[lldb] If the function cannot be found, use the symbol to get instructions. #7114
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| @@ -15,11 +15,25 @@ def test(self): | |||
| target, _, thread, _ = lldbutil.run_to_source_breakpoint(self, "await f()", src) | |||
| self.assertEqual(thread.frame[0].function.mangled, "$s1a5entryO4mainyyYaFZ") | |||
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| function = target.FindFunctions("$s1a5entryO4mainyyYaFZTQ0_")[0].function | |||
| instructions = list(function.GetInstructions(target)) | |||
| sym_ctx_list = target.FindFunctions("$s1a5entryO4mainyyYaFZTQ0_", lldb.eFunctionNameTypeAuto) | |||
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eFunctionNameTypeAuto is effectively the default parameter value, so it seems it can be left off.
| instructions = list(function.GetInstructions(target)) | ||
| sym_ctx_list = target.FindFunctions("$s1a5entryO4mainyyYaFZTQ0_", lldb.eFunctionNameTypeAuto) | ||
| self.assertEquals(sym_ctx_list.GetSize(), 1) | ||
| symbolContext = sym_ctx_list.GetContextAtIndex(0) |
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for consistency, could you name this symbol_context or symbol_ctx, thanks.
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Sorry, my mistake.
I will update if this PR is still needed.
| else: | ||
| symbol = symbolContext.GetSymbol() | ||
| self.assertIsNotNone(symbol) | ||
| instructions = list(symbol.GetInstructions(target)) |
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this seems like the crux of the change, is that correct? Does this mean the test is being run without debug info? Or does it mean that even with debug info, somehow GetFunction returns None? If the reason for this else case is understood, then could you add a comment explaining?
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I may know what the problem is. If I understand correctly, GetFunction is taken from the debuginfo.
An incorrect DW_TAG_subprogram caused the GetFunction returns None.
| control_flow_kind = inst.GetControlFlowKind(target) | ||
| if control_flow_kind == lldb.eInstructionControlFlowKindOther: | ||
| continue |
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can you say why some instructions need to be skipped? Padding instructions?
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Yes. Getting from the symbol will include the padding directive at the end.
But I'm not clear on lldb's difference between GetSymbol and GetFunction.
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I checked the generated debug information. I think that it generates debug message errors. 0x000000ef: DW_TAG_subprogram
DW_AT_low_pc (0x0000000100005d10)
DW_AT_high_pc (0x0000000100005d95)
DW_AT_frame_base (DW_OP_reg6 RBP)
- DW_AT_linkage_name ("$s1a5entryO4mainyyYaFZTQ0_")
- DW_AT_name ("main")
- DW_AT_decl_file ("/Users/dianqk/swift-project/llvm-project/lldb/test/API/lang/swift/async/stepping/step-in/task-switch/main.swift")
- DW_AT_decl_line (2)
- DW_AT_type (0x0000059a "$sytD")
- DW_AT_external (true)
+ DW_AT_specification (0x00000000000000b2 "$s1a5entryO4mainyyYaFZ")
+
0x0000010c: DW_TAG_formal_parameter
DW_AT_name ("self")I guess that this error is related to the following code.
I'll debug it later. |
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I found the problem and I tried to submit a patch. https://reviews.llvm.org/D157184 |
In swiftlang/swift#67077, we split a method's debugging information into declaration and definition to address some compatibility issues under LTO.
However, a test case from lldb was found to have failed.
Sorry, I have no lldb related knowledge. This change may not be correct, so please let me know if there are any problems.
cc @kastiglione @adrian-prantl