[msbuild] bump to help debug wrench build failure

[mono.git] / mono / utils / mono-hwcap-arm.c

diff --git a/mono/utils/mono-hwcap-arm.c b/mono/utils/mono-hwcap-arm.c
index 431a188314e7a0889a4c9f6a3378da7df26703a3..4ab9cd7b05ecb8898fe3738ac3e21cf940e13049 100644 (file)
--- a/mono/utils/mono-hwcap-arm.c
+++ b/mono/utils/mono-hwcap-arm.c
@@ -1,5 +1,6 @@
-/*
- * mono-hwcap-arm.c: ARM hardware feature detection
+/**
+ * \file
+ * ARM hardware feature detection
  *
  * Authors:
  *    Alex Rønne Petersen (alexrp@xamarin.com)
@@ -16,9 +17,10 @@
  * Copyright 2006 Broadcom
  * Copyright 2007-2008 Andreas Faerber
  * Copyright 2011-2013 Xamarin Inc
+ * Licensed under the MIT license. See LICENSE file in the project root for full license information.
  */
 
-#include "mono/utils/mono-hwcap-arm.h"
+#include "mono/utils/mono-hwcap.h"
 
 #if defined(HAVE_SYS_AUXV_H) && !defined(PLATFORM_ANDROID)
 #include <sys/auxv.h>
@@ -27,19 +29,12 @@
 #include <sys/sysctl.h>
 #include <sys/types.h>
 #else
+#if defined (HAVE_SYS_UTSNAME_H)
+#include <sys/utsname.h>
+#endif
 #include <stdio.h>
 #endif
 
-gboolean mono_hwcap_arm_is_v5 = FALSE;
-gboolean mono_hwcap_arm_is_v6 = FALSE;
-gboolean mono_hwcap_arm_is_v7 = FALSE;
-gboolean mono_hwcap_arm_is_v7s = FALSE;
-gboolean mono_hwcap_arm_has_vfp = FALSE;
-gboolean mono_hwcap_arm_has_vfp3 = FALSE;
-gboolean mono_hwcap_arm_has_vfp3_d16 = FALSE;
-gboolean mono_hwcap_arm_has_thumb = FALSE;
-gboolean mono_hwcap_arm_has_thumb2 = FALSE;
-
 void
 mono_hwcap_arch_init (void)
 {
@@ -105,6 +100,50 @@ mono_hwcap_arch_init (void)
         * hit this path if the target doesn't have sys/auxv.h.
         */
 
+#if defined (HAVE_SYS_UTSNAME_H)
+       struct utsname name;
+
+       /* Only fails if `name` is invalid (it isn't). */
+       g_assert (!uname (&name));
+
+       if (!strncmp (name.machine, "aarch64", 7) || !strncmp (name.machine, "armv8", 5)) {
+               /*
+                * We're a 32-bit program running on an ARMv8 system.
+                * Whether the system is actually 32-bit or 64-bit
+                * doesn't matter to us. The important thing is that
+                * all 3 of ARMv8's execution states (A64, A32, T32)
+                * are guaranteed to have all of the features that
+                * we want to detect and use.
+                *
+                * We do this ARMv8 detection via uname () because
+                * in the early days of ARMv8 on Linux, the
+                * /proc/cpuinfo format was a disaster and there
+                * were multiple (merged into mainline) attempts at
+                * cleaning it up (read: breaking applications that
+                * tried to rely on it). So now multiple ARMv8
+                * systems in the wild have different /proc/cpuinfo
+                * output, some of which are downright useless.
+                *
+                * So, when it comes to detecting ARMv8 in a 32-bit
+                * program, it's better to just avoid /proc/cpuinfo
+                * entirely. Maybe in a decade or two, we won't
+                * have to worry about this mess that the Linux ARM
+                * maintainers created. One can hope.
+                */
+
+               mono_hwcap_arm_is_v5 = TRUE;
+               mono_hwcap_arm_is_v6 = TRUE;
+               mono_hwcap_arm_is_v7 = TRUE;
+
+               mono_hwcap_arm_has_vfp = TRUE;
+               mono_hwcap_arm_has_vfp3 = TRUE;
+               mono_hwcap_arm_has_vfp3_d16 = TRUE;
+
+               mono_hwcap_arm_has_thumb = TRUE;
+               mono_hwcap_arm_has_thumb2 = TRUE;
+       }
+#endif
+
        char buf [512];
        char *line;
 
@@ -112,7 +151,8 @@ mono_hwcap_arch_init (void)
 
        if (file) {
                while ((line = fgets (buf, 512, file))) {
-                       if (!strncmp (line, "Processor", 9)) {
+                       if (!strncmp (line, "Processor", 9) ||
+                           !strncmp (line, "model name", 10)) {
                                char *ver = strstr (line, "(v");
 
                                if (ver) {
@@ -154,17 +194,3 @@ mono_hwcap_arch_init (void)
        }
 #endif
 }
-
-void
-mono_hwcap_print(FILE *f)
-{
-       g_fprintf (f, "mono_hwcap_arm_is_v5 = %i\n", mono_hwcap_arm_is_v5);
-       g_fprintf (f, "mono_hwcap_arm_is_v6 = %i\n", mono_hwcap_arm_is_v6);
-       g_fprintf (f, "mono_hwcap_arm_is_v7 = %i\n", mono_hwcap_arm_is_v7);
-       g_fprintf (f, "mono_hwcap_arm_is_v7s = %i\n", mono_hwcap_arm_is_v7s);
-       g_fprintf (f, "mono_hwcap_arm_has_vfp = %i\n", mono_hwcap_arm_has_vfp);
-       g_fprintf (f, "mono_hwcap_arm_has_vfp3 = %i\n", mono_hwcap_arm_has_vfp3);
-       g_fprintf (f, "mono_hwcap_arm_has_vfp3_d16 = %i\n", mono_hwcap_arm_has_vfp3_d16);
-       g_fprintf (f, "mono_hwcap_arm_has_thumb = %i\n", mono_hwcap_arm_has_thumb);
-       g_fprintf (f, "mono_hwcap_arm_has_thumb2 = %i\n", mono_hwcap_arm_has_thumb2);
-}