0.5.1

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 ex...

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0.5

V 0.5.0

31 Dec 2025

Improvements in the language

• Add comptime if is shared support (fix #25600) (#25602)
• Make defer{} scoped by default, use defer(fn){} to get the old behavior #25639) (#25665)
• Add gotodef support for nested struct members, fn return types, etc (#26131)
• Add a new v.comptime stage COMPTIME, that runs after the checker (CHECK), and before the transformer (TRANSFORM), to simplify the work that later stages do #26068 (#26161)

Checker improvements/fixes

• Correctly detect variadic arg passed to struct fn (fix #25504) (#25509)
• Fix $(field.name) access on closure fn (fix #25513) (#25514)
• vls: skip unrelated files (#25531)
• Fix mutability in for in loops with pointer values (fix #25520) (#25536)
• Fix type inference, when pushing an empty array to a 2D array (fix #23854) (#25508)
• Prevent array.insert for array of references when non-reference is passed (fix #25511) (#25557)
• Add more support for mod autocomplete, allow for .vv files too (#25562)
• Fix cast from an empty struct to option (fix #25566) (#25581)
• Ensure ?Struct is not parsed as ??Struct when param is ?T (fix #25559) (#25564)
• Fix if branch type nr_muls mismatch (fix #25556) (fix #25555) (#25571)
• Fix comptime else branch handling (fix #25586) (#25589)
• Smart detect or {} inside loop when using c <-val (fix #24550) (#25435)
• Vls fix goto definition (#25595)
• Fix generic resolve for external module generic static method call (fix #21476) (#25634)
• Correctly detect type, when prepending to generic array (fix #25585) (#25645)
• Allow cast from voidptr to sumtype in unsafe block (fix #25652) (#25657)
• Disallow calls to a shared receiver method, on a non-shared var (fix #25577) (#25656)
• Fix or block endwiths expr (fix #25329) (#25667)
• Set ast file fallbacks for vls (fix #25678) (#25679)
• Error/warn when using defer(fn) inside function-scope and lock stmts (#25681)
• Maintain correct ref level in generic fn (fix #25676) (#25687)
• In vls mode, make ensure_type_exists return true (#25695)
• Only collect/hoist inner vars, when defer is function-scoped (#25693)
• Improve type checking for sumtypes with generics (fix #25690) (#25699)
• Unwrap for base type if ft.typ and inferred_typ are both opt (fix #25517) (#25728)
• Disallow deference of nil (fix #25740) (#25746)
• Fix comptime main fn (#25747)
• Parser,fmt,checker: use a trie for matching the generic array methods all, any, count, filter, map, sort and sorted (#25759)
• Fix array fixed unresolved return check and resolver (fix #25774) (#25790)
• Allow explicit sumtype to option casts (fix #25796) (#25812)
• Fix possible race on expected arg types unwrapping on cgen (#25815)
• Skip init check for options (fix #25798) (#25830)
• Fix module var set at change_current_file() (fix #25845) (#25846)
• Improve handling of array decompose for dynamic arrays and array init (fix #25838) (#25843)
• Force all fn declarations to follow after all other top level statements (fix #25889) (#25890)
• Fix used features tracking when printing pointer values (fix #25899) (#25901)
• Match type when auto deref occurs (fix #25913) (#25916)
• Relax the redundant () check to a notice, to enable a future v -W test vlib/builtin job on the CI
• remove () from match branch exprs (fix #25950) (#25952)
• Fix array map anon fn return fixed array (fix #25928) (#25977)
• Cleanup the output of v new --web abcd after feedback from https://youtu.be/IuE6Bo1klK0?t=555
• Allow assign to a shared int var (fix #25986) (#25988)
• Ensure type of global exists (fix #25910) (#25998)
• Ensure fn pointer cannot be used as non-fn argument (fix #26017) (#26022)
• Make sure $for eval body statements at least once to set types and avoid markused issues later (fix #26058) (#26063)
• Fix return static method name (fix #26105) (#26110)
• Support gotodef for struct init and sumtype rhs (#26157)
• Detect circular type references in sumtype declarations (fix #24511) (#26162)
• Add interface type handling and new testcase (fix #24116) (#26165)
• Allow enum fields to reference previously declared fields (fix #25241) (#26173)
• Clear all ref from autostr receiver_type (needed by #25857) (#26202)
• Allow for _ being used as both import x as _ and fn f(_ int) { (fix (#26219) #26230

