# HG changeset patch
# Parent  1f757467f1bed35373c55b65cde4f9b0506172f5
libsanitizer: Require assembler support for sanitizer_redefine_builtins.h [PR112563]

diff --git a/libsanitizer/configure.ac b/libsanitizer/configure.ac
--- a/libsanitizer/configure.ac
+++ b/libsanitizer/configure.ac
@@ -214,6 +214,19 @@ if test "$libsanitizer_cv_sys_atomic" = 
 	    [Define to 1 if you have the __atomic functions])
 fi
 
+# Check if assembler supports symbol assignment.
+AC_CACHE_CHECK([assembler symbol assignment],
+[libsanitizer_cv_as_sym_assign],
+[AC_COMPILE_IFELSE(
+  [AC_LANG_PROGRAM([],
+		   [asm("a = b");])],
+  [libsanitizer_cv_as_sym_assign=yes],
+  [libsanitizer_cv_as_sym_assign=no])])
+if test "$libsanitizer_cv_as_sym_assign" = "yes"; then
+  AC_DEFINE([HAVE_AS_SYM_ASSIGN], 1,
+  	    [Define to 1 if assembler supports symbol assignment])
+fi
+
 # The library needs to be able to read the executable itself.  Compile
 # a file to determine the executable format.  The awk script
 # filetype.awk prints out the file type.
diff --git a/libsanitizer/sanitizer_common/sanitizer_internal_defs.h b/libsanitizer/sanitizer_common/sanitizer_internal_defs.h
--- a/libsanitizer/sanitizer_common/sanitizer_internal_defs.h
+++ b/libsanitizer/sanitizer_common/sanitizer_internal_defs.h
@@ -12,6 +12,7 @@
 #ifndef SANITIZER_DEFS_H
 #define SANITIZER_DEFS_H
 
+#include "config.h"
 #include "sanitizer_platform.h"
 #include "sanitizer_redefine_builtins.h"
 
diff --git a/libsanitizer/sanitizer_common/sanitizer_redefine_builtins.h b/libsanitizer/sanitizer_common/sanitizer_redefine_builtins.h
--- a/libsanitizer/sanitizer_common/sanitizer_redefine_builtins.h
+++ b/libsanitizer/sanitizer_common/sanitizer_redefine_builtins.h
@@ -15,7 +15,7 @@
 #    define SANITIZER_REDEFINE_BUILTINS_H
 
 // The asm hack only works with GCC and Clang.
-#    if !defined(_WIN32)
+#    if !defined(_WIN32) && defined(HAVE_AS_SYM_ASSIGN)
 
 asm("memcpy = __sanitizer_internal_memcpy");
 asm("memmove = __sanitizer_internal_memmove");
@@ -50,7 +50,7 @@ using vector = Define_SANITIZER_COMMON_N
 }  // namespace std
 
 #      endif  // __cpluplus
-#    endif    // !_WIN32
+#    endif    // !_WIN32 && HAVE_AS_SYM_ASSIGN
 
 #  endif  // SANITIZER_REDEFINE_BUILTINS_H
 #endif    // SANITIZER_COMMON_NO_REDEFINE_BUILTINS