[gcc/devel/omp/gcc-9] Fix -Wreturn-type for static naked functions in C

[Tobias Burnus]

https://gcc.gnu.org/g:56544a47e0a36563ff12cbe3fb21ba9f36414fe6

commit 56544a47e0a36563ff12cbe3fb21ba9f36414fe6
Author: Richard Sandiford <richard.sandiford@arm.com>
Date:   Sat Jul 20 18:50:20 2019 +0000

    Fix -Wreturn-type for static naked functions in C
    
    This patch extends the fix for PR53633 to include static functions,
    which were giving a bogus -Wreturn-type warning for C but not for C++.
    
    2019-07-20  Richard Sandiford  <richard.sandiford@arm.com>
    
    gcc/c/
    	Backport from mainline
    	2019-07-18  Richard Sandiford  <richard.sandiford@arm.com>
    
    	PR c/53633
    	* c-decl.c (finish_function): Check targetm.warn_func_return
    	before issuing a -Wreturn-type warning.
    
    gcc/testsuite/
    	Backport from mainline
    	2019-07-18  Richard Sandiford  <richard.sandiford@arm.com>
    
    	* c-c++-common/pr53633-2.c: New test.
    
    From-SVN: r273635

Diff:
---
 gcc/c/ChangeLog                        |  9 +++++++++
 gcc/c/c-decl.c                         |  1 +
 gcc/testsuite/ChangeLog                |  7 +++++++
 gcc/testsuite/c-c++-common/pr53633-2.c | 19 +++++++++++++++++++
 4 files changed, 36 insertions(+)

diff --git a/gcc/c/ChangeLog b/gcc/c/ChangeLog
index 65e2f92..0411099 100644
--- a/gcc/c/ChangeLog
+++ b/gcc/c/ChangeLog
@@ -1,3 +1,12 @@
+2019-07-20  Richard Sandiford  <richard.sandiford@arm.com>
+
+	Backport from mainline
+	2019-07-18  Richard Sandiford  <richard.sandiford@arm.com>
+
+	PR c/53633
+	* c-decl.c (finish_function): Check targetm.warn_func_return
+	before issuing a -Wreturn-type warning.
+
 2019-05-17  Jakub Jelinek  <jakub@redhat.com>
 
 	Backported from mainline
diff --git a/gcc/c/c-decl.c b/gcc/c/c-decl.c
index c8e7cd0..04e0f4d 100644
--- a/gcc/c/c-decl.c
+++ b/gcc/c/c-decl.c
@@ -9685,6 +9685,7 @@ finish_function (void)
       /* Normally, with -Wreturn-type, flow will complain, but we might
          optimize out static functions.  */
       && !TREE_PUBLIC (fndecl)
+      && targetm.warn_func_return (fndecl)
       && warning (OPT_Wreturn_type,
 		  "no return statement in function returning non-void"))
     TREE_NO_WARNING (fndecl) = 1;
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index de0b52c..e57acad 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,10 @@
+2019-07-20  Richard Sandiford  <richard.sandiford@arm.com>
+
+	Backport from mainline
+	2019-07-18  Richard Sandiford  <richard.sandiford@arm.com>
+
+	* c-c++-common/pr53633-2.c: New test.
+
 2019-07-18  Kito Cheng  <kito.cheng@sifive.com>
 
 	Backport from mainline
diff --git a/gcc/testsuite/c-c++-common/pr53633-2.c b/gcc/testsuite/c-c++-common/pr53633-2.c
new file mode 100644
index 0000000..c26cb10
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr53633-2.c
@@ -0,0 +1,19 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target naked_functions } */
+/* { dg-options "-O2 -Wall" } */
+/* Check that we do not get warnings about missing return statements
+   or bogus looking noreturn functions.  */
+static int __attribute__((naked))
+foo (void)
+{
+  __asm__ ("");
+}
+
+static int __attribute__((naked,noreturn))
+bar (void)
+{
+  __asm__ ("");
+}
+
+int foo_caller (void) { return foo (); }
+int bar_caller (void) { return bar (); }