Bug report
Bug description:
I'm trying to build CPython 3.13.2 with JIT supported (--enable-experimental-jit=yes-off), but the build process crashes after reporting like this:
python3> | Traceback (most recent call last):
python3> | File "/build/Python-3.13.2/Tools/jit/_targets.py", line 181, in _compile
python3> | return await self._parse(o)
python3> | ^^^^^^^^^^^^^^^^^^^^
python3> | File "/build/Python-3.13.2/Tools/jit/_targets.py", line 89, in _parse
python3> | self._handle_section(wrapped_section["Section"], group)
python3> | File "/build/Python-3.13.2/Tools/jit/_targets.py", line 330, in _handle_section
python3> | value, base = group.symbols[section["Info"]]
python3> | ~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^
python3> | KeyError: 5
I've tracked the build process and found that the _parse routine in Tools/_targets.py almost fails for all the object files produced by the _compile process. When handling a ELF section of type SHT_PROGBITS, if SHF_ALLOC is not included in its flags, then the symbol tables of the stencil group will not be updated. Then if a later section refers to the symbol, a KeyError occurs. For example, an object file (_NOP.o) like this:
[
{
"Section": {
"Index": 5,
"Name": { "Name": ".debug_info", "Value": 108 },
"Type": { "Name": "SHT_PROGBITS", "Value": 1 },
"Flags": {
"Value": 2048,
"Flags": [{ "Name": "SHF_COMPRESSED", "Value": 2048 }]
},
"Address": 0,
"Offset": 463,
"Size": 29486,
"Link": 0,
"Info": 0
// ...
},
{
"Section": {
"Index": 6,
"Name": { "Name": ".rela.debug_info", "Value": 103 },
"Type": { "Name": "SHT_RELA", "Value": 4 },
"Flags": {
"Value": 64,
"Flags": [{ "Name": "SHF_INFO_LINK", "Value": 64 }]
},
"Address": 0,
"Offset": 44968,
"Size": 96,
"Link": 20,
"Info": 5
// ...
}When handling the 5th section, L349 is not executed:
|
elif section_type == "SHT_PROGBITS": |
|
if "SHF_ALLOC" not in flags: |
|
return |
|
if "SHF_EXECINSTR" in flags: |
|
value = _stencils.HoleValue.CODE |
|
stencil = group.code |
|
else: |
|
value = _stencils.HoleValue.DATA |
|
stencil = group.data |
|
group.symbols[section["Index"]] = value, len(stencil.body) |
|
for wrapped_symbol in section["Symbols"]: |
|
symbol = wrapped_symbol["Symbol"] |
|
offset = len(stencil.body) + symbol["Value"] |
|
name = symbol["Name"]["Name"] |
|
name = name.removeprefix(self.prefix) |
|
group.symbols[name] = value, offset |
|
stencil.body.extend(section["SectionData"]["Bytes"]) |
|
assert not section["Relocations"] |
Then when handling the 6th section, L330 will try to index group.symbols[5]:
|
if section_type == "SHT_RELA": |
|
assert "SHF_INFO_LINK" in flags, flags |
|
assert not section["Symbols"] |
|
value, base = group.symbols[section["Info"]] |
|
if value is _stencils.HoleValue.CODE: |
|
stencil = group.code |
|
else: |
|
assert value is _stencils.HoleValue.DATA |
|
stencil = group.data |
|
for wrapped_relocation in section["Relocations"]: |
|
relocation = wrapped_relocation["Relocation"] |
|
hole = self._handle_relocation(base, relocation, stencil.body) |
|
stencil.holes.append(hole) |
where the error occurs.
I'm not sure whether it's because of the version of LLVM (18.1.8) I'm using.
CPython versions tested on:
3.13.2
Operating systems tested on:
GNU/Linux
Build Toolchains
- Python 3.12.4
- LLVM 18.1.8
Linked PRs
Bug report
Bug description:
I'm trying to build CPython 3.13.2 with JIT supported (
--enable-experimental-jit=yes-off), but the build process crashes after reporting like this:I've tracked the build process and found that the
_parseroutine inTools/_targets.pyalmost fails for all the object files produced by the_compileprocess. When handling a ELF section of typeSHT_PROGBITS, ifSHF_ALLOCis not included in its flags, then the symbol tables of the stencil group will not be updated. Then if a later section refers to the symbol, aKeyErroroccurs. For example, an object file (_NOP.o) like this:[ { "Section": { "Index": 5, "Name": { "Name": ".debug_info", "Value": 108 }, "Type": { "Name": "SHT_PROGBITS", "Value": 1 }, "Flags": { "Value": 2048, "Flags": [{ "Name": "SHF_COMPRESSED", "Value": 2048 }] }, "Address": 0, "Offset": 463, "Size": 29486, "Link": 0, "Info": 0 // ... }, { "Section": { "Index": 6, "Name": { "Name": ".rela.debug_info", "Value": 103 }, "Type": { "Name": "SHT_RELA", "Value": 4 }, "Flags": { "Value": 64, "Flags": [{ "Name": "SHF_INFO_LINK", "Value": 64 }] }, "Address": 0, "Offset": 44968, "Size": 96, "Link": 20, "Info": 5 // ... }When handling the 5th section, L349 is not executed:
cpython/Tools/jit/_targets.py
Lines 340 to 357 in 4f8bb39
Then when handling the 6th section, L330 will try to index
group.symbols[5]:cpython/Tools/jit/_targets.py
Lines 327 to 339 in 4f8bb39
where the error occurs.
I'm not sure whether it's because of the version of LLVM (18.1.8) I'm using.
CPython versions tested on:
3.13.2
Operating systems tested on:
GNU/Linux
Build Toolchains
Linked PRs