From 6d4ef19c46b8dd1d629b70c7603985e3a001a187 Mon Sep 17 00:00:00 2001
From: David Malcolm <dmalcolm@redhat.com>
Date: Thu, 23 Jan 2025 10:43:09 -0500
Subject: [PATCH 94/98] FIXME: add suggest_missing_header::maybe_make

---
 gcc/c-family/known-headers.cc | 23 +++++++++++++++++++++++
 gcc/c-family/known-headers.h  |  4 ++++
 gcc/c/c-decl.cc               |  6 +++---
 gcc/c/c-parser.cc             |  7 +++----
 gcc/cp/name-lookup.cc         |  6 +++---
 gcc/cp/parser.cc              |  6 +++---
 6 files changed, 39 insertions(+), 13 deletions(-)

diff --git a/gcc/c-family/known-headers.cc b/gcc/c-family/known-headers.cc
index 36f3f88601fb..283edbbd8601 100644
--- a/gcc/c-family/known-headers.cc
+++ b/gcc/c-family/known-headers.cc
@@ -23,6 +23,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "c-family/c-common.h"
 #include "c-family/name-hint.h"
 #include "c-family/known-headers.h"
+#include "c-family/c-pragma.h"
 #include "gcc-rich-location.h"
 #include "opts.h"
 
@@ -299,6 +300,28 @@ get_cp_stdlib_header_for_string_macro_name (const char *name)
 
 /* Implementation of class suggest_missing_header.  */
 
+// FIXME
+
+std::unique_ptr<suggest_missing_header>
+suggest_missing_header::maybe_make (location_t loc, const char *name,
+				    const char *header_hint)
+{
+  // TODO: check to see if this header was already included,
+  // in which case the hint is likely to be meaningless
+
+  /* If NAME is a macro, then we likely have a macro expansion problem
+     rather than a missing include.  */
+  if (const cpp_hashnode *hashnode = cpp_lookup (parse_in,
+						 (const unsigned char *) (name),
+						 strlen (name)))
+    if (cpp_macro_p (hashnode))
+      return nullptr; // TODO: or a different suggestion
+
+  // FIXME: use should_suggest_as_macro_p ?
+
+  return std::make_unique<suggest_missing_header> (loc, name, header_hint);
+}
+
 /* suggest_missing_header's ctor.  */
 
 suggest_missing_header::suggest_missing_header (location_t loc,
diff --git a/gcc/c-family/known-headers.h b/gcc/c-family/known-headers.h
index 72fe3d745226..fc78e2670553 100644
--- a/gcc/c-family/known-headers.h
+++ b/gcc/c-family/known-headers.h
@@ -32,6 +32,10 @@ extern const char *get_cp_stdlib_header_for_string_macro_name (const char *n);
 class suggest_missing_header : public deferred_diagnostic
 {
  public:
+  static std::unique_ptr<suggest_missing_header>
+  maybe_make (location_t loc, const char *name,
+	      const char *header_hint);
+
   suggest_missing_header (location_t loc, const char *name,
 			  const char *header_hint);
   ~suggest_missing_header ();
diff --git a/gcc/c/c-decl.cc b/gcc/c/c-decl.cc
index 98249b922695..4c352eec1dac 100644
--- a/gcc/c/c-decl.cc
+++ b/gcc/c/c-decl.cc
@@ -4689,9 +4689,9 @@ lookup_name_fuzzy (tree name, enum lookup_name_fuzzy_kind kind, location_t loc)
   if (header_hint)
     return name_hint
       (nullptr,
-       std::make_unique<suggest_missing_header> (loc,
-						 IDENTIFIER_POINTER (name),
-						 header_hint));
+       suggest_missing_header::maybe_make (loc,
+					   IDENTIFIER_POINTER (name),
+					   header_hint));
 
   /* Next, look for exact matches for builtin defines that would have been
      defined if the user had passed a command-line option (e.g. -fopenmp
diff --git a/gcc/c/c-parser.cc b/gcc/c/c-parser.cc
index 0abdeedb3bc5..071dd655bdfb 100644
--- a/gcc/c/c-parser.cc
+++ b/gcc/c/c-parser.cc
@@ -1162,10 +1162,9 @@ c_parser_error_richloc (c_parser *parser, const char *gmsgid,
 	= get_c_stdlib_header_for_string_macro_name (token_name);
       if (header_hint != NULL)
 	h = name_hint (nullptr,
-		       std::make_unique<suggest_missing_header>
-			 (token->location,
-			  token_name,
-			  header_hint));
+		       suggest_missing_header::maybe_make (token->location,
+							   token_name,
+							   header_hint));
     }
 
   c_parse_error (gmsgid,
diff --git a/gcc/cp/name-lookup.cc b/gcc/cp/name-lookup.cc
index 524e1dfd470f..3271238839d2 100644
--- a/gcc/cp/name-lookup.cc
+++ b/gcc/cp/name-lookup.cc
@@ -8060,9 +8060,9 @@ lookup_name_fuzzy (tree name, enum lookup_name_fuzzy_kind kind, location_t loc)
   if (header_hint)
     return name_hint
       (nullptr,
-       std::make_unique<suggest_missing_header> (loc,
-						 IDENTIFIER_POINTER (name),
-						 header_hint));
+       suggest_missing_header::maybe_make (loc,
+					   IDENTIFIER_POINTER (name),
+					   header_hint));
 
   best_match <tree, const char *> bm (name);
 
diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
index 5c9ba69d12f3..d1a87d54e41d 100644
--- a/gcc/cp/parser.cc
+++ b/gcc/cp/parser.cc
@@ -3515,9 +3515,9 @@ cp_parser_error_1 (cp_parser* parser, const char* gmsgid,
 	  if (header_hint != NULL)
 	    h = name_hint
 	      (nullptr,
-	       std::make_unique<suggest_missing_header> (token->location,
-							 token_name,
-							 header_hint));
+	       suggest_missing_header::maybe_make (token->location,
+						   token_name,
+						   header_hint));
 	}
 
   /* Actually emit the error.  */
-- 
2.49.0