[PATCH] D102312: [llvm-dwp] Skip type unit debug info sections

[David Blaikie via Phabricator via llvm-commits]

dblaikie added inline comments.


================
Comment at: llvm/tools/llvm-dwp/llvm-dwp.cpp:779-781
+    if (CurInfoSection.size() != 1)
+      return make_error<DWPError>("expected exactly one occurrence of a debug "
+                                  "info section in a .dwp file");
----------------
kimanh wrote:
> dblaikie wrote:
> > Test coverage?
> I tried to add a *.s test for this case but I'm not entirely sure how to create one properly. If I add multiple .debug_info sections, after running llvm-mc there will only be one. 
> 
> Is there a  way to create a test with multiple .debug_info sections but one index than actually writing the byte code?
I think the way this happens with GCC is that it produces a single .o file that has the usual comdat groups for type units - then it runs objcopy to split out the .dwo sections, and objcopy doesn't propagate the comdat groups but it does keep the separate sections.

Probably the easiest thing to do might be to have an input file use a comdat group? (try compiling without Split DWARF and check the assembly - you'll see the .debug_info section directive for the type unit will have something like `.section        .debug_types.dwo,"G", at progbits,wt.b0cf918beae249c9,comdat` - so maybe you can do something like that - the consumer (llvm-dwp) won't care that it happens to be in a section group, I shouldn't think - also, maybe use an obvious made-up value for the hash (like 0xFDFDFDFDFD or whatever))


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  https://reviews.llvm.org/D102312/new/

https://reviews.llvm.org/D102312