81 lines · python
1"""2Test absolute symbols in ELF files to make sure they don't create sections and3to verify that symbol values and size can still be accessed via SBSymbol APIs.4"""5 6from lldbsuite.test.decorators import *7from lldbsuite.test.lldbtest import *8from lldbsuite.test import lldbutil9import os10 11 12class TestAbsoluteSymbol(TestBase):13 @no_debug_info_test14 def test_absolute_symbol(self):15 """16 Load an ELF file that contains two symbols:17 - "absolute" which is a symbol with the section SHN_ABS18 - "main" which is a code symbol in .text19 20 Index st_name st_value st_size st_info st_other st_shndx Name21 ======= ---------- ------------------ ------------------ ----------------------------------- -------- -------- ===========================22 [ 0] 0x00000000 0x0000000000000000 0x0000000000000000 0x00 (STB_LOCAL STT_NOTYPE ) 0x00 023 [ 1] 0x00000001 0x0000000000001000 0x0000000000000004 0x12 (STB_GLOBAL STT_FUNC ) 0x00 1 main24 [ 2] 0x00000006 0xffffffff80000000 0x0000000000000009 0x10 (STB_GLOBAL STT_NOTYPE ) 0x00 SHN_ABS absolute25 26 We used to create sections for symbols whose section ID was SHN_ABS27 and this caused problems as the new sections could interfere with28 with address resolution. Absolute symbols' values are not addresses29 and should not be treated this way.30 31 New APIs were added to SBSymbol to allow access to the raw integer32 value and size of symbols so symbols whose value was not an address33 could be accessed. Prior to this commit, you could only call:34 35 SBAddress SBSymbol::GetStartAddress()36 SBAddress SBSymbol::GetEndAddress()37 38 If the symbol's value was not an address, you couldn't access the39 raw value because the above accessors would return invalid SBAddress40 objects if the value wasn't an address. New APIs were added for this:41 42 uint64_t SBSymbol::GetValue()43 uint64_t SBSymbol::GetSize();44 """45 src_dir = self.getSourceDir()46 yaml_path = os.path.join(src_dir, "absolute.yaml")47 yaml_base, ext = os.path.splitext(yaml_path)48 obj_path = self.getBuildArtifact("a.out")49 self.yaml2obj(yaml_path, obj_path)50 51 # Create a target with the object file we just created from YAML52 target = self.dbg.CreateTarget(obj_path)53 self.assertTrue(target, VALID_TARGET)54 55 module = target.modules[0]56 57 # Make sure the 'main' symbol is valid and has address values. Also make58 # sure we can access the raw file address and size via the new APIS.59 symbol = module.FindSymbol("main")60 self.assertTrue(symbol.IsValid())61 self.assertTrue(symbol.GetStartAddress().IsValid())62 self.assertTrue(symbol.GetEndAddress().IsValid())63 self.assertEqual(symbol.GetValue(), 0x1000)64 self.assertEqual(symbol.GetSize(), 0x4)65 66 # Make sure the 'absolute' symbol is valid and has no address values.67 # Also make sure we can access the raw file address and size via the new68 # APIS.69 symbol = module.FindSymbol("absolute")70 self.assertTrue(symbol.IsValid())71 self.assertFalse(symbol.GetStartAddress().IsValid())72 self.assertFalse(symbol.GetEndAddress().IsValid())73 self.assertEqual(symbol.GetValue(), 0xFFFFFFFF80000000)74 self.assertEqual(symbol.GetSize(), 9)75 76 # Make sure no sections were created for the absolute symbol with a77 # prefix of ".absolute." followed by the symbol name as they interfere78 # with address lookups if they are treated like real sections.79 for section in module.sections:80 self.assertNotEqual(section.GetName(), ".absolute.absolute")81