V 0.5.1

9 Mar 2026

Improvements in the language

• New clean and fast v2 backends: cleanc (similar to the old C backend), ssa/arm64, ssa/amd64. cleanc backend can already self host!
• Add a new generic solver stage (gated behind -new-generic-solver) (#26280)
• Refactor $var to ${var} across entire repository, make vfmt always output the newer form ${expr} (#26494)
• Fix support for match exprs with nested if exprs (#26599)
• Add OS-specific headers support for #include directives (#26654) (fixes #26562)

Checker improvements/fixes

• Fix compiler panic on wrong arg count with or block (#26665)
• Support gotodef for fn param and []Type (#26193)
• Error for unwrapped option/result types used with in operator (fix #26208) (#26223)
• Expand @VEXEROOT, @VMODROOT, DIR, $d(), $env() inside $embed_file(path) too (#26319)
• Fix global empty const type check (fix #26324) (#26332)
• Add error message call stack support (requested by #16127, #24575, etc) (#26356)
• Fix option in struct member infix expr and swapped none comparion (fix #26351) (#26373)
• Disallow foo()? == foo where foo returns !string (fix #26383) (#26403)
• Unset @VCURRENTHASH for V build/bootstrapped outside of a Git repository (fix #26407) (#26426)
• Check generic struct fields and initialisation (fix #26433) (fix #26436) (#26450)
• Preserve mut in other non-none if branch (fix #26491) (#26495)
• Fix sql statement using an unwrapped option value from an if guard (fix #26496) (#26505)
• Add type checking for param of fn passed as generic arg (fix #26195) (#26257)
• Add warning for fn f(x u8) {} f(999) (fix #26584) (fix #26585) (#26586)
• Add passes for top level decls (fix #26306) (#26589)
• Avoid panic on unresolved infix operand types in -check (fixes #26458) (#26607)
• Fix shared array slice type with implicit clone (fixes #26663) (#26666)
• Fix autofree crash with option/result method chains (#26694)

Parser improvements

• Disallow [3]!int{} (fix #26244) (#26249)
• Get correct generics for generics struct fn with generic param (fix #26191) (#26251)
• Fix dump() free bug for v.ast.TypeSymbol (fix #26282) (#26283)
• Disallow [T] as fn return type (#26530)
• Show where another declaration is located (fixes #26483)
• Fix pub: not being detected in structs in -vls-mode (#26581)
• Fix anonymous function name collisions across files (#26642)
• Remove @[minify] from structs with enum fields (#26661)

Compiler internals

• v.comptime,v.generics: unwrap receiver type, support more generic comptime exprs (#26350)
• v.generic: improve new generic stage, unwrap generic ident info, set ct_expr to false if solved, update receiver_type generic flag (#26366)
• v.generics: improve the new generics stage, by fixing unwrapping in nested generic struct, also fix suggestions from previous PR (#26430)
• table: fix generics crash (fix #26438)
• markused: add array method map and filter support (fix #26233) (#26238)
• v.pref: exit early with an error message, if coroutines are not supported yet on the current platform, instead of producing a cgen error (#26342)
• builder: fix compile error message for -m32 (fix #16639) (#26353)
• v.builder: add -stats for top level statements and non-vlib top level statements (#26451)
• v.pref: improve musl detection; fixes __atomic_thread_fence for all musl nixes (fix #26449) (#26460)
• v.builder: always apply -fno-strict-aliasing too, on -cc gcc -prod to avoid the need for the -cflags -fno-inline-small-functions workaround with gcc > 12.0 (fix #26512) (#26552)
• v.scanner: optimise ident_dec_number, ident_oct_number, ident_hex_number, by using precomputed digit_table and letter_table consts, instead of u8 method calls
• v.scanner: eliminate str_helper_tokens changes outside string interpolation (fix speed loss after 106da40)
• markused: add typ==0 guard for MapInit to fix panic in comptime $else branch (#26652)

