aarch64-linux: Default to FramePointer::NonLeaf

For aarch64-apple and aarch64-windows, platform docs state that code
must use frame pointers correctly. This is because the AAPCS64 mandates
that a platform specify its frame pointer conformance requirements:
- Apple: https://developer.apple.com/documentation/xcode/writing-arm64-code-for-apple-platforms#Respect-the-purpose-of-specific-CPU-registers
- Windows: https://learn.microsoft.com/en-us/cpp/build/arm64-windows-abi-conventions?view=msvc-170#integer-registers
- AAPCS64: https://github.com/ARM-software/abi-aa/blob/4492d1570eb70c8fd146623e0db65b2d241f12e7/aapcs64/aapcs64.rst#the-frame-pointer

Unwinding code either requires unwind tables or frame pointers, and
on aarch64 the expectation is that one can use frame pointers for this.
Most Linux targets represent a motley variety of possible distributions,
so it is unclear who to defer to on conformance, other than perhaps Arm.
In the absence of a specific edict for a given aarch64-linux target,
Rust will assume aarch64-linux targets use non-leaf frame pointers.
This reflects what compilers like clang do.

7 files changed, 46 insertions, 8 deletions

diff --git a/compiler/rustc_target/src/spec/targets/aarch64_be_unknown_linux_gnu.rs b/compiler/rustc_target/src/spec/targets/aarch64_be_unknown_linux_gnu.rs
index 87c07cd3109..4b75a6e5dbf 100644
--- a/compiler/rustc_target/src/spec/targets/aarch64_be_unknown_linux_gnu.rs
+++ b/compiler/rustc_target/src/spec/targets/aarch64_be_unknown_linux_gnu.rs
@@ -1,6 +1,6 @@
 use rustc_abi::Endian;
 
-use crate::spec::{StackProbeType, Target, TargetMetadata, TargetOptions, base};
+use crate::spec::{FramePointer, StackProbeType, Target, TargetMetadata, TargetOptions, base};
 
 pub(crate) fn target() -> Target {
     Target {
@@ -16,6 +16,10 @@ pub(crate) fn target() -> Target {
         arch: "aarch64".into(),
         options: TargetOptions {
             features: "+v8a,+outline-atomics".into(),
+            // the AAPCS64 expects use of non-leaf frame pointers per
+            // https://github.com/ARM-software/abi-aa/blob/4492d1570eb70c8fd146623e0db65b2d241f12e7/aapcs64/aapcs64.rst#the-frame-pointer
+            // and we tend to encounter interesting bugs in AArch64 unwinding code if we do not
+            frame_pointer: FramePointer::NonLeaf,
             max_atomic_width: Some(128),
             stack_probes: StackProbeType::Inline,
             mcount: "\u{1}_mcount".into(),
diff --git a/compiler/rustc_target/src/spec/targets/aarch64_be_unknown_linux_gnu_ilp32.rs b/compiler/rustc_target/src/spec/targets/aarch64_be_unknown_linux_gnu_ilp32.rs
index e785069c78a..2a16d1de3b5 100644
--- a/compiler/rustc_target/src/spec/targets/aarch64_be_unknown_linux_gnu_ilp32.rs
+++ b/compiler/rustc_target/src/spec/targets/aarch64_be_unknown_linux_gnu_ilp32.rs
@@ -1,6 +1,6 @@
 use rustc_abi::Endian;
 
-use crate::spec::{StackProbeType, Target, TargetMetadata, TargetOptions, base};
+use crate::spec::{FramePointer, StackProbeType, Target, TargetMetadata, TargetOptions, base};
 
 pub(crate) fn target() -> Target {
     let mut base = base::linux_gnu::opts();
@@ -20,6 +20,10 @@ pub(crate) fn target() -> Target {
         options: TargetOptions {
             abi: "ilp32".into(),
             features: "+v8a,+outline-atomics".into(),
+            // the AAPCS64 expects use of non-leaf frame pointers per
+            // https://github.com/ARM-software/abi-aa/blob/4492d1570eb70c8fd146623e0db65b2d241f12e7/aapcs64/aapcs64.rst#the-frame-pointer
+            // and we tend to encounter interesting bugs in AArch64 unwinding code if we do not
+            frame_pointer: FramePointer::NonLeaf,
             stack_probes: StackProbeType::Inline,
             mcount: "\u{1}_mcount".into(),
             endian: Endian::Big,
diff --git a/compiler/rustc_target/src/spec/targets/aarch64_linux_android.rs b/compiler/rustc_target/src/spec/targets/aarch64_linux_android.rs
index 41c25393e12..d8651f305fe 100644
--- a/compiler/rustc_target/src/spec/targets/aarch64_linux_android.rs
+++ b/compiler/rustc_target/src/spec/targets/aarch64_linux_android.rs
@@ -1,4 +1,6 @@
-use crate::spec::{SanitizerSet, StackProbeType, Target, TargetMetadata, TargetOptions, base};
+use crate::spec::{
+    FramePointer, SanitizerSet, StackProbeType, Target, TargetMetadata, TargetOptions, base,
+};
 
