Rollup merge of #86652 - nagisa:nagisa/non-leaf-fp, r=petrochenkov

Add support for leaf function frame pointer elimination

This PR adds ability for the target specifications to specify frame
pointer emission type that's not just “always” or “whatever cg decides”.

In particular there's a new mode that allows omission of the frame
pointer for leaf functions (those that don't call any other functions).

We then set this new mode for Aarch64-based Apple targets.

Fixes #86196

24 files changed, 149 insertions, 60 deletions

diff --git a/compiler/rustc_codegen_llvm/src/attributes.rs b/compiler/rustc_codegen_llvm/src/attributes.rs
index 6a032b9be72..56b93f83466 100644
--- a/compiler/rustc_codegen_llvm/src/attributes.rs
+++ b/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);
 
diff --git a/compiler/rustc_codegen_llvm/src/context.rs b/compiler/rustc_codegen_llvm/src/context.rs
index 7415a570453..f662887abf8 100644
--- a/compiler/rustc_codegen_llvm/src/context.rs
+++ b/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) {
diff --git a/compiler/rustc_codegen_llvm/src/intrinsic.rs b/compiler/rustc_codegen_llvm/src/intrinsic.rs
index 22d513d66d1..1fb201eda6b 100644
--- a/compiler/rustc_codegen_llvm/src/intrinsic.rs
+++ b/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) };
diff --git a/compiler/rustc_codegen_ssa/src/base.rs b/compiler/rustc_codegen_ssa/src/base.rs
index 31ae84f4ca1..2e9aae467f8 100644
--- a/compiler/rustc_codegen_ssa/src/base.rs
+++ b/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");
diff --git a/compiler/rustc_codegen_ssa/src/traits/misc.rs b/compiler/rustc_codegen_ssa/src/traits/misc.rs
index 6fff64bfcb6..46f2adbe552 100644
--- a/compiler/rustc_codegen_ssa/src/traits/misc.rs
+++ b/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.
diff --git a/compiler/rustc_session/src/session.rs b/compiler/rustc_session/src/session.rs
index d8a58ee18cd..f792e319867 100644
--- a/compiler/rustc_session/src/session.rs
+++ b/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.
diff --git a/compiler/rustc_target/src/spec/aarch64_apple_darwin.rs b/compiler/rustc_target/src/spec/aarch64_apple_darwin.rs
index feadd4e891c..bf3ec8f9160 100644
--- a/compiler/rustc_target/src/spec/aarch64_apple_darwin.rs
+++ b/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
+        },
     }
 }
diff --git a/compiler/rustc_target/src/spec/aarch64_apple_ios.rs b/compiler/rustc_target/src/spec/aarch64_apple_ios.rs
index 5682039b865..9fa8ef69d81 100644
--- a/compiler/rustc_target/src/spec/aarch64_apple_ios.rs
+++ b/compiler/rustc_target/src/spec/aarch64_apple_ios.rs
@@ -1,5 +1,5 @@
 use super::apple_sdk_base::{opts, Arch};
-use crate::spec::{Target, TargetOptions};
+use crate::spec::{FramePointer, Target, TargetOptions};
 
 pub fn target() -> Target {
     let base = opts("ios", Arch::Arm64);
@@ -13,6 +13,7 @@ pub fn target() -> Target {
             max_atomic_width: Some(128),
             unsupported_abis: super::arm_base::unsupported_abis(),
             forces_embed_bitcode: true,
+            frame_pointer: FramePointer::NonLeaf,
             // Taken from a clang build on Xcode 11.4.1.
             // These arguments are not actually invoked - they just have
             // to look right to pass App Store validation.
diff --git a/compiler/rustc_target/src/spec/aarch64_apple_ios_macabi.rs b/compiler/rustc_target/src/spec/aarch64_apple_ios_macabi.rs
index 8a832546d09..a43eb99a1d7 100644
--- a/compiler/rustc_target/src/spec/aarch64_apple_ios_macabi.rs
+++ b/compiler/rustc_target/src/spec/aarch64_apple_ios_macabi.rs
@@ -1,5 +1,5 @@
 use super::apple_sdk_base::{opts, Arch};
-use crate::spec::{Target, TargetOptions};
+use crate::spec::{FramePointer, Target, TargetOptions};
 
