[llvm-branch-commits] [GSYM] Include end_sequence debug_line rows in Dwarf transform (PR #90535)

[David Blaikie via llvm-branch-commits]

================
@@ -424,19 +439,13 @@ static void convertFunctionLineTable(OutputAggregator &Out, CUInfo &CUI,
     auto LastLE = FI.OptLineTable->last();
     if (LastLE && LastLE->File == FileIdx && LastLE->Line == Row.Line)
         continue;
+
     // Only push a row if it isn't an end sequence. End sequence markers are
     // included for the last address in a function or the last contiguous
     // address in a sequence.
-    if (Row.EndSequence) {
----------------
dwblaikie wrote:

I'm not quite following the collection of thoughts here, they seem disjoint to me, so trying to discuss:

> We used to not break out on Row.EndSequence 

I don't understand the relationship between end_sequence and functions with discontiguous ranges - could you describe this connection in more detail?

> as it allows functions to have discontiguous ranges. 

Agreed with @pogo59, I believe both Bolt and Propeller can create discontiguous address ranges for a function (but you'll see DW_AT_ranges on the subprogram)

> I was assuming that if we asked for the rows for a given address range we wouldn't get all entries if two merged functions with different line table entries were found, but that assumption might not be correct?

Yeah, looking at the implementation of `lookupAddressRangeImpl` it finds a single sequence that starts closest to the start address, then adds all rows within that sequence that cover the range requested. So, no, it won't retrieve addresses/ranges from multiple sequences.

https://github.com/llvm/llvm-project/pull/90535