xref: /llvm-project/lldb/test/API/functionalities/lazy-loading/TestLazyLoading.py (revision 4cc8f2a017c76af25234afc7c380550e9c93135c)
1from lldbsuite.test.decorators import *
2from lldbsuite.test.lldbtest import *
3from lldbsuite.test import lldbutil
4
5"""
6This test ensures that we only create Clang AST nodes in our module AST
7when we actually need them.
8
9All tests in this file behave like this:
10  1. Use LLDB to do something (expression evaluation, breakpoint setting, etc.).
11  2. Check that certain Clang AST nodes were not loaded during the previous
12     step.
13"""
14
15class TestCase(TestBase):
16
17    NO_DEBUG_INFO_TESTCASE = True
18
19    def setUp(self):
20      TestBase.setUp(self)
21      # Only build this test once.
22      self.build()
23
24    # Clang declaration kind we are looking for.
25    class_decl_kind = "CXXRecordDecl"
26    # FIXME: This shouldn't be a CXXRecordDecl, but that's how we model
27    # structs in Clang.
28    struct_decl_kind = "CXXRecordDecl"
29
30    # The decls we use in this program in the format that
31    # decl_in_line and decl_completed_in_line expect (which is a pair of
32    # node type and the unqualified declaration name.
33    struct_first_member_decl = [struct_decl_kind, "StructFirstMember"]
34    struct_behind_ptr_decl = [struct_decl_kind, "StructBehindPointer"]
35    struct_behind_ref_decl = [struct_decl_kind, "StructBehindRef"]
36    struct_member_decl = [struct_decl_kind, "StructMember"]
37    some_struct_decl = [struct_decl_kind, "SomeStruct"]
38    other_struct_decl = [struct_decl_kind, "OtherStruct"]
39    class_in_namespace_decl = [class_decl_kind, "ClassInNamespace"]
40    class_we_enter_decl = [class_decl_kind, "ClassWeEnter"]
41    class_member_decl = [struct_decl_kind, "ClassMember"]
42    class_static_member_decl = [struct_decl_kind, "StaticClassMember"]
43    unused_class_member_decl = [struct_decl_kind, "UnusedClassMember"]
44    unused_class_member_ptr_decl = [struct_decl_kind, "UnusedClassMemberPtr"]
45
46    def assert_no_decls_loaded(self):
47        """
48        Asserts that no known declarations in this test are loaded
49        into the module's AST.
50        """
51        self.assert_decl_not_loaded(self.struct_first_member_decl)
52        self.assert_decl_not_loaded(self.struct_behind_ptr_decl)
53        self.assert_decl_not_loaded(self.struct_behind_ref_decl)
54        self.assert_decl_not_loaded(self.struct_member_decl)
55        self.assert_decl_not_loaded(self.some_struct_decl)
56        self.assert_decl_not_loaded(self.other_struct_decl)
57        self.assert_decl_not_loaded(self.class_in_namespace_decl)
58        self.assert_decl_not_loaded(self.class_member_decl)
59        self.assert_decl_not_loaded(self.class_static_member_decl)
60        self.assert_decl_not_loaded(self.unused_class_member_decl)
61
62    def get_ast_dump(self):
63        """Returns the dumped Clang AST of the module as a string"""
64        res = lldb.SBCommandReturnObject()
65        ci = self.dbg.GetCommandInterpreter()
66        ci.HandleCommand('target modules dump ast a.out', res)
67        self.assertTrue(res.Succeeded())
68        return res.GetOutput()
69
70    def decl_in_line(self, line, decl):
71        """
72        Returns true iff the given line declares the given Clang decl.
73        The line is expected to be in the form of Clang's AST dump.
74        """
75        line = line.rstrip() + "\n"
76        decl_kind = "-" + decl[0] + " "
77        # Either the decl is somewhere in the line or at the end of
78        # the line.
79        decl_name = " " + decl[1] + " "
80        decl_name_eol = " " + decl[1] + "\n"
81        if not decl_kind in line:
82          return False
83        return decl_name in line or decl_name_eol in line
84
85    def decl_completed_in_line(self, line, decl):
86        """
87        Returns true iff the given line declares the given Clang decl and
88        the decl was completed (i.e., it has no undeserialized declarations
89        in it).
90        """
91        return self.decl_in_line(line, decl) and not "<undeserialized declarations>" in line
92
93    # The following asserts are used for checking if certain Clang declarations
94    # were loaded or not since the target was created.
95
96    def assert_decl_loaded(self, decl):
97        """
98        Asserts the given decl is currently loaded.
99        Note: This test is about checking that types/declarations are not
100        loaded. If this assert fails it is usually fine to turn it into a
101        assert_decl_not_loaded or assert_decl_not_completed assuming LLDB's
102        functionality has not suffered by not loading this declaration.
103        """
104        ast = self.get_ast_dump()
105        found = False
106        for line in ast.splitlines():
107          if self.decl_in_line(line, decl):
108            found = True
109            self.assertTrue(self.decl_completed_in_line(line, decl),
110                            "Should have called assert_decl_not_completed")
111        self.assertTrue(found, "Declaration no longer loaded " + str(decl) +
112            ".\nAST:\n" + ast)
113
114    def assert_decl_not_completed(self, decl):
115        """
116        Asserts that the given decl is currently not completed in the module's
117        AST. It may be loaded but then can can only contain undeserialized
118        declarations.
