Rollup of 8 pull requests

compiler/rustc_builtin_macros/src/test_harness.rs

@@ -63,8 +63,8 @@ pub fn inject(
 
     if sess.is_test_crate() {
         let panic_strategy = match (panic_strategy, sess.opts.unstable_opts.panic_abort_tests) {
-            (PanicStrategy::Abort, true) => PanicStrategy::Abort,
-            (PanicStrategy::Abort, false) => {
+            (PanicStrategy::Abort | PanicStrategy::ImmediateAbort, true) => panic_strategy,
+            (PanicStrategy::Abort | PanicStrategy::ImmediateAbort, false) => {
                 if panic_strategy == platform_panic_strategy {
                     // Silently allow compiling with panic=abort on these platforms,
                     // but with old behavior (abort if a test fails).
@@ -287,10 +287,8 @@ fn mk_main(cx: &mut TestCtxt<'_>) -> Box<ast::Item> {
     let ecx = &cx.ext_cx;
     let test_ident = Ident::new(sym::test, sp);
 
-    let runner_name = match cx.panic_strategy {
-        PanicStrategy::Unwind => "test_main_static",
-        PanicStrategy::Abort => "test_main_static_abort",
-    };
+    let runner_name =
+        if cx.panic_strategy.unwinds() { "test_main_static" } else { "test_main_static_abort" };
 
     // test::test_main_static(...)
     let mut test_runner = cx.test_runner.clone().unwrap_or_else(|| {

compiler/rustc_codegen_gcc/src/asm.rs

@@ -698,8 +698,12 @@ fn reg_class_to_gcc(reg_class: InlineAsmRegClass) -> &'static str {
         InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::reg_nonzero) => "b",
         InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::freg) => "f",
         InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::vreg) => "v",
-        InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::cr)
-        | InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::xer) => {
+        InlineAsmRegClass::PowerPC(
+            PowerPCInlineAsmRegClass::cr
+            | PowerPCInlineAsmRegClass::ctr
+            | PowerPCInlineAsmRegClass::lr
+            | PowerPCInlineAsmRegClass::xer,
+        ) => {
             unreachable!("clobber-only")
         }
         InlineAsmRegClass::RiscV(RiscVInlineAsmRegClass::reg) => "r",
@@ -777,8 +781,12 @@ fn dummy_output_type<'gcc, 'tcx>(cx: &CodegenCx<'gcc, 'tcx>, reg: InlineAsmRegCl
         InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::vreg) => {
             cx.type_vector(cx.type_i32(), 4)
         }
-        InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::cr)
-        | InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::xer) => {
+        InlineAsmRegClass::PowerPC(
+            PowerPCInlineAsmRegClass::cr
+            | PowerPCInlineAsmRegClass::ctr
+            | PowerPCInlineAsmRegClass::lr
+            | PowerPCInlineAsmRegClass::xer,
+        ) => {
             unreachable!("clobber-only")
         }
         InlineAsmRegClass::RiscV(RiscVInlineAsmRegClass::reg) => cx.type_i32(),

compiler/rustc_codegen_gcc/src/base.rs

@@ -15,9 +15,9 @@ use rustc_middle::mir::mono::Visibility;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::config::DebugInfo;
 use rustc_span::Symbol;
+use rustc_target::spec::RelocModel;
 #[cfg(feature = "master")]
 use rustc_target::spec::SymbolVisibility;
-use rustc_target::spec::{PanicStrategy, RelocModel};
 
 use crate::builder::Builder;
 use crate::context::CodegenCx;
@@ -101,7 +101,7 @@ pub fn compile_codegen_unit(
         // Instantiate monomorphizations without filling out definitions yet...
         let context = new_context(tcx);
 
