Auto merge of rust-lang#134952 - Zalathar:rollup-i6g97md, r=Zalathar

Rollup of 8 pull requests

Successful merges:

 - rust-lang#134919 (bootstrap: Make `./x test compiler` actually run the compiler unit tests)
 - rust-lang#134927 (Make slice::as_flattened_mut unstably const)
 - rust-lang#134930 (ptr docs: make it clear that we are talking only about memory accesses)
 - rust-lang#134932 (explicitly set float ABI for all ARM targets)
 - rust-lang#134933 (Make sure we check the future type is `Sized` in `AsyncFn*`)
 - rust-lang#134934 (Fix typos)
 - rust-lang#134941 (compiler: Add a statement-of-intent to `rustc_abi`)
 - rust-lang#134949 (Convert some `Into` impls into `From` impls)

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

compiler/rustc_abi/src/lib.rs

@@ -8,6 +8,38 @@
 #![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
+/*! ABI handling for rustc
+
+## What is an "ABI"?
+
+Literally, "application binary interface", which means it is everything about how code interacts,
+at the machine level, with other code. This means it technically covers all of the following:
+- object binary format for e.g. relocations or offset tables
+- in-memory layout of types
+- procedure calling conventions
+
+When we discuss "ABI" in the context of rustc, we are probably discussing calling conventions.
+To describe those `rustc_abi` also covers type layout, as it must for values passed on the stack.
+Despite `rustc_abi` being about calling conventions, it is good to remember these usages exist.
+You will encounter all of them and more if you study target-specific codegen enough!
+Even in general conversation, when someone says "the Rust ABI is unstable", it may allude to
+either or both of
+- `repr(Rust)` types have a mostly-unspecified layout
+- `extern "Rust" fn(A) -> R` has an unspecified calling convention
+
+## Crate Goal
+
+ABI is a foundational concept, so the `rustc_abi` crate serves as an equally foundational crate.
+It cannot carry all details relevant to an ABI: those permeate code generation and linkage.
+Instead, `rustc_abi` is intended to provide the interface for reasoning about the binary interface.
+It should contain traits and types that other crates then use in their implementation.
+For example, a platform's `extern "C" fn` calling convention will be implemented in `rustc_target`
+but `rustc_abi` contains the types for calculating layout and describing register-passing.
+This makes it easier to describe things in the same way across targets, codegen backends, and
+even other Rust compilers, such as rust-analyzer!
+
+*/
+
 use std::fmt;
 #[cfg(feature = "nightly")]
 use std::iter::Step;

compiler/rustc_ast/src/ast.rs

@@ -241,15 +241,15 @@ impl AngleBracketedArg {
     }
 }
 
-impl Into<P<GenericArgs>> for AngleBracketedArgs {
-    fn into(self) -> P<GenericArgs> {
-        P(GenericArgs::AngleBracketed(self))
+impl From<AngleBracketedArgs> for P<GenericArgs> {
+    fn from(val: AngleBracketedArgs) -> Self {
+        P(GenericArgs::AngleBracketed(val))
     }
 }
 
-impl Into<P<GenericArgs>> for ParenthesizedArgs {
-    fn into(self) -> P<GenericArgs> {
-        P(GenericArgs::Parenthesized(self))
+impl From<ParenthesizedArgs> for P<GenericArgs> {
+    fn from(val: ParenthesizedArgs) -> Self {
+        P(GenericArgs::Parenthesized(val))
     }
 }
 

compiler/rustc_ast/src/ptr.rs

@@ -158,9 +158,9 @@ impl<T> From<Vec<T>> for P<[T]> {
     }
 }
 
-impl<T> Into<Vec<T>> for P<[T]> {
-    fn into(self) -> Vec<T> {
-        self.into_vec()
+impl<T> From<P<[T]>> for Vec<T> {
+    fn from(val: P<[T]>) -> Self {
+        val.into_vec()
     }
 }
 

compiler/rustc_codegen_llvm/src/back/owned_target_machine.rs

@@ -25,7 +25,7 @@ impl OwnedTargetMachine {
         model: llvm::CodeModel,
         reloc: llvm::RelocModel,
         level: llvm::CodeGenOptLevel,
-        use_soft_fp: bool,
+        float_abi: llvm::FloatAbi,
         function_sections: bool,
         data_sections: bool,
         unique_section_names: bool,
@@ -57,7 +57,7 @@ impl OwnedTargetMachine {
                 model,
                 reloc,
                 level,
-                use_soft_fp,
+                float_abi,
                 function_sections,
                 data_sections,
                 unique_section_names,

compiler/rustc_codegen_llvm/src/back/write.rs

@@ -26,7 +26,7 @@ use rustc_session::config::{
     self, Lto, OutputType, Passes, RemapPathScopeComponents, SplitDwarfKind, SwitchWithOptPath,
 };
 use rustc_span::{BytePos, InnerSpan, Pos, SpanData, SyntaxContext, sym};
-use rustc_target::spec::{CodeModel, RelocModel, SanitizerSet, SplitDebuginfo, TlsModel};
+use rustc_target::spec::{CodeModel, FloatAbi, RelocModel, SanitizerSet, SplitDebuginfo, TlsModel};
 use tracing::debug;
 
 use crate::back::lto::ThinBuffer;
@@ -181,6 +181,14 @@ pub(crate) fn to_llvm_code_model(code_model: Option<CodeModel>) -> llvm::CodeMod
     }
 }
 
