
+// { dg-options "-std=c++98" }
+
+constexpr int a = 1; // { dg-bogus "did you mean" }
+// { dg-error ".constexpr. does not name a type" "" { target *-*-* } .-1 }
+// { dg-message "C\\+\\+11 .constexpr. only available with -std=c\\+\\+11 or -std=gnu\\+\\+11" "" { target *-*-* } .-2 }
+
+/* If the user typos "constexpr" (here as "consexpr"), don't offer it as a
+   spelling suggestion in C++98 mode.  */
+consexpr int a = 1; // { dg-bogus "did you mean" }
+// { dg-error ".consexpr. does not name a type" "" { target *-*-* } .-1 }
+
+decltype i = 0; // { dg-bogus "did you mean" }
+// { dg-error ".decltype. does not name a type" "" { target *-*-* } .-1 }
diff --git a/gcc/testsuite/g++.dg/spellcheck-macro-ordering.C b/gcc/testsuite/g++.dg/spellcheck-macro-ordering.C
new file mode 100644
index 0000000..3b888c6
--- /dev/null
+++ b/gcc/testsuite/g++.dg/spellcheck-macro-ordering.C
@@ -0,0 +1,15 @@
+// PR c++/72786
+
+/* Example of a macro-ordering issue, where the use is before the defn.  */
+
+class DocTargetDriver {
+  virtual void clone() const OVERRIDE { }
+  /* Offering "OVERRIDE" as a spelling suggestion for "OVERRIDE" would be
+     nonsensical.  */
+  // { dg-bogus "did you mean" "" { target *-*-* } .-3 }
+  // { dg-error "expected .;. at end of member declaration" "" { target *-*-* } .-4 }
+  // { dg-error ".OVERRIDE. does not name a type" "" { target *-*-* } .-5 }
+};
+
+#define OVERRIDE override
+
diff --git a/gcc/testsuite/g++.dg/spellcheck-pr78313.C b/gcc/testsuite/g++.dg/spellcheck-pr78313.C
new file mode 100644
index 0000000..e34176d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/spellcheck-pr78313.C
@@ -0,0 +1,11 @@
+// PR c++/78313 (see also PR c++/72774)
+// { dg-do compile }
+
+void baz ();
+namespace A { void foo (); }
+void bar ()
+{
+  using A::foo;
+  0 ? static_cast<foo> (0) : baz; // { dg-bogus "did you mean" }
+  // { dg-error "does not name a type" "" { target *-*-* } .-1 }
+}