BOLT --update-debug-sections causes infinite loop when processing binaries generated with dwarf5 and compressed debug section

[yabinc]

The binary is generated with -fdebug-default-version=5 and --compress-debug-sections=zstd.

The reproduce cmdline is: llvm-bolt libart.so -o=libart_bolt.so --data libart.bolt --reorder-blocks=ext-tsp --reorder-functions=cdsort --split-functions --split-strategy=profile2 --update-debug-sections --dyno-stats

The output is:
BOLT-ERROR: could not extract string from .debug_line_strBOLT-ERROR: could not extract strin'g from .debug_line_strBOLT-ERROR: could not extract string from .debug_line_strBOLT-ERROR: could not extract string from .debug_line_strBOLT-ERROR: could not extract string from .debug_line_strBOLT-ERROR: could not extract string from .debug_line_str

The libart.so can be constructed by the following cmds:
unzip libart_part1.zip
unzip libart_part2.zip
unzip libart_part3.zip
dd if=libart.so.part1 of=libart.so bs=28347826 count=1
dd if=libart.so.part2 of=libart.so bs=28347826 count=1 seek=1
dd if=libart.so.part3 of=libart.so bs=56695652 count=1 seek=1`

libart_part1.zip
libart_part2.zip
libart_part3.zip
libart_bolt.zip

[llvmbot]

@llvm/issue-subscribers-bolt

Author: None (yabinc)

The binary is generated with -fdebug-default-version=5 and --compress-debug-sections=zstd.

The reproduce cmdline is: llvm-bolt libart.so -o=libart_bolt.so --data libart.bolt --reorder-blocks=ext-tsp --reorder-functions=cdsort --split-functions --split-strategy=profile2 --update-debug-sections --dyno-stats

The output is:
BOLT-ERROR: could not extract string from .debug_line_strBOLT-ERROR: could not extract strin'g from .debug_line_strBOLT-ERROR: could not extract string from .debug_line_strBOLT-ERROR: could not extract string from .debug_line_strBOLT-ERROR: could not extract string from .debug_line_strBOLT-ERROR: could not extract string from .debug_line_str

The libart.so can be constructed by the following cmds:
unzip libart_part1.zip
unzip libart_part2.zip
unzip libart_part3.zip
dd if=libart.so.part1 of=libart.so bs=28347826 count=1
dd if=libart.so.part2 of=libart.so bs=28347826 count=1 seek=1
dd if=libart.so.part3 of=libart.so bs=56695652 count=1 seek=1`

libart_part1.zip
libart_part2.zip
libart_part3.zip
libart_bolt.zip

[aaupov]

I don't think BOLT supports compressed debug sections.