use std::env;
fn main() {
println!("cargo:rerun-if-changed=build.rs");
let target = env::var("TARGET").unwrap();
let cwd = env::current_dir().unwrap();
println!("cargo:compiler-rt={}", cwd.join("compiler-rt").display());
// Emscripten's runtime includes all the builtins
if target.contains("emscripten") {
return;
}
// OpenBSD provides compiler_rt by default, use it instead of rebuilding it from source
if target.contains("openbsd") {
println!("cargo:rustc-link-search=native=/usr/lib");
println!("cargo:rustc-link-lib=compiler_rt");
return;
}
// Forcibly enable memory intrinsics on wasm32 & SGX as we don't have a libc to
// provide them.
if (target.contains("wasm32") && !target.contains("wasi")) ||
(target.contains("sgx") && target.contains("fortanix")) {
println!("cargo:rustc-cfg=feature=\"mem\"");
}
// NOTE we are going to assume that llvm-target, what determines our codegen option, matches the
// target triple. This is usually correct for our built-in targets but can break in presence of
// custom targets, which can have arbitrary names.
let llvm_target = target.split('-').collect::<Vec<_>>();
// Build missing intrinsics from compiler-rt C source code. If we're
// mangling names though we assume that we're also in test mode so we don't
// build anything and we rely on the upstream implementation of compiler-rt
// functions
if !cfg!(feature = "mangled-names") && cfg!(feature = "c") {
// Don't use C compiler for bitcode-only wasm and nvptx
if !target.contains("wasm32") && !target.contains("nvptx") {
#[cfg(feature = "c")]
c::compile(&llvm_target);
println!("cargo:rustc-cfg=use_c");
}
}
// To compile intrinsics.rs for thumb targets, where there is no libc
if llvm_target[0].starts_with("thumb") {
println!("cargo:rustc-cfg=thumb")
}
// compiler-rt `cfg`s away some intrinsics for thumbv6m and thumbv8m.base because
// these targets do not have full Thumb-2 support but only original Thumb-1.
// We have to cfg our code accordingly.
if llvm_target[0] == "thumbv6m" || llvm_target[0] == "thumbv8m.base" {
println!("cargo:rustc-cfg=thumb_1")
}
// Only emit the ARM Linux atomic emulation on pre-ARMv6 architectures.
if llvm_target[0] == "armv4t" || llvm_target[0] == "armv5te" {
println!("cargo:rustc-cfg=kernel_user_helpers")
}
}
#[cfg(feature = "c")]
mod c {
extern crate cc;
use std::collections::BTreeMap;
use std::env;
use std::path::Path;
struct Sources {
// SYMBOL -> PATH TO SOURCE
map: BTreeMap<&'static str, &'static str>,
}
impl Sources {
fn new() -> Sources {
Sources { map: BTreeMap::new() }
}
fn extend(&mut self, sources: &[&'static str]) {
// NOTE Some intrinsics have both a generic implementation (e.g.
// `floatdidf.c`) and an arch optimized implementation
// (`x86_64/floatdidf.c`). In those cases, we keep the arch optimized
// implementation and discard the generic implementation. If we don't
// and keep both implementations, the linker will yell at us about
// duplicate symbols!
for &src in sources {
let symbol = Path::new(src).file_stem().unwrap().to_str().unwrap();
if src.contains("/") {
// Arch-optimized implementation (preferred)
self.map.insert(symbol, src);
} else {
// Generic implementation
if !self.map.contains_key(symbol) {
self.map.insert(symbol, src);
}
}
}
}
fn remove(&mut self, symbols: &[&str]) {
for symbol in symbols {
self.map.remove(*symbol).unwrap();
}
}
}
/// Compile intrinsics from the compiler-rt C source code
pub fn compile(llvm_target: &[&str]) {
let target_arch = env::var("CARGO_CFG_TARGET_ARCH").unwrap();
let target_env = env::var("CARGO_CFG_TARGET_ENV").unwrap();
let target_os = env::var("CARGO_CFG_TARGET_OS").unwrap();
let target_vendor = env::var("CARGO_CFG_TARGET_VENDOR").unwrap();
let cfg = &mut cc::Build::new();
cfg.warnings(false);
if target_env == "msvc" {
// Don't pull in extra libraries on MSVC
cfg.flag("/Zl");
// Emulate C99 and C++11's __func__ for MSVC prior to 2013 CTP
cfg.define("__func__", Some("__FUNCTION__"));
} else {
// Turn off various features of gcc and such, mostly copying
// compiler-rt's build system already
cfg.flag("-fno-builtin");
cfg.flag("-fvisibility=hidden");
cfg.flag("-ffreestanding");
// Avoid the following warning appearing once **per file**:
// clang: warning: optimization flag '-fomit-frame-pointer' is not supported for target 'armv7' [-Wignored-optimization-argument]
//
// Note that compiler-rt's build system also checks
//
// `check_cxx_compiler_flag(-fomit-frame-pointer COMPILER_RT_HAS_FOMIT_FRAME_POINTER_FLAG)`
//
// in https://github.com/rust-lang/compiler-rt/blob/c8fbcb3/cmake/config-ix.cmake#L19.
