Auto merge of #159579 - JonathanBrouwer:rollup-TlvztYP, r=JonathanBrouwer

Rollup of 5 pull requests

Successful merges:

 - #159188 (Always generate private and hidden items in JSON docs of the stdlib)
 - #159567 (Update rustc crate crossbeam-epoch to 0.9.20)
 - #150732 (Convert `-Ctarget-cpu` into a target-modifier for AVR, AMDGCN and NVPTX )
 - #159549 (restrict const-eval-related 'content' triggers to library/ folder)
 - #159570 (fix ICE in opsem inhabitedness check)

Author: bors

Cargo.lock

@@ -1001,9 +1001,9 @@ dependencies = [
 
 [[package]]
 name = "crossbeam-epoch"
-version = "0.9.18"
+version = "0.9.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5b82ac4a3c2ca9c3460964f020e1402edd5753411d7737aa39c3714ad1b5420e"
+checksum = "2d6914041f254d6e9176c01941b21115dcfb7089e55135a35411081bd106ef3f"
 dependencies = [
  "crossbeam-utils",
 ]

compiler/rustc_codegen_cranelift/src/lib.rs

@@ -42,7 +42,7 @@ use rustc_codegen_ssa::{CompiledModules, CrateInfo, TargetConfig, back};
 use rustc_log::tracing::info;
 use rustc_middle::dep_graph::WorkProductMap;
 use rustc_session::Session;
-use rustc_session::config::OutputFilenames;
+use rustc_session::config::{NATIVE_CPU, OutputFilenames};
 use rustc_span::{Symbol, sym};
 use rustc_target::spec::{Arch, CfgAbi, Env, Os};
 
@@ -341,7 +341,7 @@ fn build_isa(sess: &Session, jit: bool) -> Arc<dyn TargetIsa + 'static> {
     let flags = settings::Flags::new(flags_builder);
 
     let isa_builder = match sess.opts.cg.target_cpu.as_deref() {
-        Some("native") => cranelift_native::builder_with_options(true).unwrap(),
+        Some(NATIVE_CPU) => cranelift_native::builder_with_options(true).unwrap(),
         Some(value) => {
             let mut builder =
                 cranelift_codegen::isa::lookup(target_triple.clone()).unwrap_or_else(|err| {

compiler/rustc_codegen_gcc/src/gcc_util.rs

@@ -3,6 +3,7 @@ use gccjit::Context;
 use rustc_codegen_ssa::target_features;
 use rustc_data_structures::smallvec::{SmallVec, smallvec};
 use rustc_session::Session;
+use rustc_session::config::NATIVE_CPU;
 use rustc_target::spec::Arch;
 
 fn gcc_features_by_flags(sess: &Session, features: &mut Vec<String>) {
@@ -115,7 +116,7 @@ fn arch_to_gcc(name: &str) -> &str {
 }
 
 fn handle_native(name: &str) -> &str {
-    if name != "native" {
+    if name != NATIVE_CPU {
         return arch_to_gcc(name);
     }
 

compiler/rustc_codegen_llvm/src/llvm_util.rs

@@ -14,7 +14,7 @@ use rustc_data_structures::small_c_str::SmallCStr;
 use rustc_fs_util::path_to_c_string;
 use rustc_middle::bug;
 use rustc_session::Session;
-use rustc_session::config::{PrintKind, PrintRequest};
+use rustc_session::config::{NATIVE_CPU, PrintKind, PrintRequest};
 use rustc_target::spec::{
     Arch, CfgAbi, Env, MergeFunctions, Os, PanicStrategy, SmallDataThresholdSupport,
 };
@@ -514,10 +514,12 @@ fn print_target_cpus(sess: &Session, tm: &llvm::TargetMachine, out: &mut String)
 
