From: Jozef Lawrynowicz <jozef.l@somniumtech.com>
Date: Tue, 29 Aug 2017 13:20:54 +0000 (+0000)
Subject: re PR target/80993 ([msp430] __attribute__((interrupt)) should imply __attribute__... 
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=10bcba61fcfb0cd7f7a2ba64f1a14c62e3512eca;p=gcc.git

re PR target/80993 ([msp430] __attribute__((interrupt)) should imply __attribute__((used)))

	PR target/80993
	* gcc/config/msp430/msp430.c (msp430_attr): Mark interrupt
	handlers as used.

From-SVN: r251410
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 0002ce1ff48..951e6e8fd9c 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2017-08-29  Jozef Lawrynowicz  <jozef.l@somniumtech.com>
+
+	PR target/80993
+	* gcc/config/msp430/msp430.c (msp430_attr): Mark interrupt
+	handlers as used.
+
 2017-08-29  Richard Biener  <rguenther@suse.de>
 
 	* dwarf2out.c (add_dwarf_attr): When checking is enabled verify
diff --git a/gcc/config/msp430/msp430.c b/gcc/config/msp430/msp430.c
index 2b4427d8eb2..48fc12d9a91 100644
--- a/gcc/config/msp430/msp430.c
+++ b/gcc/config/msp430/msp430.c
@@ -1904,6 +1904,10 @@ msp430_attr (tree * node,
 
       if (! TREE_PUBLIC (* node))
 	message = "interrupt handlers cannot be static";
+
+      /* Ensure interrupt handlers never get optimised out.  */
+      TREE_USED (* node) = 1;
+      DECL_PRESERVE_P (* node) = 1;
     }
   else if (TREE_NAME_EQ (name, ATTR_REENT))
     {
diff --git a/gcc/testsuite/gcc.target/msp430/pr80993.c b/gcc/testsuite/gcc.target/msp430/pr80993.c
new file mode 100644
index 00000000000..4da5cf95532
--- /dev/null
+++ b/gcc/testsuite/gcc.target/msp430/pr80993.c
@@ -0,0 +1,13 @@
+/* { dg-do link } */
+/* { dg-options "--save-temps -msim -flto -Os" } */
+/* { dg-final { scan-file "pr80993.exe.ltrans0.s" no_ref_handler } } */
+
+void __attribute__((interrupt)) no_ref_handler (void)
+{
+  while (1);
+}
+
+int main (void)
+{
+  return 0;
+}