From 85d1195708cf977bd90afeb9ad51aba085993fb7 Mon Sep 17 00:00:00 2001
From: Joseph Myers <joseph@codesourcery.com>
Date: Tue, 3 Dec 2019 01:27:43 +0000
Subject: [PATCH] Diagnose use of [*] in old-style parameter definitions (PR
 c/88704).

GCC wrongly accepts [*] in old-style parameter definitions because
because parm_flag is set on the scope used for those definitions and,
unlike the case of a prototype in a function definition, there is no
subsequent check to disallow this invalid usage.  This patch adds such
a check.  (At this point we don't have location information for the
[*], so the diagnostic location isn't ideal.)

Bootstrapped with no regressions for x86_64-pc-linux-gnu.

	PR c/88704
gcc/c:
	* c-decl.c (store_parm_decls_oldstyle): Diagnose use of [*] in
	old-style parameter definitions.

gcc/testsuite:
	* gcc.dg/vla-25.c: New test.

From-SVN: r278917
---
 gcc/c/ChangeLog               | 6 ++++++
 gcc/c/c-decl.c                | 3 +++
 gcc/testsuite/ChangeLog       | 5 +++++
 gcc/testsuite/gcc.dg/vla-25.c | 9 +++++++++
 4 files changed, 23 insertions(+)
 create mode 100644 gcc/testsuite/gcc.dg/vla-25.c

diff --git a/gcc/c/ChangeLog b/gcc/c/ChangeLog
index c04443ea6f9..3ea177ffbd6 100644
--- a/gcc/c/ChangeLog
+++ b/gcc/c/ChangeLog
@@ -1,3 +1,9 @@
+2019-12-03  Joseph Myers  <joseph@codesourcery.com>
+
+	PR c/88704
+	* c-decl.c (store_parm_decls_oldstyle): Diagnose use of [*] in
+	old-style parameter definitions.
+
 2019-12-01  Sandra Loosemore  <sandra@codesourcery.com>
 
 	PR target/92499
diff --git a/gcc/c/c-decl.c b/gcc/c/c-decl.c
index bf1857dc3fa..0450fcd3514 100644
--- a/gcc/c/c-decl.c
+++ b/gcc/c/c-decl.c
@@ -9394,6 +9394,9 @@ store_parm_decls_oldstyle (tree fndecl, const struct c_arg_info *arg_info)
 		    "old-style function definition");
     }
 
+  if (current_scope->had_vla_unspec)
+    error ("%<[*]%> not allowed in other than function prototype scope");
+
   /* Match each formal parameter name with its declaration.  Save each
      decl in the appropriate TREE_PURPOSE slot of the parmids chain.  */
   for (parm = parmids; parm; parm = TREE_CHAIN (parm))
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index d5c7b0d1cf9..915c062b76e 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2019-12-03  Joseph Myers  <joseph@codesourcery.com>
+
+	PR c/88704
+	* gcc.dg/vla-25.c: New test.
+
 2019-12-03  Jakub Jelinek  <jakub@redhat.com>
 
 	* g++.dg/lto/inline-crossmodule-1_0.C: Use -fdump-ipa-inline-details
diff --git a/gcc/testsuite/gcc.dg/vla-25.c b/gcc/testsuite/gcc.dg/vla-25.c
new file mode 100644
index 00000000000..f6041575a09
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vla-25.c
@@ -0,0 +1,9 @@
+/* Test [*] diagnosed on old-style parameter declaration.  PR c/88704.  */
+/* { dg-do compile } */
+/* { dg-options "-std=c99 -pedantic-errors" } */
+
+void
+f (x)
+     int x[*];
+{ /* { dg-error "not allowed in other than function prototype scope" } */
+}