[Get-fix]

What

An FDE whose address range is 0 describes no instructions, and an unwinder never matches a pc in it. The exception-table reader rejected one, which stopped the conversion of Limbo (CUSA01664) on main 5d9dcc42d:

FAIL: Strict filter: inconsistent FDE function range (offset 0x3f4ffc)

One of Limbo's 17328 FDEs covers 0 bytes at 0x47dd0, where the next record starts. Such a record is now read and validated as before, but left out of the function list. A record whose start differs from the .eh_frame_hdr entry, or whose range overflows, is still rejected. Part of the PS4 work tracked in #3093.

Tested

Windows 11 Pro 26200, WinLibs GCC 15.2.0 r7, Release, on main 5d9dcc42d:

• unwind_record_bounds has a new case: the fixture's FDE with a range of 0 reads as no functions. Each of these makes it fail: rejecting the record as before, and keeping it as an empty function.
• This branch alone, with CI's relinker-only configuration (-DANYPS5_RELINKER_ONLY=ON): 177 of 177 tests pass. The relinker it builds gets Limbo past this record to its inline jump tables, which fix(relinker): skip jump tables placed after a function's code #6618 handles; with both, Limbo converts.
• Full ctest with my open pull requests: 1305 of 1308 pass; see fix(relinker): skip jump tables placed after a function's code #6618 for the three that do not.
• tools/check_conventions.py passes.

Not tested on Linux or macOS hosts.

Checklist

• Based on current main; no other open PR implements the same functions
• One topic per PR; follow-ups go in a new PR
• No comments in code except technical debt
• Unimplemented paths throw (NotImplemented_nid_no_patch); silent stubs are listed under Silent stubs in their library's technical debt file
• No notes, investigation .md files or images added to the repository (attach them to this PR)
• New third-party code is a submodule built from source
• Generic behaviour, not specific to one title
• Depends on: none
• Unblocks: conversion of CUSA01664 (Limbo) with fix(relinker): skip jump tables placed after a function's code #6618, Relinker rejects PS4 executables: SCE dynamic tables and data in the code segment (two ready branches) + remaining PS4 work #3093
• GPUs tested: n/a
• AI-assisted: yes (Claude Code)

🤖 Generated with Claude Code

[simonbbby]

Independent Linux and native macOS parser coverage for exact head a9fa0e8b088432e6a7ba7182390a41ff31648550, filling the host gap in the description.

• Ubuntu 24.04 / GCC 13.3 / x86-64, and macOS 27.2 / Apple clang 21 / arm64.
• Compiled the unchanged UnwindRecordBoundsTests.cpp, EhFrameReader.cpp and BufferUtils.cpp, using the include directories of unwind_record_bounds_tests. The stock test reports 14 cases passed on both hosts. Substituting only EhFrameReader.cpp from HEAD^ fails on both with Strict filter: inconsistent FDE function range.
• An external probe reuses Fixture() and sets the FDE range at offset 112 to zero while retaining eight existing malformed CIE/FDE/segment cases, plus a mismatched .eh_frame_hdr start. All nine malformed zero-length cases remain rejected on both hosts.
• Both the stock test and external probe also pass with AddressSanitizer + UndefinedBehaviorSanitizer on both hosts, with no diagnostics.

One small extra regression is worth keeping: a zero-sized FDE whose start disagrees with its header entry. In a scratch production copy, returning an empty region immediately after reading size == 0 still passes all 14 stock cases, but the external probe catches this malformed record on both hosts. Current PR code correctly rejects it. The case is:

auto bytes = Fixture();
Io::WriteU64(bytes, 112, 0);
Io::WriteU64(bytes, 16, 0x2001);
bool rejected = false;
try { Relinker::UnusedNidFilter::ReadExceptionFunctions(bytes, {load, eh}, {}, {}); }
catch (const std::exception&) { rejected = true; }
Require(rejected);

No repository source changed. Scope: the production exception-table reader and synthetic byte fixtures; no full relinker/CTest build, Limbo conversion, guest execution or Rosetta run. The existing Windows title-conversion evidence remains the title evidence.

[savvaniss]

Second-title data point: Hasbro Family Fun Pack (CUSA03312, my own dump) needs this PR, on Linux and Windows.

Relinker-only Release build, Windows 11 Pro 26300, WinLibs GCC 15.2.0 r7. Starting from main f3059421f, I merged, in this order: #7660, #6619 (a9fa0e8b0), #5138 (5f5641732), #6381 (6f8d9a09d), 3b158c1 from #6977, #6354 (81561867f), #6357 (32fe3aa8b), #6684 (ab9d21afc) and #6618 (bf06a8e5c). With that stack, the Linux and --windows conversions of the eboot and its 9 bundled modules complete. I then rebuilt the relinker once per member with only that member left out. Without this PR, both targets stop in the eboot:

FAIL: Strict filter: inconsistent FDE function range (offset 0xd42390)

The other members each stop at their own step, so every one of them is needed for this title; the whole table is on #6977.

AI-assisted: yes (Claude Code)

[adriadam10]

Checked: a zero-range FDE is still read and validated (start vs .eh_frame_hdr, overflow) and only dropped from the function list; the new case in unwind_record_bounds pins it and fails without the change. Relinker CI green on Linux, macOS and Windows, plus the independent Linux/macOS and Hasbro runs in the thread. Merged.