[gcc r14-6811] MIPS: Put the ret to the end of args of reconcat [PR112759]

[YunQiang Su]

https://gcc.gnu.org/g:384dbb0b4e751e6eb7ba3f9993a6cce466743926

commit r14-6811-g384dbb0b4e751e6eb7ba3f9993a6cce466743926
Author: YunQiang Su <syq@gcc.gnu.org>
Date:   Tue Dec 19 07:36:52 2023 +0800

    MIPS: Put the ret to the end of args of reconcat [PR112759]
    
    The function `reconcat` cannot append string(s) to NULL,
    as the concat process will stop at the first NULL.
    
    Let's always put the `ret` to the end, as it may be NULL.
    We keep use reconcat here, due to that reconcat can make it
    easier if we add more hardware features detecting, for example
    by hwcap.
    
    gcc/
    
            PR target/112759
            * config/mips/driver-native.cc (host_detect_local_cpu):
            Put the ret to the end of args of reconcat.

Diff:
---
 gcc/config/mips/driver-native.cc | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/gcc/config/mips/driver-native.cc b/gcc/config/mips/driver-native.cc
index afc276f5278..4ef48e14916 100644
--- a/gcc/config/mips/driver-native.cc
+++ b/gcc/config/mips/driver-native.cc
@@ -44,6 +44,8 @@ const char *
 host_detect_local_cpu (int argc, const char **argv)
 {
   const char *cpu = NULL;
+  /* Don't assigne any static string to ret.  If you need to do so,
+     use concat.  */
   char *ret = NULL;
   char buf[128];
   FILE *f;
@@ -90,7 +92,8 @@ host_detect_local_cpu (int argc, const char **argv)
 
 fallback_cpu:
 #if defined (__mips_nan2008)
-  ret = reconcat (ret, " -mnan=2008 ", NULL);
+  /* Put the ret to the end of list, since it may be NULL.  */
+  ret = reconcat (ret, " -mnan=2008 ", ret, NULL);
 #endif
 
 #ifdef HAVE_GETAUXVAL
@@ -104,7 +107,7 @@ fallback_cpu:
 #endif
 
   if (cpu)
-    ret = reconcat (ret, ret, "-m", argv[0], "=", cpu, NULL);
+    ret = reconcat (ret, " -m", argv[0], "=", cpu, ret, NULL);
 
   return ret;
 }