[Lldb-commits] [lldb] Add a test for evicting unreachable modules from the global module cache (PR #74894)

[David Spickett via lldb-commits]

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@@ -0,0 +1,169 @@
+"""
+Test the use of the global module cache in lldb
+"""
+
+import lldb
+
+from lldbsuite.test.decorators import *
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test import lldbutil
+import os
+import shutil
+from pathlib import Path
+import time
+
+class GlobalModuleCacheTestCase(TestBase):
+    # NO_DEBUG_INFO_TESTCASE = True
+
+    def check_counter_var(self, thread, value):
+        frame = thread.frames[0]
+        var = frame.FindVariable("counter")
+        self.assertTrue(var.GetError().Success(), "Got counter variable")
+        self.assertEqual(var.GetValueAsUnsigned(), value, "This was one-print")
+
+    def copy_to_main(self, src, dst):
+        # We are relying on the source file being newer than the .o file from
+        # a previous build, so sleep a bit here to ensure that the touch is later.
+        time.sleep(2)
+        try:
+            shutil.copy(src, dst)
+        except:
+            self.fail(f"Could not copy {src} to {dst}")
+        Path(dst).touch()
+
+    # The rerun tests indicate rerunning on Windows doesn't really work, so
+    # this one won't either.
+    @skipIfWindows
+    def test_OneTargetOneDebugger(self):
+        self.do_test(True, True)
+
+    # This behaves as implemented but that behavior is not desirable.
+    # This test tests for the desired behavior as an expected fail.
+    @skipIfWindows
+    @expectedFailureAll
+    def test_TwoTargetsOneDebugger(self):
+        self.do_test(False, True)
+
+    @skipIfWindows
+    @expectedFailureAll
+    def test_OneTargetTwoDebuggers(self):
+        self.do_test(True, False)
+
+    def do_test(self, one_target, one_debugger):
+        # Make sure that if we have one target, and we run, then
+        # change the binary and rerun, the binary (and any .o files
+        # if using dwarf in .o file debugging) get removed from the
+        # shared module cache.  They are no longer reachable.
+        debug_style = self.getDebugInfo()
+
+        # Before we do anything, clear the global module cache so we don't
+        # see objects from other runs:
+        lldb.SBDebugger.MemoryPressureDetected()
+
+        # Set up the paths for our two versions of main.c:
+        main_c_path = os.path.join(self.getBuildDir(), "main.c")
+        one_print_path = os.path.join(self.getSourceDir(), "one-print.c")
+        two_print_path = os.path.join(self.getSourceDir(), "two-print.c")
+        main_filespec = lldb.SBFileSpec(main_c_path)
+
+        # First copy the one-print.c to main.c in the build folder and
+        # build our a.out from there:
+        self.copy_to_main(one_print_path, main_c_path)
+        self.build(dictionary={"C_SOURCES": main_c_path, "EXE": "a.out"})
+
+        (target, process, thread, bkpt) = lldbutil.run_to_source_breakpoint(
+            self, "return counter;", main_filespec
+        )
+
+        # Make sure we ran the version we intended here:
+        self.check_counter_var(thread, 1)
+        process.Kill()
+
+        # Now copy two-print.c over main.c, rebuild, and rerun:
+        # os.unlink(target.GetExecutable().fullpath)
----------------
DavidSpickett wrote:

Also commented out code here.

https://github.com/llvm/llvm-project/pull/74894