[Bug binutils/26520] New: "objdump: DWARF error: could not find variable specification at offset ..." when generating assembly listing of .elf file containing symbols from libstdc++.a

[freddie_chopin at op dot pl]

https://sourceware.org/bugzilla/show_bug.cgi?id=26520

            Bug ID: 26520
           Summary: "objdump: DWARF error: could not find variable
                    specification at offset ..." when generating assembly
                    listing of .elf file containing symbols from
                    libstdc++.a
           Product: binutils
           Version: 2.35
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: binutils
          Assignee: unassigned at sourceware dot org
          Reporter: freddie_chopin at op dot pl
  Target Milestone: ---

Created attachment 12787
  --> https://sourceware.org/bugzilla/attachment.cgi?id=12787&action=edit
Problematic .elf file

I have multiple embedded C++ projects that - as part of the compilation process
- produce also assembly listing with command similar to this one:

$ arm-none-eabi-objdump -S --demangle distortosTest.elf > distortosTest.lss

This worked flawlessly up to (and including) previous release of binutils. In
2.35 something changed. The assembly listing is still generated and it seems to
be correct (I did not check it very thoroughly), the command ends with no fatal
errors (it returns "0" to the shell), however I see multiple errors like these:

arm-none-eabi-objdump: DWARF error: could not find variable specification at
offset 2f9
arm-none-eabi-objdump: DWARF error: could not find variable specification at
offset 305
arm-none-eabi-objdump: DWARF error: could not find variable specification at
offset 311
...

If I take the .elf file produced by the "new" toolchain (it also includes GCC
10.2) and do the command above but with objdump from the "old" toolchain
(binutils 2.34), then there is no error. In a reversed scenario (.elf produced
by "old" toolchain, passed to "new" objdump) I see 10x more errors like the
ones above.

I attach the problematic .elf file for ARM Cortex-M4 which produces such
errors.

After further inspection it turns out that none of "my" .o object files or .a
archives produce such error. When examining toolchain libraries, such errors
are produced by only ONE library there - libstdc++.a.

arm-none-eabi-objdump -S --demangle libstdc++.a > libstdc++.lss
arm-none-eabi-objdump: DWARF error: could not find variable specification at
offset 76c
arm-none-eabi-objdump: DWARF error: could not find variable specification at
offset 1733
arm-none-eabi-objdump: DWARF error: could not find variable specification at
offset 1740
...
(a lot...)

No other toolchain libraries or toolchain object files produce such error, only
libstdc++.a.

At this moment I cannot confirm whether or not this is arm-none-eabi specific
or not, as Arch Linux still has binutils 2.34 in the repos.

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