[gmorer]

Hello,
I'm getting a segfault while running wasm-opt on my wasm (it started with version 123)

$> wasm-opt --enable-threads -g -O4 -ol 100 -s 0 -all -o out.wasm in.wasm
fish: Job 1, 'wasm-opt --enable-threads -g -O…' terminated by signal SIGSEGV (Address boundary error)

After a little sesion with gdb, found out in third_party/llvm-project/dwarf2yaml.cpp:122 the CU variables equals the end of the iterator.

WASM analysis:

$> wasm-objdump -h in.wasm
[...]
   Custom start=0x037bac4b end=0x0508e814 (size=0x018d3bc9) "name"
   Custom start=0x0508e816 end=0x0508e822 (size=0x0000000c) ".debug_info"
   Custom start=0x0508e824 end=0x0508e82f (size=0x0000000b) ".debug_loc"
   Custom start=0x0508e831 end=0x0508e83f (size=0x0000000e) ".debug_ranges"
[...]

$>  wasm-objdump -j .debug_loc -s in.wasm
in.wasm:	file format wasm 0x1

Contents of section Custom:
508e824: 0a2e 6465 6275 675f 6c6f 63              ..debug_loc

So it look like it is an empty .debug_loc causing the crash