xref: /llvm-project/lldb/test/API/functionalities/lazy-loading/TestLazyLoading.py (revision e439a463a30833f1c7d366ed722f0f12d1682638)
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    mydir = TestBase.compute_mydir(__file__)
19
20    def setUp(self):
21      TestBase.setUp(self)
22      # Only build this test once.
23      self.build()
24
25    # Clang declaration kind we are looking for.
26    class_decl_kind = "CXXRecordDecl"
27    # FIXME: This shouldn't be a CXXRecordDecl, but that's how we model
28    # structs in Clang.
29    struct_decl_kind = "CXXRecordDecl"
30
31    # The decls we use in this program in the format that
32    # decl_in_line and decl_completed_in_line expect (which is a pair of
33    # node type and the unqualified declaration name.
34    struct_first_member_decl = [struct_decl_kind, "StructFirstMember"]
35    struct_behind_ptr_decl = [struct_decl_kind, "StructBehindPointer"]
36    struct_behind_ref_decl = [struct_decl_kind, "StructBehindRef"]
37    struct_member_decl = [struct_decl_kind, "StructMember"]
38    some_struct_decl = [struct_decl_kind, "SomeStruct"]
39    other_struct_decl = [struct_decl_kind, "OtherStruct"]
40    class_in_namespace_decl = [class_decl_kind, "ClassInNamespace"]
41    class_we_enter_decl = [class_decl_kind, "ClassWeEnter"]
42    class_member_decl = [struct_decl_kind, "ClassMember"]
43    class_static_member_decl = [struct_decl_kind, "StaticClassMember"]
44    class_pointer_to_member_decl = [struct_decl_kind, "PointerToMember"]
45    unused_class_member_decl = [struct_decl_kind, "UnusedClassMember"]
46    unused_class_member_ptr_decl = [struct_decl_kind, "UnusedClassMemberPtr"]
47
48    def assert_no_decls_loaded(self):
49        """
50        Asserts that no known declarations in this test are loaded
51        into the module's AST.
52        """
53        self.assert_decl_not_loaded(self.struct_first_member_decl)
54        self.assert_decl_not_loaded(self.struct_behind_ptr_decl)
55        self.assert_decl_not_loaded(self.struct_behind_ref_decl)
56        self.assert_decl_not_loaded(self.struct_member_decl)
57        self.assert_decl_not_loaded(self.some_struct_decl)
58        self.assert_decl_not_loaded(self.other_struct_decl)
59        self.assert_decl_not_loaded(self.class_in_namespace_decl)
60        self.assert_decl_not_loaded(self.class_member_decl)
61        self.assert_decl_not_loaded(self.class_static_member_decl)
62        self.assert_decl_not_loaded(self.class_pointer_to_member_decl)
63        self.assert_decl_not_loaded(self.unused_class_member_decl)
64
65    def get_ast_dump(self):
66        """Returns the dumped Clang AST of the module as a string"""
67        res = lldb.SBCommandReturnObject()
68        ci = self.dbg.GetCommandInterpreter()
69        ci.HandleCommand('target modules dump ast a.out', res)
70        self.assertTrue(res.Succeeded())
71        return res.GetOutput()
72
73    def decl_in_line(self, line, decl):
74        """
75        Returns true iff the given line declares the given Clang decl.
76        The line is expected to be in the form of Clang's AST dump.
77        """
78        line = line.rstrip() + "\n"
79        decl_kind = "-" + decl[0] + " "
80        # Either the decl is somewhere in the line or at the end of
81        # the line.
82        decl_name = " " + decl[1] + " "
83        decl_name_eol = " " + decl[1] + "\n"
84        if not decl_kind in line:
85          return False
86        return decl_name in line or decl_name_eol in line
87
88    def decl_completed_in_line(self, line, decl):
89        """
90        Returns true iff the given line declares the given Clang decl and
91        the decl was completed (i.e., it has no undeserialized declarations
92        in it).
93        """
94        return self.decl_in_line(line, decl) and not "<undeserialized declarations>" in line
95
96    # The following asserts are used for checking if certain Clang declarations
97    # were loaded or not since the target was created.
98
99    def assert_decl_loaded(self, decl):
100        """
101        Asserts the given decl is currently loaded.
102        Note: This test is about checking that types/declarations are not
103        loaded. If this assert fails it is usually fine to turn it into a
104        assert_decl_not_loaded or assert_decl_not_completed assuming LLDB's
105        functionality has not suffered by not loading this declaration.
106        """
107        ast = self.get_ast_dump()
108        found = False
109        for line in ast.splitlines():
110          if self.decl_in_line(line, decl):
111            found = True
112            self.assertTrue(self.decl_completed_in_line(line, decl),
113                            "Should have called assert_decl_not_completed")
114        self.assertTrue(found, "Declaration no longer loaded " + str(decl) +
115            ".\nAST:\n" + ast)
116
117    def assert_decl_not_completed(self, decl):
118        """
119        Asserts that the given decl is currently not completed in the module's
120        AST. It may be loaded but then can can only contain undeserialized
121        declarations.