-        if tcx.sess.panic_strategy() == PanicStrategy::Unwind {
+        if tcx.sess.panic_strategy().unwinds() {
             context.add_command_line_option("-fexceptions");
             context.add_driver_option("-fexceptions");
         }

compiler/rustc_codegen_gcc/src/intrinsic/mod.rs

@@ -29,7 +29,6 @@ use rustc_middle::ty::layout::LayoutOf;
 use rustc_middle::ty::{self, Instance, Ty};
 use rustc_span::{Span, Symbol, sym};
 use rustc_target::callconv::{ArgAbi, PassMode};
-use rustc_target::spec::PanicStrategy;
 
 #[cfg(feature = "master")]
 use crate::abi::FnAbiGccExt;
@@ -1334,7 +1333,7 @@ fn try_intrinsic<'a, 'b, 'gcc, 'tcx>(
     _catch_func: RValue<'gcc>,
     dest: PlaceRef<'tcx, RValue<'gcc>>,
 ) {
-    if bx.sess().panic_strategy() == PanicStrategy::Abort {
+    if !bx.sess().panic_strategy().unwinds() {
         bx.call(bx.type_void(), None, None, try_func, &[data], None, None);
         // Return 0 unconditionally from the intrinsic call;
         // we can never unwind.

compiler/rustc_codegen_llvm/src/asm.rs

@@ -340,8 +340,8 @@ impl<'ll, 'tcx> AsmBuilderMethods<'tcx> for Builder<'_, 'll, 'tcx> {
             attrs.push(llvm::AttributeKind::WillReturn.create_attr(self.cx.llcx));
         } else if options.contains(InlineAsmOptions::NOMEM) {
             attrs.push(llvm::MemoryEffects::InaccessibleMemOnly.create_attr(self.cx.llcx));
-        } else {
-            // LLVM doesn't have an attribute to represent ReadOnly + SideEffect
+        } else if options.contains(InlineAsmOptions::READONLY) {
+            attrs.push(llvm::MemoryEffects::ReadOnlyNotPure.create_attr(self.cx.llcx));
         }
         attributes::apply_to_callsite(result, llvm::AttributePlace::Function, &{ attrs });
 
@@ -662,7 +662,12 @@ fn reg_to_llvm(reg: InlineAsmRegOrRegClass, layout: Option<&TyAndLayout<'_>>) ->
             PowerPC(PowerPCInlineAsmRegClass::reg_nonzero) => "b",
             PowerPC(PowerPCInlineAsmRegClass::freg) => "f",
             PowerPC(PowerPCInlineAsmRegClass::vreg) => "v",
-            PowerPC(PowerPCInlineAsmRegClass::cr) | PowerPC(PowerPCInlineAsmRegClass::xer) => {
+            PowerPC(
+                PowerPCInlineAsmRegClass::cr
+                | PowerPCInlineAsmRegClass::ctr
+                | PowerPCInlineAsmRegClass::lr
+                | PowerPCInlineAsmRegClass::xer,
+            ) => {
                 unreachable!("clobber-only")
             }
             RiscV(RiscVInlineAsmRegClass::reg) => "r",
@@ -830,7 +835,12 @@ fn dummy_output_type<'ll>(cx: &CodegenCx<'ll, '_>, reg: InlineAsmRegClass) -> &'
         PowerPC(PowerPCInlineAsmRegClass::reg_nonzero) => cx.type_i32(),
         PowerPC(PowerPCInlineAsmRegClass::freg) => cx.type_f64(),
         PowerPC(PowerPCInlineAsmRegClass::vreg) => cx.type_vector(cx.type_i32(), 4),
-        PowerPC(PowerPCInlineAsmRegClass::cr) | PowerPC(PowerPCInlineAsmRegClass::xer) => {
+        PowerPC(
+            PowerPCInlineAsmRegClass::cr
+            | PowerPCInlineAsmRegClass::ctr
+            | PowerPCInlineAsmRegClass::lr
+            | PowerPCInlineAsmRegClass::xer,
+        ) => {
             unreachable!("clobber-only")
         }
         RiscV(RiscVInlineAsmRegClass::reg) => cx.type_i32(),

