From 0735ec2e76541d51678ec9da0cc3392ffbad71ce Mon Sep 17 00:00:00 2001
From: Oleksandr Tymoshenko <ovt@google.com>
Date: Wed, 10 Feb 2021 22:59:41 +0000
Subject: [PATCH 6/8] grub-lakitu: fix clang build

- Hack _data value for a backtrace code, it's not used so no functional impact
- Remove gcc-specific -fno-trampolines
- Rewrite hack with a nested function
- Fix -isystem check, clang ships with some headers, but not all, so
  test was false positive
- Remove duplicate clang-specific definition of abort() function
---
 conf/Makefile.common             |  2 +-
 configure.ac                     |  5 ++-
 grub-core/kern/arm64/backtrace.c |  2 +-
 grub-core/kern/compiler-rt.c     |  9 -----
 grub-core/kern/i386/backtrace.c  |  2 +-
 grub-core/net/net.c              | 64 ++++++++++++++++----------------
 6 files changed, 38 insertions(+), 46 deletions(-)

diff --git a/conf/Makefile.common b/conf/Makefile.common
index 6b85eb394..b484c5abe 100644
--- a/conf/Makefile.common
+++ b/conf/Makefile.common
@@ -69,7 +69,7 @@ starfielddir = $(pkgdatadir)/themes/starfield
 systemdunitdir = ${prefix}/lib/systemd/system
 systemd_logind_service_ddir = $(systemdunitdir)/systemd-logind.service.d
 
-CFLAGS_GNULIB = -Wno-undef -Wno-unused -Wno-unused-parameter -Wno-redundant-decls -Wno-unreachable-code -Werror=trampolines -fno-trampolines
+CFLAGS_GNULIB = -Wno-undef -Wno-unused -Wno-unused-parameter -Wno-redundant-decls -Wno-unreachable-code -Werror=trampolines
 CPPFLAGS_GNULIB = -I$(top_builddir)/grub-core/lib/gnulib -I$(top_srcdir)/grub-core/lib/gnulib
 
 CFLAGS_POSIX = -fno-builtin
diff --git a/configure.ac b/configure.ac
index d150a2e4a..dc6b75c9d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1492,6 +1492,7 @@ AC_CACHE_CHECK([whether -nostdinc -isystem works], [grub_cv_cc_isystem], [
   CPPFLAGS="$TARGET_CPPFLAGS -nostdlib -nostdinc -isystem `$TARGET_CC -print-file-name=include`"
   AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <stdarg.h>
 #include <stddef.h>
+#include <stdio.h>
 int va_arg_func (int fixed, va_list args);]], [[]])],
       [grub_cv_cc_isystem=yes],
       [grub_cv_cc_isystem=no])
@@ -2015,8 +2016,8 @@ if test x"$enable_wextra" != xno ; then
   HOST_CFLAGS="$HOST_CFLAGS -Wextra"
 fi
 
-TARGET_CFLAGS="$TARGET_CFLAGS -Werror=trampolines -fno-trampolines"
-HOST_CFLAGS="$HOST_CFLAGS -Werror=trampolines -fno-trampolines"
+TARGET_CFLAGS="$TARGET_CFLAGS -Werror=trampolines"
+HOST_CFLAGS="$HOST_CFLAGS -Werror=trampolines"
 
 TARGET_CPP="$TARGET_CC -E"
 TARGET_CCAS=$TARGET_CC
diff --git a/grub-core/kern/arm64/backtrace.c b/grub-core/kern/arm64/backtrace.c
index 019c6fdfe..9d3d8d50d 100644
--- a/grub-core/kern/arm64/backtrace.c
+++ b/grub-core/kern/arm64/backtrace.c
@@ -78,7 +78,7 @@ asm ("\t.global \"_text\"\n"
      "\t.quad .text\n"
      "\t.global \"_data\"\n"
      "_data:\n"
-     "\t.quad .data\n"
+     "\t.quad 0\n"
      );
 
 extern grub_uint64_t _text;
diff --git a/grub-core/kern/compiler-rt.c b/grub-core/kern/compiler-rt.c
index a464200c6..762d1a251 100644
--- a/grub-core/kern/compiler-rt.c
+++ b/grub-core/kern/compiler-rt.c
@@ -195,15 +195,6 @@ __ctzsi2 (grub_uint32_t x)
 #endif
 
