[review] gdb/testsuite: Introduce compiler_supports_ctf_debug guard function

["Andrew Burgess (Code Review)" <gerrit at gnutoolchain-gerrit dot osci dot io>]

Andrew Burgess has uploaded a new change for review.

Change URL: https://gnutoolchain-gerrit.osci.io/r/c/binutils-gdb/+/121
......................................................................

gdb/testsuite: Introduce compiler_supports_ctf_debug guard function

Most versions of GCC in the wild don't support CTF debug format right
now, so, rather than attempting to compile the tests and failing each
time, this patch introduces a guard function to check if the compiler
supports CTF.  If we don't have CTF support then the CTF tests are
skipped.

This patch only updates 3 of the 4 CTF tests, the fourth will be
handled in the next patch.

gdb/testsuite/ChangeLog:

	* gdb.base/ctf-constvars.exp: Skip test if CTF is not supported in
	the compiler.  Clean up header comment a little.
	* gdb.base/ctf-ptype.exp: Likewise.
	* gdb.base/ctf-whatis.exp: Likewise.
	* lib/gdb.exp (compiler_supports_ctf_debug): New proc.

Change-Id: I505c11169a9bc9871a31fc0c61e119f92f32cc63
---
M gdb/testsuite/ChangeLog
M gdb/testsuite/gdb.base/ctf-constvars.exp
M gdb/testsuite/gdb.base/ctf-ptype.exp
M gdb/testsuite/gdb.base/ctf-whatis.exp
M gdb/testsuite/lib/gdb.exp
5 files changed, 39 insertions(+), 20 deletions(-)



diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index ce6e0f2..245b8f9 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,11 @@
+2019-10-15  Andrew Burgess  <andrew.burgess@embecosm.com>
+
+	* gdb.base/ctf-constvars.exp: Skip test if CTF is not supported in
+	the compiler.  Clean up header comment a little.
+	* gdb.base/ctf-ptype.exp: Likewise.
+	* gdb.base/ctf-whatis.exp: Likewise.
+	* lib/gdb.exp (compiler_supports_ctf_debug): New proc.
+
 2019-10-14  Simon Marchi <simon.marchi@polymtl.ca>
 
 	* gdb.mi/list-thread-groups-available.exp: Read entries one by
diff --git a/gdb/testsuite/gdb.base/ctf-constvars.exp b/gdb/testsuite/gdb.base/ctf-constvars.exp
index 4a81a94..58c0bad 100644
--- a/gdb/testsuite/gdb.base/ctf-constvars.exp
+++ b/gdb/testsuite/gdb.base/ctf-constvars.exp
@@ -18,20 +18,20 @@
 #
 # This file is part of the gdb testsuite
 #
-# tests for const variables
-#           const pointers to vars
-#           pointers to const variables
-#           const pointers to const vars
-# with mixed types
+# Tests for: const variables,
+#            const pointers to vars
+#            pointers to const variables
+#            const pointers to const vars
+# with mixed types.
 
-#
-# test running programs
-#
-# -gt generates full-fledged CTF.
+if ![compiler_supports_ctf_debug] {
+    return 0
+}
 
 standard_testfile .c
-set opts "additional_flags=-gt"
 
+# Using `-gt` generates full-fledged CTF debug information.
+set opts "additional_flags=-gt"
 if { [prepare_for_testing "failed to prepare" ${testfile} \
 	  [list $srcfile] [list $opts nowarnings]] } {
     return 0
diff --git a/gdb/testsuite/gdb.base/ctf-ptype.exp b/gdb/testsuite/gdb.base/ctf-ptype.exp
index 9f54582..172f6d1 100644
--- a/gdb/testsuite/gdb.base/ctf-ptype.exp
+++ b/gdb/testsuite/gdb.base/ctf-ptype.exp
@@ -15,14 +15,14 @@
 
 # This file is a subset of ptype.exp written by Rob Savoye. (rob@cygnus.com)
 
-#
-# test running programs
-#
-# -gt generates full-fledged CTF.
+if ![compiler_supports_ctf_debug] {
+    return 0
+}
 
 standard_testfile .c
-set opts "additional_flags=-gt"
 
+# Using `-gt` generates full-fledged CTF debug information.
+set opts "additional_flags=-gt"
 if { [prepare_for_testing "failed to prepare" ${testfile} \
 	  [list $srcfile] [list $opts nowarnings]] } {
     return 0
diff --git a/gdb/testsuite/gdb.base/ctf-whatis.exp b/gdb/testsuite/gdb.base/ctf-whatis.exp
index 3f26fc3..377eeb3 100644
--- a/gdb/testsuite/gdb.base/ctf-whatis.exp
+++ b/gdb/testsuite/gdb.base/ctf-whatis.exp
@@ -15,14 +15,14 @@
 
 # This file is a subset of whatis.exp written by Rob Savoye. (rob@cygnus.com)
 
-#
-# test running programs
-#
-# -gt generates full-fledged CTF.
+if ![compiler_supports_ctf_debug] {
+    return 0
+}
 
 standard_testfile .c
-set opts "additional_flags=-gt"
 
+# Using `-gt` generates full-fledged CTF debug information.
+set opts "additional_flags=-gt"
 if { [prepare_for_testing "failed to prepare" ${testfile} \
           [list $srcfile] [list $opts nowarnings]] } {
     return 0
diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
index fed46ec..aa93a4b 100644
--- a/gdb/testsuite/lib/gdb.exp
+++ b/gdb/testsuite/lib/gdb.exp
@@ -6737,5 +6737,16 @@
     }
 }
 
+# Does the compiler support CTF debug output using '-gt' compiler
+# flag?
+gdb_caching_proc compiler_supports_ctf_debug {
+    verbose -log "APB: Got here."
+    return [gdb_can_simple_compile ctfdebug {
+	int main () {
+	    return 0;
+	}
+    } executable "additional_flags=-gt"]
+}
+
 # Always load compatibility stuff.
 load_lib future.exp