[gcc r13-6403] analyzer: Support errno for newlib

[Hans-Peter Nilsson <hp@gcc.gnu.org>]

https://gcc.gnu.org/g:8590e4d096e4636c9384f7f885b979026861c29f

commit r13-6403-g8590e4d096e4636c9384f7f885b979026861c29f
Author: Hans-Peter Nilsson <hp@axis.com>
Date:   Wed Mar 1 03:54:03 2023 +0100

    analyzer: Support errno for newlib
    
    Without this definition, the errno definition for newlib
    isn't recognized as such, and these tests fail for newlib
    targets:
    
    FAIL: gcc.dg/analyzer/call-summaries-errno.c  (test for warnings, line 16)
    FAIL: gcc.dg/analyzer/call-summaries-errno.c (test for excess errors)
    FAIL: gcc.dg/analyzer/errno-1.c  (test for warnings, line 20)
    FAIL: gcc.dg/analyzer/errno-1.c (test for excess errors)
    FAIL: gcc.dg/analyzer/flex-without-call-summaries.c (test for excess errors)
    FAIL: gcc.dg/analyzer/isatty-1.c  (test for warnings, line 31)
    FAIL: gcc.dg/analyzer/isatty-1.c  (test for warnings, line 35)
    FAIL: gcc.dg/analyzer/isatty-1.c  (test for warnings, line 46)
    FAIL: gcc.dg/analyzer/isatty-1.c  (test for warnings, line 56)
    FAIL: gcc.dg/analyzer/isatty-1.c (test for excess errors)
    
    gcc/analyzer:
            * kf.cc (register_known_functions): Add __errno function for newlib.

Diff:
---
 gcc/analyzer/kf.cc | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/gcc/analyzer/kf.cc b/gcc/analyzer/kf.cc
index 3a91b6bd6eb..ed5f70398e1 100644
--- a/gcc/analyzer/kf.cc
+++ b/gcc/analyzer/kf.cc
@@ -1033,9 +1033,11 @@ register_known_functions (known_function_manager &kfm)
        and OS X like this:
 	 extern int * __error(void);
 	 #define errno (*__error())
+       and similarly __errno for newlib.
        Add these as synonyms for "__errno_location".  */
     kfm.add ("___errno", make_unique<kf_errno_location> ());
     kfm.add ("__error", make_unique<kf_errno_location> ());
+    kfm.add ("__errno", make_unique<kf_errno_location> ());
   }
 
   /* Language-specific support functions.  */