From 857a6ee25ff5cbb97715de4dd97e1641285c6085 Mon Sep 17 00:00:00 2001
From: Florian Weimer <fweimer@redhat.com>
Date: Fri, 20 Oct 2023 21:27:52 +0200
Subject: [PATCH] c: -Wincompatible-pointer-types should cover mismatches in ?:

gcc/c/

	PR c/109826
	PR other/44209
	* c-typeck.cc (build_conditional_expr): Use
	OPT_Wincompatible_pointer_types for pointer mismatches.
	Emit location information for the operand.

gcc/testsuite/

	* gcc.dg/Wincompatible-pointer-types-2.c: New.
	* gcc.dg/Wincompatible-pointer-types-3.c: New.
	* gcc.dg/Wincompatible-pointer-types-4.c: New.
---
 gcc/c/c-typeck.cc                                    | 16 ++++++++--------
 gcc/testsuite/gcc.dg/Wincompatible-pointer-types-2.c | 10 ++++++++++
 gcc/testsuite/gcc.dg/Wincompatible-pointer-types-3.c | 10 ++++++++++
 gcc/testsuite/gcc.dg/Wincompatible-pointer-types-4.c | 10 ++++++++++
 4 files changed, 38 insertions(+), 8 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/Wincompatible-pointer-types-2.c
 create mode 100644 gcc/testsuite/gcc.dg/Wincompatible-pointer-types-3.c
 create mode 100644 gcc/testsuite/gcc.dg/Wincompatible-pointer-types-4.c

diff --git a/gcc/c/c-typeck.cc b/gcc/c/c-typeck.cc
index f7ce13ae738..c73153c26b6 100644
--- a/gcc/c/c-typeck.cc
+++ b/gcc/c/c-typeck.cc
@@ -5564,14 +5564,14 @@ build_conditional_expr (location_t colon_loc, tree ifexp, bool ifexp_bcp,
       else
 	{
 	  int qual = ENCODE_QUAL_ADDR_SPACE (as_common);
-	  if (bltin1 && bltin2)
-	    warning_at (colon_loc, OPT_Wincompatible_pointer_types,
-			"pointer type mismatch between %qT and %qT "
-			"of %qD and %qD in conditional expression",
-			type1, type2, bltin1, bltin2);
-	  else
-	    pedwarn (colon_loc, 0,
-		     "pointer type mismatch in conditional expression");
+	  if (emit_diagnostic (bltin1 && bltin2 ? DK_WARNING : DK_PEDWARN,
+			       colon_loc, OPT_Wincompatible_pointer_types,
+			       "pointer type mismatch "
+			       "in conditional expression"))
+	    {
+	      inform (op1_loc, "first expression has type %qT", type1);
+	      inform (op2_loc, "second expression has type %qT", type2);
+	    }
 	  result_type = build_pointer_type
 			  (build_qualified_type (void_type_node, qual));
 	}
diff --git a/gcc/testsuite/gcc.dg/Wincompatible-pointer-types-2.c b/gcc/testsuite/gcc.dg/Wincompatible-pointer-types-2.c
new file mode 100644
index 00000000000..19276bbcfba
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/Wincompatible-pointer-types-2.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-options "" } */
+
+void *
+f1 (int flag, int *a, long *b)
+{
+  return flag ? a : b; /* { dg-warning "pointer type mismatch in conditional expression \\\[-Wincompatible-pointer-types\\\]" } */
+  /* { dg-note "first expression has type 'int \\*'" "" { target *-*-* } .-1 } */
+  /* { dg-note "second expression has type 'long int \\*'" "" { target *-*-* } .-2 } */
+}
diff --git a/gcc/testsuite/gcc.dg/Wincompatible-pointer-types-3.c b/gcc/testsuite/gcc.dg/Wincompatible-pointer-types-3.c
new file mode 100644
index 00000000000..3a6f35e79d9
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/Wincompatible-pointer-types-3.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-options "-std=c90 -pedantic-errors" } */
+
+void *
+f1 (int flag, int *a, long *b)
+{
+  return flag ? a : b; /* { dg-error "pointer type mismatch in conditional expression \\\[-Wincompatible-pointer-types\\\]" } */
+  /* { dg-note "first expression has type 'int \\*'" "" { target *-*-* } .-1 } */
+  /* { dg-note "second expression has type 'long int \\*'" "" { target *-*-* } .-2 } */
+}
diff --git a/gcc/testsuite/gcc.dg/Wincompatible-pointer-types-4.c b/gcc/testsuite/gcc.dg/Wincompatible-pointer-types-4.c
new file mode 100644
index 00000000000..c62a7e02bb9
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/Wincompatible-pointer-types-4.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-options "-std=c90 -pedantic-errors" } */
+
+void *
+f1 (int flag)
+{
+  return flag ? __builtin_memcpy : __builtin_memcmp; /* { dg-warning "pointer type mismatch in conditional expression \\\[-Wincompatible-pointer-types\\\]" } */
+  /* { dg-note "first expression has type 'void \\* \\(\\*\\)\\(void \\*," "" { target *-*-* } .-1 } */
+  /* { dg-note "second expression has type 'int \\(\\*\\)\\(const void \\*," "" { target *-*-* } .-2 } */
+}
-- 
2.11.4.GIT