 pub fn target() -> Target {
     let base = opts("ios", Arch::Arm64_macabi);
@@ -13,6 +13,7 @@ pub fn target() -> Target {
             max_atomic_width: Some(128),
             unsupported_abis: super::arm_base::unsupported_abis(),
             forces_embed_bitcode: true,
+            frame_pointer: FramePointer::NonLeaf,
             // Taken from a clang build on Xcode 11.4.1.
             // These arguments are not actually invoked - they just have
             // to look right to pass App Store validation.
diff --git a/compiler/rustc_target/src/spec/aarch64_apple_ios_sim.rs b/compiler/rustc_target/src/spec/aarch64_apple_ios_sim.rs
index 2187015b627..586e4043d79 100644
--- a/compiler/rustc_target/src/spec/aarch64_apple_ios_sim.rs
+++ b/compiler/rustc_target/src/spec/aarch64_apple_ios_sim.rs
@@ -1,5 +1,5 @@
 use super::apple_sdk_base::{opts, Arch};
-use crate::spec::{Target, TargetOptions};
+use crate::spec::{FramePointer, Target, TargetOptions};
 
 pub fn target() -> Target {
     let base = opts("ios", Arch::Arm64_sim);
@@ -21,6 +21,7 @@ pub fn target() -> Target {
             max_atomic_width: Some(128),
             unsupported_abis: super::arm_base::unsupported_abis(),
             forces_embed_bitcode: true,
+            frame_pointer: FramePointer::NonLeaf,
             // Taken from a clang build on Xcode 11.4.1.
             // These arguments are not actually invoked - they just have
             // to look right to pass App Store validation.
diff --git a/compiler/rustc_target/src/spec/aarch64_apple_tvos.rs b/compiler/rustc_target/src/spec/aarch64_apple_tvos.rs
index cb6c06b3711..934f3370369 100644
--- a/compiler/rustc_target/src/spec/aarch64_apple_tvos.rs
+++ b/compiler/rustc_target/src/spec/aarch64_apple_tvos.rs
@@ -1,5 +1,5 @@
 use super::apple_sdk_base::{opts, Arch};
-use crate::spec::{Target, TargetOptions};
+use crate::spec::{FramePointer, Target, TargetOptions};
 
 pub fn target() -> Target {
     let base = opts("tvos", Arch::Arm64);
@@ -13,6 +13,7 @@ pub fn target() -> Target {
             max_atomic_width: Some(128),
             unsupported_abis: super::arm_base::unsupported_abis(),
             forces_embed_bitcode: true,
+            frame_pointer: FramePointer::NonLeaf,
             ..base
         },
     }
diff --git a/compiler/rustc_target/src/spec/apple_base.rs b/compiler/rustc_target/src/spec/apple_base.rs
index 8530db179d9..0c8a89210ff 100644
--- a/compiler/rustc_target/src/spec/apple_base.rs
+++ b/compiler/rustc_target/src/spec/apple_base.rs
@@ -1,6 +1,6 @@
 use std::env;
 
-use crate::spec::{SplitDebuginfo, TargetOptions};
+use crate::spec::{FramePointer, SplitDebuginfo, TargetOptions};
 
 pub fn opts(os: &str) -> TargetOptions {
     // ELF TLS is only available in macOS 10.7+. If you try to compile for 10.6
@@ -27,7 +27,7 @@ pub fn opts(os: &str) -> TargetOptions {
         families: vec!["unix".to_string()],
         is_like_osx: true,
         dwarf_version: Some(2),
-        eliminate_frame_pointer: false,
+        frame_pointer: FramePointer::Always,
         has_rpath: true,
         dll_suffix: ".dylib".to_string(),
         archive_format: "darwin".to_string(),
diff --git a/compiler/rustc_target/src/spec/freebsd_base.rs b/compiler/rustc_target/src/spec/freebsd_base.rs
index bef2fce7c83..998d6ffe0fc 100644
--- a/compiler/rustc_target/src/spec/freebsd_base.rs
+++ b/compiler/rustc_target/src/spec/freebsd_base.rs
@@ -1,4 +1,4 @@
-use crate::spec::{RelroLevel, TargetOptions};
+use crate::spec::{FramePointer, RelroLevel, TargetOptions};
 