cfg.flag_if_supported("-fomit-frame-pointer");
cfg.define("VISIBILITY_HIDDEN", None);
}
let mut sources = Sources::new();
sources.extend(
&[
"absvdi2.c",
"absvsi2.c",
"addvdi3.c",
"addvsi3.c",
"apple_versioning.c",
"clzdi2.c",
"clzsi2.c",
"cmpdi2.c",
"ctzdi2.c",
"ctzsi2.c",
"divdc3.c",
"divsc3.c",
"divxc3.c",
"extendhfsf2.c",
"int_util.c",
"muldc3.c",
"mulsc3.c",
"mulvdi3.c",
"mulvsi3.c",
"mulxc3.c",
"negdf2.c",
"negdi2.c",
"negsf2.c",
"negvdi2.c",
"negvsi2.c",
"paritydi2.c",
"paritysi2.c",
"popcountdi2.c",
"popcountsi2.c",
"powixf2.c",
"subvdi3.c",
"subvsi3.c",
"truncdfhf2.c",
"truncdfsf2.c",
"truncsfhf2.c",
"ucmpdi2.c",
],
);
// When compiling in rustbuild (the rust-lang/rust repo) this library
// also needs to satisfy intrinsics that jemalloc or C in general may
// need, so include a few more that aren't typically needed by
// LLVM/Rust.
if cfg!(feature = "rustbuild") {
sources.extend(&[
"ffsdi2.c",
]);
}
// On iOS and 32-bit OSX these are all just empty intrinsics, no need to
// include them.
if target_os != "ios" && (target_vendor != "apple" || target_arch != "x86") {
sources.extend(
&[
"absvti2.c",
"addvti3.c",
"clzti2.c",
"cmpti2.c",
"ctzti2.c",
"ffsti2.c",
"mulvti3.c",
"negti2.c",
"negvti2.c",
"parityti2.c",
"popcountti2.c",
"subvti3.c",
"ucmpti2.c",
],
);
}
if target_vendor == "apple" {
sources.extend(
&[
"atomic_flag_clear.c",
"atomic_flag_clear_explicit.c",
"atomic_flag_test_and_set.c",
"atomic_flag_test_and_set_explicit.c",
"atomic_signal_fence.c",
"atomic_thread_fence.c",
],
);
}
if target_env == "msvc" {
if target_arch == "x86_64" {
sources.extend(
&[
"x86_64/floatdisf.c",
"x86_64/floatdixf.c",
],
);
}
} else {
// None of these seem to be used on x86_64 windows, and they've all
// got the wrong ABI anyway, so we want to avoid them.
if target_os != "windows" {
if target_arch == "x86_64" {
sources.extend(
&[
"x86_64/floatdisf.c",
"x86_64/floatdixf.c",
"x86_64/floatundidf.S",
"x86_64/floatundisf.S",
"x86_64/floatundixf.S",
],
);
}
}
if target_arch == "x86" {
sources.extend(
&[
"i386/ashldi3.S",
"i386/ashrdi3.S",
"i386/divdi3.S",
"i386/floatdidf.S",
"i386/floatdisf.S",
"i386/floatdixf.S",
"i386/floatundidf.S",
"i386/floatundisf.S",
"i386/floatundixf.S",
"i386/lshrdi3.S",
"i386/moddi3.S",
"i386/muldi3.S",
"i386/udivdi3.S",
"i386/umoddi3.S",
],
);
}
}
if target_arch == "arm" && target_os != "ios" && target_env != "msvc" {
sources.extend(
&[
"arm/aeabi_div0.c",
"arm/aeabi_drsub.c",
"arm/aeabi_frsub.c",
"arm/bswapdi2.S",
"arm/bswapsi2.S",
"arm/clzdi2.S",
"arm/clzsi2.S",
"arm/divmodsi4.S",
"arm/modsi3.S",
"arm/switch16.S",
"arm/switch32.S",
"arm/switch8.S",
"arm/switchu8.S",
"arm/sync_synchronize.S",
"arm/udivmodsi4.S",
"arm/umodsi3.S",
// Exclude these two files for now even though we haven't
// translated their implementation into Rust yet (#173).
// They appear... buggy? The `udivsi3` implementation was
// the one that seemed buggy, but the `divsi3` file
// references a symbol from `udivsi3` so we compile them
// both with the Rust versions.
