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RalfJungRalfJung
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ensure JSON-defined targets are consistent
1 parent c49a687 commit ac22231

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4 files changed

+315
-187
lines changed

4 files changed

+315
-187
lines changed

‎compiler/rustc_target/src/spec/mod.rs

+313-3
Original file line numberDiff line numberDiff line change
@@ -34,6 +34,9 @@
3434
//! the target's settings, though `target-feature` and `link-args` will *add*
3535
//! to the list specified by the target, rather than replace.
3636
37+
// ignore-tidy-filelength
38+
39+
use std::assert_matches::assert_matches;
3740
use std::borrow::Cow;
3841
use std::collections::BTreeMap;
3942
use std::hash::{Hash, Hasher};
@@ -1605,13 +1608,11 @@ macro_rules! supported_targets {
16051608

16061609
#[cfg(test)]
16071610
mod tests {
1608-
mod tests_impl;
1609-
16101611
// Cannot put this into a separate file without duplication, make an exception.
16111612
$(
16121613
#[test] // `#[test]`
16131614
fn $module() {
1614-
tests_impl::test_target(crate::spec::targets::$module::target());
1615+
crate::spec::targets::$module::target().test_target()
16151616
}
16161617
)+
16171618
}
@@ -1998,6 +1999,14 @@ impl TargetWarnings {
19981999
}
19992000
}
20002001

2002+
/// For the [`Target::check_consistency`] function, determines whether the given target is a builtin or a JSON
2003+
/// target.
2004+
#[derive(Copy, Clone, Debug, PartialEq)]
2005+
enum TargetKind {
2006+
Json,
2007+
Builtin,
2008+
}
2009+
20012010
/// Everything `rustc` knows about how to compile for a specific target.
20022011
///
20032012
/// Every field here must be specified, and has no default value.
@@ -2849,6 +2858,306 @@ impl Target {
28492858
self.max_atomic_width.unwrap_or_else(|| self.pointer_width.into())
28502859
}
28512860

