Auto merge of #86774 - GuillaumeGomez:rollup-rkcgvph, r=GuillaumeGomez

Rollup of 6 pull requests

Successful merges:

 - #86558 (Add suggestions for "undefined reference" link errors)
 - #86616 (rustc_span: Explicitly handle crates that differ from package names)
 - #86652 (Add support for leaf function frame pointer elimination)
 - #86666 (Fix misleading "impl Trait" error)
 - #86762 (mailmap: Add my work email address)
 - #86773 (Enable the tests developed with #86594)

Failed merges:

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

Author: bors

.mailmap

@@ -290,6 +290,7 @@ Xuefeng Wu <benewu@gmail.com> XuefengWu <benewu@gmail.com>
 York Xiang <bombless@126.com>
 Youngsoo Son <ysson83@gmail.com> <ysoo.son@samsung.com>
 Yuki Okushi <jtitor@2k36.org> <huyuumi.dev@gmail.com>
+Yuki Okushi <jtitor@2k36.org> <yuki.okushi@huawei.com>
 Zach Pomerantz <zmp@umich.edu>
 Zack Corr <zack@z0w0.me> <zackcorr95@gmail.com>
 Zack Slayton <zack.slayton@gmail.com>

compiler/rustc_codegen_llvm/src/attributes.rs

@@ -12,7 +12,7 @@ use rustc_middle::ty::{self, TyCtxt};
 use rustc_session::config::OptLevel;
 use rustc_session::Session;
 use rustc_target::spec::abi::Abi;
-use rustc_target::spec::{SanitizerSet, StackProbeType};
+use rustc_target::spec::{FramePointer, SanitizerSet, StackProbeType};
 
 use crate::attributes;
 use crate::llvm::AttributePlace::Function;
@@ -69,15 +69,25 @@ fn naked(val: &'ll Value, is_naked: bool) {
     Attribute::Naked.toggle_llfn(Function, val, is_naked);
 }
 
-pub fn set_frame_pointer_elimination(cx: &CodegenCx<'ll, '_>, llfn: &'ll Value) {
-    if cx.sess().must_not_eliminate_frame_pointers() {
-        llvm::AddFunctionAttrStringValue(
-            llfn,
-            llvm::AttributePlace::Function,
-            cstr!("frame-pointer"),
-            cstr!("all"),
-        );
+pub fn set_frame_pointer_type(cx: &CodegenCx<'ll, '_>, llfn: &'ll Value) {
+    let mut fp = cx.sess().target.frame_pointer;
+    // "mcount" function relies on stack pointer.
+    // See <https://sourceware.org/binutils/docs/gprof/Implementation.html>.
+    if cx.sess().instrument_mcount() || matches!(cx.sess().opts.cg.force_frame_pointers, Some(true))
+    {
+        fp = FramePointer::Always;
     }
+    let attr_value = match fp {
+        FramePointer::Always => cstr!("all"),
+        FramePointer::NonLeaf => cstr!("non-leaf"),
+        FramePointer::MayOmit => return,
+    };
+    llvm::AddFunctionAttrStringValue(
+        llfn,
+        llvm::AttributePlace::Function,
+        cstr!("frame-pointer"),
+        attr_value,
+    );
 }
 
 /// Tell LLVM what instrument function to insert.
@@ -254,7 +264,7 @@ pub fn from_fn_attrs(cx: &CodegenCx<'ll, 'tcx>, llfn: &'ll Value, instance: ty::
     }
 
     // FIXME: none of these three functions interact with source level attributes.
-    set_frame_pointer_elimination(cx, llfn);
+    set_frame_pointer_type(cx, llfn);
     set_instrument_function(cx, llfn);
     set_probestack(cx, llfn);
 

compiler/rustc_codegen_llvm/src/context.rs

@@ -410,8 +410,8 @@ impl MiscMethods<'tcx> for CodegenCx<'ll, 'tcx> {
         &self.used_statics
     }
 
-    fn set_frame_pointer_elimination(&self, llfn: &'ll Value) {
-        attributes::set_frame_pointer_elimination(self, llfn)
+    fn set_frame_pointer_type(&self, llfn: &'ll Value) {
+        attributes::set_frame_pointer_type(self, llfn)
     }
 
     fn apply_target_cpu_attr(&self, llfn: &'ll Value) {

compiler/rustc_codegen_llvm/src/intrinsic.rs

@@ -674,7 +674,7 @@ fn gen_fn<'ll, 'tcx>(
 ) -> &'ll Value {
     let fn_abi = FnAbi::of_fn_ptr(cx, rust_fn_sig, &[]);
     let llfn = cx.declare_fn(name, &fn_abi);
-    cx.set_frame_pointer_elimination(llfn);
+    cx.set_frame_pointer_type(llfn);
     cx.apply_target_cpu_attr(llfn);
     // FIXME(eddyb) find a nicer way to do this.
     unsafe { llvm::LLVMRustSetLinkage(llfn, llvm::Linkage::InternalLinkage) };