+fn to_llvm_float_abi(float_abi: Option<FloatAbi>) -> llvm::FloatAbi {
+    match float_abi {
+        None => llvm::FloatAbi::Default,
+        Some(FloatAbi::Soft) => llvm::FloatAbi::Soft,
+        Some(FloatAbi::Hard) => llvm::FloatAbi::Hard,
+    }
+}
+
 pub(crate) fn target_machine_factory(
     sess: &Session,
     optlvl: config::OptLevel,
@@ -189,12 +197,12 @@ pub(crate) fn target_machine_factory(
     let reloc_model = to_llvm_relocation_model(sess.relocation_model());
 
     let (opt_level, _) = to_llvm_opt_settings(optlvl);
-    let use_softfp = if sess.target.arch == "arm" {
-        sess.opts.cg.soft_float
+    let float_abi = if sess.target.arch == "arm" && sess.opts.cg.soft_float {
+        llvm::FloatAbi::Soft
     } else {
         // `validate_commandline_args_with_session_available` has already warned about this being
         // ignored. Let's make sure LLVM doesn't suddenly start using this flag on more targets.
-        false
+        to_llvm_float_abi(sess.target.llvm_floatabi)
     };
 
     let ffunction_sections =
@@ -290,7 +298,7 @@ pub(crate) fn target_machine_factory(
             code_model,
             reloc_model,
             opt_level,
-            use_softfp,
+            float_abi,
             ffunction_sections,
             fdata_sections,
             funique_section_names,

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -526,7 +526,7 @@ pub struct SanitizerOptions {
     pub sanitize_kernel_address_recover: bool,
 }
 
-/// LLVMRelocMode
+/// LLVMRustRelocModel
 #[derive(Copy, Clone, PartialEq)]
 #[repr(C)]
 pub enum RelocModel {
@@ -538,6 +538,15 @@ pub enum RelocModel {
     ROPI_RWPI,
 }
 
+/// LLVMRustFloatABI
+#[derive(Copy, Clone, PartialEq)]
+#[repr(C)]
+pub enum FloatAbi {
+    Default,
+    Soft,
+    Hard,
+}
+
 /// LLVMRustCodeModel
 #[derive(Copy, Clone)]
 #[repr(C)]
@@ -2192,7 +2201,7 @@ unsafe extern "C" {
         Model: CodeModel,
         Reloc: RelocModel,
         Level: CodeGenOptLevel,
-        UseSoftFP: bool,
+        FloatABIType: FloatAbi,
         FunctionSections: bool,
         DataSections: bool,
         UniqueSectionNames: bool,

compiler/rustc_error_messages/src/lib.rs

@@ -357,9 +357,9 @@ impl From<Cow<'static, str>> for DiagMessage {
 /// subdiagnostic derive refers to typed identifiers that are `DiagMessage`s, so need to be
 /// able to convert between these, as much as they'll be converted back into `DiagMessage`
 /// using `with_subdiagnostic_message` eventually. Don't use this other than for the derive.
-impl Into<SubdiagMessage> for DiagMessage {
-    fn into(self) -> SubdiagMessage {
-        match self {
+impl From<DiagMessage> for SubdiagMessage {
+    fn from(val: DiagMessage) -> Self {
+        match val {
             DiagMessage::Str(s) => SubdiagMessage::Str(s),
             DiagMessage::Translated(s) => SubdiagMessage::Translated(s),
             DiagMessage::FluentIdentifier(id, None) => SubdiagMessage::FluentIdentifier(id),

compiler/rustc_errors/src/diagnostic.rs

@@ -156,9 +156,9 @@ impl IntoDiagArg for DiagArgValue {
     }
 }
 
-impl Into<FluentValue<'static>> for DiagArgValue {
-    fn into(self) -> FluentValue<'static> {
-        match self {
+impl From<DiagArgValue> for FluentValue<'static> {
+    fn from(val: DiagArgValue) -> Self {
+        match val {
             DiagArgValue::Str(s) => From::from(s),
             DiagArgValue::Number(n) => From::from(n),
             DiagArgValue::StrListSepByAnd(l) => fluent_value_from_str_list_sep_by_and(l),

compiler/rustc_hir/src/hir.rs

@@ -4072,33 +4072,33 @@ impl<'hir> OwnerNode<'hir> {
     }
 }
 
-impl<'hir> Into<OwnerNode<'hir>> for &'hir Item<'hir> {
-    fn into(self) -> OwnerNode<'hir> {
-        OwnerNode::Item(self)
+impl<'hir> From<&'hir Item<'hir>> for OwnerNode<'hir> {
+    fn from(val: &'hir Item<'hir>) -> Self {
+        OwnerNode::Item(val)
     }
 }
 
