Auto merge of #151325 - JonathanBrouwer:rollup-YoCcqTr, r=JonathanBrouwer

Rollup of 7 pull requests

Successful merges:

 - #150767 (Allow invoking all help options at once)
 - #150886 (Added mGCA related tests)
 - #151245 (Explicitly list crate level attrs)
 - #151268 (Fix ICE on inconsistent import resolution with macro-attributed extern crate)
 - #151275 (Normalize type_const items even with feature `generic_const_exprs`)
 - #151288 (Use `find_attr` instead of `attr::contains_name` in `lower_const_item_rhs`)
 - #151321 (Port #![no_main] to the attribute parser.)

r? @ghost

Author: bors

compiler/rustc_ast_lowering/src/lib.rs

@@ -2384,7 +2384,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
             Some(ConstItemRhs::TypeConst(anon)) => {
                 hir::ConstItemRhs::TypeConst(self.lower_anon_const_to_const_arg_and_alloc(anon))
             }
-            None if attr::contains_name(attrs, sym::type_const) => {
+            None if find_attr!(attrs, AttributeKind::TypeConst(_)) => {
                 let const_arg = ConstArg {
                     hir_id: self.next_id(),
                     kind: hir::ConstArgKind::Error(

compiler/rustc_attr_parsing/src/attributes/crate_level.rs

@@ -136,6 +136,15 @@ impl<S: Stage> NoArgsAttributeParser<S> for NoStdParser {
     const CREATE: fn(Span) -> AttributeKind = AttributeKind::NoStd;
 }
 
+pub(crate) struct NoMainParser;
+
+impl<S: Stage> NoArgsAttributeParser<S> for NoMainParser {
+    const PATH: &[Symbol] = &[sym::no_main];
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Warn;
+    const ALLOWED_TARGETS: AllowedTargets = AllowedTargets::AllowList(&[Allow(Target::Crate)]);
+    const CREATE: fn(Span) -> AttributeKind = |_| AttributeKind::NoMain;
+}
+
 pub(crate) struct RustcCoherenceIsCoreParser;
 
 impl<S: Stage> NoArgsAttributeParser<S> for RustcCoherenceIsCoreParser {

compiler/rustc_attr_parsing/src/context.rs

@@ -28,9 +28,9 @@ use crate::attributes::codegen_attrs::{
 };
 use crate::attributes::confusables::ConfusablesParser;
 use crate::attributes::crate_level::{
-    CrateNameParser, MoveSizeLimitParser, NoCoreParser, NoStdParser, PatternComplexityLimitParser,
-    RecursionLimitParser, RustcCoherenceIsCoreParser, TypeLengthLimitParser,
-    WindowsSubsystemParser,
+    CrateNameParser, MoveSizeLimitParser, NoCoreParser, NoMainParser, NoStdParser,
+    PatternComplexityLimitParser, RecursionLimitParser, RustcCoherenceIsCoreParser,
+    TypeLengthLimitParser, WindowsSubsystemParser,
 };
 use crate::attributes::debugger::DebuggerViualizerParser;
 use crate::attributes::deprecation::DeprecationParser;
@@ -263,6 +263,7 @@ attribute_parsers!(
         Single<WithoutArgs<NoCoreParser>>,
         Single<WithoutArgs<NoImplicitPreludeParser>>,
         Single<WithoutArgs<NoLinkParser>>,
+        Single<WithoutArgs<NoMainParser>>,
         Single<WithoutArgs<NoMangleParser>>,
         Single<WithoutArgs<NoStdParser>>,
         Single<WithoutArgs<NonExhaustiveParser>>,

compiler/rustc_driver_impl/src/lib.rs

@@ -228,8 +228,10 @@ pub fn run_compiler(at_args: &[String], callbacks: &mut (dyn Callbacks + Send))
 
     let args = args::arg_expand_all(&default_early_dcx, at_args);
 
