[PATCH] D154638: Emit a .debug_addr section with dsymutil

[Alexey Lapshin via Phabricator via llvm-commits]

avl added inline comments.


================
Comment at: llvm/include/llvm/DWARFLinker/DWARFLinker.h:656
+
+      dwarf::Form getAddrxFormForIndex(uint64_t Index) {
+        if (Index < UINT8_MAX)
----------------
Doing things that way we create many unnecessary abbreviations. f.e. for index 255 there would be used this abbreviation:

```
DW_TAG_subprogram 
  DW_AT_low_pc [DW_FORM_addrx1]

```
For index 256 there would be created new abbreviation:

```
DW_TAG_subprogram 
  DW_AT_low_pc [DW_FORM_addrx2]

```

I cann't tell whether that solution takes less space. It is necessary to measure impact of many abbreviations to the DWARF size. From one side DIE records having DW_FORM_addrx1 would take less bytes. From another side many abbreviation codes will be increased and then DIEs would take more space.

The solution from the previous version of this patch looks simpler and is OK. It is safe to just copy source form. DWARFLinker does not add new addresses for compile unit, so original form should be enough to keep address index. Just copy original form and check by assertion that everything is correct.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D154638/new/

https://reviews.llvm.org/D154638