feat(il2cpp): validate LineNumberMappings.json before packing it

CHANGELOG.md

@@ -17,6 +17,13 @@ adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
   partial set. See #69.
 
 ### Changed
+- **`debug-files upload --type il2cpp-linemap` validates `LineNumberMappings.json` before packing
+  it.** It is checked as a stream (these files run to tens of MB) against the shape the
+  symbolicator reads, `{cpp_path: {cs_path: {cpp_line: cs_line}}}` with non-negative integer line
+  numbers. A truncated, wrong or otherwise corrupt file now exits 11 naming the file and the
+  problem, in a dry run too, and uploads nothing; it used to upload "successfully" and leave every
+  IL2CPP crash unsymbolicated. The optional top-level `__debug-id__` sentinel is ignored, as the symbolicator ignores it. An empty map is still accepted (with a warning). Integrators that
+  treated this command's success as proof of a usable map can now rely on it.
 - **`--type elf` collects every input before uploading anything.** A corrupt second zip now aborts
   (exit 11) before the first zip uploads, instead of after. A path that does not exist now exits
   10 (input not found) rather than 11; both are in the no-fallback range.

README.md

@@ -69,7 +69,7 @@ Takes one or more paths: AGP's pre-built `native-debug-symbols.zip`, and/or dire
 
 #### Unity IL2CPP — `--type il2cpp-linemap`
 
-Uploads `LineNumberMappings.json` (+ sibling `MethodMap.tsv` / `il2cppFileRoot.txt`) as format `il2cpp-linemap`, keyed by the IL2CPP module UUID(s) (`libil2cpp` / `UnityFramework`). See [`docs/unity-il2cpp-linenumber-mappings.md`](docs/unity-il2cpp-linenumber-mappings.md).
+Uploads `LineNumberMappings.json` (+ sibling `MethodMap.tsv` / `il2cppFileRoot.txt`) as format `il2cpp-linemap`, keyed by the IL2CPP module UUID(s) (`libil2cpp` / `UnityFramework`). The mappings JSON is validated first (`{cpp_path: {cs_path: {cpp_line: cs_line}}}`, integer line numbers, checked as a stream): a truncated or wrong file exits 11 naming the file and uploads nothing. See [`docs/unity-il2cpp-linenumber-mappings.md`](docs/unity-il2cpp-linenumber-mappings.md).
 
 ```sh
 bugsee-cli debug-files upload path/to/Symbols/LineNumberMappings.json \

src/cli/debug_files.rs

@@ -222,7 +222,9 @@ pub enum DebugFileType {
     /// Unity IL2CPP `LineNumberMappings.json` (+ MethodMap / il2cppFileRoot)
     /// bundle. Keyed by the IL2CPP module UUID(s) (`libil2cpp` / UnityFramework);
     /// pass `--uuid` (comma-separated and/or repeated) and/or `--il2cpp-uuid`
-    /// for multi-ABI.
+    /// for multi-ABI. The mappings JSON is validated before anything is packed
+    /// (`{cpp_path: {cs_path: {cpp_line: cs_line}}}` with integer line numbers);
+    /// a corrupt or wrong file exits 11 and uploads nothing.
     Il2cppLinemap,
 }
 
@@ -1437,6 +1439,14 @@ async fn run_il2cpp_linemap_upload(
     let mut already_existed = 0u32;
     for bundle in &bundles {
         let _ = il2cpp_linemap::read_file_root(bundle, il2cpp_root)?;
+        // Corrupt mappings must fail HERE, before anything is packed or sent.
+        let mappings = il2cpp_linemap::validate_mappings(&bundle.json_path)?;
+        tracing::info!(
+            cpp_files = mappings.cpp_files,
+            cs_files = mappings.cs_files,
+            lines = mappings.lines,
+            "validated the line-number map"
+        );
         tracing::info!(
             path = %bundle.json_path.display(),
             uuids = ?uuids,