compiler/rustc_codegen_llvm/src/intrinsic.rs

@@ -18,7 +18,6 @@ use rustc_middle::{bug, span_bug};
 use rustc_span::{Span, Symbol, sym};
 use rustc_symbol_mangling::{mangle_internal_symbol, symbol_name_for_instance_in_crate};
 use rustc_target::callconv::PassMode;
-use rustc_target::spec::PanicStrategy;
 use tracing::debug;
 
 use crate::abi::FnAbiLlvmExt;
@@ -674,7 +673,7 @@ fn catch_unwind_intrinsic<'ll, 'tcx>(
     catch_func: &'ll Value,
     dest: PlaceRef<'tcx, &'ll Value>,
 ) {
-    if bx.sess().panic_strategy() == PanicStrategy::Abort {
+    if !bx.sess().panic_strategy().unwinds() {
         let try_func_ty = bx.type_func(&[bx.type_ptr()], bx.type_void());
         bx.call(try_func_ty, None, None, try_func, &[data], None, None);
         // Return 0 unconditionally from the intrinsic call;

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -710,6 +710,7 @@ pub(crate) enum MemoryEffects {
     None,
     ReadOnly,
     InaccessibleMemOnly,
+    ReadOnlyNotPure,
 }
 
 /// LLVMOpcode

compiler/rustc_codegen_llvm/src/llvm_util.rs

@@ -106,7 +106,7 @@ unsafe fn configure_llvm(sess: &Session) {
 
         if sess.target.os == "emscripten"
             && !sess.opts.unstable_opts.emscripten_wasm_eh
-            && sess.panic_strategy() == PanicStrategy::Unwind
+            && sess.panic_strategy().unwinds()
         {
             add("-enable-emscripten-cxx-exceptions", false);
         }

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -47,8 +47,8 @@ use rustc_span::Symbol;
 use rustc_target::spec::crt_objects::CrtObjects;
 use rustc_target::spec::{
     BinaryFormat, Cc, LinkOutputKind, LinkSelfContainedComponents, LinkSelfContainedDefault,
-    LinkerFeatures, LinkerFlavor, LinkerFlavorCli, Lld, PanicStrategy, RelocModel, RelroLevel,
-    SanitizerSet, SplitDebuginfo,
+    LinkerFeatures, LinkerFlavor, LinkerFlavorCli, Lld, RelocModel, RelroLevel, SanitizerSet,
+    SplitDebuginfo,
 };
 use tracing::{debug, info, warn};
 
@@ -2512,10 +2512,10 @@ fn add_order_independent_options(
     if sess.target.os == "emscripten" {
         cmd.cc_arg(if sess.opts.unstable_opts.emscripten_wasm_eh {
             "-fwasm-exceptions"
-        } else if sess.panic_strategy() == PanicStrategy::Abort {
-            "-sDISABLE_EXCEPTION_CATCHING=1"
-        } else {
+        } else if sess.panic_strategy().unwinds() {
             "-sDISABLE_EXCEPTION_CATCHING=0"
+        } else {
+            "-sDISABLE_EXCEPTION_CATCHING=1"
         });
     }
 

compiler/rustc_interface/messages.ftl

@@ -47,7 +47,7 @@ interface_out_dir_error =
     failed to find or create the directory specified by `--out-dir`
 
 interface_proc_macro_crate_panic_abort =
-    building proc macro crate with `panic=abort` may crash the compiler should the proc-macro panic
+    building proc macro crate with `panic=abort` or `panic=immediate-abort` may crash the compiler should the proc-macro panic
 
 interface_temps_dir_error =
     failed to find or create the directory specified by `--temps-dir`

compiler/rustc_interface/src/passes.rs

@@ -42,7 +42,6 @@ use rustc_span::{
     DUMMY_SP, ErrorGuaranteed, ExpnKind, FileName, SourceFileHash, SourceFileHashAlgorithm, Span,
     Symbol, sym,
 };
-use rustc_target::spec::PanicStrategy;
 use rustc_trait_selection::{solve, traits};
 use tracing::{info, instrument};
 