-    let Some(matches) = handle_options(&default_early_dcx, &args) else {
-        return;
+    let (matches, help_only) = match handle_options(&default_early_dcx, &args) {
+        HandledOptions::None => return,
+        HandledOptions::Normal(matches) => (matches, false),
+        HandledOptions::HelpOnly(matches) => (matches, true),
     };
 
     let sopts = config::build_session_options(&mut default_early_dcx, &matches);
@@ -291,6 +293,11 @@ pub fn run_compiler(at_args: &[String], callbacks: &mut (dyn Callbacks + Send))
             return early_exit();
         }
 
+        // We have now handled all help options, exit
+        if help_only {
+            return early_exit();
+        }
+
         if print_crate_info(codegen_backend, sess, has_input) == Compilation::Stop {
             return early_exit();
         }
@@ -1097,7 +1104,7 @@ pub fn describe_flag_categories(early_dcx: &EarlyDiagCtxt, matches: &Matches) ->
     // Don't handle -W help here, because we might first load additional lints.
     let debug_flags = matches.opt_strs("Z");
     if debug_flags.iter().any(|x| *x == "help") {
-        describe_debug_flags();
+        describe_unstable_flags();
         return true;
     }
 
@@ -1137,8 +1144,8 @@ fn get_backend_from_raw_matches(
     get_codegen_backend(early_dcx, &sysroot, backend_name, &target)
 }
 
-fn describe_debug_flags() {
-    safe_println!("\nAvailable options:\n");
+fn describe_unstable_flags() {
+    safe_println!("\nAvailable unstable options:\n");
     print_flag_list("-Z", config::Z_OPTIONS);
 }
 
@@ -1162,6 +1169,16 @@ fn print_flag_list<T>(cmdline_opt: &str, flag_list: &[OptionDesc<T>]) {
     }
 }
 
+pub enum HandledOptions {
+    /// Parsing failed, or we parsed a flag causing an early exit
+    None,
+    /// Successful parsing
+    Normal(getopts::Matches),
+    /// Parsing succeeded, but we received one or more 'help' flags
+    /// The compiler should proceed only until a possible `-W help` flag has been processed
+    HelpOnly(getopts::Matches),
+}
+
 /// Process command line options. Emits messages as appropriate. If compilation
 /// should continue, returns a getopts::Matches object parsed from args,
 /// otherwise returns `None`.
@@ -1189,7 +1206,7 @@ fn print_flag_list<T>(cmdline_opt: &str, flag_list: &[OptionDesc<T>]) {
 /// This does not need to be `pub` for rustc itself, but @chaosite needs it to
 /// be public when using rustc as a library, see
 /// <https://github.com/rust-lang/rust/commit/2b4c33817a5aaecabf4c6598d41e190080ec119e>
-pub fn handle_options(early_dcx: &EarlyDiagCtxt, args: &[String]) -> Option<getopts::Matches> {
+pub fn handle_options(early_dcx: &EarlyDiagCtxt, args: &[String]) -> HandledOptions {
     // Parse with *all* options defined in the compiler, we don't worry about
     // option stability here we just want to parse as much as possible.
     let mut options = getopts::Options::new();
@@ -1235,26 +1252,69 @@ pub fn handle_options(early_dcx: &EarlyDiagCtxt, args: &[String]) -> Option<geto
     //   (unstable option being used on stable)
     nightly_options::check_nightly_options(early_dcx, &matches, &config::rustc_optgroups());
 
-    if args.is_empty() || matches.opt_present("h") || matches.opt_present("help") {
-        // Only show unstable options in --help if we accept unstable options.
-        let unstable_enabled = nightly_options::is_unstable_enabled(&matches);
-        let nightly_build = nightly_options::match_is_nightly_build(&matches);
-        usage(matches.opt_present("verbose"), unstable_enabled, nightly_build);
-        return None;
+    // Handle the special case of -Wall.
+    let wall = matches.opt_strs("W");
+    if wall.iter().any(|x| *x == "all") {
+        print_wall_help();
+        return HandledOptions::None;
     }
 