     // Only print the "native" entry when host and target are the same arch,
     // since otherwise it could be wrong or misleading.
-    if sess.host.arch == sess.target.arch {
+    // Also do not print it if `requires_consistent_cpu` is set, because in this case
+    // "native" would be rejected.
+    if sess.host.arch == sess.target.arch && !sess.target.requires_consistent_cpu {
         let host = get_host_cpu_name();
         cpus.push_front(Cpu {
-            cpu_name: "native",
+            cpu_name: NATIVE_CPU,
             remark: format!(" - Select the CPU of the current host (currently {host})."),
         });
     }
@@ -612,7 +614,7 @@ fn get_host_cpu_name() -> &'static str {
 /// LLVM. Otherwise, the string is returned as-is.
 fn handle_native(cpu_name: &str) -> &str {
     match cpu_name {
-        "native" => get_host_cpu_name(),
+        NATIVE_CPU => get_host_cpu_name(),
         _ => cpu_name,
     }
 }
@@ -666,7 +668,7 @@ pub(crate) fn global_llvm_features(sess: &Session, only_base_features: bool) ->
 
     // -Ctarget-cpu=native
     match sess.opts.cg.target_cpu {
-        Some(ref s) if s == "native" => {
+        Some(ref s) if s == NATIVE_CPU => {
             // We have already figured out the actual CPU name with `LLVMRustGetHostCPUName` and set
             // that for LLVM, so the features implied by that CPU name will be available everywhere.
             // However, that is not sufficient: e.g. `skylake` alone is not sufficient to tell if

compiler/rustc_metadata/src/creader.rs

@@ -380,6 +380,7 @@ impl CStore {
                         flag_name,
                         flag_name_prefixed,
                         extern_value: extern_value.to_string(),
+                        has_extern_value: !extern_value.is_empty(),
                     })
                 }
                 (Some(local_value), None) => {
@@ -390,6 +391,7 @@ impl CStore {
                         flag_name,
                         flag_name_prefixed,
                         local_value: local_value.to_string(),
+                        has_local_value: !local_value.is_empty(),
                     })
                 }
                 (None, None) => panic!("Incorrect target modifiers report_diff(None, None)"),

compiler/rustc_metadata/src/diagnostics.rs

@@ -606,10 +606,16 @@ pub(crate) struct IncompatibleTargetModifiers {
     "the `{$flag_name_prefixed}` flag modifies the ABI so Rust crates compiled with different values of this flag cannot be used together safely"
 )]
 #[note(
-    "unset `{$flag_name_prefixed}` in this crate is incompatible with `{$flag_name_prefixed}={$extern_value}` in dependency `{$extern_crate}`"
+    "`{$flag_name_prefixed}` is unset in this crate which is incompatible with {$has_extern_value ->
+        [false]  `{$flag_name_prefixed}` being set
+        *[other] `{$flag_name_prefixed}={$extern_value}`
+    } in dependency `{$extern_crate}`"
 )]
 #[help(
-    "set `{$flag_name_prefixed}={$extern_value}` in this crate or unset `{$flag_name_prefixed}` in `{$extern_crate}`"
+    "set {$has_extern_value ->
+        [false]  `{$flag_name_prefixed}`
+        *[other] `{$flag_name_prefixed}={$extern_value}`
+    } in this crate or unset `{$flag_name_prefixed}` in `{$extern_crate}`"
 )]
 #[help(
     "if you are sure this will not cause problems, you may use `-Cunsafe-allow-abi-mismatch={$flag_name}` to silence this error"
@@ -622,6 +628,7 @@ pub(crate) struct IncompatibleTargetModifiersLMissed {
     pub flag_name: String,
     pub flag_name_prefixed: String,
     pub extern_value: String,
+    pub has_extern_value: bool,
 }
 
