Add regression test for PR gdb/19858 (JIT code registration on attach)

This test would fail without the previous gdb/jit.c fix:

  (gdb) attach 23031
  Attaching to program: .../build/gdb/testsuite/outputs/gdb.base/jit/jit-main, process 23031
  [...]
  207           WAIT_FOR_GDB; i = 0;  /* gdb break here 1 */
  (gdb) PASS: gdb.base/jit.exp: attach: one_jit_test-2: attach
  set var wait_for_gdb = 0
  (gdb) PASS: gdb.base/jit.exp: attach: one_jit_test-2: set var wait_for_gdb = 0
  info function ^jit_function
  All functions matching regular expression "^jit_function":
  (gdb) FAIL: gdb.base/jit.exp: attach: one_jit_test-2: info function ^jit_function

gdb/testsuite/ChangeLog:
2016-03-31  Pedro Alves  <palves@redhat.com>

	PR gdb/19858
	* gdb.base/jit-main.c: Include unistd.h.
	(ATTACH): Define to 0 if not already defined.
	(wait_for_gdb, mypid): New globals.
	(WAIT_FOR_GDB): New macro.
	(MAIN): Set an alarm.  Store the process's pid.  Wait for GDB at
	some breakpoint locations.
	* gdb.base/jit.exp (clean_reattach, continue_to_test_location):
	New procedures.
	(one_jit_test): Add REATTACH parameter, and handle it.  Use
	continue_to_test_location.
	(top level): Test attach, and adjusts calls to one_jit_test.

3 files changed, 97 insertions, 10 deletions

diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 714615b..083e614 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,6 +1,21 @@
 2016-03-31  Pedro Alves  <palves@redhat.com>
 
 	PR gdb/19858
+	* gdb.base/jit-main.c: Include unistd.h.
+	(ATTACH): Define to 0 if not already defined.
+	(wait_for_gdb, mypid): New globals.
+	(WAIT_FOR_GDB): New macro.
+	(MAIN): Set an alarm.  Store the process's pid.  Wait for GDB at
+	some breakpoint locations.
+	* gdb.base/jit.exp (clean_reattach, continue_to_test_location):
+	New procedures.
+	(one_jit_test): Add REATTACH parameter, and handle it.  Use
+	continue_to_test_location.
+	(top level): Test attach, and adjusts calls to one_jit_test.
+
+2016-03-31  Pedro Alves  <palves@redhat.com>
+
+	PR gdb/19858
 	* gdb.base/jit.exp (compile_jit_test): Add intro comment.  Add
 	BINSUFFIX parameter, and handle it.
 	(top level): Adjust calls compile_jit_test.
diff --git a/gdb/testsuite/gdb.base/jit-main.c b/gdb/testsuite/gdb.base/jit-main.c
index 2f0707c..63dd1a1 100644
--- a/gdb/testsuite/gdb.base/jit-main.c
+++ b/gdb/testsuite/gdb.base/jit-main.c
@@ -27,6 +27,7 @@
 #include <string.h>
 #include <sys/mman.h>
 #include <sys/stat.h>
+#include <unistd.h>
 
 /* ElfW is coming from linux. On other platforms it does not exist.
    Let us define it here. */
@@ -116,10 +117,22 @@ update_locations (const void *const addr, int idx)
     }
 }
 
+/* Defined by the .exp file if testing attach.  */
+#ifndef ATTACH
+#define ATTACH 0
+#endif
+
 #ifndef MAIN
 #define MAIN main
 #endif
 
+/* Used to spin waiting for GDB.  */
+volatile int wait_for_gdb = ATTACH;
+#define WAIT_FOR_GDB while (wait_for_gdb)
+
+/* The current process's PID.  GDB retrieves this.  */
+int mypid;
+
 int
 MAIN (int argc, char *argv[])
 {
@@ -127,6 +140,10 @@ MAIN (int argc, char *argv[])
   const char *libname = NULL;
   int count = 0;
 
+  alarm (300);
+
+  mypid = getpid ();
+
   count = count;  /* gdb break here 0  */
 
   if (argc < 2)
@@ -190,7 +207,7 @@ MAIN (int argc, char *argv[])
           __jit_debug_register_code ();
         }
 
-      i = 0;  /* gdb break here 1 */
+      WAIT_FOR_GDB; i = 0;  /* gdb break here 1 */
 
