[lldb/test] Make "inline" tests handle multiple statements at the same location

[labath]

Summary

The test machinery translates each continuous block of "//%" comments
into a single breakpoint. If there's no code between the blocks the
breakpoints will end up at the same location in the program. When the
process stops at a breakpoint lldb correctly reports all breakpoint IDs,
but the test machinery only looks at the first one. This results in a
very dangerous situation as it means some checks can be silently
stopped.

This patch fixes that by making the test machinery iterate through all
breakpoints at a given location and execute all commands.

[labath]

• disable a check that fails now. AFAICT, this never worked.

[labath]

lldb/test/API/commands/expression/dollar-in-variable/main.c

20–21

Raphael: This check wasn't executed before this patch. As far as I can tell, this functionality hasn't worked since the test was first introduced (r365698).

[teemperor]

Will this also fix these problems?

int i = 0;
//% code_that_is_executed

//% that that isn't executed as it's behind an empty line :(

I think disabling the check is fine. You can also just change the '= 14' to a '= 11'. I originally only intended to capture the current behavior and assumed we prefer local variables, but the agreement back then was that we don't know what is the correct behavior in this situation.

[teemperor]

Changing might actually be a better idea as this way we at least know this isn't crashing.

[shafik]

Thank you! I am pleasantly surprised there was only one hidden broken test.

[vsk]

Thanks! LGTM, modulo any comments Raphael may have about the test change.

lldb/packages/Python/lldbsuite/test/lldbinline.py

155–156

nit: I think this leaves the 'id' builtin defined as the last breakpoint id after the loop is done, maybe name it something else ('breakpoint_id'?).

[JDevlieghere]

Nice

[labath]

In D79563#2024854, @teemperor wrote:

Changing might actually be a better idea as this way we at least know this isn't crashing.

Ok, I'll change the expectation then.

lldb/packages/Python/lldbsuite/test/lldbinline.py

155–156

yes, of course.

lldb/packages/Python/lldbsuite/test/lldbinline.py

class InlineTest(TestBase):
     def _test(self):
         self.BuildMakefile()
         self.build()
         self.do_test()
 
     def execute_user_command(self, __command):
         exec(__command, globals(), locals())
 
+    def _get_breakpoint_ids(self, thread):
+        ids = set()
+        for i in range(0, thread.GetStopReasonDataCount(), 2):
+            ids.add(thread.GetStopReasonDataAtIndex(i))
+        self.assertGreater(len(ids), 0)
+        return sorted(ids)
+
     def do_test(self):
         exe = self.getBuildArtifact("a.out")
         source_files = [f for f in os.listdir(self.getSourceDir())
                         if source_type(f)]
         target = self.dbg.CreateTarget(exe)
 
         parser = CommandParser()
         parser.parse_source_files(source_files)
         parser.set_breakpoints(target)
 
         process = target.LaunchSimple(None, None, self.get_process_working_directory())
         self.assertIsNotNone(process, PROCESS_IS_VALID)
 
         hit_breakpoints = 0
 
         while lldbutil.get_stopped_thread(process, lldb.eStopReasonBreakpoint):
             hit_breakpoints += 1
             thread = lldbutil.get_stopped_thread(
                 process, lldb.eStopReasonBreakpoint)
-            breakpoint_id = thread.GetStopReasonDataAtIndex(0)
-            parser.handle_breakpoint(self, breakpoint_id)
+            for bp_id in self._get_breakpoint_ids(thread):
+                parser.handle_breakpoint(self, bp_id)
             process.Continue()
 
         self.assertTrue(hit_breakpoints > 0,
                         "inline test did not hit a single breakpoint")
         # Either the process exited or the stepping plan is complete.
         self.assertTrue(process.GetState() in [lldb.eStateStopped,
                                                lldb.eStateExited],
                         PROCESS_EXITED)

lldb/test/API/commands/expression/dollar-in-variable/main.c

int main() {
   int $foo = 12;
   int $R0 = 13;
   int $0 = 14;
 
   //%self.expect("expr $__lldb_expr_result", substrs=['(int) $0 = 11'])
   //%self.expect("expr $foo", substrs=['(int)', ' = 12'])
   //%self.expect("expr $R0", substrs=['(int)', ' = 13'])
   //%self.expect("expr int $foo = 123", error=True, substrs=["declaration conflicts"])
-  return 0; //%self.expect("expr $0", substrs=['(int)', ' = 14'])
+  //%self.expect("expr $0", substrs=['(int)', ' = 11'])
+  return 0;
 }