@@ -282,7 +281,7 @@ fn configure_and_expand(
         feature_err(sess, sym::export_stable, DUMMY_SP, "`sdylib` crate type is unstable").emit();
     }
 
-    if is_proc_macro_crate && sess.panic_strategy() == PanicStrategy::Abort {
+    if is_proc_macro_crate && !sess.panic_strategy().unwinds() {
         sess.dcx().emit_warn(errors::ProcMacroCratePanicAbort);
     }
 

compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp

@@ -553,6 +553,7 @@ enum class LLVMRustMemoryEffects {
   None,
   ReadOnly,
   InaccessibleMemOnly,
+  ReadOnlyNotPure,
 };
 
 extern "C" LLVMAttributeRef
@@ -568,6 +569,10 @@ LLVMRustCreateMemoryEffectsAttr(LLVMContextRef C,
   case LLVMRustMemoryEffects::InaccessibleMemOnly:
     return wrap(Attribute::getWithMemoryEffects(
         *unwrap(C), MemoryEffects::inaccessibleMemOnly()));
+  case LLVMRustMemoryEffects::ReadOnlyNotPure:
+    return wrap(Attribute::getWithMemoryEffects(
+        *unwrap(C),
+        MemoryEffects::readOnly() | MemoryEffects::inaccessibleMemOnly()));
   default:
     report_fatal_error("bad MemoryEffects.");
   }

compiler/rustc_metadata/messages.ftl

@@ -98,6 +98,13 @@ metadata_full_metadata_not_found =
 metadata_global_alloc_required =
     no global memory allocator found but one is required; link to std or add `#[global_allocator]` to a static item that implements the GlobalAlloc trait
 
+metadata_incompatible_with_immediate_abort =
+    the crate `{$crate_name}` was compiled with a panic strategy which is incompatible with `immediate-abort`
+
+metadata_incompatible_with_immediate_abort_core =
+    the crate `core` was compiled with a panic strategy which is incompatible with `immediate-abort`
+    .help = consider building the standard library from source with `cargo build -Zbuild-std`
+
 metadata_incompatible_panic_in_drop_strategy =
     the crate `{$crate_name}` is compiled with the panic-in-drop strategy `{$found_strategy}` which is incompatible with this crate's strategy of `{$desired_strategy}`
 

compiler/rustc_metadata/src/creader.rs

@@ -1027,6 +1027,10 @@ impl CStore {
         let name = match desired_strategy {
             PanicStrategy::Unwind => sym::panic_unwind,
             PanicStrategy::Abort => sym::panic_abort,
+            PanicStrategy::ImmediateAbort => {
+                // Immediate-aborting panics don't use a runtime.
+                return;
+            }
         };
         info!("panic runtime not found -- loading {}", name);
 

compiler/rustc_metadata/src/dependency_format.rs

@@ -61,11 +61,13 @@ use rustc_session::config::CrateType;
 use rustc_session::cstore::CrateDepKind;
 use rustc_session::cstore::LinkagePreference::{self, RequireDynamic, RequireStatic};
 use rustc_span::sym;
+use rustc_target::spec::PanicStrategy;
 use tracing::info;
 