Parser improvements

• Fix vls mode strut mut keyword (fix #25548) (#25551)
• Fix vfmt comment in struct init after the update expr (fix #24361) (#25668)
• Fix infix expr comment in middle (fix #24183) (#25671)
• Disallow using generic functions as a field type name inside struct decl (fix #25452) (#25705)
• Warn on @[deprecated_after] used without a corresponding @[deprecated] attribute (#25712)
• Fix last stmt is fn call in or_expr (fix #25732) (#25739)
• Allow for |mut x, y|expr (fix #25734) (#25735)
• Allow using a, b and it as var names, when using the builtin array methods (fix #25729) (#25755)
• Disallow generic function to be exported (fix #25794) (#25806)
• Support -d trace_parse to ease diagnosing problems related to the order of parsing of .v files in modules
• Fix the language support for a nested anonymous C.struct (fix #25807) (#25789)
• Disallow untyped chan used as a fn parameter type (fix #25818) (#25854)
• Improve the unused import warning message (add fixing alternatives) (#25880)
• checker,parser,ast: make type MyBuilder = strings.Builder work (part 1); add mod fields to ast.SumTypeDecl and ast.AliasTypeDecl (#25943)
• Remove dead code in Parser.is_array_type/0 (#26080)
• Check invalid struct name in struct_init() (fix #26030) (#26093)
• Remove the support for the obsolete generic fn call syntax f() (first deprecated in 2022/11) (#26126)
• Fix comptime for lock shared field (fix #26143) (#26146)
• checker,parser: add multifile gotodef support for -line-info (#26167)
• Optmize Parser.call_kind (#26196)

Compiler internals

• markused: fix markused struct heap (#25542)
• markused: fix array.prepend C code dependency (fix #25573) (#25582)
• markused: fix fn marked as used when variable and fn uses same name (fix #25649) (#25650)
• checker,transformer: add always true/false branch detection for the if and match constructs (#25674)
• v.util: measure more precisely how long a new tool recompilation lasts in launch_tool, when using v -d trace_launch_tool self
• transformer: fix struct init comparison turning into boolean (#25724)
• v.builder: support V_NO_RM_CLEANUP_FILES=1, to ease debugging of -usecache issues
• v.builder: make it easier to reproduce the exact specific stages of -usecache module compilation by logging the full CLI options for each
• v.builder: fix .vsh mode doing an implicit import os, now only for .vsh file itself (fix issue spotted in #25736) (#25745)
• v.builder: improve diagnostic information for a failed build_thirdparty_obj_file
• transformer: transform ArrayInit into a function call for C and native backends (part 1)
• builder,pref: add -file-list support (implement feature #25707) (#25749)
• pref: for -usecache, set .parallel_cc = false and .no_parallel = true to make compilations more deterministic and ease CI diagnostics
• markused: fix missing builtin__memdup definition, when an option struct field is used (fix #25801) (#25802)
• transformer: move array logic to array.v
• v.builder: improve the error message for failing cgen; suggest -g and -show-c-output
• v.pref: fix GitHub download URL for the photonwrapper .so file (fix #25708) (#25831)
• v.pref: use v download for downloading the prebuilt photonwrapper shared library (#25849)
• markused: fix const as fn mark as used (fix #25888) (#25895)
• transformer: disable generic str_intp opt (fix #25896) (#25897)
• v.scanner: remove obsolete .is_crlf and .is_vh fields (#25918)
• v.scanner: use a named return for decode_XXX_escape_single methods, to reduce the generated C diff churn, during scanner code updates
• markused: add new auto_str() used funcs for bootstrap (#25938)
• v.builder: provide more detailed error message, on msvc: failed to build a thirdparty object, not just the failed command
• v.builder: improve formatting of the failed to build a thirdparty object message for msvc
• scanner: remove old generic check logic (fix #25959) (#25997)
• transformer: fix the setting of a generic flag for fixed array type with -new-transformer (#26009)
• transformer: add file/line info for fn with expand_simple_interpolation (#26135)
• transformer: add early return to avoid transform getting applied twice for a for x < y { body (#26153)
• markused: fix option none markused (fix #26147) (#26151)
• v.builder: enable gc back with msvc, build separate .debug.obj thirdparty files when -g is passed, to prevent linking issues (#26215)
• v.builder: support compiling asm .S files to .o files, mentioned in #flag directives (needed for #26185) (#26211)
• v.builder: fix compile asm file, followup of PR #26211 (#26227)

Standard library

• arrays: fix rotate_left() and rotate_right(), add test (#25539)
• encoding.base58: fix encoding, add test (#25538)
• x.crypto.chacha20poly1305: move up responsibility for allocs into higher caller (#25574)
• crypto.cipher: fix decryption in CBC mode, add test (#25584)
• os: use @[noinline] on os.create/1 to workaround a -cc gcc -prod panic (fix #25549)
• time: fix non-digit checks for parse_rfc3339() (#25597)
• gg: add explicit bounds checking for image caching methods in gg (fix #25590) (#25591)
• time: fix quarter calculation in custom_format() (#25608)
• rand: fix randomness in shuffle() (#25617)
• gg: destroy unused GPU resources before replacing cached images (#25615)
• encoding.binary: fix serialize skip struct shared fields (related to issue #25600) (#25613)
• x.crypto.chacha20poly1305: make implementation use fixed sized arrays more (#25627)
• builtin: make result stri...

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