 pub fn opts() -> TargetOptions {
     TargetOptions {
@@ -8,7 +8,7 @@ pub fn opts() -> TargetOptions {
         families: vec!["unix".to_string()],
         has_rpath: true,
         position_independent_executables: true,
-        eliminate_frame_pointer: false, // FIXME 43575
+        frame_pointer: FramePointer::Always, // FIXME 43575: should be MayOmit...
         relro_level: RelroLevel::Full,
         abi_return_struct_as_int: true,
         dwarf_version: Some(2),
diff --git a/compiler/rustc_target/src/spec/i686_apple_darwin.rs b/compiler/rustc_target/src/spec/i686_apple_darwin.rs
index 06d71db4af2..f2635f0656d 100644
--- a/compiler/rustc_target/src/spec/i686_apple_darwin.rs
+++ b/compiler/rustc_target/src/spec/i686_apple_darwin.rs
@@ -1,4 +1,4 @@
-use crate::spec::{LinkerFlavor, StackProbeType, Target, TargetOptions};
+use crate::spec::{FramePointer, LinkerFlavor, StackProbeType, Target, TargetOptions};
 
 pub fn target() -> Target {
     let mut base = super::apple_base::opts("macos");
@@ -8,7 +8,7 @@ pub fn target() -> Target {
     base.link_env_remove.extend(super::apple_base::macos_link_env_remove());
     // don't use probe-stack=inline-asm until rust#83139 and rust#84667 are resolved
     base.stack_probes = StackProbeType::Call;
-    base.eliminate_frame_pointer = false;
+    base.frame_pointer = FramePointer::Always;
 
     // Clang automatically chooses a more specific target based on
     // MACOSX_DEPLOYMENT_TARGET.  To enable cross-language LTO to work
diff --git a/compiler/rustc_target/src/spec/i686_pc_windows_gnu.rs b/compiler/rustc_target/src/spec/i686_pc_windows_gnu.rs
index 7002d88c512..92c3a1554ac 100644
--- a/compiler/rustc_target/src/spec/i686_pc_windows_gnu.rs
+++ b/compiler/rustc_target/src/spec/i686_pc_windows_gnu.rs
@@ -1,4 +1,4 @@
-use crate::spec::{LinkerFlavor, LldFlavor, Target};
+use crate::spec::{FramePointer, LinkerFlavor, LldFlavor, Target};
 
 pub fn target() -> Target {
     let mut base = super::windows_gnu_base::opts();
@@ -6,7 +6,7 @@ pub fn target() -> Target {
     base.pre_link_args
         .insert(LinkerFlavor::Lld(LldFlavor::Ld), vec!["-m".to_string(), "i386pe".to_string()]);
     base.max_atomic_width = Some(64);
-    base.eliminate_frame_pointer = false; // Required for backtraces
+    base.frame_pointer = FramePointer::Always; // Required for backtraces
     base.linker = Some("i686-w64-mingw32-gcc".to_string());
 
     // Mark all dynamic libraries and executables as compatible with the larger 4GiB address
diff --git a/compiler/rustc_target/src/spec/i686_unknown_linux_musl.rs b/compiler/rustc_target/src/spec/i686_unknown_linux_musl.rs
index 228976779f0..d95cb6a82d5 100644
--- a/compiler/rustc_target/src/spec/i686_unknown_linux_musl.rs
+++ b/compiler/rustc_target/src/spec/i686_unknown_linux_musl.rs
@@ -1,4 +1,4 @@
-use crate::spec::{LinkerFlavor, StackProbeType, Target};
+use crate::spec::{FramePointer, LinkerFlavor, StackProbeType, Target};
 
 pub fn target() -> Target {
     let mut base = super::linux_musl_base::opts();
@@ -21,7 +21,7 @@ pub fn target() -> Target {
     //
     // This may or may not be related to this bug:
     // https://llvm.org/bugs/show_bug.cgi?id=30879
-    base.eliminate_frame_pointer = false;
+    base.frame_pointer = FramePointer::Always;
 
