The self-hosted compiler crashed with SIGSEGV when processing files
that generated >=256 parser diagnostics (e.g. truncated source files).
The parser allocated a fixed-size diag buffer of 256 entries, but
parserExpect, parserExpectIdentOrKeyword, and parserEmitDiag wrote
into it without checking bounds. Once diagCount exceeded 256, writes
overflowed into adjacent heap objects (Decl structs), corrupting
their kind/childDecl2 fields and causing crashes during AST traversal.
This fix adds bounds checks to all three sites so excess diagnostics
are silently dropped rather than corrupting memory. The file size
threshold (7037 vs 7062 bytes) was a red herring — it determined
how many parser errors were generated before EOF.
Closes: selfhost segfault on 250+ line files
- Fix lexer unterminated char error test (was treating 'a as lifetime)
- Fix parser test sample.bux path for root-dir execution
- Add bux_system() to runtime.c and run command to selfhost CLI
- Switch bux_alloc from malloc to calloc for zero-init
- Fix module flattening in Cli_Check/Cli_Compile to scan full decl list
- Make test passes fully, selfhost builds successfully
- README.md: drop 'inspired by Rux' and 'improves on Rux' language
- PLAN.md: remove Rux from comparison table, milestones, and appendix
- PLAN.md: delete entire Appendix A (Rux Language Reference)
- docs/PHASE8_STRATEGY.md: rephrase without Rux
- docs/Packages.md: drop 'Compatible with Rux.toml spec'
- Parser_Parse: add beforePos safeguard to skip unrecognized tokens
instead of looping forever when parserParseDecl returns null
- Lexer: increase maxTokens 4096 -> 32768; add explicit break on limit
- CLI: null-check ReadFile result before String_Eq
- Nim CLI: add -O2 to cc invocation for faster self-hosted builds
- Fixed module flattening in self-hosted compiler (Cli_Compile now unwraps module wrappers)
- buxc2 check now finds functions in module-wrapped files (token.bux: funcCount=6, Main.bux: funcCount=2)
- Added debug prints to trace lexer.bux timeout and check x segfault
- Remaining issues: lexer.bux hangs in self-hosted pipeline, check x segfaults in runtime
- Added exprSpawnAsync flag to AST ekSpawn
- Sema checks if callee is async and sets the flag
- HIR hSpawn carries spawnAsync flag
- C backend uses bux_task_spawn for non-async (OS threads) and bux_async_spawn for async (coroutines)
- Added concurrency example to test suite
- T[] slices are now fat pointers {data: T*, len: size_t} in C backend
- Added hSliceIndex HIR node for slice indexing (distinct from hIndexPtr for raw pointers)
- Added exprIndexBoundsCheck flag to AST ekIndex
- Sema sets bounds-check flag in @[Checked] functions
- C backend emits Slice_<T> typedefs and compound literals for slice init
- bux_bounds_check() called automatically on slice indexing in @[Checked] funcs
- Unchecked functions allow raw access (C behavior) for performance
- Lexer tokenizes 'a as tkLifetime
- Parser accepts lifetimes in type params <'a> and reference types &'a T / &'a mut T
- AST TypeExpr has refLifetime field for tekRef/tekMutRef
- TypeParam gains isLifetime flag for generic monomorphization
- Sema infers lifetime params as no-op dummy values; unwraps pointee types for params inside refs
- HIR lower skips lifetime params when generating mangled names and substitution tables
- &mut expr syntax supported in parser (consumed as part of unary &)
Self-hosted compiler (buxc2):
- Add async/await/spawn tokens, parsing, HIR, lowering, C emission
- Fix pointer type emission (*T -> T*) in C backend
- Fix sizeof(Type) parsing with parentheses
- Fix import ::{...} infinite loop guard
- Fix int64 emission by avoiding else-if chain workaround
- Add debug-free cli and hir_lower
Bootstrap compiler (Nim):
- Fix critical else-if lowering bug in hir_lower.nim:
when both elseIfs and else block exist, elseIfs were dropped
causing all else-if chains to collapse to if+else only
Runtime:
- Fix bux_async_await memory corruption (don't free in run)
- Add bux_remove_from_ready for safe cleanup
- Fix forward declaration and deduplicate bux_now_ms
Docs & examples:
- Update async.bux example with proper int64 params
- Update README, LanguageRef, Stdlib, PLAN for async features
- Mark Phase 7.10 bootstrap loop as completed
All 27 examples pass. buxc2 check/build work on all examples.
- runtime: bux_async_return(value, size) copies result to task->result
- runtime: bux_async_await returns void* result pointer
- runtime: bux_async_result(handle) to retrieve result
- sema: ekAwait returns *void
- HIR: await lowered to bux_async_await returning *void
- Example: async Compute() -> int with interleaved execution and result await
Parser (src_bux/parser.bux):
- Increased struct field limit from 8 to 64
- Added field4-field7 slots in struct field assignment
- Safeguard: fields beyond slot 7 are parsed but not stored (counted only)
Known issues:
- buxc2 segfaults on ast.bux (Decl struct has 30+ fields, sizeof mismatch
between Bux parser's Decl and C compiler's Decl)
- Full bootstrap requires Decl struct in ast.bux to match actual Decl layout
All 18 examples pass, all unit tests pass.
Lexer (src_bux/lexer.bux):
- Rewrote lexSkipWhitespace to use nested if/else instead of else-if
chain (workaround for Nim C backend else-if lowering bug)
- lexPeek: mask with & 255 for UTF-8 signed char bytes
Known: buxc2 project build hangs on ast.bux parsing (infinite loop).
buxc2 single-file build works correctly with else-if.
All 18 examples pass, all unit tests pass.
Parser (src_bux/parser.bux):
- Block stores statements as linked list (firstStmt/lastStmt/nextStmt)
- Block struct: added firstStmt, lastStmt fields
- Stmt struct: added nextStmt field
HIR Lowering (src_bux/hir_lower.bux):
- Lcx_LowerBlock: iterates statement linked list, chains HirNodes via child3
- hIf: else block stored in extraData (child3 reserved for block chaining)
C Backend (src_bux/c_backend.bux):
- hBlock: emits statements via child3 linked list with proper indentation
- hStore: combines alloca + value into single declaration (int x = value;)
- hIf: full if/else emission with proper newlines
- Function decl: proper return types and parameter types (not just "int")
- int main() wrapper: generated when Main function exists
- No duplicate return 0 when body already has return
Tested:
- buxc2 compiles hello world program → runs correctly
- buxc2 compiles multi-statement program (let, if, function calls) → runs correctly
- All 18 examples still pass, all unit tests pass
Runtime:
- bux_argc()/bux_argv() — command-line arg access from Bux programs
- g_argc/g_argv globals — set by C main() wrapper
Compiler:
- C backend generates extern g_argc/g_argv + int main(argc,argv) wrapper
- main.bux reads args via bux_argc/bux_argv and passes to Cli_Run
buxc2 verified:
- buxc2 version — reads CLI args correctly
- buxc2 check <file.bux> — lexes, parses, type-checks, generates C
- buxc2 build <file.bux> <output.c> — writes C output
PLAN.md updated with Phase 7.10 status and remaining work.
All 18 examples pass, all unit tests pass.
dimgigov