119        """
120        ast = self.get_ast_dump()
121        found = False
122        for line in ast.splitlines():
123          error_msg = "Unexpected completed decl: '" + line + "'.\nAST:\n" + ast
124          self.assertFalse(self.decl_completed_in_line(line, decl), error_msg)
125
126    def assert_decl_not_loaded(self, decl):
127        """
128        Asserts that the given decl is currently not loaded in the module's
129        AST.
130        """
131        ast = self.get_ast_dump()
132        found = False
133        for line in ast.splitlines():
134          error_msg = "Unexpected loaded decl: '" + line + "'\nAST:\n" + ast
135          self.assertFalse(self.decl_in_line(line, decl), error_msg)
136
137
138    def clean_setup(self, location):
139        """
140        Runs to the line with the source line with the given location string
141        and ensures that our module AST is empty.
142        """
143        lldbutil.run_to_source_breakpoint(self,
144            "// Location: " + location, lldb.SBFileSpec("main.cpp"))
145        # Make sure no declarations are loaded initially.
146        self.assert_no_decls_loaded()
147
148    @add_test_categories(["dwarf"])
149    def test_arithmetic_expression_in_main(self):
150        """ Runs a simple arithmetic expression which should load nothing. """
151        self.clean_setup(location="multiple locals function")
152
153        self.expect("expr 1 + (int)2.0", substrs=['(int) $0'])
154
155        # This should not have loaded any decls.
156        self.assert_no_decls_loaded()
157
158    @add_test_categories(["dwarf"])
159    def test_printing_local_variable_in_other_struct_func(self):
160        """
161        Prints a local variable and makes sure no unrelated types are loaded.
162        """
163        self.clean_setup(location="other struct function")
164
165        self.expect("expr other_struct_var", substrs=['(OtherStruct) $0'])
166        # The decl we run on was loaded.
167        self.assert_decl_loaded(self.other_struct_decl)
168
169        # This should not have loaded anything else.
170        self.assert_decl_not_loaded(self.some_struct_decl)
171        self.assert_decl_not_loaded(self.class_in_namespace_decl)
172
173    @add_test_categories(["dwarf"])
174    def test_printing_struct_with_multiple_locals(self):
175        """
176        Prints a local variable and checks that we don't load other local
177        variables.
178        """
179        self.clean_setup(location="multiple locals function")
180
181        self.expect("expr struct_var", substrs=['(SomeStruct) $0'])
182
183        # We loaded SomeStruct and its member types for printing.
184        self.assert_decl_loaded(self.some_struct_decl)
185        self.assert_decl_loaded(self.struct_behind_ptr_decl)
186        self.assert_decl_loaded(self.struct_behind_ref_decl)
187
188        # FIXME: We don't use these variables, but we seem to load all local
189        # local variables.
190        self.assert_decl_not_completed(self.other_struct_decl)
191        self.assert_decl_not_completed(self.class_in_namespace_decl)
192
193    @add_test_categories(["dwarf"])
194    def test_addr_of_struct(self):
195        """
196        Prints the address of a local variable (which is a struct).
197        """
198        self.clean_setup(location="multiple locals function")
199
200        self.expect("expr &struct_var", substrs=['(SomeStruct *) $0'])
201
202        # We loaded SomeStruct.
203        self.assert_decl_loaded(self.some_struct_decl)
204
205        # The member declarations should not be completed.
206        self.assert_decl_not_completed(self.struct_behind_ptr_decl)
207        self.assert_decl_not_completed(self.struct_behind_ref_decl)
208
209        # FIXME: The first member was behind a pointer so it shouldn't be
210        # completed. Somehow LLDB really wants to load the first member, so
211        # that is why have it defined here.
212        self.assert_decl_loaded(self.struct_first_member_decl)
213
214        # FIXME: We don't use these variables, but we seem to load all local
215        # local variables.
216        self.assert_decl_not_completed(self.other_struct_decl)
217        self.assert_decl_not_completed(self.class_in_namespace_decl)
218
219    @add_test_categories(["dwarf"])
220    def test_class_function_access_member(self):
221        self.clean_setup(location="class function")
222
223        self.expect("expr member", substrs=['(ClassMember) $0'])
224
225        # We loaded the current class we touched.
226        self.assert_decl_loaded(self.class_we_enter_decl)
227        # We loaded the unused members of this class.
228        self.assert_decl_loaded(self.unused_class_member_decl)
229        self.assert_decl_not_completed(self.unused_class_member_ptr_decl)
230        # We loaded the member we used.
231        self.assert_decl_loaded(self.class_member_decl)
232        # We didn't load the type of the unused static member.
233        self.assert_decl_not_completed(self.class_static_member_decl)
234
235        # This should not have loaded anything else.
236        self.assert_decl_not_loaded(self.other_struct_decl)
237        self.assert_decl_not_loaded(self.some_struct_decl)
238        self.assert_decl_not_loaded(self.class_in_namespace_decl)
239
240