     Target {
         llvm_target: "i686-unknown-linux-musl".to_string(),
diff --git a/compiler/rustc_target/src/spec/i686_uwp_windows_gnu.rs b/compiler/rustc_target/src/spec/i686_uwp_windows_gnu.rs
index 426df59882d..27a0ac585e3 100644
--- a/compiler/rustc_target/src/spec/i686_uwp_windows_gnu.rs
+++ b/compiler/rustc_target/src/spec/i686_uwp_windows_gnu.rs
@@ -1,4 +1,4 @@
-use crate::spec::{LinkerFlavor, LldFlavor, Target};
+use crate::spec::{FramePointer, LinkerFlavor, LldFlavor, Target};
 
 pub fn target() -> Target {
     let mut base = super::windows_uwp_gnu_base::opts();
@@ -6,7 +6,7 @@ pub fn target() -> Target {
     base.pre_link_args
         .insert(LinkerFlavor::Lld(LldFlavor::Ld), vec!["-m".to_string(), "i386pe".to_string()]);
     base.max_atomic_width = Some(64);
-    base.eliminate_frame_pointer = false; // Required for backtraces
+    base.frame_pointer = FramePointer::Always; // Required for backtraces
 
     // Mark all dynamic libraries and executables as compatible with the larger 4GiB address
     // space available to x86 Windows binaries on x86_64.
diff --git a/compiler/rustc_target/src/spec/illumos_base.rs b/compiler/rustc_target/src/spec/illumos_base.rs
index 9d9da50be7a..f598f0f38f3 100644
--- a/compiler/rustc_target/src/spec/illumos_base.rs
+++ b/compiler/rustc_target/src/spec/illumos_base.rs
@@ -1,4 +1,4 @@
-use crate::spec::{LinkArgs, LinkerFlavor, TargetOptions};
+use crate::spec::{FramePointer, LinkArgs, LinkerFlavor, TargetOptions};
 use std::default::Default;
 
 pub fn opts() -> TargetOptions {
@@ -35,7 +35,7 @@ pub fn opts() -> TargetOptions {
         is_like_solaris: true,
         linker_is_gnu: false,
         limit_rdylib_exports: false, // Linker doesn't support this
-        eliminate_frame_pointer: false,
+        frame_pointer: FramePointer::Always,
         eh_frame_header: false,
         late_link_args,
 
diff --git a/compiler/rustc_target/src/spec/linux_kernel_base.rs b/compiler/rustc_target/src/spec/linux_kernel_base.rs
index 145aa4a5894..a332e3b847a 100644
--- a/compiler/rustc_target/src/spec/linux_kernel_base.rs
+++ b/compiler/rustc_target/src/spec/linux_kernel_base.rs
@@ -1,4 +1,5 @@
-use crate::spec::{PanicStrategy, RelocModel, RelroLevel, StackProbeType, TargetOptions};
+use crate::spec::TargetOptions;
+use crate::spec::{FramePointer, PanicStrategy, RelocModel, RelroLevel, StackProbeType};
 
 pub fn opts() -> TargetOptions {
     TargetOptions {
@@ -7,7 +8,7 @@ pub fn opts() -> TargetOptions {
         panic_strategy: PanicStrategy::Abort,
         // don't use probe-stack=inline-asm until rust#83139 and rust#84667 are resolved
         stack_probes: StackProbeType::Call,
-        eliminate_frame_pointer: false,
+        frame_pointer: FramePointer::Always,
         position_independent_executables: true,
         needs_plt: true,
         relro_level: RelroLevel::Full,
diff --git a/compiler/rustc_target/src/spec/mod.rs b/compiler/rustc_target/src/spec/mod.rs
index 0bf89c3f93b..cfdae9623f3 100644
--- a/compiler/rustc_target/src/spec/mod.rs
+++ b/compiler/rustc_target/src/spec/mod.rs
@@ -671,6 +671,42 @@ impl ToJson for SanitizerSet {
     }
 }
 