2861+
fn check_consistency(&self, kind: TargetKind) -> Result<(), String> {
2862+
macro_rules! check {
2863+
($b:expr, $($msg:tt)*) => {
2864+
if !$b {
2865+
return Err(format!($($msg)*));
2866+
}
2867+
}
2868+
}
2869+
macro_rules! check_eq {
2870+
($left:expr, $right:expr, $($msg:tt)*) => {
2871+
if ($left) != ($right) {
2872+
return Err(format!($($msg)*));
2873+
}
2874+
}
2875+
}
2876+
macro_rules! check_ne {
2877+
($left:expr, $right:expr, $($msg:tt)*) => {
2878+
if ($left) == ($right) {
2879+
return Err(format!($($msg)*));
2880+
}
2881+
}
2882+
}
2883+
macro_rules! check_matches {
2884+
($left:expr, $right:pat, $($msg:tt)*) => {
2885+
if !matches!($left, $right) {
2886+
return Err(format!($($msg)*));
2887+
}
2888+
}
2889+
}
2890+
2891+
check_eq!(
2892+
self.is_like_osx,
2893+
self.vendor == "apple",
2894+
"`is_like_osx` must be set if and only if `vendor` is `apple`"
2895+
);
2896+
check_eq!(
2897+
self.is_like_solaris,
2898+
self.os == "solaris" || self.os == "illumos",
2899+
"`is_like_solaris` must be set if and only if `os` is `solaris` or `illumos`"
2900+
);
2901+
check_eq!(
2902+
self.is_like_windows,
2903+
self.os == "windows" || self.os == "uefi",
2904+
"`is_like_windows` must be set if and only if `os` is `windows` or `uefi`"
2905+
);
2906+
check_eq!(
2907+
self.is_like_wasm,
2908+
self.arch == "wasm32" || self.arch == "wasm64",
2909+
"`is_like_wasm` must be set if and only if `arch` is `wasm32` or `wasm64`"
2910+
);
2911+
if self.is_like_msvc {
2912+
check!(self.is_like_windows, "if `is_like_msvc` is set, `is_like_windows` must be set");
2913+
}
2914+
2915+
// Check that default linker flavor is compatible with some other key properties.
2916+
check_eq!(
2917+
self.is_like_osx,
2918+
matches!(self.linker_flavor, LinkerFlavor::Darwin(..)),
2919+
"`linker_flavor` must be `darwin` if and only if `is_like_osx` is set"
2920+
);
2921+
check_eq!(
2922+
self.is_like_msvc,
2923+
matches!(self.linker_flavor, LinkerFlavor::Msvc(..)),
2924+
"`linker_flavor` must be `mscv` if and only if `is_like_msvc` is set"
2925+
);
2926+
check_eq!(
2927+
self.is_like_wasm && self.os != "emscripten",
2928+
matches!(self.linker_flavor, LinkerFlavor::WasmLld(..)),
2929+
"`linker_flavor` must be `wasm-lld` if and only if `is_like_wasm` is set and the `os` is not `emscripten`",
2930+
);
2931+
check_eq!(
2932+
self.os == "emscripten",
2933+
matches!(self.linker_flavor, LinkerFlavor::EmCc),
2934+
"`linker_flavor` must be `em-cc` if and only if `os` is `emscripten`"
2935+
);
2936+
check_eq!(
2937+
self.arch == "bpf",
2938+
matches!(self.linker_flavor, LinkerFlavor::Bpf),
2939+
"`linker_flavor` must be `bpf` if and only if `arch` is `bpf`"
2940+
);
2941+
check_eq!(
2942+
self.arch == "nvptx64",
2943+
matches!(self.linker_flavor, LinkerFlavor::Ptx),
2944+
"`linker_flavor` must be `ptc` if and only if `arch` is `nvptx64`"
2945+
);
2946+
2947+
for args in [
2948+
&self.pre_link_args,
2949+
&self.late_link_args,
2950+
&self.late_link_args_dynamic,
2951+
&self.late_link_args_static,
2952+
&self.post_link_args,
2953+
] {
2954+
for (&flavor, flavor_args) in args {
2955+
check!(!flavor_args.is_empty(), "linker flavor args must not be empty");
2956+
// Check that flavors mentioned in link args are compatible with the default flavor.
2957+
match self.linker_flavor {
2958+
LinkerFlavor::Gnu(..) => {
2959+
check_matches!(
2960+
flavor,
2961+
LinkerFlavor::Gnu(..),
2962+
"mixing GNU and non-GNU linker flavors"
2963+
);
2964+
}
2965+
LinkerFlavor::Darwin(..) => {
2966+
check_matches!(
2967+
flavor,
2968+
LinkerFlavor::Darwin(..),
2969+
"mixing Darwin and non-Darwin linker flavors"
2970+
)
2971+
}
2972+
LinkerFlavor::WasmLld(..) => {
2973+
check_matches!(
