[lld] [llvm] [Symbolizer] Support for Missing Line Numbers. (PR #82240)

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ampandey-1995 wrote:

> @ampandey-1995 this might well be my failing but I'm afraid that I'm struggling to understand the tests. Before going on though I would like to say that I appreciate the effort you have put into them :) 

Thanks for the input.

>However, I don't understand why we would want to invoke the compiler and the linker (which is a complicated process to understand and results in input full of unnecessary features e.g. lots of crt symbols etc) rather than just hand coding the input?

Linker is not getting invoked in approximate-line-handcrafted.yaml. If you see @MaskRay comment https://github.com/llvm/llvm-project/pull/82240#discussion_r1602749928, Linker is not getting invoked in the lit test. However, it is required to generate or reproduce the yaml file only a once. Linker is not getting invoked in any RUN lines.

>I also don't understand why we need two tests - can't we use one test for all the cases we need? 

It's not mandatory, but from my perspective two separate tests are fine.
```approximate-line-generated.s```(Single Sequence .text) is the generated assembly where no manual modification is happening. The test is basically to reflect on the understanding/showcase that clang produces line-zero for addresses. 
```approximate-line-handcrafted.yaml```(Two Sequences .text && .def_section) is the manually modified assembly where individual .loc directives of debug info are modified to zero so as to stress test the sequence boundaries and also to show approximated output for address which are in different functions(in different files). Check @dwblaikie comment https://github.com/llvm/llvm-project/pull/82240#discussion_r1595660179. 

>I think that the names of the tests need to clearly describe to what they are testing (not how they are implemented e.g. "handcrafted") and the tests need comments describing what the test features and cases are.

Ok, will change the name the name of the tests. Can you suggest me appropriate name?
Ok, I will write more descriptive comments for each lit test case run.



https://github.com/llvm/llvm-project/pull/82240