+#[derive(Clone, Copy, PartialEq, Hash, Debug)]
+pub enum FramePointer {
+    /// Forces the machine code generator to always preserve the frame pointers.
+    Always,
+    /// Forces the machine code generator to preserve the frame pointers except for the leaf
+    /// functions (i.e. those that don't call other functions).
+    NonLeaf,
+    /// Allows the machine code generator to omit the frame pointers.
+    ///
+    /// This option does not guarantee that the frame pointers will be omitted.
+    MayOmit,
+}
+
+impl FromStr for FramePointer {
+    type Err = ();
+    fn from_str(s: &str) -> Result<Self, ()> {
+        Ok(match s {
+            "always" => Self::Always,
+            "non-leaf" => Self::NonLeaf,
+            "may-omit" => Self::MayOmit,
+            _ => return Err(()),
+        })
+    }
+}
+
+impl ToJson for FramePointer {
+    fn to_json(&self) -> Json {
+        match *self {
+            Self::Always => "always",
+            Self::NonLeaf => "non-leaf",
+            Self::MayOmit => "may-omit",
+        }
+        .to_json()
+    }
+}
+
 macro_rules! supported_targets {
     ( $(($( $triple:literal, )+ $module:ident ),)+ ) => {
         $(mod $module;)+
@@ -1068,8 +1104,8 @@ pub struct TargetOptions {
     pub tls_model: TlsModel,
     /// Do not emit code that uses the "red zone", if the ABI has one. Defaults to false.
     pub disable_redzone: bool,
-    /// Eliminate frame pointers from stack frames if possible. Defaults to true.
-    pub eliminate_frame_pointer: bool,
+    /// Frame pointer mode for this target. Defaults to `MayOmit`.
+    pub frame_pointer: FramePointer,
     /// Emit each function in its own section. Defaults to true.
     pub function_sections: bool,
     /// String to prepend to the name of every dynamic library. Defaults to "lib".
@@ -1330,7 +1366,7 @@ impl Default for TargetOptions {
             code_model: None,
             tls_model: TlsModel::GeneralDynamic,
             disable_redzone: false,
-            eliminate_frame_pointer: true,
+            frame_pointer: FramePointer::MayOmit,
             function_sections: true,
             dll_prefix: "lib".to_string(),
             dll_suffix: ".so".to_string(),
@@ -1833,6 +1869,16 @@ impl Target {
             }
         }
 
+        if let Some(fp) = obj.remove_key("frame-pointer") {
+            if let Some(s) = Json::as_string(&fp) {
+                base.frame_pointer = s
+                    .parse()
+                    .map_err(|()| format!("'{}' is not a valid value for frame-pointer", s))?;
+            } else {
+                incorrect_type.push("frame-pointer".to_string())
+            }
+        }
+
         key!(is_builtin, bool);
         key!(c_int_width = "target-c-int-width");
         key!(os);
@@ -1864,7 +1910,6 @@ impl Target {
         key!(code_model, CodeModel)?;
         key!(tls_model, TlsModel)?;
         key!(disable_redzone, bool);
-        key!(eliminate_frame_pointer, bool);
         key!(function_sections, bool);
         key!(dll_prefix);
         key!(dll_suffix);
@@ -2128,7 +2173,7 @@ impl ToJson for Target {
         target_option_val!(code_model);
         target_option_val!(tls_model);
         target_option_val!(disable_redzone);
-        target_option_val!(eliminate_frame_pointer);
+        target_option_val!(frame_pointer);
         target_option_val!(function_sections);
         target_option_val!(dll_prefix);
         target_option_val!(dll_suffix);
diff --git a/compiler/rustc_target/src/spec/openbsd_base.rs b/compiler/rustc_target/src/spec/openbsd_base.rs
index 29b415e7726..70e9e4aed92 100644
--- a/compiler/rustc_target/src/spec/openbsd_base.rs
+++ b/compiler/rustc_target/src/spec/openbsd_base.rs
@@ -1,4 +1,4 @@
-use crate::spec::{RelroLevel, TargetOptions};
+use crate::spec::{FramePointer, RelroLevel, TargetOptions};
 
 pub fn opts() -> TargetOptions {
     TargetOptions {
@@ -9,7 +9,7 @@ pub fn opts() -> TargetOptions {
         has_rpath: true,
         abi_return_struct_as_int: true,
         position_independent_executables: true,
-        eliminate_frame_pointer: false, // FIXME 43575
+        frame_pointer: FramePointer::Always, // FIXME 43575: should be MayOmit...
         relro_level: RelroLevel::Full,
         dwarf_version: Some(2),
         ..Default::default()
diff --git a/compiler/rustc_target/src/spec/thumb_base.rs b/compiler/rustc_target/src/spec/thumb_base.rs
index ec24807fec4..fbe4dd5b501 100644
--- a/compiler/rustc_target/src/spec/thumb_base.rs
+++ b/compiler/rustc_target/src/spec/thumb_base.rs
@@ -27,7 +27,8 @@
 // differentiate these targets from our other `arm(v7)-*-*-gnueabi(hf)` targets in the context of
 // build scripts / gcc flags.
 
