Auto merge of #115685 - matthiaskrgr:rollup-t31gowy, r=matthiaskrgr

Rollup of 5 pull requests

Successful merges:

 - #113807 (Tests crash from inappropriate use of common linkage)
 - #115358 (debuginfo: add compiler option to allow compressed debuginfo sections)
 - #115630 (Dont suggest use between `use` and cfg attr)
 - #115662 (Improve "associated type not found" diagnostics)
 - #115673 (Fix sanitize/cfg.rs test)

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

compiler/rustc_codegen_llvm/messages.ftl

@@ -83,6 +83,8 @@ codegen_llvm_unknown_ctarget_feature_prefix =
     unknown feature specified for `-Ctarget-feature`: `{$feature}`
     .note = features must begin with a `+` to enable or `-` to disable it
 
+codegen_llvm_unknown_debuginfo_compression = unknown debuginfo compression algorithm {$algorithm} - will fall back to uncompressed debuginfo
+
 codegen_llvm_write_bytecode = failed to write bytecode to {$path}: {$err}
 
 codegen_llvm_write_ir = failed to write LLVM IR to {$path}

compiler/rustc_codegen_llvm/src/back/write.rs

@@ -5,13 +5,17 @@ use crate::back::profiling::{
 use crate::base;
 use crate::common;
 use crate::errors::{
-    CopyBitcode, FromLlvmDiag, FromLlvmOptimizationDiag, LlvmError, WithLlvmError, WriteBytecode,
+    CopyBitcode, FromLlvmDiag, FromLlvmOptimizationDiag, LlvmError, UnknownCompression,
+    WithLlvmError, WriteBytecode,
 };
 use crate::llvm::{self, DiagnosticInfo, PassManager};
 use crate::llvm_util;
 use crate::type_::Type;
 use crate::LlvmCodegenBackend;
 use crate::ModuleLlvm;
+use llvm::{
+    LLVMRustLLVMHasZlibCompressionForDebugSymbols, LLVMRustLLVMHasZstdCompressionForDebugSymbols,
+};
 use rustc_codegen_ssa::back::link::ensure_removed;
 use rustc_codegen_ssa::back::write::{
     BitcodeSection, CodegenContext, EmitObj, ModuleConfig, TargetMachineFactoryConfig,
@@ -234,6 +238,22 @@ pub fn target_machine_factory(
         args_cstr_buff
     };
 
+    let debuginfo_compression = sess.opts.debuginfo_compression.to_string();
+    match sess.opts.debuginfo_compression {
+        rustc_session::config::DebugInfoCompression::Zlib => {
+            if !unsafe { LLVMRustLLVMHasZlibCompressionForDebugSymbols() } {
+                sess.emit_warning(UnknownCompression { algorithm: "zlib" });
+            }
+        }
+        rustc_session::config::DebugInfoCompression::Zstd => {
+            if !unsafe { LLVMRustLLVMHasZstdCompressionForDebugSymbols() } {
+                sess.emit_warning(UnknownCompression { algorithm: "zstd" });
+            }
+        }
+        rustc_session::config::DebugInfoCompression::None => {}
+    };
+    let debuginfo_compression = SmallCStr::new(&debuginfo_compression);
+
     Arc::new(move |config: TargetMachineFactoryConfig| {
         let split_dwarf_file =
             path_mapping.map_prefix(config.split_dwarf_file.unwrap_or_default()).0;
@@ -259,6 +279,7 @@ pub fn target_machine_factory(
                 relax_elf_relocations,
                 use_init_array,
                 split_dwarf_file.as_ptr(),
+                debuginfo_compression.as_ptr(),
                 force_emulated_tls,
                 args_cstr_buff.as_ptr() as *const c_char,
                 args_cstr_buff.len(),

compiler/rustc_codegen_llvm/src/errors.rs

@@ -226,3 +226,9 @@ pub(crate) struct WriteBytecode<'a> {
 pub(crate) struct CopyBitcode {
     pub err: std::io::Error,
 }
+
+#[derive(Diagnostic)]
+#[diag(codegen_llvm_unknown_debuginfo_compression)]
+pub struct UnknownCompression {
+    pub algorithm: &'static str,
+}