2974+
flavor,
2975+
LinkerFlavor::WasmLld(..),
2976+
"mixing wasm and non-wasm linker flavors"
2977+
)
2978+
}
2979+
LinkerFlavor::Unix(..) => {
2980+
check_matches!(
2981+
flavor,
2982+
LinkerFlavor::Unix(..),
2983+
"mixing unix and non-unix linker flavors"
2984+
);
2985+
}
2986+
LinkerFlavor::Msvc(..) => {
2987+
check_matches!(
2988+
flavor,
2989+
LinkerFlavor::Msvc(..),
2990+
"mixing MSVC and non-MSVC linker flavors"
2991+
);
2992+
}
2993+
LinkerFlavor::EmCc
2994+
| LinkerFlavor::Bpf
2995+
| LinkerFlavor::Ptx
2996+
| LinkerFlavor::Llbc => {
2997+
check_eq!(flavor, self.linker_flavor, "mixing different linker flavors")
2998+
}
2999+
}
3000+
3001+
// Check that link args for cc and non-cc versions of flavors are consistent.
3002+
let check_noncc = |noncc_flavor| -> Result<(), String> {
3003+
if let Some(noncc_args) = args.get(&noncc_flavor) {
3004+
for arg in flavor_args {
3005+
if let Some(suffix) = arg.strip_prefix("-Wl,") {
3006+
check!(
3007+
noncc_args.iter().any(|a| a == suffix),
3008+
" link args for cc and non-cc versions of flavors are not consistent"
3009+
);
3010+
}
3011+
}
3012+
}
3013+
Ok(())
3014+
};
3015+
3016+
match self.linker_flavor {
3017+
LinkerFlavor::Gnu(Cc::Yes, lld) => check_noncc(LinkerFlavor::Gnu(Cc::No, lld))?,
3018+
LinkerFlavor::WasmLld(Cc::Yes) => check_noncc(LinkerFlavor::WasmLld(Cc::No))?,
3019+
LinkerFlavor::Unix(Cc::Yes) => check_noncc(LinkerFlavor::Unix(Cc::No))?,
3020+
_ => {}
3021+
}
3022+
}
3023+
3024+
// Check that link args for lld and non-lld versions of flavors are consistent.
3025+
for cc in [Cc::No, Cc::Yes] {
3026+
check_eq!(
3027+
args.get(&LinkerFlavor::Gnu(cc, Lld::No)),
3028+
args.get(&LinkerFlavor::Gnu(cc, Lld::Yes)),
3029+
"link args for lld and non-lld versions of flavors are not consistent",
3030+
);
3031+
check_eq!(
3032+
args.get(&LinkerFlavor::Darwin(cc, Lld::No)),
3033+
args.get(&LinkerFlavor::Darwin(cc, Lld::Yes)),
3034+
"link args for lld and non-lld versions of flavors are not consistent",
3035+
);
3036+
}
3037+
check_eq!(
3038+
args.get(&LinkerFlavor::Msvc(Lld::No)),
3039+
args.get(&LinkerFlavor::Msvc(Lld::Yes)),
3040+
"link args for lld and non-lld versions of flavors are not consistent",
3041+
);
3042+
}
3043+
3044+
if self.link_self_contained.is_disabled() {
3045+
check!(
3046+
self.pre_link_objects_self_contained.is_empty()
3047+
&& self.post_link_objects_self_contained.is_empty(),
3048+
"if `link_self_contained` is disabled, then `pre_link_objects_self_contained` and `post_link_objects_self_contained` must be empty",
3049+
);
3050+
}
3051+
3052+
// If your target really needs to deviate from the rules below,
3053+
// except it and document the reasons.
3054+
// Keep the default "unknown" vendor instead.
3055+
check_ne!(self.vendor, "", "`vendor` cannot be empty");
3056+
check_ne!(self.os, "", "`os` cannot be empty");
3057+
if !self.can_use_os_unknown() {
3058+
// Keep the default "none" for bare metal targets instead.
3059+
check_ne!(
3060+
self.os,
3061+
"unknown",
3062+
"`unknown` os can only be used on particular targets; use `none` for bare-metal targets"
3063+
);
3064+
}
3065+
3066+
// Check dynamic linking stuff
3067+
// BPF: when targeting user space vms (like rbpf), those can load dynamic libraries.
3068+
// hexagon: when targeting QuRT, that OS can load dynamic libraries.
3069+
// wasm{32,64}: dynamic linking is inherent in the definition of the VM.
3070+
if self.os == "none"
3071+
&& (self.arch != "bpf"
3072+
&& self.arch != "hexagon"
3073+
&& self.arch != "wasm32"
3074+
&& self.arch != "wasm64")
3075+
{
3076+
check!(
3077+
!self.dynamic_linking,
3078+
"dynamic linking is not supported on this OS/architecture"
3079+
);
3080+
}
3081+
