[AArch64] Restrict pic-small.c by new test directive

2015-07-01  Jiong Wang  <jiong.wang@arm.com>

      gcc/
	* doc/sourcebuild.texi (AArch64-specific attributes): New subsection.
	Document "aarch64_small_fpic".

      gcc/testsuite/
	* lib/target-supports.exp (check_effective_target_aarch64_small_fpic): New function.
	* gcc.target/aarch64/pic-small.c: Restrict this test under
	check_effective_target_aarch64_small_fpic.

From-SVN: r225232

gcc/ChangeLog

 2015-07-01  Jiong Wang  <jiong.wang@arm.com>
 
+	* doc/sourcebuild.texi (AArch64-specific attributes): New subsection.
+	Document "aarch64_small_fpic".
+
+2015-07-01  Jiong Wang  <jiong.wang@arm.com>
+
 	* configure.ac: Add check for aarch64 assembler -fpic relocation
 	modifier support.
 	* configure: Regenerate.

gcc/doc/sourcebuild.texi

@@ -1580,6 +1580,15 @@ ARM target prefers @code{LDRD} and @code{STRD} instructions over
 
 @end table
 
+@subsubsection AArch64-specific attributes
+
+@table @code
+@item aarch64_small_fpic
+Binutils installed on test system supports relocation types required by -fpic
+for AArch64 small memory model.
+
+@end table
+
 @subsubsection MIPS-specific attributes
 
 @table @code

gcc/testsuite/ChangeLog

+2015-07-01  Jiong Wang  <jiong.wang@arm.com>
+
+	* lib/target-supports.exp (check_effective_target_aarch64_small_fpic): New function.
+	* gcc.target/aarch64/pic-small.c: Restrict this test under
+	check_effective_target_aarch64_small_fpic.
+
 2015-07-01  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* gfortran.dg/gomp/pr66633.f90: New test.

gcc/testsuite/gcc.target/aarch64/pic-small.c

 /* { dg-do compile } */
+/* { dg-require-effective-target aarch64_small_fpic } */
 /* { dg-options "-O2 -fpic -fno-inline --save-temps" } */
 
 void abort ();

gcc/testsuite/lib/target-supports.exp

@@ -937,6 +937,26 @@ proc check_effective_target_fpic { } {
     return 0
 }
 
+# On AArch64, if -fpic is not supported, then we will fall back to -fPIC
+# silently.  So, we can't rely on above "check_effective_target_fpic" as it
+# assumes compiler will give warning if -fpic not supported.  Here we check
+# whether binutils supports those new -fpic relocation modifiers, and assume
+# -fpic is supported if there is binutils support.  GCC configuration will
+# enable -fpic for AArch64 in this case.
+#
+# "check_effective_target_aarch64_small_fpic" is dedicated for checking small
+# memory model -fpic relocation types.
+
+proc check_effective_target_aarch64_small_fpic { } {
+    if { [istarget aarch64*-*-*] } {
+	return [check_no_compiler_messages aarch64_small_fpic object {
+	    void foo (void) { asm ("ldr	x0, [x2, #:gotpage_lo15:globalsym]"); }
+	}]
+    } else {
+	return 0
+    }
+}
+
 # Return 1 if -shared is supported, as in no warnings or errors
 # emitted, 0 otherwise.