[PATCH] D81144: [MC] Generate .debug_line in the 64-bit DWARF format [2/7]

[Igor Kudrin via Phabricator via llvm-commits]

ikudrin marked 2 inline comments as done.
ikudrin added inline comments.


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Comment at: llvm/lib/MC/MCDwarf.cpp:487
+  emitAbsValue(*MCOS,
+               MakeStartMinusEndExpr(context, *LineStartSym, *LineEndSym,
+                                     UnitLengthBytes),
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jhenderson wrote:
> Aside: I think this function may be misnamed - shouldn't it be `MakeEndMinusStartExpr`?
Looks like you are right. Would you like to prepare the patch?


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Comment at: llvm/test/MC/ELF/gen-dwarf64.s:20
+# DUMP5-NEXT: file_names[  0]:
+# DUMP5-NEXT:            name: .debug_line_str[0x00000000[[FILEOFF:[[:xdigit:]]{8}]]] = "[[FILE:.+]]"
+# DUMP5-NEXT:       dir_index: 0
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jhenderson wrote:
> FileCheck has relatively recently been extended to improve numeric variable capturing. You can change this line to something like:
> 
> `name: .debug_line_str[0x00000000[[#FILEOFF:]]] = "[[FILE:.+]]"`
> 
> and the usage to: `0x[[#FILEOFF]]`.
> 
> Beware that there are some issues relating to leading zeros that I can't quite remember the details of.
I believe the feature would be great if there was a need for an expression, but here we can just compare exact strings.

With numeric substitutions, the first match would be something like `0x[[#%x,FILEOFF:]]`, and the usage would look like `0x{{0*}}[[#FILEOFF]]`. To my taste, the current variant is much simpler. Moreover, the current variant shows the exact number of hex digits we expect in the dump, which is, AFAIK, impossible with numeric substitutions.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D81144/new/

https://reviews.llvm.org/D81144