-    if describe_flag_categories(early_dcx, &matches) {
-        return None;
+    if handle_help(&matches, args) {
+        return HandledOptions::HelpOnly(matches);
+    }
+
+    if matches.opt_strs("C").iter().any(|x| x == "passes=list") {
+        get_backend_from_raw_matches(early_dcx, &matches).print_passes();
+        return HandledOptions::None;
     }
 
     if matches.opt_present("version") {
         version!(early_dcx, "rustc", &matches);
-        return None;
+        return HandledOptions::None;
     }
 
     warn_on_confusing_output_filename_flag(early_dcx, &matches, args);
 
-    Some(matches)
+    HandledOptions::Normal(matches)
+}
+
+/// Handle help options in the order they are provided, ignoring other flags. Returns if any options were handled
+/// Handled options:
+/// - `-h`/`--help`/empty arguments
+/// - `-Z help`
+/// - `-C help`
+/// NOTE: `-W help` is NOT handled here, as additional lints may be loaded.
+pub fn handle_help(matches: &getopts::Matches, args: &[String]) -> bool {
+    let opt_pos = |opt| matches.opt_positions(opt).first().copied();
+    let opt_help_pos = |opt| {
+        matches
+            .opt_strs_pos(opt)
+            .iter()
+            .filter_map(|(pos, oval)| if oval == "help" { Some(*pos) } else { None })
+            .next()
+    };
+    let help_pos = if args.is_empty() { Some(0) } else { opt_pos("h").or_else(|| opt_pos("help")) };
+    let zhelp_pos = opt_help_pos("Z");
+    let chelp_pos = opt_help_pos("C");
+    let print_help = || {
+        // Only show unstable options in --help if we accept unstable options.
+        let unstable_enabled = nightly_options::is_unstable_enabled(&matches);
+        let nightly_build = nightly_options::match_is_nightly_build(&matches);
+        usage(matches.opt_present("verbose"), unstable_enabled, nightly_build);
+    };
+
+    let mut helps = [
+        (help_pos, &print_help as &dyn Fn()),
+        (zhelp_pos, &describe_unstable_flags),
+        (chelp_pos, &describe_codegen_flags),
+    ];
+    helps.sort_by_key(|(pos, _)| pos.clone());
+    let mut printed_any = false;
+    for printer in helps.iter().filter_map(|(pos, func)| pos.is_some().then_some(func)) {
+        printer();
+        printed_any = true;
+    }
+    printed_any
 }
 
 /// Warn if `-o` is used without a space between the flag name and the value

compiler/rustc_hir/src/attrs/data_structures.rs

@@ -852,6 +852,9 @@ pub enum AttributeKind {
     /// Represents `#[no_link]`
     NoLink,
 
+    /// Represents `#[no_main]`
+    NoMain,
+
     /// Represents `#[no_mangle]`
     NoMangle(Span),
 

compiler/rustc_hir/src/attrs/encode_cross_crate.rs

@@ -79,6 +79,7 @@ impl AttributeKind {
             NoCore(..) => No,
             NoImplicitPrelude(..) => No,
             NoLink => No,
+            NoMain => No,
             NoMangle(..) => Yes, // Needed for rustdoc
             NoStd(..) => No,
             NonExhaustive(..) => Yes, // Needed for rustdoc