Standard library

• builtin.closure: improve ppc64le closure if PIE (#26172)
• rand.xoroshiro128pp: prevent generation of extra zeros in u16() (#26229)
• thirdparty: fix tcc __atomic_thread_fence (fix #25856) (fix #26158) (#26185)
• builtin.closure: use volatile register for s390x (fix #24383) (#26256)
• thirdparty: update zstd patch with commit 8aa0369 (#26312)
• regex.pcre: add non-greedy quantifiers like *?, +?, ?? (fix #26579) (#26582)
• regex.pcre: optimise for speed the PCRE implementation (#26609)
• atomic: and/or bitwise ops (#26646)
• x.json2: add a strict: true mode for x.json2.decode(), that rejects string-to-number type casting during decoding (fix #26082) (#26220)
• builtin: add array.last_index() (#26252)
• bitfield: fix pop_count(), add test (#26262)
• io: deprecate the io.string_reader module (not used in vlib, with confusing and under tested/documented API - see #25713 ) (#26274)
• time: add Duration.times/1
• os: add Pipe.write_string/1 (#26286)
• gg: add .draw_ellipse_filled_rotate and .draw_ellipse_empty_rotate APIs (#26309)
• gg: add draw_ellipse_thick and draw_ellipse_thick_rotate (#26327)
• os: fix args quoting in win_spawn_process (fix #26261) (#26339)
• gg: optimize ellipses draw functions (#26340)
• gg: text_width_f
• math: fix acosh() for 0.0 (#26360)
• math: rewrite round() to match closely the Go version (and mpfr's one), update test (#26381)
• gg: optimise the draw_rounded_rect_filled function (#26390)
• os: add missing is_opened checks to File.read* functions (fix #26096) (#26413)
• x.json2: add @[json: name] attr support for enum values (fix #26437) (#26441)
• x.json2: rename Any.arr() to Any.as_array() for consistency with as_map(), as_map_of_string(); deprecate Any.arr() (#26455)
• breaking,x.ttf: extract vlib/x/ttf/render_sokol_cpu.v in a separate module x.ttf.render_sokol, to enable headless programs, that do not use gg, to not depend on OpenGL, DX12, Metal etc, through sokol (#26477)
• crypto.blake3: add @[direct_array_access] and improve f() performance (#26480)
• crypto.rc4: add @[direct_array_access] (#26507)
• x.crypto.slhdsa: fix slh signature testing on latest version (fix #24086) (#26519)
• crypto.pbkdf2: replace a panic with an error return (#26526)
• regex: fixed missing OR operation on anchor flag (#26540)
• regex: new PCRE compliant regex submodule written in pure V, available through import regex.pcre (#26545)
• x.json2: fix decoding wrong value depending on field order (fix #26503) (#26571)
• crypto: add shake128 and shake256 entries into crypto.Hash enum (#26576)
• vlib: add x.atomics - implement native_x86-64_atomics in V and assembly, without depending on an external C library (impl #26474) (#26529)
• os: use _dyld_get_image_name() to increase compatibility with older versions of Mac OS X like 10.4 (#26617)
• crypto: move up AEAD interface from experimental namespace to cipher.AEAD (#26632)
• builtin: fix camel_to_snake underscore placement in uppercase runs (#26634)
• time: parse_http_header_string (#26636)
• flag: add DocOptions/Show to FlagParser (#26630)
• runtime: fix issues with nr_cpus() (#26679)
• thirdparty,sokol: add wayland support (#26682)
• thirdparty,sokol: fix frame pacing issues on xwayland sessions, prevent sending some keycode events on wayland (#26706)

Web

• net: add raw sockets support (implement feature request from #19565) (#26237)
• veb: remove 2 clones of response bodies; reduce the GC load for the most common case (fix #25423) (#26236)
• wasm: support basic match keyword handling (#26246)
• wasm: fix infinite loop using continue in C-like for loops (#26250)
• wasm: add basic for x in start .. end { support (#26248)
• wasm: implement basic string operations (#26260)
• veb: fix double-send error when after-middleware sends response (#26270)
• builder,wasm: fix pointer size to 4 for -b wasm before the checker stage (#26281)
• wasm: support basic string interpolation (#26288)
• wasm: fix string plus assign with call expr (#26287)
• wasm: handle for in strings and FixedArrays (#26290)
• wasm: support WASI program arguments and IO functions (#26294)
• net.mbedtls: increase default timeout to 10s (like in Go): 550ms was too low
• net: add jsonrpc module (#26330)
• fasthttp,veb: static files via sendfile
• wasm: fix size of pointers in structs (#26357)
• thirdparty.mbedtls: upgrade to v3.6.5 (#26365)
• wasm: only compile .wasm.v, and platform independent .v files (#26386)
• fasthttp: fix sendfile (#26402)
• wasm: add run support with wasm-micro-runtime/iwasm (#26417)
• veb: fix unset Content-Length header, in responses with an empty body (#26431)
• veb: fix error lines for html templates via source to source mapping
• net.http: enable test for relative redirects (#26513)
• fasthttp: fix IPv6 support (fix #26548) (#26549)
• mbedtls: better ux around client timeout by mentioning the mbedtls_client_read_timeout_ms flag (#26574)
• Document $veb.html() too in the compiler error messages, as a known comptime function (#26605)
• fasthttp: remove zero-byte initialization in read buffer #26640
• net.http: stop reading after Content-Length bytes on keep-alive responses (#26669)

ORM

• Add explicit JOIN support (INNER, LEFT, RIGHT, FULL OUTER) (fix #21635) (#26400)
• Support embedded structs
• Make work with generic structs
• Fix generic struct creation inside a generic function
• Resolve generic inserting object type
• Cgen bug fix (fixes #25847)
• Handle inserting enum fields (#26680)
• Add aggregate function support (#26697)
• Add transaction API with savepoint-backed nesting (#26707)

Database drivers

• mysql: use correct link flag for both tcc and msvc (#26539)
• pg: exec_no_null(); gx: remove deprecated test; parser/tmpl: %raw translations; veb: time_to_render()
• fix(db.sqlite): replace vstring() with tos_clone() to prevent use-after-free (#26700)
• feat(db.sqlite): add Row.names, get_string/get_int, and improve exec_map (#26702)