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -2131,6 +2131,7 @@ extern "C" {
         RelaxELFRelocations: bool,
         UseInitArray: bool,
         SplitDwarfFile: *const c_char,
+        DebugInfoCompression: *const c_char,
         ForceEmulatedTls: bool,
         ArgsCstrBuff: *const c_char,
         ArgsCstrBuffLen: usize,
@@ -2366,6 +2367,10 @@ extern "C" {
 
     pub fn LLVMRustIsBitcode(ptr: *const u8, len: usize) -> bool;
 
+    pub fn LLVMRustLLVMHasZlibCompressionForDebugSymbols() -> bool;
+
+    pub fn LLVMRustLLVMHasZstdCompressionForDebugSymbols() -> bool;
+
     pub fn LLVMRustGetSymbols(
         buf_ptr: *const u8,
         buf_len: usize,

compiler/rustc_hir_analysis/src/astconv/errors.rs

@@ -110,16 +110,22 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
     {
         // The fallback span is needed because `assoc_name` might be an `Fn()`'s `Output` without a
         // valid span, so we point at the whole path segment instead.
-        let span = if assoc_name.span != DUMMY_SP { assoc_name.span } else { span };
+        let is_dummy = assoc_name.span == DUMMY_SP;
+
         let mut err = struct_span_err!(
             self.tcx().sess,
-            span,
+            if is_dummy { span } else { assoc_name.span },
             E0220,
             "associated type `{}` not found for `{}`",
             assoc_name,
             ty_param_name
         );
 
+        if is_dummy {
+            err.span_label(span, format!("associated type `{assoc_name}` not found"));
+            return err.emit();
+        }
+
         let all_candidate_names: Vec<_> = all_candidates()
             .flat_map(|r| self.tcx().associated_items(r.def_id()).in_definition_order())
             .filter_map(|item| {
@@ -131,10 +137,9 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
             })
             .collect();
 
-        if let (Some(suggested_name), true) = (
-            find_best_match_for_name(&all_candidate_names, assoc_name.name, None),
-            assoc_name.span != DUMMY_SP,
-        ) {
+        if let Some(suggested_name) =
+            find_best_match_for_name(&all_candidate_names, assoc_name.name, None)
+        {
             err.span_suggestion(
                 assoc_name.span,
                 "there is an associated type with a similar name",
@@ -172,10 +177,9 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
             })
             .collect();
 
-        if let (Some(suggested_name), true) = (
-            find_best_match_for_name(&wider_candidate_names, assoc_name.name, None),
-            assoc_name.span != DUMMY_SP,
-        ) {
+        if let Some(suggested_name) =
+            find_best_match_for_name(&wider_candidate_names, assoc_name.name, None)
+        {
             if let [best_trait] = visible_traits
                 .iter()
                 .filter(|trait_def_id| {
@@ -197,7 +201,28 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
             }
         }
 
-        err.span_label(span, format!("associated type `{assoc_name}` not found"));
+        // If we still couldn't find any associated type, and only one associated type exists,
+        // suggests using it.
+
+        if all_candidate_names.len() == 1 {
+            // this should still compile, except on `#![feature(associated_type_defaults)]`
+            // where it could suggests `type A = Self::A`, thus recursing infinitely
+            let applicability = if self.tcx().features().associated_type_defaults {
+                Applicability::Unspecified
+            } else {
+                Applicability::MaybeIncorrect
+            };
+
+            err.span_suggestion(
+                assoc_name.span,
+                format!("`{ty_param_name}` has the following associated type"),
+                all_candidate_names.first().unwrap().to_string(),
+                applicability,
+            );
+        } else {
+            err.span_label(assoc_name.span, format!("associated type `{assoc_name}` not found"));
+        }
+
         err.emit()
     }
 

compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp

@@ -410,6 +410,7 @@ extern "C" LLVMTargetMachineRef LLVMRustCreateTargetMachine(
     bool RelaxELFRelocations,
     bool UseInitArray,
     const char *SplitDwarfFile,
+    const char *DebugInfoCompression,
     bool ForceEmulatedTls,
     const char *ArgsCstrBuff, size_t ArgsCstrBuffLen) {
 
