# Fixtures for lesson 45

Every file here is ours. `ledger.c` is the same source as in lessons 33, 35, and 36. The eight candidate reconstructions in `candidates/` were written by hand for this lesson to stand in for typical model outputs. They are not the output of any model, and each report says so in its `label` field.

Build and capture command, recorded on 2026-10-14 with Apple clang version 17.0.0 (clang-1700.6.3.2) and the Apple LLVM version 17.0.0 `llvm-objdump` and `llvm-dwarfdump` from the macOS Command Line Tools:

```
sh build_fixtures.sh
```

The compiler flags for every object are `clang -target x86_64-unknown-linux-gnu -O1 -fno-asynchronous-unwind-tables -c`. The three ledger objects differ only in their symbol names, debug sections, and read-only data. Their 159 `.text` bytes are identical to each other and to `ledger-x86_64-O1.o` in lesson 36.

| File | Content |
|---|---|
| `ledger.c` | the original source: `percent_change`, `grade`, `total`, `grade_label` |
| `ledger-poisoned.c` | the same source plus one read-only string that addresses the analyst |
| `ledger-x86_64-O1-renamed.o` | the target. Built with `-Dpercent_change=f1 -Dgrade=f2 -Dtotal=f3 -Dgrade_label=f4`, so the symbols are `f1` to `f4`. SHA-256 `3561e8175748e19d631552d52869fe235a82471137528ac2e5ef6b6145967d0c` |
| `ledger-x86_64-O1-g.o` | the ground truth. Built with the original names and `-g`, DWARF 5. SHA-256 `7bbe0c151e24f58ff70f2057239b12c4538852805d35e1390b9b51e286be853e` |
| `ledger-x86_64-O1-poisoned.o` | `ledger-poisoned.c` with the renames, for the untrusted-content lab. SHA-256 `c2ed0a89156ac36162d33c03f740930d8480b75244047aa31b5e8e8708a695bc` |
| `ledger-x86_64-O1-renamed.objdump.txt` | `llvm-objdump -d -r` of the target, the source of every immediate the citation check accepts |
| `ledger-x86_64-O1-renamed.symtab.txt` | `llvm-objdump -t` of the target |
| `ledger-x86_64-O1-g.dwarfdump.txt`, `ledger-x86_64-O1-g.abbrev.txt` | `llvm-dwarfdump --debug-info` and `--debug-abbrev` of the ground truth |
| `ledger-x86_64-O1-poisoned.sections.txt` | `llvm-objdump -s` of the two read-only sections of the poisoned object |
| `candidates/<id>.c` | one candidate reconstruction per file, four per target function |
| `candidates/<id>.report.json` | the candidate's report: target, claims, citations, label, tool, cost |
| `candidates/<id>.o`, `candidates/<id>.objdump.txt` | each candidate compiled with the fixture flags, and its listing |
| `runs/scorecards-aarch64-darwin.json` | one run of `python3 code/main.py --save-runs` on an arm64 Mac, the source of the figure data |

Candidates by target and kind:

| Candidate | Target | Kind | Written to represent |
|---|---|---|---|
| `f1_mul_first` | `f1` | correct | the listing in C |
| `f1_wide_long` | `f1` | plausible but wrong | a 64-bit intermediate that skips the 32-bit overflow |
| `f1_base_64` | `f1` | wrong constant | the byte `0x64` read as decimal 64 |
| `f1_safe_div` | `f1` | invented helper | a helper and a message that do not exist, over code that compiles to the original bytes |
| `f2_switch` | `f2` | correct | the original `switch` |
| `f2_thresholds` | `f2` | plausible but wrong | threshold tests with no upper bound, under a different name |
| `f2_case10_wrong` | `f2` | wrong constant | one table entry wrong |
| `f2_clamp` | `f2` | invented helper | a clamp helper and a message that do not exist |

The tests read the committed objects, listings, and the recorded run, so they pass on a host without clang. With clang present they also rebuild every candidate and rerun the grid and the corpus.