compiler/rustc_passes/src/check_attr.rs

@@ -297,6 +297,7 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                     | AttributeKind::PatternComplexityLimit { .. }
                     | AttributeKind::NoCore { .. }
                     | AttributeKind::NoStd { .. }
+                    | AttributeKind::NoMain
                     | AttributeKind::ObjcClass { .. }
                     | AttributeKind::ObjcSelector { .. }
                     | AttributeKind::RustcCoherenceIsCore(..)
@@ -389,13 +390,25 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                             | sym::rustc_partition_reused
                             | sym::rustc_partition_codegened
                             | sym::rustc_expected_cgu_reuse
-                            | sym::rustc_nounwind,
+                            | sym::rustc_nounwind
+                            // crate-level attrs, are checked below
+                            | sym::feature
+                            | sym::register_tool
+                            | sym::rustc_no_implicit_bounds
+                            | sym::test_runner
+                            | sym::reexport_test_harness_main
+                            | sym::no_main
+                            | sym::no_builtins
+                            | sym::crate_type
+                            | sym::compiler_builtins
+                            | sym::profiler_runtime
+                            | sym::needs_panic_runtime
+                            | sym::panic_runtime
+                            | sym::rustc_preserve_ub_checks,
                             ..
                         ] => {}
                         [name, rest@..] => {
                             match BUILTIN_ATTRIBUTE_MAP.get(name) {
-                                // checked below
-                                Some(BuiltinAttribute { type_: AttributeType::CrateLevel, .. }) => {}
                                 Some(_) => {
                                     if rest.len() > 0 && AttributeParser::<Late>::is_parsed_attribute(slice::from_ref(name)) {
                                         // Check if we tried to use a builtin attribute as an attribute namespace, like `#[must_use::skip]`.

compiler/rustc_passes/src/entry.rs

@@ -1,4 +1,3 @@
-use rustc_ast::attr;
 use rustc_ast::entry::EntryPointType;
 use rustc_errors::codes::*;
 use rustc_hir::attrs::AttributeKind;
@@ -7,7 +6,7 @@ use rustc_hir::{CRATE_HIR_ID, ItemId, Node, find_attr};
 use rustc_middle::query::Providers;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::config::{CrateType, EntryFnType, sigpipe};
-use rustc_span::{RemapPathScopeComponents, Span, sym};
+use rustc_span::{RemapPathScopeComponents, Span};
 
 use crate::errors::{ExternMain, MultipleRustcMain, NoMainErr};
 
@@ -30,7 +29,7 @@ fn entry_fn(tcx: TyCtxt<'_>, (): ()) -> Option<(DefId, EntryFnType)> {
     }
 
     // If the user wants no main function at all, then stop here.
-    if attr::contains_name(tcx.hir_attrs(CRATE_HIR_ID), sym::no_main) {
+    if find_attr!(tcx.hir_attrs(CRATE_HIR_ID), AttributeKind::NoMain) {
         return None;
     }
 

compiler/rustc_resolve/src/imports.rs

@@ -989,7 +989,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             PathResult::Module(module) => {
                 // Consistency checks, analogous to `finalize_macro_resolutions`.
                 if let Some(initial_module) = import.imported_module.get() {
-                    if module != initial_module && no_ambiguity {
+                    if module != initial_module && no_ambiguity && !self.issue_145575_hack_applied {
                         span_bug!(import.span, "inconsistent resolution for an import");
                     }
                 } else if self.privacy_errors.is_empty() {

compiler/rustc_session/src/options.rs

@@ -2126,6 +2126,7 @@ options! {
     #[rustc_lint_opt_deny_field_access("use `Session::must_emit_unwind_tables` instead of this field")]
     force_unwind_tables: Option<bool> = (None, parse_opt_bool, [TRACKED],
         "force use of unwind tables"),
+    help: bool = (false, parse_no_value, [UNTRACKED], "Print codegen options"),
     incremental: Option<String> = (None, parse_opt_string, [UNTRACKED],
         "enable incremental compilation"),
     #[rustc_lint_opt_deny_field_access("documented to do nothing")]
@@ -2398,6 +2399,7 @@ options! {
         environment variable `RUSTC_GRAPHVIZ_FONT` (default: `Courier, monospace`)"),
     has_thread_local: Option<bool> = (None, parse_opt_bool, [TRACKED],
         "explicitly enable the `cfg(target_thread_local)` directive"),
+    help: bool = (false, parse_no_value, [UNTRACKED], "Print unstable compiler options"),
     higher_ranked_assumptions: bool = (false, parse_bool, [TRACKED],
         "allow deducing higher-ranked outlives assumptions from coroutines when proving auto traits"),
     hint_mostly_unused: bool = (false, parse_bool, [TRACKED],