ada: c++: Get rid of libposix4, librt on Solaris

I recently noticed that neither libposix4 nor librt are needed on
Solaris 11 any longer:

* libposix4 was renamed to librt in Solaris 7 back in 1998.

* librt was folded into libc in the OpenSolaris timeframe, leaving librt
  only as a filter on libc.  Thus, it's no longer needed on either
  Solaris 11 or Illumos.

The following patch removes both uses.  At the same time, Ada's use of
libthread has gone: it was folded into libc in Solaris 10 already.
TIME_LIBRARY and friends in g++ are likewise removed: Solaris was the
only user.

Bootstrapped without regressions on i386-pc-solaris2.11,
sparc-sun-solaris2.11, and x86_64-pc-linux-gnu.


2020-11-16  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>

	gcc/cp:
	* g++spec.c (TIMELIB, TIME_LIBRARY): Remove.
	(lang_specific_driver): Remove TIME_LIBRARY handling.

	gcc:
	* config/sol2.h (TIME_LIBRARY): Remove.

	libstdc++-v3:
	* acinclude.m4 (GLIBCXX_ENABLE_LIBSTDCXX_TIME): Remove libposix4
	references.
	<solaris*>: Don't use -lrt any longer.
	* configure: Regenerate.

	* doc/xml/manual/configure.xml (--enable-libstdcxx-time=OPTION):
	Remove libposix4 reference.

	gcc/ada:
	* Makefile.rtl <sparc*-sun-solaris*> (THREADSLIB): Remove.
	(MISCLIB): Remove -lposix4.
	<*86-*-solaris2*>: Likewise.
	* libgnarl/s-osinte__solaris.ads (System.OS_Interface): Remove
	-lposix4 -lthread.

4 files changed, 5 insertions, 40 deletions

diff --git a/gcc/ada/Makefile.rtl b/gcc/ada/Makefile.rtl
index 97792b4..1809bdb 100644
--- a/gcc/ada/Makefile.rtl
+++ b/gcc/ada/Makefile.rtl
@@ -1674,8 +1674,7 @@ ifeq ($(strip $(filter-out sparc% sun solaris%,$(target_cpu) $(target_vendor) $(
   endif
 
   EH_MECHANISM=-gcc
-  THREADSLIB = -lposix4 -lthread
-  MISCLIB = -lposix4 -lnsl -lsocket
+  MISCLIB = -lnsl -lsocket
   SO_OPTS = -Wl,-h,
   GNATLIB_SHARED = gnatlib-shared-dual
   GMEM_LIB = gmemlib
@@ -1728,8 +1727,7 @@ ifeq ($(strip $(filter-out %86 %x86_64 solaris2%,$(target_cpu) $(target_os))),)
   EXTRA_GNATRTL_NONTASKING_OBJS += $(TRASYM_DWARF_UNIX_OBJS)
 
   EH_MECHANISM=-gcc
-  THREADSLIB = -lposix4 -lthread
-  MISCLIB = -lposix4 -lnsl -lsocket
+  MISCLIB = -lnsl -lsocket
   SO_OPTS = -Wl,-h,
   GNATLIB_SHARED = gnatlib-shared-dual
   GMEM_LIB = gmemlib
diff --git a/gcc/ada/libgnarl/s-osinte__solaris.ads b/gcc/ada/libgnarl/s-osinte__solaris.ads
index b3faa10..b9d6b88 100644
--- a/gcc/ada/libgnarl/s-osinte__solaris.ads
+++ b/gcc/ada/libgnarl/s-osinte__solaris.ads
@@ -45,9 +45,6 @@ with Ada.Unchecked_Conversion;
 package System.OS_Interface is
    pragma Preelaborate;
 
-   pragma Linker_Options ("-lposix4");
-   pragma Linker_Options ("-lthread");
-
    subtype int            is Interfaces.C.int;
    subtype short          is Interfaces.C.short;
    subtype long           is Interfaces.C.long;
diff --git a/gcc/config/sol2.h b/gcc/config/sol2.h
index 91b4602..7a21f22 100644
--- a/gcc/config/sol2.h
+++ b/gcc/config/sol2.h
@@ -381,9 +381,6 @@ along with GCC; see the file COPYING3.  If not see
   { "endfile_vtv",		ENDFILE_VTV_SPEC },		\
   SUBTARGET_CPU_EXTRA_SPECS
 