@@ -441,6 +442,16 @@ extern "C" LLVMTargetMachineRef LLVMRustCreateTargetMachine(
   if (SplitDwarfFile) {
       Options.MCOptions.SplitDwarfFile = SplitDwarfFile;
   }
+#if LLVM_VERSION_GE(16, 0)
+  if (!strcmp("zlib", DebugInfoCompression) && llvm::compression::zlib::isAvailable()) {
+    Options.CompressDebugSections = DebugCompressionType::Zlib;
+  } else if (!strcmp("zstd", DebugInfoCompression) && llvm::compression::zstd::isAvailable()) {
+    Options.CompressDebugSections = DebugCompressionType::Zstd;
+  } else if (!strcmp("none", DebugInfoCompression)) {
+    Options.CompressDebugSections = DebugCompressionType::None;
+  }
+#endif
+
   Options.RelaxELFRelocations = RelaxELFRelocations;
   Options.UseInitArray = UseInitArray;
 

compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp

@@ -2044,3 +2044,19 @@ extern "C" bool LLVMRustIsNonGVFunctionPointerTy(LLVMValueRef V) {
   }
   return false;
 }
+
+extern "C" bool LLVMRustLLVMHasZlibCompressionForDebugSymbols() {
+#if LLVM_VERSION_GE(16, 0)
+  return llvm::compression::zlib::isAvailable();
+#else
+  return false;
+#endif
+}
+
+extern "C" bool LLVMRustLLVMHasZstdCompressionForDebugSymbols() {
+#if LLVM_VERSION_GE(16, 0)
+  return llvm::compression::zstd::isAvailable();
+#else
+  return false;
+#endif
+}

compiler/rustc_resolve/src/diagnostics.rs

@@ -2753,7 +2753,13 @@ fn search_for_any_use_in_items(items: &[P<ast::Item>]) -> Option<Span> {
     for item in items {
         if let ItemKind::Use(..) = item.kind {
             if is_span_suitable_for_use_injection(item.span) {
-                return Some(item.span.shrink_to_lo());
+                let mut lo = item.span.lo();
+                for attr in &item.attrs {
+                    if attr.span.eq_ctxt(item.span) {
+                        lo = std::cmp::min(lo, attr.span.lo());
+                    }
+                }
+                return Some(Span::new(lo, lo, item.span.ctxt(), item.span.parent()));
             }
         }
     }

compiler/rustc_session/src/config.rs

@@ -381,6 +381,24 @@ pub enum DebugInfo {
     Full,
 }
 
+#[derive(Clone, Copy, Debug, PartialEq, Hash)]
+pub enum DebugInfoCompression {
+    None,
+    Zlib,
+    Zstd,
+}
+
+impl ToString for DebugInfoCompression {
+    fn to_string(&self) -> String {
+        match self {
+            DebugInfoCompression::None => "none",
+            DebugInfoCompression::Zlib => "zlib",
+            DebugInfoCompression::Zstd => "zstd",
+        }
+        .to_owned()
+    }
+}
+
 /// Split debug-information is enabled by `-C split-debuginfo`, this enum is only used if split
 /// debug-information is enabled (in either `Packed` or `Unpacked` modes), and the platform
 /// uses DWARF for debug-information.
@@ -1015,6 +1033,7 @@ impl Default for Options {
             crate_types: Vec::new(),
             optimize: OptLevel::No,
             debuginfo: DebugInfo::None,
+            debuginfo_compression: DebugInfoCompression::None,
             lint_opts: Vec::new(),
             lint_cap: None,
             describe_lints: false,
@@ -2277,6 +2296,13 @@ fn select_debuginfo(matches: &getopts::Matches, cg: &CodegenOptions) -> DebugInf
     if max_g > max_c { DebugInfo::Full } else { cg.debuginfo }
 }
 
