--- a/gcc/config/sol2.h	Fri Oct 27 22:46:09 2017 +0900
+++ b/gcc/config/sol2.h	Thu Oct 25 07:37:49 2018 +0900
@@ -1,6 +1,6 @@
 /* Operating system specific defines to be used when targeting GCC for any
    Solaris 2 system.
-   Copyright (C) 2002-2017 Free Software Foundation, Inc.
+   Copyright (C) 2002-2018 Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -113,6 +113,7 @@
 	builtin_define ("_XOPEN_SOURCE=600");		\
 	builtin_define ("_LARGEFILE_SOURCE=1");		\
 	builtin_define ("_LARGEFILE64_SOURCE=1");	\
+	builtin_define ("_FILE_OFFSET_BITS=64");	\
 	builtin_define ("__EXTENSIONS__");		\
       }							\
     TARGET_SUB_OS_CPP_BUILTINS();			\
@@ -169,9 +170,37 @@
 #undef SUPPORTS_INIT_PRIORITY
 #define SUPPORTS_INIT_PRIORITY HAVE_INITFINI_ARRAY_SUPPORT
 
+/* Solaris libc and libm implement multiple behaviours for various
+   interfaces that have changed over the years in different versions of the
+   C standard.  The behaviour is controlled by linking corresponding
+   values-*.o objects.  Each of these objects contain alternate definitions
+   of one or more variables that the libraries use to select which
+   conflicting behaviour they should exhibit.  There are two sets of these
+   objects, values-X*.o and values-xpg*.o.
+
+   The values-X[ac].o objects set the variable _lib_version.  The Studio C
+   compilers use values-Xc.o with either -Xc or (since Studio 12.6)
+   -pedantic to select strictly conformant ISO C behaviour, otherwise
+   values-Xa.o.  Since -pedantic is a diagnostic option only in GCC, we
+   need to specifiy the -std=c* options and -std=iso9899:199409.  We
+   traditionally include -ansi, which affects C and C++, and also -std=c++*
+   for consistency.
+
+   The values-xpg[46].o objects define either or both __xpg[46] variables,
+   selecting XPG4 mode (__xpg4) and conforming C99/SUSv3 behavior (__xpg6).
+
+   Since GCC 5, gcc defaults to -std=gnu11 or higher, so we link
+   values-xpg6.o to get C99 semantics.  Besides, most of the runtime
+   libraries always require C99 semantics.
+
+   Since only one instance of _lib_version and __xpg[46] takes effekt (the
+   first in ld.so.1's search path), we only link the values-*.o files into
+   executable programs.  */
 #undef STARTFILE_ARCH_SPEC
-#define STARTFILE_ARCH_SPEC "%{ansi:values-Xc.o%s} \
-			    %{!ansi:values-Xa.o%s}"
+#define STARTFILE_ARCH_SPEC \
+  "%{!shared:%{!symbolic: \
+     %{ansi|std=c*|std=iso9899\\:199409:values-Xc.o%s; :values-Xa.o%s} \
+     %{std=c90|std=gnu90:values-xpg4.o%s; :values-xpg6.o%s}}}"
 
 #if defined(HAVE_LD_PIE) && defined(HAVE_SOLARIS_CRTS)
 #define STARTFILE_CRTBEGIN_SPEC "%{static:crtbegin.o%s; \
@@ -205,8 +234,8 @@
 /* We don't use the standard svr4 STARTFILE_SPEC because it's wrong for us.  */
 #undef STARTFILE_SPEC
 #ifdef HAVE_SOLARIS_CRTS
-/* Since Solaris 11.x and Solaris 12, the OS delivers crt1.o, crti.o, and
-   crtn.o, with a hook for compiler-dependent stuff like profile handling.  */
+/* Since Solaris 11.4, the OS delivers crt1.o, crti.o, and crtn.o, with a hook
+   for compiler-dependent stuff like profile handling.  */
 #define STARTFILE_SPEC "%{!shared:%{!symbolic: \
 			  crt1.o%s \
 			  %{p:%e-p is not supported; \
@@ -394,9 +423,6 @@
    produce the same format.  */
 #define NM_FLAGS "-png"
 
-/* The system headers under Solaris 2 are C++-aware since 2.0.  */
-#define NO_IMPLICIT_EXTERN_C
-
 #define STDC_0_IN_SYSTEM_HEADERS 1
 
 /* Support Solaris-specific format checking for cmn_err.  */
@@ -406,8 +432,8 @@
 /* #pragma init and #pragma fini are implemented on top of init and
    fini attributes.  */
 #define SOLARIS_ATTRIBUTE_TABLE						\
-  { "init",      0, 0, true,  false,  false, NULL, false },		\
-  { "fini",      0, 0, true,  false,  false, NULL, false }
+  { "init",      0, 0, true,  false,  false, false, NULL, NULL },	\
+  { "fini",      0, 0, true,  false,  false, false, NULL, NULL }
 
 /* Solaris-specific #pragmas are implemented on top of attributes.  Hook in
    the bits from config/sol2.c.  */