if self.only_cdylib
3082+
|| self.crt_static_allows_dylibs
3083+
|| !self.late_link_args_dynamic.is_empty()
3084+
{
3085+
check!(
3086+
self.dynamic_linking,
3087+
"dynamic linking must be allowed when `only_cdylib` or `crt_static_allows_dylibs` or `late_link_args_dynamic` are set"
3088+
);
3089+
}
3090+
// Apparently PIC was slow on wasm at some point, see comments in wasm_base.rs
3091+
if self.dynamic_linking && !(self.is_like_wasm && self.os != "emscripten") {
3092+
check_eq!(
3093+
self.relocation_model,
3094+
RelocModel::Pic,
3095+
"targets that support dynamic linking must use the `pic` relocation model"
3096+
);
3097+
}
3098+
if self.position_independent_executables {
3099+
check_eq!(
3100+
self.relocation_model,
3101+
RelocModel::Pic,
3102+
"targets that support position-independent executables must use the `pic` relocation model"
3103+
);
3104+
}
3105+
// The UEFI targets do not support dynamic linking but still require PIC (#101377).
3106+
// We also allow this for JSON targets since otherwise, our default values would fail this test.
3107+
// FIXME (https://github.com/rust-lang/rust/issues/133459): can we fix the defaults?
3108+
if self.relocation_model == RelocModel::Pic
3109+
&& (self.os != "uefi" && kind == TargetKind::Builtin)
3110+
{
3111+
check!(
3112+
self.dynamic_linking || self.position_independent_executables,
3113+
"when the relocation model is `pic`, the target must support dynamic linking or use position-independent executables. \
3114+
Set the relocation model to `static` to avoid this requirement"
3115+
);
3116+
}
3117+
if self.static_position_independent_executables {
3118+
assert!(self.position_independent_executables);
3119+
}
3120+
if self.position_independent_executables {
3121+
assert!(self.executables);
3122+
}
3123+
3124+
// Check crt static stuff
3125+
if self.crt_static_default || self.crt_static_allows_dylibs {
3126+
assert!(self.crt_static_respected);
3127+
}
3128+
3129+
// Check that RISC-V targets always specify which ABI they use.
3130+
match &*self.arch {
3131+
"riscv32" => {
3132+
assert_matches!(&*self.llvm_abiname, "ilp32" | "ilp32f" | "ilp32d" | "ilp32e")
3133+
}
3134+
"riscv64" => {
3135+
// Note that the `lp64e` is still unstable as it's not (yet) part of the ELF psABI.
3136+
assert_matches!(&*self.llvm_abiname, "lp64" | "lp64f" | "lp64d" | "lp64q" | "lp64e")
3137+
}
3138+
_ => {}
3139+
}
3140+
3141+
Ok(())
3142+
}
3143+
3144+
/// Test target self-consistency and JSON encoding/decoding roundtrip.
3145+
#[cfg(test)]
3146+
fn test_target(mut self) {
3147+
let recycled_target = Target::from_json(self.to_json()).map(|(j, _)| j);
3148+
self.update_to_cli();
3149+
self.check_consistency(TargetKind::Builtin).unwrap();
3150+
assert_eq!(recycled_target, Ok(self));
3151+
}
3152+
3153+
// Add your target to the whitelist if it has `std` library
3154+
// and you certainly want "unknown" for the OS name.
3155+
fn can_use_os_unknown(&self) -> bool {
3156+
self.llvm_target == "wasm32-unknown-unknown"
3157+
|| self.llvm_target == "wasm64-unknown-unknown"
3158+
|| (self.env == "sgx" && self.vendor == "fortanix")
3159+
}
3160+
28523161
/// Loads a target descriptor from a JSON object.
28533162
pub fn from_json(obj: Json) -> Result<(Target, TargetWarnings), String> {
28543163
// While ugly, this code must remain this way to retain
@@ -3456,6 +3765,7 @@ impl Target {
34563765
key!(supports_xray, bool);
34573766

34583767
base.update_from_cli();
3768+
base.check_consistency(TargetKind::Json)?;
34593769

34603770
// Each field should have been read using `Json::remove` so any keys remaining are unused.
34613771
let remaining_keys = obj.keys();

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