+fn select_debuginfo_compression(
+    _handler: &EarlyErrorHandler,
+    unstable_opts: &UnstableOptions,
+) -> DebugInfoCompression {
+    unstable_opts.debuginfo_compression
+}
+
 pub(crate) fn parse_assert_incr_state(
     handler: &EarlyErrorHandler,
     opt_assertion: &Option<String>,
@@ -2752,6 +2778,8 @@ pub fn build_session_options(
     // for more details.
     let debug_assertions = cg.debug_assertions.unwrap_or(opt_level == OptLevel::No);
     let debuginfo = select_debuginfo(matches, &cg);
+    let debuginfo_compression: DebugInfoCompression =
+        select_debuginfo_compression(handler, &unstable_opts);
 
     let mut search_paths = vec![];
     for s in &matches.opt_strs("L") {
@@ -2828,6 +2856,7 @@ pub fn build_session_options(
         crate_types,
         optimize: opt_level,
         debuginfo,
+        debuginfo_compression,
         lint_opts,
         lint_cap,
         describe_lints,
@@ -3113,11 +3142,11 @@ impl PpMode {
 /// how the hash should be calculated when adding a new command-line argument.
 pub(crate) mod dep_tracking {
     use super::{
-        BranchProtection, CFGuard, CFProtection, CrateType, DebugInfo, ErrorOutputType,
-        InstrumentCoverage, InstrumentXRay, LdImpl, LinkerPluginLto, LocationDetail, LtoCli,
-        OomStrategy, OptLevel, OutFileName, OutputType, OutputTypes, Passes, ResolveDocLinks,
-        SourceFileHashAlgorithm, SplitDwarfKind, SwitchWithOptPath, SymbolManglingVersion,
-        TraitSolver, TrimmedDefPaths,
+        BranchProtection, CFGuard, CFProtection, CrateType, DebugInfo, DebugInfoCompression,
+        ErrorOutputType, InstrumentCoverage, InstrumentXRay, LdImpl, LinkerPluginLto,
+        LocationDetail, LtoCli, OomStrategy, OptLevel, OutFileName, OutputType, OutputTypes,
+        Passes, ResolveDocLinks, SourceFileHashAlgorithm, SplitDwarfKind, SwitchWithOptPath,
+        SymbolManglingVersion, TraitSolver, TrimmedDefPaths,
     };
     use crate::lint;
     use crate::options::WasiExecModel;
@@ -3195,6 +3224,7 @@ pub(crate) mod dep_tracking {
         OptLevel,
         LtoCli,
         DebugInfo,
+        DebugInfoCompression,
         UnstableFeatures,
         NativeLib,
         NativeLibKind,