-/* C++11 programs need -lrt for nanosleep.  */
-#define TIME_LIBRARY "rt"
-
 #ifndef USE_GLD
 /* With Sun ld, -rdynamic is a no-op.  */
 #define RDYNAMIC_SPEC ""
diff --git a/gcc/cp/g++spec.c b/gcc/cp/g++spec.c
index 0ab63bc..0f17148 100644
--- a/gcc/cp/g++spec.c
+++ b/gcc/cp/g++spec.c
@@ -27,12 +27,10 @@ along with GCC; see the file COPYING3.  If not see
 #define LANGSPEC	(1<<1)
 /* This bit is set if they did `-lm' or `-lmath'.  */
 #define MATHLIB		(1<<2)
-/* This bit is set if they did `-lrt' or equivalent.  */
-#define TIMELIB		(1<<3)
 /* This bit is set if they did `-lc'.  */
-#define WITHLIBC	(1<<4)
+#define WITHLIBC	(1<<3)
 /* Skip this option.  */
-#define SKIPOPT		(1<<5)
+#define SKIPOPT		(1<<4)
 
 #ifndef MATH_LIBRARY
 #define MATH_LIBRARY "m"
@@ -41,10 +39,6 @@ along with GCC; see the file COPYING3.  If not see
 #define MATH_LIBRARY_PROFILE MATH_LIBRARY
 #endif
 
-#ifndef TIME_LIBRARY
-#define TIME_LIBRARY ""
-#endif
-
 #ifndef LIBSTDCXX
 #define LIBSTDCXX "stdc++"
 #endif
@@ -95,15 +89,12 @@ lang_specific_driver (struct cl_decoded_option **in_decoded_options,
   const struct cl_decoded_option *saw_libc = NULL;
 
   /* An array used to flag each argument that needs a bit set for
-     LANGSPEC, MATHLIB, TIMELIB, or WITHLIBC.  */
+     LANGSPEC, MATHLIB, or WITHLIBC.  */
   int *args;
 
   /* By default, we throw on the math library if we have one.  */
   int need_math = (MATH_LIBRARY[0] != '\0');
 
-  /* By default, we throw on the time library if we have one.  */
-  int need_time = (TIME_LIBRARY[0] != '\0');
-
   /* True if we saw -static.  */
   int static_link = 0;
 
@@ -147,11 +138,6 @@ lang_specific_driver (struct cl_decoded_option **in_decoded_options,
 	      args[i] |= MATHLIB;
 	      need_math = 0;
 	    }
-	  else if (strcmp (arg, TIME_LIBRARY) == 0)
-	    {
-	      args[i] |= TIMELIB;
-	      need_time = 0;
-	    }
 	  else if (strcmp (arg, "c") == 0)
 	    args[i] |= WITHLIBC;
 	  else
@@ -285,12 +271,6 @@ lang_specific_driver (struct cl_decoded_option **in_decoded_options,
 	  saw_math = &decoded_options[i];
 	}
 
-      if (!saw_time && (args[i] & TIMELIB) && library > 0)
-	{
-	  --j;
-	  saw_time = &decoded_options[i];
-	}
-
       if (!saw_libc && (args[i] & WITHLIBC) && library > 0)
 	{
 	  --j;
@@ -377,13 +357,6 @@ lang_specific_driver (struct cl_decoded_option **in_decoded_options,
     }
   if (saw_time)
     new_decoded_options[j++] = *saw_time;
-  else if (library > 0 && need_time)
-    {
-      generate_option (OPT_l, TIME_LIBRARY, 1, CL_DRIVER,
-		       &new_decoded_options[j]);
-      added_libraries++;
-      j++;
-    }
   if (saw_libc)
     new_decoded_options[j++] = *saw_libc;
   if (shared_libgcc && !static_link)