From a4d2774c9c1e213cb129c8b81a591297669838c8 Mon Sep 17 00:00:00 2001
From: Matthew Malcomson <matthew.malcomson@arm.com>
Date: Thu, 9 Apr 2020 16:11:09 +0100
Subject: [PATCH] [Arm] Allow the use of arm_cde.h for C++

arm_cde.h includes the arm_mve_types.h header, which declares some C++
overloaded functions.

There is a superfluous `extern "C"` statement in arm_cde.h, which
encompasses these functions.  This means that if compiling for C++, the
overloaded functions are declared, but are declared without name
mangling.  Hence all the function names are the same and we have many
conflicting declarations.

Testing Done:
  Regression tested for arm-none-eabi.

gcc/ChangeLog:

2020-04-09  Matthew Malcomson  <matthew.malcomson@arm.com>

	* config/arm/arm_cde.h: Remove `extern "C"` when compiling for
	C++.

gcc/testsuite/ChangeLog:

2020-04-09  Matthew Malcomson  <matthew.malcomson@arm.com>

	* g++.target/arm/cde_mve.C: New test.
---
 gcc/ChangeLog                          |  5 +++++
 gcc/config/arm/arm_cde.h               |  8 --------
 gcc/testsuite/ChangeLog                |  4 ++++
 gcc/testsuite/g++.target/arm/cde_mve.C | 10 ++++++++++
 4 files changed, 19 insertions(+), 8 deletions(-)
 create mode 100644 gcc/testsuite/g++.target/arm/cde_mve.C

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 368dfd6094e..d081003609f 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2020-04-09  Matthew Malcomson  <matthew.malcomson@arm.com>
+
+	* config/arm/arm_cde.h: Remove `extern "C"` when compiling for
+	C++.
+
 2020-04-09  Martin Jambor  <mjambor@suse.cz>
 	    Richard Biener  <rguenther@suse.de>
 
diff --git a/gcc/config/arm/arm_cde.h b/gcc/config/arm/arm_cde.h
index d8ddda6bd64..0ba3ee02d05 100644
--- a/gcc/config/arm/arm_cde.h
+++ b/gcc/config/arm/arm_cde.h
@@ -27,10 +27,6 @@
 #ifndef _GCC_ARM_CDE_H
 #define _GCC_ARM_CDE_H 1
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 #include <stdint.h>
 
 #if defined (__ARM_FEATURE_CDE)
@@ -177,8 +173,4 @@ extern "C" {
 
 #endif
 
-#ifdef __cplusplus
-}
-#endif
-
 #endif
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 5e56c38ffff..d79c4db1aee 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2020-04-09  Matthew Malcomson  <matthew.malcomson@arm.com>
+
+	* g++.target/arm/cde_mve.C: New test.
+
 2020-04-09  Christophe Lyon  <christophe.lyon@linaro.org>
 
 	* gcc.target/arm/cmse/cmse-15.c: Use check-function-bodies.
diff --git a/gcc/testsuite/g++.target/arm/cde_mve.C b/gcc/testsuite/g++.target/arm/cde_mve.C
new file mode 100644
index 00000000000..897cbd2b811
--- /dev/null
+++ b/gcc/testsuite/g++.target/arm/cde_mve.C
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target arm_v8_1m_main_cde_mve_fp_ok } */
+/* { dg-add-options arm_v8_1m_main_cde_mve_fp } */
+
+/* Ensure this compiles.  */
+#include "arm_cde.h"
+int foo ()
+{
+  return 1;
+}
-- 
2.30.2