As reported in PR80993, enabling lto causes interrupt handlers to be removed. This patch marks interrupt handlers as used, preventing them from being optimized out.
If the attached patch is acceptable, I would appreciate if someone could commit it for me, as I do not have write access. Thanks, Jozef
From 44b14ffae0e8956f40cd5356a9f00f5d055709c7 Mon Sep 17 00:00:00 2001 From: Jozef Lawrynowicz <joze...@somniumtech.com> Date: Thu, 24 Aug 2017 11:10:24 +0000 Subject: [PATCH] MSP430: Prevent lto removing interrupt handlers 2017-08-XX Jozef Lawrynowicz <joze...@somniumtech.com> PR target/80993 * gcc/config/msp430/msp430.c (msp430_attr): Mark interrupt handlers as used. gcc/testsuite 2017-08-XX Jozef Lawrynowicz <joze...@somniumtech.com> PR target/80993 * gcc.target/msp430/pr80993.c: New test. --- gcc/config/msp430/msp430.c | 4 ++++ gcc/testsuite/gcc.target/msp430/pr80993.c | 13 +++++++++++++ 2 files changed, 17 insertions(+) create mode 100644 gcc/testsuite/gcc.target/msp430/pr80993.c diff --git a/gcc/config/msp430/msp430.c b/gcc/config/msp430/msp430.c index 2b4427d..48fc12d 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 0000000..4da5cf9 --- /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; +} -- 1.8.3.1