New proc is_aarch32_target

GDB tests running on arm target should be also run on aarch32
(32-bit mode on aarch64).  There should be no difference.  It is not
precise to check target triplet to decide which tests should be run,
because if I compiler all the test binary in 32-bit (arm program),
but target triplet is still aarch64, so that these arm specific tests
are skipped.

This patch is to add a new proc is_aarch32_target which return true
if target triplet is arm or the test binary is compiled for arm.

gdb/testsuite:

2015-07-07  Yao Qi  <yao.qi@linaro.org>

	* lib/gdb.exp (is_aarch32_target): New proc.
	* gdb.arch/arm-bl-branch-dest.exp: Check is_aarch32_target
	instead of "istarget "arm*-*-*"".
	* gdb.arch/arm-disp-step.exp: Likewise.
	* gdb.arch/thumb-bx-pc.exp: Likewise.
	* gdb.arch/thumb-prologue.exp: Likewise.
	* gdb.arch/thumb-singlestep.exp: Likewise.
	* gdb.base/disp-step-syscall.exp: Likewise.
	* gdb.base/float.exp: Likewise.

1 files changed, 37 insertions, 0 deletions

diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
index 381297a..e8ae08c 100644
--- a/gdb/testsuite/lib/gdb.exp
+++ b/gdb/testsuite/lib/gdb.exp
@@ -2271,6 +2271,43 @@ proc is_x86_like_target {} {
     return [expr [is_ilp32_target] && ![is_amd64_regs_target]]
 }
 
+# Return 1 if this target is an arm or aarch32 on aarch64.
+
+gdb_caching_proc is_aarch32_target {
+    if { [istarget "arm*-*-*"] } {
+	return 1
+    }
+
+    if { ![istarget "aarch64*-*-*"] } {
+	return 0
+    }
+
+    set me "is_aarch32_target"
+
+    set src [standard_temp_file aarch32[pid].s]
+    set obj [standard_temp_file aarch32[pid].o]
+
+    set list {}
+    foreach reg \
+	{r0 r1 r2 r3} {
+	    lappend list "\tmov $reg, $reg"
+	}
+    gdb_produce_source $src [join $list \n]
+
+    verbose "$me:  compiling testfile $src" 2
+    set lines [gdb_compile $src $obj object {quiet}]
+    file delete $src
+    file delete $obj
+
+    if ![string match "" $lines] then {
+	verbose "$me:  testfile compilation failed, returning 0" 2
+	return 0
+    }
+
+    verbose "$me:  returning 1" 2
+    return 1
+}
+
 # Return 1 if displaced stepping is supported on target, otherwise, return 0.
 proc support_displaced_stepping {} {