UniDecompiler Pseudocode for VS Code

This extension provides a permissive VS Code language mode for the generic pseudocode emitted by UniDecompiler.

It intentionally does not try to make the output valid Python, JavaScript, Lua, Java, or C#. The output is a VM-neutral mixture of function blocks, structured control flow, low-level labels/gotos, and explicit recovery helpers.

Included features

• TextMate syntax highlighting for the generic pseudocode vocabulary.
• UniDecompiler-aware coloring for function declarations and function-value references (<function func_N>), parameters, local/generated variables, dotted members, constructor/type positions, labels/gotos, recovery helpers, CFG markers, literals, strings, and comments. The grammar only colors categories that can be established from syntax; ambiguous names remain ordinary identifiers.
• Bracket matching and folding for brace-delimited regions.
• Outline entries for functions (labels remain available to navigation but are intentionally not top-level outline items).
• Same-name definition lookup for functions, parameters, local let bindings, and labels.
• Same-name reference lookup for calls, variables, and goto targets.
• Label declarations and goto targets use the same symbol range (the declaration colon is excluded), so Find All References works from either side without adding labels to the top-level Outline.
• Hover information for indexed names.
• Optional sidecar metadata support. When a matching <pseudocode-file>.unidec.json is present, hover also shows the mapped VM instruction, function ID, VM offset, and proven artifact byte range.
• A VM @offset status-bar item appears while the cursor is inside a mapped pseudocode range. Click it, or run UniDecompiler: Show VM Instruction Metadata, to display the complete mapped instruction.
• UniDecompiler: Refresh Pseudocode Index command.
• Function and VM-instruction navigation, sidecar diagnostics, and a read-only artifact hex viewer when a proven byte range is available.
• Optional heuristic CFG/structure summaries, workspace search commands, and configurable CodeLens/multi-file indexing support.
• UniDecompiler: Show Heuristic CFG opens a read-only interactive Activity Bar view with clickable control-flow nodes, direction arrows, and edge kinds. UniDecompiler: Show Heuristic Structure opens a clickable nested tree. UniDecompiler: Show Call Graph opens a one-hop callers/current/callees graph. Clicking a node reveals its source range in the pseudocode editor. These views update in the background and do not steal focus from Explorer or Search; only an explicit Show command focuses the requested UniDecompiler view.
• Read-only Hex is an Activity Bar view linked to a proven artifact byte range. Bytes can navigate back to pseudocode source-map ranges, and selecting a mapped pseudocode instruction updates the Hex highlight. The artifact is never modified. If no reliable byte_range exists, the extension does not guess one. Selecting a pseudocode function updates the view to that function's first reliable mapping; when the sidecar has byte ranges but no trusted artifact path, use the explicit Select artifact file action to choose the original file without any metadata-derived path guess.

The indexer is deliberately tolerant. Compiler-generated names such as <>1__state, <member>, .ctor, and order_tmp_12 are treated as names. Unknown syntax remains visible as ordinary text instead of producing parser errors.

The extension does not send pseudocode, sidecars, artifacts, absolute paths, or function IDs to a remote service. UI labels shorten path-shaped IDs by default; full IDs are shown only when unidecompiler.showFullFunctionId is explicitly enabled by the user. Published extension files contain only the compiled extension, grammar, configuration, README, and license.

File associations

The language is registered for UniDecompiler's current .pse export suffix, the legacy .pseudo, .pseudocode, and .unidec suffixes, and files ending in .pseudocode.txt or .pseudo.txt.

Matching sidecars are grouped under their pseudocode file in Explorer using VS Code's native file nesting. For example:

Advanced.pse
└── Advanced.pse.unidec.json

This only changes how the files are displayed; it does not rename, merge, or modify either file. The default nesting can be changed with VS Code's explorer.fileNesting.* settings if a workspace wants a different layout.

Build locally

npm install
npm run compile

Then press F5 in VS Code with this directory open to launch an Extension Development Host.

Future metadata integration

The decompiler can optionally emit a sidecar JSON file next to pseudocode, named <pseudocode-file>.unidec.json. The extension discovers this file automatically, validates its schema and SHA-256 binding to the currently open text, and uses its UTF-16 source ranges for instruction hover details. Missing, invalid, unsupported, out-of-bounds, dangling, or stale entries are reported as warnings in Problems while the permissive text index remains the fallback. The sidecar is never required for syntax highlighting or ordinary same-name navigation. CFG and structure views are explicitly heuristic and are not claims about a core AST/CFG.