-impl<'hir> Into<OwnerNode<'hir>> for &'hir ForeignItem<'hir> {
-    fn into(self) -> OwnerNode<'hir> {
-        OwnerNode::ForeignItem(self)
+impl<'hir> From<&'hir ForeignItem<'hir>> for OwnerNode<'hir> {
+    fn from(val: &'hir ForeignItem<'hir>) -> Self {
+        OwnerNode::ForeignItem(val)
     }
 }
 
-impl<'hir> Into<OwnerNode<'hir>> for &'hir ImplItem<'hir> {
-    fn into(self) -> OwnerNode<'hir> {
-        OwnerNode::ImplItem(self)
+impl<'hir> From<&'hir ImplItem<'hir>> for OwnerNode<'hir> {
+    fn from(val: &'hir ImplItem<'hir>) -> Self {
+        OwnerNode::ImplItem(val)
     }
 }
 
-impl<'hir> Into<OwnerNode<'hir>> for &'hir TraitItem<'hir> {
-    fn into(self) -> OwnerNode<'hir> {
-        OwnerNode::TraitItem(self)
+impl<'hir> From<&'hir TraitItem<'hir>> for OwnerNode<'hir> {
+    fn from(val: &'hir TraitItem<'hir>) -> Self {
+        OwnerNode::TraitItem(val)
     }
 }
 
-impl<'hir> Into<Node<'hir>> for OwnerNode<'hir> {
-    fn into(self) -> Node<'hir> {
-        match self {
+impl<'hir> From<OwnerNode<'hir>> for Node<'hir> {
+    fn from(val: OwnerNode<'hir>) -> Self {
+        match val {
             OwnerNode::Item(n) => Node::Item(n),
             OwnerNode::ForeignItem(n) => Node::ForeignItem(n),
             OwnerNode::ImplItem(n) => Node::ImplItem(n),

compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp

@@ -308,6 +308,24 @@ static Reloc::Model fromRust(LLVMRustRelocModel RustReloc) {
   report_fatal_error("Bad RelocModel.");
 }
 
+enum class LLVMRustFloatABI {
+  Default,
+  Soft,
+  Hard,
+};
+
+static FloatABI::ABIType fromRust(LLVMRustFloatABI RustFloatAbi) {
+  switch (RustFloatAbi) {
+  case LLVMRustFloatABI::Default:
+    return FloatABI::Default;
+  case LLVMRustFloatABI::Soft:
+    return FloatABI::Soft;
+  case LLVMRustFloatABI::Hard:
+    return FloatABI::Hard;
+  }
+  report_fatal_error("Bad FloatABI.");
+}
+
 /// getLongestEntryLength - Return the length of the longest entry in the table.
 template <typename KV> static size_t getLongestEntryLength(ArrayRef<KV> Table) {
   size_t MaxLen = 0;
@@ -358,7 +376,7 @@ extern "C" const char *LLVMRustGetHostCPUName(size_t *OutLen) {
 extern "C" LLVMTargetMachineRef LLVMRustCreateTargetMachine(
     const char *TripleStr, const char *CPU, const char *Feature,
     const char *ABIStr, LLVMRustCodeModel RustCM, LLVMRustRelocModel RustReloc,
-    LLVMRustCodeGenOptLevel RustOptLevel, bool UseSoftFloat,
+    LLVMRustCodeGenOptLevel RustOptLevel, LLVMRustFloatABI RustFloatABIType,
     bool FunctionSections, bool DataSections, bool UniqueSectionNames,
     bool TrapUnreachable, bool Singlethread, bool VerboseAsm,
     bool EmitStackSizeSection, bool RelaxELFRelocations, bool UseInitArray,
@@ -369,6 +387,7 @@ extern "C" LLVMTargetMachineRef LLVMRustCreateTargetMachine(
   auto OptLevel = fromRust(RustOptLevel);
   auto RM = fromRust(RustReloc);
   auto CM = fromRust(RustCM);
+  auto FloatABIType = fromRust(RustFloatABIType);
 
   std::string Error;
   auto Trip = Triple(Triple::normalize(TripleStr));
@@ -381,10 +400,7 @@ extern "C" LLVMTargetMachineRef LLVMRustCreateTargetMachine(
 
   TargetOptions Options = codegen::InitTargetOptionsFromCodeGenFlags(Trip);
 
-  Options.FloatABIType = FloatABI::Default;
-  if (UseSoftFloat) {
-    Options.FloatABIType = FloatABI::Soft;
-  }
+  Options.FloatABIType = FloatABIType;
   Options.DataSections = DataSections;
   Options.FunctionSections = FunctionSections;
   Options.UniqueSectionNames = UniqueSectionNames;