0.10.0

This release comes with a lot of bug fixes. Most of the new features are linker-script related. You
can see the current status of linker script support in
LINKER_SCRIPT_SUPPORT.md. Another significant feature worth calling out
is support for --gdb-index.

Not much changed in terms of performance. The most notable change was that we now avoid using mmap
on the output file if it's on a btrfs or vfat filesystem, which gives a bit of a speed-up, although
you're still much better off avoiding these filesystems for your builds if at all possible. You can see benchmarks for this release here.

Much porting work has been done. The Wasm port can now link a range of programs. Mach-O still has a
way to go, but can link some very simple programs. We've also started work on adding 32 bit support,
which will make it easier for projects doing embedded work to be able to use Wild.

Wild is starting to get used by some other projects as a library (libwild). This release makes it
possible to use libwild with input and output files in memory.

🚀 Features

• Support evaluating SEGMENT_START with evaluate_expression (#1959)
• Add support for the DISCARD section in linker scripts (#1978)
• Add --discard-sframe flag (#1982)
• Support top-level symbol definitions within the sections command (#2002)
• Support using an expression when setting the location counter (#2005)
• Support defining custom phdrs in linker scripts (#2013)
• Support --rosegment and --no-rosegment (#2022)
• Always emit .riscv.attribute when using linker scripts (#2021)
• Add support for the SIZEOF_HEADERS builtin function (#2030)
• Add support for the AT keyword in output sections (#2043)
• Use the LMA when calling LOADADDR in linker scripts (#2048)
• Support GDB index (#1990)
• Support setting an output section's region (#2078)
• Add --compress-debug-section=zlib-gabi as an alias for --compress-debug-section=zlib (#2097)
• Calculate section layouts and part layouts at the same time (#2103)
• Add built-in symbol __bss_start (#2124)
• Use location counters within output sections in linker scripts (#2136)
• Implement SORT() directive for linker scripts (#1994)
• Implement ternary operations in linker scripts (#2166)
• Parse and ignore CONSTRUCTORS in linker scripts (#2180)
• Define multiple location counters that are relative to each other (#2151)
• Support the DEFINED command in linker scripts (#2181)
• GOT-based RELR bitmap packing (#2196)
• Print version and emulation info when the -V flag is used (#2201)
• Support specifying an output section's fill pattern in a linker script (#2226)
• Implement --sort-section flag (#2230)
• Parse an optional comma after output sections in linker scripts (#2246)
• Define multiple program headers per output section in linker scripts (#2256)
• Introduce FileSystem abstraction (#2267)
• Evaluate the modulo operator in linker scripts (#2292)
• Implement OUTPUT_FORMAT and OUTPUT_ARCH in linker scripts (#2295)
• Implement SORT_BY_NAME and SORT_BY_ALIGNMENT (#2296)

⚡ Performance

• Default to --no-mmap-output-file when writing to btrfs/vfat (#2051)
• Make gdb-index building do less heap allocation (#2057)
• Avoid b-tree and parallelise symbol sort in gdb-index (#2073)
• Parallelise merging of gdb index scans (#2079)
• Write GDB index concurrently with rest of file (#2084)
• Don't sort GDB index symbols (#2087)
• Don't flatten symbol buckets when writing GDB index (#2088)
• Remove unnecessary Vecs for cv_offsets and name_offsets (#2094)
• Write gdb index constant pool in parallel (#2095)

💻 CLI

• Drop unused flag --debug-address (#2219)
• Unify more arguments among platforms (#2036)

🪲 Bug Fixes

• Keep --defsym/linker-script redirect targets alive through LTO (#1979)
• Properly handle PLT references via thunks (#1989)
• (LoongArch64/RV64) Allow empty sequence for merge_eflags (#1996)
• Don't bail when a linker plugin doesn't claim an IR archive member (#2027)
• Support R_X86_64_PC32 relocations to absolute addresses (#2050)
• Don't output -ggnu-pubnames sections when --gdb-index is active (#2054)
• Use 0x10000 as default load address for RISC-V (#2055)
• Support --wrap combined with linker plugin LTO (#2081)
• (loongarch64) Treat R_LARCH_CALL36 as PLT-generating (#2093)
• Error on sub-pointer-size absolute relocations in shared objects (#2083)
• Don't panic on linker script section names shorter than 4 bytes (#2104)
• Accept full byte range for R_X86_64_8 and R_X86_64_16 relocations (#2105)
• Add RWX LOAD segment for sections with writable+executable flags (#2111)
• Don't compress SHF_ALLOC debug sections (#2119)
• Apply linker-managed section rules when using linker scripts (#2123)
• --compress-debug-sections drops merged-string offset map (#2118)
• Error on R_X86_64_32/32S against DSO symbols in PIE output (#2125)
• Error on R_X86_64_PC32 to DSO symbols in non-executable sections in PIE (#2132)
• Reject R_X86_64_8/16/PC8/PC16 against preemptible symbols in shared objects (#2146)
• Reject absolute R_X86_64_8/16 against non-preemptible symbols in shared objects (#2150)
• Create canonical PLT entry for R_X86_64_PC32 to STT_FUNC DSO symbols in PIE (#2152)
• Relax -z noplt form of TLS GD to Local Exec on x86_64 (#2160)
• Relax -z noplt form of TLS GD to Initial Exec on x86_64 (#2165)
• Emit one zlib stream per compressed debug section (#2162)
• Implement RELR bitmap packing for consecutive relocations (#2179)
• Don't count .tbss size towards TLS segment file size (#2190)
• Do not allocate space for uninitialized tls variables (#1788)
• Use nop padding bytes in executable sections on x86 (#2200)
• Properly handle eh_frame terminators (#2208)
• Don't double count section sizes in scripts (#2214)
• Do not retain a linker script output section if a symbol is defined after it (#2243)
• Avoid segment overlap due to large .tbss (#2252)
• Properly handle large alignments in .tbss (#2253)
• Error on R_AARCH64_ABS32/ABS16 against symbols in shared objects (#2250)
• Error on non-PIC AArch64 relocations against preemptible symbols in shared objects (#2273)
• Avoid applying ELF-specific entry behaviour to other platforms (#2275)
• Error on R_AARCH64_PREL16/32/64 against preemptible symbols in shared objects (#2274)
• Avoid range error for aarch64 TPOFF rel against undefined weak tls (#2284)
• Skip mapping symbols in unloaded sections during relocatable link (#2305)
• Do not store the section name of a section symbol in .strtab (#2310)
• OR GNU property notes within file before ANDing across files (#2309)

