[gcc r8-10416] Arm: Add GCC_CPUINFO override

[gcc r8-10416] Arm: Add GCC_CPUINFO override

[Tamar Christina]

https://gcc.gnu.org/g:f7f6626f0398b9977a67a9e219302274c4121e3a

commit r8-10416-gf7f6626f0398b9977a67a9e219302274c4121e3a
Author: Tamar Christina <tamar.christina@arm.com>
Date:   Fri Jul 17 13:12:00 2020 +0100

    Arm: Add GCC_CPUINFO override
    
    This adds an in intentionally undocumented environment variable
    GCC_CPUINFO which can be used to test -mcpu=native.
    
    Tests using these are added later on.
    
    gcc/ChangeLog:
    
            * config/arm/driver-arm.c (host_detect_local_cpu): Add GCC_CPUINFO.
    
    (cherry picked from commit 34a6c43487caf3a2a0ec9c7c79c526d116abc8b9)

Diff:
---
 gcc/config/arm/driver-arm.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/gcc/config/arm/driver-arm.c b/gcc/config/arm/driver-arm.c
index dc2f1de01a8..a53c2272864 100644
--- a/gcc/config/arm/driver-arm.c
+++ b/gcc/config/arm/driver-arm.c
@@ -97,6 +97,7 @@ host_detect_local_cpu (int argc, const char **argv)
   FILE *f = NULL;
   bool arch;
   const struct vendor_cpu *cpu_table = NULL;
+  char *fcpu_info = NULL;
 
   if (argc < 1)
     goto not_found;
@@ -105,7 +106,12 @@ host_detect_local_cpu (int argc, const char **argv)
   if (!arch && strcmp (argv[0], "cpu") != 0 && strcmp (argv[0], "tune"))
     goto not_found;
 
-  f = fopen ("/proc/cpuinfo", "r");
+  fcpu_info = getenv ("GCC_CPUINFO");
+  if (fcpu_info)
+    f = fopen (fcpu_info, "r");
+  else
+    f = fopen ("/proc/cpuinfo", "r");
+
   if (f == NULL)
     goto not_found;