 
-#if defined (__clang__) && !defined(GRUB_EMBED_DECOMPRESSOR)
-/* clang emits references to abort().  */
-void __attribute__ ((noreturn))
-abort (void)
-{
-  grub_fatal ("compiler abort");
-}
-#endif
-
 #if (defined (__MINGW32__) || defined (__CYGWIN__))
 void __register_frame_info (void)
 {
diff --git a/grub-core/kern/i386/backtrace.c b/grub-core/kern/i386/backtrace.c
index 2413f9a57..99ca5322a 100644
--- a/grub-core/kern/i386/backtrace.c
+++ b/grub-core/kern/i386/backtrace.c
@@ -78,7 +78,7 @@ asm ("\t.global \"_text\"\n"
      "\t.quad .text\n"
      "\t.global \"_data\"\n"
      "_data:\n"
-     "\t.quad .data\n"
+     "\t.quad 0\n"
      );
 #elif defined(__i386__)
 asm ("\t.global \"_text\"\n"
diff --git a/grub-core/net/net.c b/grub-core/net/net.c
index ad024c9ef..beb12de57 100644
--- a/grub-core/net/net.c
+++ b/grub-core/net/net.c
@@ -1893,43 +1893,43 @@ grub_net_restore_hw (void)
   return GRUB_ERR_NONE;
 }
 
-grub_err_t
-grub_net_search_configfile (char *config)
+static int
+search_through (char *config, char *suffix, grub_size_t num_tries, grub_size_t slice_size)
 {
-  grub_size_t config_len;
-  char *suffix;
-
-  auto int search_through (grub_size_t num_tries, grub_size_t slice_size);
-  int search_through (grub_size_t num_tries, grub_size_t slice_size)
+  while (num_tries-- > 0)
     {
-      while (num_tries-- > 0)
-        {
 	  grub_dprintf ("net", "probe %s\n", config);
 
-          grub_file_t file;
-          file = grub_file_open (config, GRUB_FILE_TYPE_CONFIG);
+      grub_file_t file;
+      file = grub_file_open (config, GRUB_FILE_TYPE_CONFIG);
 
-          if (file)
-            {
-              grub_file_close (file);
-              grub_dprintf ("net", "found!\n");
-              return 0;
-            }
-          else
-            {
-              if (grub_errno == GRUB_ERR_IO)
-                grub_errno = GRUB_ERR_NONE;
-            }
-
-          if (grub_strlen (suffix) < slice_size)
-            break;
-
-          config[grub_strlen (config) - slice_size] = '\0';
+      if (file)
+        {
+          grub_file_close (file);
+          grub_dprintf ("net", "found!\n");
+          return 0;
         }
+      else
+        {
+          if (grub_errno == GRUB_ERR_IO)
+            grub_errno = GRUB_ERR_NONE;
+        }
+
+      if (grub_strlen (suffix) < slice_size)
+        break;
 
-      return 1;
+      config[grub_strlen (config) - slice_size] = '\0';
     }
 
+  return 1;
+}
+
+grub_err_t
+grub_net_search_configfile (char *config)
+{
+  grub_size_t config_len;
+  char *suffix;
+
   config_len = grub_strlen (config);
   config[config_len] = '-';
   suffix = config + config_len + 1;
@@ -1959,7 +1959,7 @@ grub_net_search_configfile (char *config)
       if (client_uuid)
         {
           grub_strcpy (suffix, client_uuid);
-          if (search_through (1, 0) == 0) return GRUB_ERR_NONE;
+          if (search_through (config, suffix, 1, 0) == 0) return GRUB_ERR_NONE;
         }
 
       /* By the MAC address. */
@@ -1974,7 +1974,7 @@ grub_net_search_configfile (char *config)
         if (*ptr == ':')
           *ptr = '-';
 
-      if (search_through (1, 0) == 0) return GRUB_ERR_NONE;
+      if (search_through (config, suffix, 1, 0) == 0) return GRUB_ERR_NONE;
 
       /* By IP address */
 
@@ -1987,7 +1987,7 @@ grub_net_search_configfile (char *config)
                              ((n >> 24) & 0xff), ((n >> 16) & 0xff), \
                              ((n >> 8) & 0xff), ((n >> 0) & 0xff));
 
-              if (search_through (8, 1) == 0) return GRUB_ERR_NONE;
+              if (search_through (config, suffix, 8, 1) == 0) return GRUB_ERR_NONE;
               break;
             }
         case GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV6:
@@ -2003,7 +2003,7 @@ grub_net_search_configfile (char *config)
                   *ptr = '-';
 
               grub_snprintf (suffix, GRUB_NET_MAX_STR_ADDR_LEN, "%s", buf);
-              if (search_through (1, 0) == 0) return GRUB_ERR_NONE;
+              if (search_through (config, suffix, 1, 0) == 0) return GRUB_ERR_NONE;
               break;
             }
         case GRUB_NET_NETWORK_LEVEL_PROTOCOL_DHCP_RECV:
-- 
2.30.1.766.gb4fecdf3b7-goog