Re: [Patch,ld testsuite] Support check_lto_shared_available

[Vidya Praveen <vidyapraveen at arm dot com>]

On Wed, Dec 18, 2013 at 07:35:14PM +0000, H.J. Lu wrote:
> On Wed, Dec 18, 2013 at 11:20 AM, Vidya Praveen <vidyapraveen@arm.com> wrote:
> > Hello,
> >
> > This patch implements the check_lto_shared_available improvement suggested by
> > H.J.Lu[1] as a part of fixing check_lto_available[2].
> >
> > In abstract, check_lto_available checks if the compiler supports LTO by creating
> > an executable while check_lto_shared_available checks for LTO support as well as
> > LTO shared library support. This is essentially the old implementation of
> > check_lto_available which has been recently modified but with the support for
> > cflags & ldflags from the board file.
> >
> > This patch also modifies lto.exp to use check_lto_shared_available.
> >
> > OK?
> >
> > [1] https://sourceware.org/ml/binutils/2013-12/msg00136.html
> > [2] https://sourceware.org/ml/binutils/2013-12/msg00132.html
> >
> > Tested for aarch64-none-elf, arm-none-eabi, arm-none-linux-gnueabihf and
> > x86_64-unknown-linux-gnu.
> >
> > Regards
> > VP
> >
> > ld/testsuite/ChangeLog:
> >
> > 2013-12-18  Vidya Praveen  <vidyapraveen@arm.com>
> >
> >         * lib/ld-lib.exp (check_lto_shared_available): New check.
> >         * ld-plugin/lto.exp: Use check_lto_shared_available.
> >
> 
> 
> +# Returns true if the target compiler supports LTO
> 
> Please mention "-shared".
> 
> +    set status [remote_exec host $CC "$flags -shared
> -B[pwd]/tmpdir/ld/ -flto -fuse-linker-plugin $src -o $output"]
> 
> Please add -fPIC.

Sorry for the delay. Attached patch has the changes suggested.

Tested for aarch64-none-elf, arm-none-eabi, arm-none-linux-gnueabihf and
x86_64-unknown-linux-gnu.

OK?

Regards
VP

ld/testsuite/ChangeLog:

2014-01-07  Vidya Praveen  <vidyapraveen@arm.com>

	* lib/ld-lib.exp (check_lto_shared_available): New check.
	* ld-plugin/lto.exp: Use check_lto_shared_available.

diff --git a/ld/testsuite/ld-plugin/lto.exp b/ld/testsuite/ld-plugin/lto.exp
index 69946de..d55dca4 100644
--- a/ld/testsuite/ld-plugin/lto.exp
+++ b/ld/testsuite/ld-plugin/lto.exp
@@ -300,8 +300,7 @@ set lto_run_elf_tests {
 run_cc_link_tests $lto_link_tests
 
 # Restrict these to ELF targets that support shared libs and PIC.
-if { [is_elf_format]
-     && [run_host_cmd_yesno $CC "-shared -fPIC $srcdir/$subdir/dummy.c -o tmpdir/t.so"] } {
+if { [is_elf_format] && [check_lto_shared_available] } {
     run_cc_link_tests $lto_link_elf_tests
     set testname "PR ld/15146 (2)"
     set exec_output [run_host_cmd "$CC" "$gcc_gas_flag $gcc_ld_flag -O2 -flto -fuse-linker-plugin -Wl,-rpath-link,. -Wl,--no-copy-dt-needed-entries -Wl,--no-as-needed tmpdir/pr15146d.o tmpdir/pr15146c.so"]
diff --git a/ld/testsuite/lib/ld-lib.exp b/ld/testsuite/lib/ld-lib.exp
index c04b56f..54b617f 100644
--- a/ld/testsuite/lib/ld-lib.exp
+++ b/ld/testsuite/lib/ld-lib.exp
@@ -1679,6 +1679,45 @@ proc check_lto_available { } {
     return $lto_available_saved
 }
 
+# Returns true if the target compiler supports LTO and -shared
+proc check_lto_shared_available { } {
+    global lto_shared_available_saved
+    global CC
+
+    set flags ""
+
+    if [board_info [target_info name] exists cflags] {
+        append flags " [board_info [target_info name] cflags]"
+    }
+
+    if [board_info [target_info name] exists ldflags] {
+        append flags " [board_info [target_info name] ldflags]"
+    }
+
+    if {![info exists lto_shared_available_saved]} {
+	# Check if gcc supports -flto -fuse-linker-plugin -shared
+	if { [which $CC] == 0 } {
+	    set lto_shared_available_saved 0
+	    return 0
+	}
+	set basename "lto_shared"
+	set src ${basename}[pid].c
+	set output ${basename}[pid].so
+	set f [open $src "w"]
+	puts $f ""
+	close $f
+	set status [remote_exec host $CC "$flags -shared -fPIC -B[pwd]/tmpdir/ld/ -flto -fuse-linker-plugin $src -o $output"]
+	if { [lindex $status 0] == 0 } {
+	    set lto_shared_available_saved 1
+	} else {
+	    set lto_shared_available_saved 0
+	}
+	file delete $src
+	file delete $output
+    }
+    return $lto_shared_available_saved
+}
+
 # Check if the assembler supports CFI statements.
 
 proc check_as_cfi { } {