122        """
123        ast = self.get_ast_dump()
124        found = False
125        for line in ast.splitlines():
126          error_msg = "Unexpected completed decl: '" + line + "'.\nAST:\n" + ast
127          self.assertFalse(self.decl_completed_in_line(line, decl), error_msg)
128
129    def assert_decl_not_loaded(self, decl):
130        """
131        Asserts that the given decl is currently not loaded in the module's
132        AST.
133        """
134        ast = self.get_ast_dump()
135        found = False
136        for line in ast.splitlines():
137          error_msg = "Unexpected loaded decl: '" + line + "'\nAST:\n" + ast
138          self.assertFalse(self.decl_in_line(line, decl), error_msg)
139
140
141    def clean_setup(self, location):
142        """
143        Runs to the line with the source line with the given location string
144        and ensures that our module AST is empty.
145        """
146        lldbutil.run_to_source_breakpoint(self,
147            "// Location: " + location, lldb.SBFileSpec("main.cpp"))
148        # Make sure no declarations are loaded initially.
149        self.assert_no_decls_loaded()
150
151    @add_test_categories(["dwarf"])
152    def test_arithmetic_expression_in_main(self):
153        """ Runs a simple arithmetic expression which should load nothing. """
154        self.clean_setup(location="multiple locals function")
155
156        self.expect("expr 1 + (int)2.0", substrs=['(int) $0'])
157
158        # This should not have loaded any decls.
159        self.assert_no_decls_loaded()
160
161    @add_test_categories(["dwarf"])
162    def test_printing_local_variable_in_other_struct_func(self):
163        """
164        Prints a local variable and makes sure no unrelated types are loaded.
165        """
166        self.clean_setup(location="other struct function")
167
168        self.expect("expr other_struct_var", substrs=['(OtherStruct) $0'])
169        # The decl we run on was loaded.
170        self.assert_decl_loaded(self.other_struct_decl)
171
172        # This should not have loaded anything else.
173        self.assert_decl_not_loaded(self.some_struct_decl)
174        self.assert_decl_not_loaded(self.class_in_namespace_decl)
175
176    @add_test_categories(["dwarf"])
177    def test_printing_struct_with_multiple_locals(self):
178        """
179        Prints a local variable and checks that we don't load other local
180        variables.
181        """
182        self.clean_setup(location="multiple locals function")
183
184        self.expect("expr struct_var", substrs=['(SomeStruct) $0'])
185
186        # We loaded SomeStruct and its member types for printing.
187        self.assert_decl_loaded(self.some_struct_decl)
188        self.assert_decl_loaded(self.struct_behind_ptr_decl)
189        self.assert_decl_loaded(self.struct_behind_ref_decl)
190
191        # FIXME: We don't use these variables, but we seem to load all local
192        # local variables.
193        self.assert_decl_not_completed(self.other_struct_decl)
194        self.assert_decl_not_completed(self.class_in_namespace_decl)
195
196    @add_test_categories(["dwarf"])
197    def test_addr_of_struct(self):
198        """
199        Prints the address of a local variable (which is a struct).
200        """
201        self.clean_setup(location="multiple locals function")
202
203        self.expect("expr &struct_var", substrs=['(SomeStruct *) $0'])
204
205        # We loaded SomeStruct.
206        self.assert_decl_loaded(self.some_struct_decl)
207
208        # The member declarations should not be completed.
209        self.assert_decl_not_completed(self.struct_behind_ptr_decl)
210        self.assert_decl_not_completed(self.struct_behind_ref_decl)
211
212        # FIXME: The first member was behind a pointer so it shouldn't be
213        # completed. Somehow LLDB really wants to load the first member, so
214        # that is why have it defined here.
215        self.assert_decl_loaded(self.struct_first_member_decl)
216
217        # FIXME: We don't use these variables, but we seem to load all local
218        # local variables.
219        self.assert_decl_not_completed(self.other_struct_decl)
220        self.assert_decl_not_completed(self.class_in_namespace_decl)
221
222    @add_test_categories(["dwarf"])
223    def test_class_function_access_member(self):
224        self.clean_setup(location="class function")
225
226        self.expect("expr member", substrs=['(ClassMember) $0'])
227
228        # We loaded the current class we touched.
229        self.assert_decl_loaded(self.class_we_enter_decl)
230        # We loaded the unused members of this class.
231        self.assert_decl_loaded(self.unused_class_member_decl)
232        self.assert_decl_not_completed(self.unused_class_member_ptr_decl)
233        # We loaded the member we used.
234        self.assert_decl_loaded(self.class_member_decl)
235        # We didn't load the type of the unused static member.
236        self.assert_decl_not_completed(self.class_static_member_decl)
237        # We didn't load the type of the unused pointer-to-member member.
238        self.assert_decl_not_completed(self.class_pointer_to_member_decl)
239
240        # This should not have loaded anything else.
241        self.assert_decl_not_loaded(self.other_struct_decl)
242        self.assert_decl_not_loaded(self.some_struct_decl)
243        self.assert_decl_not_loaded(self.class_in_namespace_decl)
244
245