[gcc r14-4728] [c] Fix PR 101364: ICE after error due to diagnose_arglist_conflict not checking for error

[Andrew Pinski <pinskia@gcc.gnu.org>]

https://gcc.gnu.org/g:879c91fcccf93681bd7e13290bfbb384cadcd268

commit r14-4728-g879c91fcccf93681bd7e13290bfbb384cadcd268
Author: Andrew Pinski <pinskia@gmail.com>
Date:   Sat Oct 14 13:40:05 2023 -0700

    [c] Fix PR 101364: ICE after error due to diagnose_arglist_conflict not checking for error
    
    When checking to see if we have a function declaration has a conflict due to
    promotations, there is no test to see if the type was an error mark and then calls
    c_type_promotes_to. c_type_promotes_to is not ready for error_mark and causes an
    ICE.
    
    This adds a check for error before the call of c_type_promotes_to.
    
    OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.
    
            PR c/101364
    
    gcc/c/ChangeLog:
    
            * c-decl.cc (diagnose_arglist_conflict): Test for
            error mark before calling of c_type_promotes_to.
    
    gcc/testsuite/ChangeLog:
    
            * gcc.dg/pr101364-1.c: New test.

Diff:
---
 gcc/c/c-decl.cc                   | 3 ++-
 gcc/testsuite/gcc.dg/pr101364-1.c | 8 ++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/gcc/c/c-decl.cc b/gcc/c/c-decl.cc
index 0de384783041..7a145bed281f 100644
--- a/gcc/c/c-decl.cc
+++ b/gcc/c/c-decl.cc
@@ -1899,7 +1899,8 @@ diagnose_arglist_conflict (tree newdecl, tree olddecl,
 	  break;
 	}
 
-      if (c_type_promotes_to (type) != type)
+      if (!error_operand_p (type)
+	  && c_type_promotes_to (type) != type)
 	{
 	  inform (input_location, "an argument type that has a default "
 		  "promotion cannot match an empty parameter name list "
diff --git a/gcc/testsuite/gcc.dg/pr101364-1.c b/gcc/testsuite/gcc.dg/pr101364-1.c
new file mode 100644
index 000000000000..e7c94a05553c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr101364-1.c
@@ -0,0 +1,8 @@
+/* { dg-do compile } */
+/* { dg-options "-std=c90 "} */
+
+void fruit(); /* { dg-message "previous declaration" } */
+void fruit( /* { dg-error "conflicting types for" } */
+    int b[x], /* { dg-error "undeclared " } */
+    short c)
+{} /* { dg-message "an argument type that has a" } */