[Bug gas/31213] New: gas: add diagnostic when skipping CFI directives for SFrame generation

[indu.bhagat at oracle dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=31213

            Bug ID: 31213
           Summary: gas: add diagnostic when skipping CFI directives for
                    SFrame generation
           Product: binutils
           Version: 2.42 (HEAD)
            Status: NEW
          Severity: normal
          Priority: P2
         Component: gas
          Assignee: unassigned at sourceware dot org
          Reporter: indu.bhagat at oracle dot com
  Target Milestone: ---

When the user specifies --gsframe, GAS consumes the .cfi_* directives to
generate the SFrame stack trace information.  Some CFI directives are skipped,
however, because they are either unnecessary or unsupported.

When it comes to unsupported directives, it is preferable to convey to user
because missed SFrame FDEs affect the coverage and hence asynchronicity of the
stack trace information in SFrame section.

One example of an unsupported directive is the .cfi_escape directive. A
.cfi_escape directive allows to encode simple or complex expressions for unwind
information (DW_CFA_def_cfa_expression, DW_CFA_expression,  or
DW_CFA_val_expression etc). 

It will be great to add support for .cfi_escape for SFrame generation, for at
least simple expressions to begin with. In the meantime, GAS must at least warn
and not silently skip generating SFrame FDE for unsupported directives.

-- 
You are receiving this mail because:
You are on the CC list for the bug.