📚 Documentation

• (README.md) Structure "using Wild" part (#2023)
• Update LINKER_SCRIPT_SUPPORT.md (#2034)
• Fix cross-arch setup instructions for loongarch64 and add ppc64le (#2197)
• Document usage with CMake 4.4+ (#2331)

🕹️ Porting (Wasm)

• Add section emitters for type / import / function / global / export (#1987)
• Build initial output module layout (#2037)
• Build and emit metadata section (#2042)
• Build and emit code and memory sections (#2047)
• Apply code section index relocations (#2058)
• Resolve cross-object imports (#2092)
• Add per-object data segment layout and emission (#2117)
• Apply data relocations (#2135)
• Link clang objects with memory, stack, and data addresses (#2145)
• Allow linking against archives containing Wasm objects (#2154)
• Absorb indirect function tables and apply table relocations (#2163)
• Keep standard sections off the generic allocation path (#2170)
• Add linker-defined memory base, MEMORY_ADDR_REL_SLEB relocation, and call_ctors stubs (#2176)
• Deduplicate the output type section (#2187)
• Resolve __data_end and __heap_base as linker data addresses (#2188)
• Synthesize __wasm_call_ctors from InitFuncs and wrap the command entry (#2192)
• Link static WASI libraries and preserve host imports (#2202)
• Align data segments and stack like wasm-ld (#2206)
• Support --export in Wasm (#2211)
• Support -z stack-size for Wasm (#2224)
• Synthesize __wasm_first_page_end and __heap_end for WASI heap (#2227)
• Emit the custom name section for function and global names (#2233)
• Speed up Wasm data segment layout by fixing reloc classification (#2235)
• Speed up data symbol address lookup with O(1) segment indexing (#2239)
• Define Wasm linker symbols through SymbolDb (#2238)
• Accept constructors with non-void return types (#2244)
• Support R_WASM_TABLE_INDEX_REL_SLEB (#2245)
• Define linker-synthesized __table_base (#2251)
• Defer reloc entry decoding to layout (#2262)
• Support --stack-first for Wasm (#2254)
• Support --entry / --no-entry (#2272)
• Change default to --stack-first (#2278)
• Synthesize GOT.mem globals for R_WASM_GLOBAL_INDEX (#2271)
• Avoid cloning symbol tables during module layout (#2293)
• Resolve undefined weak functions to unreachable stubs (#2307)
• Emit target_features custom section from linked objects (#2308)
• Coalesce identical host imports across objects (#2313)
• Use RelocationType from wasmparse crate (#2317)
• Report unrecognized options (#2318)
• Parallelize code and data section emission (#2322)
• Add symlinks and support -m wasm32 (#2329)
• Support --initial-memory (#2325)

🕹️ Porting (Mach-O)

• Improve error message about FAT objects (#1972)
• Parse more options and identify stub libs (#1973)
• Support for linking against stub libraries (#2031)
• Simplify LOAD_COMMANDS and support more LC_LOAD_DYLIB (#2062)
• Switch from arm64-macos to arm64e-macos (#2086)
• Allow linking against archives containing MachO objects (#2110)
• Refactor how imported_symbols and imported_libraries work (#2109)
• Add BuildVersion cmd (#2121)
• Add support for fat objects (#2122)
• Use sequential imported library ordinals (#2128)
• Add support for fat-64 objects (#2127)
• Error on undefined symbol (#2129)
• Don't strip unused dylibs by default (#2142)
• Support direct linking against dylibs (#2158)
• Support fat dylibs (#2159)
• Align __LINKEDIT sections (#2186)
• Fix chained fixups __DATA_CONST segment index (#2195)
• Write LC_UUID hash (#2223)
• Add __const section to output order (#2249)
• Introduce SectionIdentity (#2312)
• Plug stub symbols into symbol DB (#1984)

🕹️ Porting (other)

• (ppc64) Recognise ppc64 (PowerPC64, ELFv2) ELF objects (#1976)
• (ppc64) Decode the static relocation subset (#1977)
• (ppc64) REL24 local entry plus REL32/ADDR32/REL64 (#1999)
• (zkvm) Workaround weird behavior of env::var (#2213)

🏛️ libwild

• Do not override the global Rayon thread pool (#2209)
• Make zstd support optional at build time (#2210)

🛠️ Dev tooling

• Change save-dir so that arguments go at the end, not the start (#2232)
• Only move arguments after -- to the end in save-dir (#2270)
• Allow experimental platforms via env var (#2321)
• Use ANSI colors for the tracing output (#2010)

💲 Sponsors

Thanks to everyone who has sponsored davidlattimore, in particular AWS for sponsoring via the Rust Innovation Lab and the following people who have sponsored at least $30 since the last release:

• rerun-io
• teburd
• wasmerio
• pmarks
• repi
• mati865
• marxin
• Urgau
• flba-eb
• bes
• Tudyx
• +47 others