       /* Now unregister them all in reverse order.  */
       while (__jit_debug_descriptor.relevant_entry != NULL)
@@ -215,5 +232,5 @@ MAIN (int argc, char *argv[])
           free (entry);
         }
     }
-  return 0;  /* gdb break here 2  */
+  WAIT_FOR_GDB; return 0;  /* gdb break here 2  */
 }
diff --git a/gdb/testsuite/gdb.base/jit.exp b/gdb/testsuite/gdb.base/jit.exp
index 3e12301..da9449b 100644
--- a/gdb/testsuite/gdb.base/jit.exp
+++ b/gdb/testsuite/gdb.base/jit.exp
@@ -66,7 +66,49 @@ proc compile_jit_test {testname binsuffix options} {
     return 0
 }
 
-proc one_jit_test {count match_str} {
+# Detach, restart GDB, and re-attach to the program.
+
+proc clean_reattach {} {
+    global decimal gdb_prompt srcfile testfile
+
+    # Get PID of test program.
+    set testpid -1
+    set test "get inferior process ID"
+    gdb_test_multiple "p mypid" $test {
+	-re ".* = ($decimal).*$gdb_prompt $" {
+	    set testpid $expect_out(1,string)
+	    pass $test
+	}
+    }
+
+    gdb_test_no_output "set var wait_for_gdb = 1"
+    gdb_test "detach" "Detaching from .*"
+
+    clean_restart $testfile
+
+    set test "attach"
+    gdb_test_multiple "attach $testpid" "$test" {
+	-re "Attaching to program.*.*main.*at .*$srcfile:.*$gdb_prompt $" {
+	    pass "$test"
+	}
+    }
+
+    gdb_test_no_output "set var wait_for_gdb = 0"
+}
+
+# Continue to LOCATION in the program.  If REATTACH, detach and
+# re-attach to the program from scratch.
+proc continue_to_test_location {location reattach} {
+    gdb_breakpoint [gdb_get_line_number $location]
+    gdb_continue_to_breakpoint $location
+    if {$reattach} {
+	with_test_prefix "$location" {
+	    clean_reattach
+	}
+    }
+}
+
+proc one_jit_test {count match_str reattach} {
     with_test_prefix "one_jit_test-$count" {
 	global verbose testfile solib_binfile_target solib_binfile_test_msg
 
@@ -91,8 +133,7 @@ proc one_jit_test {count match_str} {
 	gdb_test_no_output "set var libname = \"$solib_binfile_target\"" "set var libname = \"$solib_binfile_test_msg\""
 	gdb_test_no_output "set var count = $count"
 
-	gdb_breakpoint [gdb_get_line_number "break here 1"]
-	gdb_continue_to_breakpoint "break here 1"
+	continue_to_test_location "break here 1" $reattach
 
 	gdb_test "info function ^jit_function" "$match_str"
 
@@ -102,8 +143,8 @@ proc one_jit_test {count match_str} {
 	    gdb_test "maintenance info break"
 	}
 
-	gdb_breakpoint [gdb_get_line_number "break here 2"]
-	gdb_continue_to_breakpoint "break here 2"
+	continue_to_test_location "break here 2" $reattach
+
 	# All jit librares must have been unregistered
 	gdb_test "info function jit_function" \
 	    "All functions matching regular expression \"jit_function\":"
@@ -113,8 +154,22 @@ proc one_jit_test {count match_str} {
 if {[compile_jit_test jit.exp "" {}] < 0} {
     return
 }
-one_jit_test 1 "${hex}  jit_function_0000"
-one_jit_test 2 "${hex}  jit_function_0000\[\r\n\]+${hex}  jit_function_0001"
+one_jit_test 1 "${hex}  jit_function_0000" 0
+one_jit_test 2 "${hex}  jit_function_0000\[\r\n\]+${hex}  jit_function_0001" 0
+
+# Test attaching to an inferior with some JIT libraries already
+# registered.  We reuse the normal test, and detach/reattach at
+# specific interesting points.
+if {[can_spawn_for_attach]} {
+    if {[compile_jit_test "jit.exp attach tests" \
+	     "-attach" {additional_flags=-DATTACH=1}] < 0} {
+	return
+    }
+
+    with_test_prefix attach {
+	one_jit_test 2 "${hex}  jit_function_0000\[\r\n\]+${hex}  jit_function_0001" 1
+    }
+}
 
 with_test_prefix PIE {
     if {[compile_jit_test "jit.exp PIE tests" \
@@ -122,5 +177,5 @@ with_test_prefix PIE {
 	return
     }
 
-    one_jit_test 1 "${hex}  jit_function_0000"
+    one_jit_test 1 "${hex}  jit_function_0000" 0
 }