[PATCH] Anonymous namespaces are missing import DW_TAG_imported_module.

[David Blaikie]

In http://reviews.llvm.org/D7895#131608, @kromanova wrote:

> Hi David,
>
> Yes, these are exactly 4 differences that I wanted to point out. 
>  The questionable differences are #1 and #3.
>
> - GCC doesn't put line/file on a namespace, Clang does. Clang should omit them for brevity Should I remove generation of  line/file names for anonymous namespaces before I commit my change?


No - it seems like a simple orthogonal change that could go in before/after/whenever someone decides they care about it.

> --GCC adds line/file on imported_module, Clang doesn't. Clang could add these, I'm not sure if any debugger cares - notionally they could do more accurate expression evaluation with that information (not using the using directive when the user is evaluating an expression in a context lexically prior to the using directive).

>  Our debugger doesn't care. I'm not sure if other debuggers care. So, I won't do any changes with respect of this.


*nod* if someone files a bug one day because a debugger cares, I'm happy to worry about it then.

> Is my latest patch look OK or should I change anything?


I still don't know if it's the right thing to do - I'm still sort of inclined to treating this as a debugger bug & avoiding the extra code/complexity in LLVM (though it's not a lot, of course).


================
Comment at: test/DebugInfo/anonymous-namespace.ll:12
@@ +11,3 @@
+; {
+;   a = a+2;
+;   return a;
----------------
You could simplify this to "return a"

It might be even simpler/smaller IR to drop the 'foo' function and just keep 'a' alive with a global variable:

  int *b = &a;

http://reviews.llvm.org/D7895

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