gdb/testsuite: add gcore_cmd_available predicate proc

Add a new gcore_cmd_available predicate proc that can be used in a
'requires' line, and make use of it in a few tests.

All of the tests I have modified call gdb_gcore_cmd as one of their
first actions and exit if the gcore command is not available, so it
makes sense (I think) to move the gcore command check into a requires
call.

There should be no change in what is actually run after this commit.

7 files changed, 25 insertions, 4 deletions

diff --git a/gdb/testsuite/gdb.ada/task_switch_in_core.exp b/gdb/testsuite/gdb.ada/task_switch_in_core.exp
index 3aafc2b..bded377 100644
--- a/gdb/testsuite/gdb.ada/task_switch_in_core.exp
+++ b/gdb/testsuite/gdb.ada/task_switch_in_core.exp
@@ -15,7 +15,7 @@
 
 load_lib "ada.exp"
 
-require allow_ada_tests
+require allow_ada_tests gcore_cmd_available
 
 standard_ada_testfile crash
 
diff --git a/gdb/testsuite/gdb.base/coredump-filter-build-id.exp b/gdb/testsuite/gdb.base/coredump-filter-build-id.exp
index 7594cc2..eb5b489 100644
--- a/gdb/testsuite/gdb.base/coredump-filter-build-id.exp
+++ b/gdb/testsuite/gdb.base/coredump-filter-build-id.exp
@@ -28,7 +28,7 @@ if { ![istarget *-*-linux*] } {
     untested "$testfile.exp"
     return -1
 }
-require is_x86_64_m64_target
+require is_x86_64_m64_target gcore_cmd_available
 
 if { [prepare_for_testing "failed to prepare" $testfile $srcfile {debug build-id}] } {
     return -1
diff --git a/gdb/testsuite/gdb.base/gcore.exp b/gdb/testsuite/gdb.base/gcore.exp
index 5251e3f..0a9f099 100644
--- a/gdb/testsuite/gdb.base/gcore.exp
+++ b/gdb/testsuite/gdb.base/gcore.exp
@@ -16,6 +16,7 @@
 # This file was written by Michael Snyder (msnyder@redhat.com)
 # This is a test for the gdb command "generate-core-file".
 
+require gcore_cmd_available
 
 standard_testfile
 
diff --git a/gdb/testsuite/gdb.base/print-symbol-loading.exp b/gdb/testsuite/gdb.base/print-symbol-loading.exp
index 15f2c19..c9e2480 100644
--- a/gdb/testsuite/gdb.base/print-symbol-loading.exp
+++ b/gdb/testsuite/gdb.base/print-symbol-loading.exp
@@ -15,7 +15,7 @@
 
 # Test the "print symbol-loading" option.
 
-require allow_shlib_tests
+require allow_shlib_tests gcore_cmd_available
 
 standard_testfile print-symbol-loading-main.c
 set libfile print-symbol-loading-lib
diff --git a/gdb/testsuite/gdb.base/solib-search.exp b/gdb/testsuite/gdb.base/solib-search.exp
index 2efad18..35b0314 100644
--- a/gdb/testsuite/gdb.base/solib-search.exp
+++ b/gdb/testsuite/gdb.base/solib-search.exp
@@ -16,7 +16,7 @@
 # Test solib-search-path, and in the case of solib-svr4.c whether l_addr_p
 # is properly reset when the path is changed.
 
-require allow_shlib_tests
+require allow_shlib_tests gcore_cmd_available
 require {!is_remote target}
 
 # Build "wrong" and "right" versions of the libraries in separate directories.
diff --git a/gdb/testsuite/gdb.tui/corefile-run.exp b/gdb/testsuite/gdb.tui/corefile-run.exp
index 89a48b5..657fc83 100644
--- a/gdb/testsuite/gdb.tui/corefile-run.exp
+++ b/gdb/testsuite/gdb.tui/corefile-run.exp
@@ -18,6 +18,8 @@
 #
 # Ref.: https://bugzilla.redhat.com/show_bug.cgi?id=1765117
 
+require gcore_cmd_available
+
 tuiterm_env
 
 standard_testfile tui-layout.c
diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
index ead14bd..2a5d37c 100644
--- a/gdb/testsuite/lib/gdb.exp
+++ b/gdb/testsuite/lib/gdb.exp
@@ -7007,6 +7007,24 @@ proc gdb_load_cmd { args } {
     return -1
 }
 
+# Return non-zero if 'gcore' command is available.
+gdb_caching_proc gcore_cmd_available { } {
+    gdb_exit
+    gdb_start
+
+    # Does this gdb support gcore?
+    gdb_test_multiple "help gcore" "" {
+	-re -wrap "Undefined command: .*" {
+	    return 0
+	}
+	-re -wrap "Save a core file .*" {
+	    return 1
+	}
+    }
+
+    return 0
+}
+
 # Invoke "gcore".  CORE is the name of the core file to write.  TEST
 # is the name of the test case.  This will return 1 if the core file
 # was created, 0 otherwise.  If this fails to make a core file because