C backend

• Fix multi dim fixed array with opt elem (fix #26243) (#26258)
• Fix array.contains() when right is ref (fix #26253) (#26255)
• Ast,checker,cgen,parser: fix comptime $if assign expr (fix #26061) (#26242)
• Promote non generic sumtype pointer initialiations to the heap too (#26285)
• Fix generic function error propagation type mismatch (fix #26263) (#26295)
• Fix interface pass string ref arg (fix #26293) (#26296)
• Fix shared array assigned call expr with fixed array (#26320)
• Fix fixed array of option with different size (#26326)
• Fix call with fixed array of builtin struct (#26328)
• Fix array init with option array (fix #26329) (#26331)
• Fix alias indent (fix #26272) (#26333)
• Fix chan autostr (fix #26337) (#26338)
• Transformer,markused,cgen: fix some problem for array init when use -new-transformer (#26341)
• Fix -assert backtraces after e317c63
• Fix for function-like macro '_BIONIC_AVAILABILITY_GUARD' which is not defined in older termux releases (#26345)
• Fix empty shared struct init (fix #16234) (#26354)
• Add rv32 inline assembly support (#26362)
• Fix fn arg for struct nested fields (fix #26346) (#26349)
• Fix += overloading for aliases, regression after 29e60da #23967 (fix #26416) (#26423)
• Fix unused functions returning fixed arrays of custom structs (fix #26439) (#26440)
• Fix or-block with fixed array constants with GCC 15.2 (fix #26442) (#26443)
• Fix uninitialized interface bug (closes #17372)
• Fix regression in ./v test vlib/toml after 38ac4e6 (#26485)
• Fix generation of struct initialisers for structs with option fields, inside ternaries (fix #26476) (#26493)
• Fix the saving of g.skip_stmt_pos and g.stmt_path_pos when generating anonymous fns (fix #26498) (#26508)
• Fix generic type handling bugs
• Fix -autofree used for code doing "string ${f(@VEXE)} interpolation" (#26521)
• Fix multi-return match in closure (fix #26558) (#26566)
• Fix alias for interface and option types (fix #26551) (#26565)
• Autofree fix generic math.min[T] used with time.Time (fix #26575) (#26577)
• Fix extra dereference when indexing array of fns passed by pointer (fix #26556) (#26591)
• Fix orm shared conn on sql expr (fixes #26479) (#26610)
• Fix comptime match assign in generic fn, T.name string intp (fix #26053) (#26597)
• Fix bit-field generation for option/result types in minified st… (#26670)
• Use unsigned int for enum bit fields or unspecified size in @[minify] structs (#26678)
• Fix auto-deref var in autofree string re-assignment (#26689)

vfmt

• Fix parser failing on duplicate methods in $if/$else blocks (fix #26271) (#26278)

Tools

• vwatch: fix process handle leak in kill_pgroup() (#26269)
• vwatch: fix -o short flag conflict that broke hot reload (fix #26221) (#26277)
• vcomplete: add git-fmt-hook command (#26396)
• vrepl: fix handling of // inside string literals (fix #25603) (#26240)
• v.help: add help for git-fmt-hook tool (#26394)
• Add support for v missdoc @vlib
• Add support for v quest
• Add support for v install --local gui
• Support .vcheckignore pattern files for v check-md . (#26623)

Operating System support

• msvc: split multi-token -I/-L values from pkg-config (#26637)
• wasm: fix path separator in windows (#26264)
• time: fix overflow in time.sys_mono_now() on windows (#26273)
• sokol: fix errors for audio unsupported on OpenBSD (fix #26299) (#26305)
• db.pg: improve support on OpenBSD (#26316)
• os: fix get_raw_line for EOF on OpenBSD (fix #26361) (#26368)
• Add support for vgit-fmt-hook on OpenBSD (fix #26344) (#26388)
• builtin: use -Xlinker flags on macos, for compilers != tcc, to pass the rpath folder (fix for folders with spaces)
• builtin: fix for tcc builds on paths with spaces on linux
• os: implement readlink/1 on !windows (#26405)
• builtin: fix compilation with tcc on OpenBSD using libgc (fix #26447) (#26448)
• fasthttp: multi threading fix reads in the socket in linux (#26478)
• time: prevent linux time functions from being included in non-linux platforms (#26596)
• Fix hanging when printing to console in a -subsystem windows executable (#26572)
• builder: fix Windows pkgconfig paths and MSVC flags (#26631)
• net.vschannel: chunk large TLS payloads to fix 16KB EncryptMessage crash on Windows (#26681)

Examples

• examples,strings: add a new strings.lorem module; use it in the Markov chain text generator example (#26387)
• Add examples/gg/pong/pong.v (#26528)
• Improve pidigits.v using a much faster spigot algorithm
• sokol: fix v run examples/2048/ on macos (regressed after 5d6de17) (#26705)