//
// Note that if these are added back they should be removed
// from thumbv6m below.
//
// "arm/divsi3.S",
// "arm/udivsi3.S",
],
);
if target_os == "freebsd" {
sources.extend(&["clear_cache.c"]);
}
// First of all aeabi_cdcmp and aeabi_cfcmp are never called by LLVM.
// Second are little-endian only, so build fail on big-endian targets.
// Temporally workaround: exclude these files for big-endian targets.
if !llvm_target[0].starts_with("thumbeb") &&
!llvm_target[0].starts_with("armeb") {
sources.extend(
&[
"arm/aeabi_cdcmp.S",
"arm/aeabi_cdcmpeq_check_nan.c",
"arm/aeabi_cfcmp.S",
"arm/aeabi_cfcmpeq_check_nan.c",
],
);
}
}
if llvm_target[0] == "armv7" {
sources.extend(
&[
"arm/sync_fetch_and_add_4.S",
"arm/sync_fetch_and_add_8.S",
"arm/sync_fetch_and_and_4.S",
"arm/sync_fetch_and_and_8.S",
"arm/sync_fetch_and_max_4.S",
"arm/sync_fetch_and_max_8.S",
"arm/sync_fetch_and_min_4.S",
"arm/sync_fetch_and_min_8.S",
"arm/sync_fetch_and_nand_4.S",
"arm/sync_fetch_and_nand_8.S",
"arm/sync_fetch_and_or_4.S",
"arm/sync_fetch_and_or_8.S",
"arm/sync_fetch_and_sub_4.S",
"arm/sync_fetch_and_sub_8.S",
"arm/sync_fetch_and_umax_4.S",
"arm/sync_fetch_and_umax_8.S",
"arm/sync_fetch_and_umin_4.S",
"arm/sync_fetch_and_umin_8.S",
"arm/sync_fetch_and_xor_4.S",
"arm/sync_fetch_and_xor_8.S",
],
);
}
if llvm_target.last().unwrap().ends_with("eabihf") {
if !llvm_target[0].starts_with("thumbv7em") &&
!llvm_target[0].starts_with("thumbv8m.main") {
// The FPU option chosen for these architectures in cc-rs, ie:
// -mfpu=fpv4-sp-d16 for thumbv7em
// -mfpu=fpv5-sp-d16 for thumbv8m.main
// do not support double precision floating points conversions so the files
// that include such instructions are not included for these targets.
sources.extend(
&[
"arm/fixdfsivfp.S",
"arm/fixunsdfsivfp.S",
"arm/floatsidfvfp.S",
"arm/floatunssidfvfp.S",
],
);
}
sources.extend(
&[
"arm/fixsfsivfp.S",
"arm/fixunssfsivfp.S",
"arm/floatsisfvfp.S",
"arm/floatunssisfvfp.S",
"arm/floatunssisfvfp.S",
"arm/restore_vfp_d8_d15_regs.S",
"arm/save_vfp_d8_d15_regs.S",
"arm/negdf2vfp.S",
"arm/negsf2vfp.S",
]
);
}
if target_arch == "aarch64" {
sources.extend(
&[
"comparetf2.c",
"extenddftf2.c",
"extendsftf2.c",
"fixtfdi.c",
"fixtfsi.c",
"fixtfti.c",
"fixunstfdi.c",
"fixunstfsi.c",
"fixunstfti.c",
"floatditf.c",
"floatsitf.c",
"floatunditf.c",
"floatunsitf.c",
"trunctfdf2.c",
"trunctfsf2.c",
],
);
if target_os != "windows" {
sources.extend(&["multc3.c"]);
}
}
// Remove the assembly implementations that won't compile for the target
if llvm_target[0] == "thumbv6m" || llvm_target[0] == "thumbv8m.base" {
sources.remove(
&[
"clzdi2",
"clzsi2",
"divmodsi4",
"modsi3",
"switch16",
"switch32",
"switch8",
"switchu8",
"udivmodsi4",
"umodsi3",
],
);
// But use some generic implementations where possible
sources.extend(&["clzdi2.c", "clzsi2.c"])
}
if llvm_target[0] == "thumbv7m" || llvm_target[0] == "thumbv7em" {
sources.remove(&["aeabi_cdcmp", "aeabi_cfcmp"]);
}
// When compiling in rustbuild (the rust-lang/rust repo) this build
// script runs from a directory other than this root directory.
let root = if cfg!(feature = "rustbuild") {
Path::new("../../libcompiler_builtins")
} else {
Path::new(".")
};
let src_dir = root.join("compiler-rt/lib/builtins");
for src in sources.map.values() {
let src = src_dir.join(src);
cfg.file(&src);
println!("cargo:rerun-if-changed={}", src.display());
}
cfg.compile("libcompiler-rt.a");
}
}