 use crate::creader::CStore;
 use crate::errors::{
-    BadPanicStrategy, CrateDepMultiple, IncompatiblePanicInDropStrategy, LibRequired,
+    BadPanicStrategy, CrateDepMultiple, IncompatiblePanicInDropStrategy,
+    IncompatibleWithImmediateAbort, IncompatibleWithImmediateAbortCore, LibRequired,
     NonStaticCrateDep, RequiredPanicStrategy, RlibRequired, RustcDriverHelp, RustcLibRequired,
     TwoPanicRuntimes,
 };
@@ -402,15 +404,43 @@ fn activate_injected_dep(
 /// there's only going to be one panic runtime in the output.
 fn verify_ok(tcx: TyCtxt<'_>, list: &DependencyList) {
     let sess = &tcx.sess;
+    let list: Vec<_> = list
+        .iter_enumerated()
+        .filter_map(
+            |(cnum, linkage)| if *linkage == Linkage::NotLinked { None } else { Some(cnum) },
+        )
+        .collect();
     if list.is_empty() {
         return;
     }
-    let mut panic_runtime = None;
-    for (cnum, linkage) in list.iter_enumerated() {
-        if let Linkage::NotLinked = *linkage {
-            continue;
+    let desired_strategy = sess.panic_strategy();
+
+    // If we are panic=immediate-abort, make sure everything in the dependency tree has also been
+    // compiled with immediate-abort.
+    if list
+        .iter()
+        .any(|cnum| tcx.required_panic_strategy(*cnum) == Some(PanicStrategy::ImmediateAbort))
+    {
+        let mut invalid_crates = Vec::new();
+        for cnum in list.iter().copied() {
+            if tcx.required_panic_strategy(cnum) != Some(PanicStrategy::ImmediateAbort) {
+                invalid_crates.push(cnum);
+                // If core is incompatible, it's very likely that we'd emit an error for every
+                // sysroot crate, so instead of doing that emit a single fatal error that suggests
+                // using build-std.
+                if tcx.crate_name(cnum) == sym::core {
+                    sess.dcx().emit_fatal(IncompatibleWithImmediateAbortCore);
+                }
+            }
         }
+        for cnum in invalid_crates {
+            sess.dcx()
+                .emit_err(IncompatibleWithImmediateAbort { crate_name: tcx.crate_name(cnum) });
+        }
+    }
 
+    let mut panic_runtime = None;
+    for cnum in list.iter().copied() {
         if tcx.is_panic_runtime(cnum) {
             if let Some((prev, _)) = panic_runtime {
                 let prev_name = tcx.crate_name(prev);
@@ -430,8 +460,6 @@ fn verify_ok(tcx: TyCtxt<'_>, list: &DependencyList) {
     // only one, but we perform validation here that all the panic strategy
     // compilation modes for the whole DAG are valid.
     if let Some((runtime_cnum, found_strategy)) = panic_runtime {
-        let desired_strategy = sess.panic_strategy();
-
         // First up, validate that our selected panic runtime is indeed exactly
         // our same strategy.
         if found_strategy != desired_strategy {
@@ -445,10 +473,7 @@ fn verify_ok(tcx: TyCtxt<'_>, list: &DependencyList) {
         // strategy. If the dep isn't linked, we ignore it, and if our strategy
         // is abort then it's compatible with everything. Otherwise all crates'
         // panic strategy must match our own.
-        for (cnum, linkage) in list.iter_enumerated() {
-            if let Linkage::NotLinked = *linkage {
-                continue;
-            }
+        for cnum in list.iter().copied() {
             if cnum == runtime_cnum || tcx.is_compiler_builtins(cnum) {
                 continue;
             }

compiler/rustc_metadata/src/errors.rs

@@ -75,6 +75,16 @@ pub struct RequiredPanicStrategy {
     pub desired_strategy: PanicStrategy,
 }
 
+#[derive(Diagnostic)]
+#[diag(metadata_incompatible_with_immediate_abort)]
+pub struct IncompatibleWithImmediateAbort {
+    pub crate_name: Symbol,
+}
+
+#[derive(Diagnostic)]
+#[diag(metadata_incompatible_with_immediate_abort_core)]
+pub struct IncompatibleWithImmediateAbortCore;
+
 #[derive(Diagnostic)]
 #[diag(metadata_incompatible_panic_in_drop_strategy)]
 pub struct IncompatiblePanicInDropStrategy {

compiler/rustc_middle/src/middle/lang_items.rs

@@ -98,5 +98,6 @@ pub fn required(tcx: TyCtxt<'_>, lang_item: LangItem) -> bool {
             lang_item != LangItem::EhPersonality && lang_item != LangItem::EhCatchTypeinfo
         }
         PanicStrategy::Unwind => true,
+        PanicStrategy::ImmediateAbort => false,
     }
 }