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -912,14 +912,23 @@ fn link_natively<'a, B: ArchiveBuilder<'a>>(
             if !prog.status.success() {
                 let mut output = prog.stderr.clone();
                 output.extend_from_slice(&prog.stdout);
-                sess.struct_err(&format!(
+                let escaped_output = escape_stdout_stderr_string(&output);
+                let mut err = sess.struct_err(&format!(
                     "linking with `{}` failed: {}",
                     linker_path.display(),
                     prog.status
-                ))
-                .note(&format!("{:?}", &cmd))
-                .note(&escape_stdout_stderr_string(&output))
-                .emit();
+                ));
+                err.note(&format!("{:?}", &cmd)).note(&escaped_output);
+                if escaped_output.contains("undefined reference to") {
+                    err.help(
+                        "some `extern` functions couldn't be found; some native libraries may \
+                         need to be installed or have their path specified",
+                    );
+                    err.note("use the `-l` flag to specify native libraries to link");
+                    err.note("use the `cargo:rustc-link-lib` directive to specify the native \
+                              libraries to link with Cargo (see https://doc.rust-lang.org/cargo/reference/build-scripts.html#cargorustc-link-libkindname)");
+                }
+                err.emit();
 
                 // If MSVC's `link.exe` was expected but the return code
                 // is not a Microsoft LNK error then suggest a way to fix or

compiler/rustc_codegen_ssa/src/base.rs

@@ -406,7 +406,7 @@ pub fn maybe_create_entry_wrapper<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
         };
 
         // `main` should respect same config for frame pointer elimination as rest of code
-        cx.set_frame_pointer_elimination(llfn);
+        cx.set_frame_pointer_type(llfn);
         cx.apply_target_cpu_attr(llfn);
 
         let llbb = Bx::append_block(&cx, llfn, "top");

compiler/rustc_codegen_ssa/src/traits/misc.rs

@@ -16,7 +16,7 @@ pub trait MiscMethods<'tcx>: BackendTypes {
     fn sess(&self) -> &Session;
     fn codegen_unit(&self) -> &'tcx CodegenUnit<'tcx>;
     fn used_statics(&self) -> &RefCell<Vec<Self::Value>>;
-    fn set_frame_pointer_elimination(&self, llfn: Self::Function);
+    fn set_frame_pointer_type(&self, llfn: Self::Function);
     fn apply_target_cpu_attr(&self, llfn: Self::Function);
     fn create_used_variable(&self);
     /// Declares the extern "C" main function for the entry point. Returns None if the symbol already exists.

compiler/rustc_session/src/session.rs

@@ -792,18 +792,6 @@ impl Session {
         !self.target.is_like_windows && !self.target.is_like_osx
     }
 
-    pub fn must_not_eliminate_frame_pointers(&self) -> bool {
-        // "mcount" function relies on stack pointer.
-        // See <https://sourceware.org/binutils/docs/gprof/Implementation.html>.
-        if self.instrument_mcount() {
-            true
-        } else if let Some(x) = self.opts.cg.force_frame_pointers {
-            x
-        } else {
-            !self.target.eliminate_frame_pointer
-        }
-    }
-
     pub fn must_emit_unwind_tables(&self) -> bool {
         // This is used to control the emission of the `uwtable` attribute on
         // LLVM functions.

compiler/rustc_span/Cargo.toml

@@ -17,6 +17,6 @@ scoped-tls = "1.0"
 unicode-width = "0.1.4"
 cfg-if = "0.1.2"
 tracing = "0.1"
-sha-1 = "0.9"
+sha1 = { package = "sha-1", version = "0.9" }
 sha2 = "0.9"
-md-5 = "0.9"
+md5 = { package = "md-5", version = "0.9" }

compiler/rustc_target/src/spec/aarch64_apple_darwin.rs

@@ -1,4 +1,4 @@
-use crate::spec::{LinkerFlavor, SanitizerSet, Target, TargetOptions};
+use crate::spec::{FramePointer, LinkerFlavor, SanitizerSet, Target, TargetOptions};
 
 pub fn target() -> Target {
     let mut base = super::apple_base::opts("macos");
@@ -20,6 +20,10 @@ pub fn target() -> Target {
         pointer_width: 64,
         data_layout: "e-m:o-i64:64-i128:128-n32:64-S128".to_string(),
         arch: arch.to_string(),
-        options: TargetOptions { mcount: "\u{1}mcount".to_string(), ..base },
+        options: TargetOptions {
+            mcount: "\u{1}mcount".to_string(),
+            frame_pointer: FramePointer::NonLeaf,
+            ..base
+        },
     }
 }