[pushed] c: add name hints to c_parser_declspecs [PR107583]

[David Malcolm via Gcc-patches]

PR c/107583 notes that we weren't issuing a hint for

  struct foo {
    time_t mytime; /* missing <time.h> include should trigger fixit */
  };

in the C frontend.

The root cause is that one of the "unknown type name" diagnostics
was missing logic to emit hints, which this patch fixes.

Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu.
Pushed to trunk as r14-1876-g57446d1bc9757e.

gcc/c/ChangeLog:
        PR c/107583
        * c-parser.cc (c_parser_declspecs): Add hints to "unknown type
        name" error.

gcc/testsuite/ChangeLog:
        PR c/107583
        * c-c++-common/spellcheck-pr107583.c: New test.
---
 gcc/c/c-parser.cc                                | 14 +++++++++++++-
 gcc/testsuite/c-c++-common/spellcheck-pr107583.c | 10 ++++++++++
 2 files changed, 23 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/c-c++-common/spellcheck-pr107583.c

diff --git a/gcc/c/c-parser.cc b/gcc/c/c-parser.cc
index 5baa501dbee..f8b14e4c688 100644
--- a/gcc/c/c-parser.cc
+++ b/gcc/c/c-parser.cc
@@ -3182,7 +3182,19 @@ c_parser_declspecs (c_parser *parser, struct c_declspecs 
*specs,
          attrs_ok = true;
          if (kind == C_ID_ID)
            {
-             error_at (loc, "unknown type name %qE", value);
+             auto_diagnostic_group d;
+             name_hint hint = lookup_name_fuzzy (value, FUZZY_LOOKUP_TYPENAME,
+                                                 loc);
+             if (const char *suggestion = hint.suggestion ())
+               {
+                 gcc_rich_location richloc (loc);
+                 richloc.add_fixit_replace (suggestion);
+                 error_at (&richloc,
+                           "unknown type name %qE; did you mean %qs?",
+                           value, suggestion);
+               }
+             else
+               error_at (loc, "unknown type name %qE", value);
              t.kind = ctsk_typedef;
              t.spec = error_mark_node;
            }
diff --git a/gcc/testsuite/c-c++-common/spellcheck-pr107583.c 
b/gcc/testsuite/c-c++-common/spellcheck-pr107583.c
new file mode 100644
index 00000000000..86a9e7dbcb6
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/spellcheck-pr107583.c
@@ -0,0 +1,10 @@
+struct s1 {
+  time_t mytime; /* { dg-error "unknown type name 'time_t'" "c error" { target 
c } } */
+  /* { dg-error "'time_t' does not name a type" "c++ error" { target c++ } .-1 
} */
+  /* { dg-message "'time_t' is defined in header" "hint" { target *-*-* } .-2 
} */
+};
+
+struct s2 {
+  unsinged i; /* { dg-error "unknown type name 'unsinged'; did you mean 
'unsigned'." "c error" { target c } } */
+  /* { dg-error "'unsinged' does not name a type; did you mean 'unsigned'." 
"c++ error" { target c++ } .-1 } */
+};
-- 
2.26.3