compiler/rustc_session/src/options.rs

@@ -139,6 +139,7 @@ top_level_options!(
         /// can influence whether overflow checks are done or not.
         debug_assertions: bool [TRACKED],
         debuginfo: DebugInfo [TRACKED],
+        debuginfo_compression: DebugInfoCompression [TRACKED],
         lint_opts: Vec<(String, lint::Level)> [TRACKED_NO_CRATE_HASH],
         lint_cap: Option<lint::Level> [TRACKED_NO_CRATE_HASH],
         describe_lints: bool [UNTRACKED],
@@ -376,6 +377,7 @@ mod desc {
         "either a boolean (`yes`, `no`, `on`, `off`, etc), `checks`, or `nochecks`";
     pub const parse_cfprotection: &str = "`none`|`no`|`n` (default), `branch`, `return`, or `full`|`yes`|`y` (equivalent to `branch` and `return`)";
     pub const parse_debuginfo: &str = "either an integer (0, 1, 2), `none`, `line-directives-only`, `line-tables-only`, `limited`, or `full`";
+    pub const parse_debuginfo_compression: &str = "one of `none`, `zlib`, or `zstd`";
     pub const parse_strip: &str = "either `none`, `debuginfo`, or `symbols`";
     pub const parse_linker_flavor: &str = ::rustc_target::spec::LinkerFlavorCli::one_of();
     pub const parse_optimization_fuel: &str = "crate=integer";
@@ -782,6 +784,19 @@ mod parse {
         true
     }
 
+    pub(crate) fn parse_debuginfo_compression(
+        slot: &mut DebugInfoCompression,
+        v: Option<&str>,
+    ) -> bool {
+        match v {
+            Some("none") => *slot = DebugInfoCompression::None,
+            Some("zlib") => *slot = DebugInfoCompression::Zlib,
+            Some("zstd") => *slot = DebugInfoCompression::Zstd,
+            _ => return false,
+        };
+        true
+    }
+
     pub(crate) fn parse_linker_flavor(slot: &mut Option<LinkerFlavorCli>, v: Option<&str>) -> bool {
         match v.and_then(LinkerFlavorCli::from_str) {
             Some(lf) => *slot = Some(lf),
@@ -1424,6 +1439,8 @@ options! {
         "emit discriminators and other data necessary for AutoFDO"),
     debug_macros: bool = (false, parse_bool, [TRACKED],
         "emit line numbers debug info inside macros (default: no)"),
+    debuginfo_compression: DebugInfoCompression = (DebugInfoCompression::None, parse_debuginfo_compression, [TRACKED],
+        "compress debug info sections (none, zlib, zstd, default: none)"),
     deduplicate_diagnostics: bool = (true, parse_bool, [UNTRACKED],
         "deduplicate identical diagnostics (default: yes)"),
     dep_info_omit_d_target: bool = (false, parse_bool, [TRACKED],

tests/run-make/compressed-debuginfo/Makefile

@@ -0,0 +1,15 @@
+# ignore-cross-compile
+include ../tools.mk
+
+# only-linux
+# min-llvm-version: 16.0
+#
+# This tests debuginfo-compression.
+
+all: zlib zstandard
+
+zlib:
+	test "`$(RUSTC) --crate-name=foo --crate-type=lib --emit=obj -C debuginfo=full -Z debuginfo-compression=zlib foo.rs 2>&1 | sed 's/.*unknown.*zlib.*/missing/' | head -n 1`" = missing || readelf -t $(TMPDIR)/foo.o | grep -q ZLIB
+
+zstandard:
+	test "`$(RUSTC) --crate-name=foo --crate-type=lib --emit=obj -C debuginfo=full -Z debuginfo-compression=zstd foo.rs 2>&1 | sed 's/.*unknown.*zstd.*/missing/' | head -n 1`" = missing || readelf -t $(TMPDIR)/foo.o | grep -q ZST

tests/run-make/compressed-debuginfo/foo.rs

@@ -0,0 +1,3 @@
+pub fn foo() -> i32 {
+    42
+}

tests/ui/associated-types/issue-23595-2.stderr

@@ -2,7 +2,7 @@ error[E0220]: associated type `anything_here_kills_it` not found for `Self`
   --> $DIR/issue-23595-2.rs:6:22
    |
 LL |     type B = C<Self::anything_here_kills_it>;
-   |                      ^^^^^^^^^^^^^^^^^^^^^^ associated type `anything_here_kills_it` not found
+   |                      ^^^^^^^^^^^^^^^^^^^^^^ help: `Self` has the following associated type: `B`
 
 error: aborting due to previous error