slang-code-reader

name	slang-code-reader
license	MIT
description	Read-only investigation of the Slang compiler codebase. Navigate source, trace compiler pipelines, understand architecture.
provides	["code.read","doc.read"]
allowed-tools	Bash, Read, Grep, Glob, mcp__deepwiki__ask_question

From project

Drawn from: repos/slang/CLAUDE.md (architecture overview, development workflow), repos/slang/.claude/agents/code-quality-reviewer.md (consistency checks, semantic checker patterns, unchecked casts), repos/slang/.claude/agents/cross-backend-reviewer.md (emit parity, sibling emitter grep), repos/slang/.claude/agents/ir-correctness-reviewer.md (SSA invariants, pass ordering, type legalization), repos/slang/.claude/agents/documentation-accuracy-reviewer.md (doc drift, stale comments), repos/slang/.claude/agents/security-code-reviewer.md (memory safety, UB, input handling), repos/slang/.claude/agents/test-coverage-reviewer.md (regression test requirements, test quality).

Compiler pipeline

Lexer (compiler-core/slang-lexer.cpp)
  -> Preprocessor (slang/slang-preprocessor.cpp)
    -> Parser (slang/slang-parser.cpp) -- recursive descent, produces AST
      -> Semantic Checker (slang/slang-check.cpp) -- type checking, name resolution
        -> IR Generation (slang/slang-lower-to-ir.cpp)
          -> IR Passes (slang/slang-ir-*.cpp) -- optimization, lowering
            -> Code Emission (slang/slang-emit-*.cpp) -- target-specific codegen

Key search strategies

• Emitters: source/slang/slang-emit-*.cpp -- SPIRV, HLSL, GLSL, Metal, CUDA, WGSL. When investigating one emitter, always grep sibling emitters for the same pattern.
• IR passes: source/slang/slang-ir-*.cpp. IR instructions defined in slang-ir-insts.lua. Generated enum: build/source/slang/fiddle/slang-ir-insts-enum.h.fiddle.
• Semantic checker: source/slang/slang-check-*.cpp -- overload resolution, generic constraints, witness tables.
• Type legalization: slang-ir-spirv-legalize.cpp, slang-legalize-types.h, slang-ir-lower-buffer-element-type.cpp.
• Standard library: prelude/ and source/slang-core-module/ -- built-in functions, *.meta.slang.
• Public API: include/slang.h -- COM-style vtable interfaces. ABI-stable.
• Tests: tests/ -- .slang files with test directives.

Review checklists (from project agents)

When investigating code, apply these domain-specific checklists:

Code quality: Verify consistency across similar locations -- new IROp in some switch statements but missing from others, null checks on as<T>() calls, new backend in dispatch tables. Check unchecked casts, missing switch cases, emit code doing transforms that belong in IR passes.

Cross-backend: When a change touches slang-emit-*.cpp, immediately grep all sibling emitters. Flag complex transforms in emit that should be IR passes. Check capability requirements, resource binding compatibility, target-specific legalization.

IR correctness: Verify SSA form (use-def chains, phi nodes). Check pass ordering -- new passes at correct pipeline position. Validate type legalization (mixing data and resources in structs). Check slang-ir-insts.lua definitions.

Security/UB: Null pointer after as<T>() casts, out-of-bounds array access, use-after-free from IR instruction deletion, signed integer overflow, uninitialized variables, input sanitization for paths and preprocessor directives.

Test coverage: Bug fixes must have regression tests. New features need .slang test files. Use CPU or INTERPRET directives for no-GPU environments. Verify filecheck patterns, not just compilation.

Documentation: Check for stale inline comments near changed code. Verify include/slang.h function comments match behavior. Check docs/user-guide/ for feature coverage.

DeepWiki

For architecture questions about the upstream repo:

mcp__deepwiki__ask_question("shader-slang/slang", "your question here")