-use crate::spec::{LinkerFlavor, LldFlavor, PanicStrategy, RelocModel, TargetOptions};
+use crate::spec::TargetOptions;
+use crate::spec::{FramePointer, LinkerFlavor, LldFlavor, PanicStrategy, RelocModel};
 
 pub fn opts() -> TargetOptions {
     // See rust-lang/rfcs#1645 for a discussion about these defaults
@@ -52,7 +53,7 @@ pub fn opts() -> TargetOptions {
         emit_debug_gdb_scripts: false,
         // LLVM is eager to trash the link register when calling `noreturn` functions, which
         // breaks debugging. Preserve LR by default to prevent that from happening.
-        eliminate_frame_pointer: false,
+        frame_pointer: FramePointer::Always,
         ..Default::default()
     }
 }
diff --git a/compiler/rustc_target/src/spec/x86_64_apple_darwin.rs b/compiler/rustc_target/src/spec/x86_64_apple_darwin.rs
index dc7597fe7b2..60fd42970c7 100644
--- a/compiler/rustc_target/src/spec/x86_64_apple_darwin.rs
+++ b/compiler/rustc_target/src/spec/x86_64_apple_darwin.rs
@@ -1,10 +1,11 @@
-use crate::spec::{LinkerFlavor, SanitizerSet, StackProbeType, Target, TargetOptions};
+use crate::spec::TargetOptions;
+use crate::spec::{FramePointer, LinkerFlavor, SanitizerSet, StackProbeType, Target};
 
 pub fn target() -> Target {
     let mut base = super::apple_base::opts("macos");
     base.cpu = "core2".to_string();
     base.max_atomic_width = Some(128); // core2 support cmpxchg16b
-    base.eliminate_frame_pointer = false;
+    base.frame_pointer = FramePointer::Always;
     base.pre_link_args.insert(
         LinkerFlavor::Gcc,
         vec!["-m64".to_string(), "-arch".to_string(), "x86_64".to_string()],
diff --git a/src/test/codegen/frame-pointer.rs b/src/test/codegen/frame-pointer.rs
new file mode 100644
index 00000000000..367591dcb96
--- /dev/null
+++ b/src/test/codegen/frame-pointer.rs
@@ -0,0 +1,35 @@
+// compile-flags: --crate-type=rlib
+// revisions: aarch64-apple aarch64-linux force x64-apple x64-linux
+// [aarch64-apple] needs-llvm-components: aarch64
+// [aarch64-apple] compile-flags: --target=aarch64-apple-darwin
+// [aarch64-linux] needs-llvm-components: aarch64
+// [aarch64-linux] compile-flags: --target=aarch64-unknown-linux-gnu
+// [force] needs-llvm-components: x86
+// [force] compile-flags: --target=x86_64-unknown-linux-gnu -Cforce-frame-pointers=yes
+// [x64-apple] needs-llvm-components: x86
+// [x64-apple] compile-flags: --target=x86_64-apple-darwin
+// [x64-linux] needs-llvm-components: x86
+// [x64-linux] compile-flags: --target=x86_64-unknown-linux-gnu
+
+#![feature(no_core, lang_items)]
+#![no_core]
+#[lang="sized"]
+trait Sized { }
+#[lang="copy"]
+trait Copy { }
+
+
+
+// CHECK: define i32 @peach{{.*}}[[PEACH_ATTRS:\#[0-9]+]] {
+#[no_mangle]
+pub fn peach(x: u32) -> u32 {
+    x
+}
+
+// CHECK: attributes [[PEACH_ATTRS]] = {
+// x64-linux-NOT: {{.*}}"frame-pointer"{{.*}}
+// aarch64-linux-NOT: {{.*}}"frame-pointer"{{.*}}
+// x64-apple-SAME: {{.*}}"frame-pointer"="all"
+// force-SAME: {{.*}}"frame-pointer"="all"
+// aarch64-apple-SAME: {{.*}}"frame-pointer"="non-leaf"
+// CHECK-SAME: }