x86: Insert ENDBR if function will be called indirectly

Since constant_call_address_operand has

;; Test for a pc-relative call operand
(define_predicate "constant_call_address_operand"
  (match_code "symbol_ref")
{
  if (ix86_cmodel == CM_LARGE || ix86_cmodel == CM_LARGE_PIC
      || flag_force_indirect_call)
    return false;
  if (TARGET_DLLIMPORT_DECL_ATTRIBUTES && SYMBOL_REF_DLLIMPORT_P (op))
    return false;
  return true;
})

even if cgraph_node::get (cfun->decl)->only_called_directly_p () returns
false, the fuction may still be called indirectly.  Copy the logic from
constant_call_address_operand to rest_of_insert_endbranch to insert ENDBR
at function entry if function will be called indirectly.

gcc/

	PR target/94417
	* config/i386/i386-features.c (rest_of_insert_endbranch): Insert
	ENDBR at function entry if function will be called indirectly.

gcc/testsuite/

	PR target/94417
	* gcc.target/i386/pr94417-1.c: New test.
	* gcc.target/i386/pr94417-2.c: Likewise.
	* gcc.target/i386/pr94417-3.c: Likewise.

gcc/ChangeLog

+2020-04-08  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR target/94417
+	* config/i386/i386-features.c (rest_of_insert_endbranch): Insert
+	ENDBR at function entry if function will be called indirectly.
+
 2020-04-08  Jakub Jelinek  <jakub@redhat.com>
 
 	PR target/94438

gcc/config/i386/i386-features.c

@@ -1963,7 +1963,12 @@ rest_of_insert_endbranch (void)
       && (!flag_manual_endbr
 	  || lookup_attribute ("cf_check",
 			       DECL_ATTRIBUTES (cfun->decl)))
-      && !cgraph_node::get (cfun->decl)->only_called_directly_p ())
+      && (!cgraph_node::get (cfun->decl)->only_called_directly_p ()
+	  || ix86_cmodel == CM_LARGE
+	  || ix86_cmodel == CM_LARGE_PIC
+	  || flag_force_indirect_call
+	  || (TARGET_DLLIMPORT_DECL_ATTRIBUTES
+	      && DECL_DLLIMPORT_P (cfun->decl))))
     {
       /* Queue ENDBR insertion to x86_function_profiler.  */
       if (crtl->profile && flag_fentry)

gcc/testsuite/ChangeLog

+2020-04-08  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR target/94417
+	* gcc.target/i386/pr94417-1.c: New test.
+	* gcc.target/i386/pr94417-2.c: Likewise.
+	* gcc.target/i386/pr94417-3.c: Likewise.
+
 2020-04-08  Jakub Jelinek  <jakub@redhat.com>
 
 	PR target/94438

gcc/testsuite/gcc.target/i386/pr94417-1.c

+/* { dg-do compile } */
+/* { dg-require-effective-target lp64 } */
+/* { dg-options "-O2 -fcf-protection -mcmodel=large" } */
+/* { dg-final { scan-assembler-times {\mendbr} 2 } } */
+
+extern void ext (void);
+
+__attribute((noclone, noinline))
+static
+void
+foo (void)
+{
+  ext ();
+}
+
+void
+bar (void)
+{
+  foo ();
+}

gcc/testsuite/gcc.target/i386/pr94417-2.c

+/* { dg-do compile } */
+/* { dg-require-effective-target lp64 } */
+/* { dg-require-effective-target fpic } */
+/* { dg-options "-O2 -fpic -mcmodel=large -fcf-protection" } */
+/* { dg-final { scan-assembler-times {\mendbr} 2 } } */
+
+extern void ext (void);
+
+__attribute((noclone, noinline))
+static
+void
+foo (void)
+{
+  ext ();
+}
+
+void
+bar (void)
+{
+  foo ();
+}

gcc/testsuite/gcc.target/i386/pr94417-3.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -fcf-protection -mforce-indirect-call" } */
+/* { dg-final { scan-assembler-times {\mendbr} 2 } } */
+
+extern void ext (void);
+
+__attribute((noclone, noinline))
+static
+void
+foo (void)
+{
+  ext ();
+}
+
+void
+bar (void)
+{
+  foo ();
+}