ld, testsuite: only run CTF tests when ld and GCC support CTF

The CTF testsuite runs GCC to generate CTF that it knows matches the
input .c files before doing a run_dump_test over it.  So we need a GCC
capable of doing that, and we need to always avoid running those tests
if libctf was disabled because the linker will never be capable of it.

ld/
	* configure.ac (enable_libctf): Substitute it.
	* Makefile.am (enablings.exp): New.
	(EXTRA_DEJAGNU_SITE_CONFIG): Add it.
	(DISTCLEANFILES): Likewise.
	* Makefile.in: Regenerate.
	* configure: Likewise.
	* testsuite/lib/ld-lib.exp (compile_one_cc): New.
	(check_ctf_available): Likewise.
	(skip_ctf_tests): Likewise.
	* testsuite/ld-ctf/ctf.exp: Call skip_ctf_tests.

2 files changed, 62 insertions, 0 deletions

diff --git a/ld/testsuite/ld-ctf/ctf.exp b/ld/testsuite/ld-ctf/ctf.exp
index 9a248f9..5d177af 100644
--- a/ld/testsuite/ld-ctf/ctf.exp
+++ b/ld/testsuite/ld-ctf/ctf.exp
@@ -18,9 +18,19 @@
 # MA 02110-1301, USA.
 #
 
+if [skip_ctf_tests] {
+    unsupported "no CTF format support in the compiler, or CTF disabled"
+    return 0
+}
+
 set ctf_test_list [lsort [glob -nocomplain $srcdir/$subdir/*.d]]
 
 foreach ctf_test $ctf_test_list {
+    if [string equal -length [string length "diag-"] "diag-" [file tail $ctf_test]] {
+	if ![is_elf_format] {
+	    continue
+	}
+    }
     verbose [file rootname $ctf_test]
     run_dump_test [file rootname $ctf_test] { { cc "-gt -fPIC" } }
 }
diff --git a/ld/testsuite/lib/ld-lib.exp b/ld/testsuite/lib/ld-lib.exp
index 69519af..d1ffab7 100644
--- a/ld/testsuite/lib/ld-lib.exp
+++ b/ld/testsuite/lib/ld-lib.exp
@@ -1569,3 +1569,55 @@ proc check_gnu2_tls_available { } {
     }
     return $gnu2_tls_available_saved
 }
+
+# Compile a C source file, with the specified additional_flags.
+proc compile_one_cc { src output additional_flags } {
+    global CC
+    global CFLAGS
+
+    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 [is_remote host] {
+	set src [remote_download host $src]
+    }
+    return [run_host_cmd_yesno "$CC" "$flags $CFLAGS $additional_flags $src -o $output"]
+}
+
+# Returns true if the target compiler supports -gt
+proc check_ctf_available { } {
+    global ctf_available_saved
+
+    if {![info exists ctf_available_saved]} {
+	set basename "tmpdir/ctf_available[pid]"
+	set src ${basename}.c
+	set output ${basename}.o
+	set f [open $src "w"]
+	puts $f "int main() { return 0; }"
+	close $f
+	set ctf_available_saved [compile_one_cc $src $output "-gt -c"]
+	remote_file host delete $src
+	remote_file host delete $output
+	file delete $src
+    }
+    return $ctf_available_saved
+}
+
+proc skip_ctf_tests { } {
+    global enable_libctf
+
+    if {$enable_libctf eq "no"} {
+	return 1
+    }
+
+    if [check_ctf_available] {
+	return 0
+    }
+
+    return 1
+}