 #[derive(Diagnostic)]
@@ -630,10 +637,16 @@ pub(crate) struct IncompatibleTargetModifiersLMissed {
     "the `{$flag_name_prefixed}` flag modifies the ABI so Rust crates compiled with different values of this flag cannot be used together safely"
 )]
 #[note(
-    "`{$flag_name_prefixed}={$local_value}` in this crate is incompatible with unset `{$flag_name_prefixed}` in dependency `{$extern_crate}`"
+    "{$has_local_value ->
+        [false]  `{$flag_name_prefixed}` being set
+        *[other] `{$flag_name_prefixed}={$local_value}`
+    } in this crate is incompatible with `{$flag_name_prefixed}` being unset in dependency `{$extern_crate}`"
 )]
 #[help(
-    "unset `{$flag_name_prefixed}` in this crate or set `{$flag_name_prefixed}={$local_value}` in `{$extern_crate}`"
+    "unset `{$flag_name_prefixed}` in this crate or set {$has_local_value ->
+        [false]  `{$flag_name_prefixed}`
+        *[other] `{$flag_name_prefixed}={$local_value}`
+    } in `{$extern_crate}`"
 )]
 #[help(
     "if you are sure this will not cause problems, you may use `-Cunsafe-allow-abi-mismatch={$flag_name}` to silence this error"
@@ -646,6 +659,7 @@ pub(crate) struct IncompatibleTargetModifiersRMissed {
     pub flag_name: String,
     pub flag_name_prefixed: String,
     pub local_value: String,
+    pub has_local_value: bool,
 }
 
 #[derive(Diagnostic)]

compiler/rustc_metadata/src/rmeta/decoder.rs

@@ -750,6 +750,7 @@ impl MetadataBlob {
             "lang_items".to_owned(),
             "features".to_owned(),
             "items".to_owned(),
+            "target_modifiers".to_owned(),
         ];
         let ls_kinds = if ls_kinds.contains(&"all".to_owned()) { &all_ls_kinds } else { ls_kinds };
 
@@ -919,11 +920,28 @@ impl MetadataBlob {
 
                     write!(out, "\n")?;
                 }
+                "target_modifiers" => {
+                    writeln!(out, "=Target modifiers=")?;
+
+                    for modifier in root.decode_target_modifiers(self) {
+                        let extended = modifier.extend();
+
+                        writeln!(
+                            out,
+                            "-{}{}={} [{}]",
+                            extended.prefix,
+                            extended.name,
+                            modifier.value_name,
+                            extended.tech_value,
+                        )?;
+                    }
+                }
 
                 _ => {
                     writeln!(
                         out,
-                        "unknown -Zls kind. allowed values are: all, root, lang_items, features, items"
+                        "unknown -Zls kind. allowed values are: all, root, lang_items, features, items, \
+                            target_modifiers"
                     )?;
                 }
             }

compiler/rustc_middle/src/ty/inhabitedness/mod.rs

@@ -339,8 +339,12 @@ fn is_opsem_inhabited_recursor<'tcx, SEEN>(
             })
         }
 
-        ty::Error(_)
-        | ty::Infer(..)
+        ty::Error(_error_guaranteed) => {
+            // We have a token proving there was an error, so we can return a dummy value.
+            true
+        }
+
+        ty::Infer(..)
         | ty::Placeholder(..)
         | ty::Bound(..)
         | ty::Param(..)

compiler/rustc_session/src/config.rs

@@ -46,6 +46,9 @@ mod native_libs;
 mod print_request;
 pub mod sigpipe;
 
+/// Special CPU name requesting the CPU of the current host.
+pub const NATIVE_CPU: &str = "native";
+
 /// The different settings that the `-C strip` flag can have.
 #[derive(Clone, Copy, PartialEq, Hash, Debug)]
 pub enum Strip {

compiler/rustc_session/src/diagnostics.rs

@@ -716,3 +716,17 @@ pub(crate) struct ThinLtoNotSupportedByBackend;
 #[derive(Diagnostic)]
 #[diag("`-Zpacked-stack` is only supported on s390x")]
 pub(crate) struct UnsupportedPackedStack;
+
+#[derive(Diagnostic)]
+#[diag("`-Ctarget-cpu=native` is not allowed for target `{$target_triple}`")]
+#[note("this target requires consistent `-Ctarget-cpu` values across all crates")]
+#[help(
+    "specify the target CPU explicitly {$need_explicit_cpu ->
+        [false] or leave it blank to use the default
+        *[other] {\"\"}
+    }"
+)]
+pub(crate) struct NativeTargetCpuNotAllowed<'a> {
+    pub(crate) target_triple: &'a TargetTuple,
+    pub(crate) need_explicit_cpu: bool,
+}