 // See https://developer.android.com/ndk/guides/abis.html#arm64-v8a
 // for target ABI requirements.
@@ -20,6 +22,10 @@ pub(crate) fn target() -> Target {
             // As documented in https://developer.android.com/ndk/guides/cpu-features.html
             // the neon (ASIMD) and FP must exist on all android aarch64 targets.
             features: "+v8a,+neon,+fp-armv8".into(),
+            // the AAPCS64 expects use of non-leaf frame pointers per
+            // https://github.com/ARM-software/abi-aa/blob/4492d1570eb70c8fd146623e0db65b2d241f12e7/aapcs64/aapcs64.rst#the-frame-pointer
+            // and we tend to encounter interesting bugs in AArch64 unwinding code if we do not
+            frame_pointer: FramePointer::NonLeaf,
             stack_probes: StackProbeType::Inline,
             supported_sanitizers: SanitizerSet::CFI
                 | SanitizerSet::HWADDRESS
diff --git a/compiler/rustc_target/src/spec/targets/aarch64_unknown_linux_gnu.rs b/compiler/rustc_target/src/spec/targets/aarch64_unknown_linux_gnu.rs
index c6be2c20ea2..4220d74dfc8 100644
--- a/compiler/rustc_target/src/spec/targets/aarch64_unknown_linux_gnu.rs
+++ b/compiler/rustc_target/src/spec/targets/aarch64_unknown_linux_gnu.rs
@@ -1,4 +1,6 @@
-use crate::spec::{SanitizerSet, StackProbeType, Target, TargetMetadata, TargetOptions, base};
+use crate::spec::{
+    FramePointer, SanitizerSet, StackProbeType, Target, TargetMetadata, TargetOptions, base,
+};
 
 pub(crate) fn target() -> Target {
     Target {
@@ -14,6 +16,10 @@ pub(crate) fn target() -> Target {
         arch: "aarch64".into(),
         options: TargetOptions {
             features: "+v8a,+outline-atomics".into(),
+            // the AAPCS64 expects use of non-leaf frame pointers per
+            // https://github.com/ARM-software/abi-aa/blob/4492d1570eb70c8fd146623e0db65b2d241f12e7/aapcs64/aapcs64.rst#the-frame-pointer
+            // and we tend to encounter interesting bugs in AArch64 unwinding code if we do not
+            frame_pointer: FramePointer::NonLeaf,
             mcount: "\u{1}_mcount".into(),
             max_atomic_width: Some(128),
             stack_probes: StackProbeType::Inline,
diff --git a/compiler/rustc_target/src/spec/targets/aarch64_unknown_linux_gnu_ilp32.rs b/compiler/rustc_target/src/spec/targets/aarch64_unknown_linux_gnu_ilp32.rs
index 166bb1ed215..a22c1289677 100644
--- a/compiler/rustc_target/src/spec/targets/aarch64_unknown_linux_gnu_ilp32.rs
+++ b/compiler/rustc_target/src/spec/targets/aarch64_unknown_linux_gnu_ilp32.rs
@@ -1,4 +1,4 @@
-use crate::spec::{StackProbeType, Target, TargetMetadata, TargetOptions, base};
+use crate::spec::{FramePointer, StackProbeType, Target, TargetMetadata, TargetOptions, base};
 
 pub(crate) fn target() -> Target {
     Target {
@@ -15,6 +15,10 @@ pub(crate) fn target() -> Target {
         options: TargetOptions {
             abi: "ilp32".into(),
             features: "+v8a,+outline-atomics".into(),
+            // the AAPCS64 expects use of non-leaf frame pointers per
+            // https://github.com/ARM-software/abi-aa/blob/4492d1570eb70c8fd146623e0db65b2d241f12e7/aapcs64/aapcs64.rst#the-frame-pointer
+            // and we tend to encounter interesting bugs in AArch64 unwinding code if we do not
+            frame_pointer: FramePointer::NonLeaf,
             max_atomic_width: Some(128),
             stack_probes: StackProbeType::Inline,
             mcount: "\u{1}_mcount".into(),
diff --git a/compiler/rustc_target/src/spec/targets/aarch64_unknown_linux_musl.rs b/compiler/rustc_target/src/spec/targets/aarch64_unknown_linux_musl.rs
index 58ba06e124c..58daaa03675 100644
--- a/compiler/rustc_target/src/spec/targets/aarch64_unknown_linux_musl.rs
+++ b/compiler/rustc_target/src/spec/targets/aarch64_unknown_linux_musl.rs
@@ -1,4 +1,6 @@
-use crate::spec::{SanitizerSet, StackProbeType, Target, TargetMetadata, TargetOptions, base};
+use crate::spec::{
+    FramePointer, SanitizerSet, StackProbeType, Target, TargetMetadata, TargetOptions, base,
+};
 
 pub(crate) fn target() -> Target {
     let mut base = base::linux_musl::opts();
@@ -26,6 +28,12 @@ pub(crate) fn target() -> Target {
         pointer_width: 64,
         data_layout: "e-m:e-p270:32:32-p271:32:32-p272:64:64-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128-Fn32".into(),
         arch: "aarch64".into(),
-        options: TargetOptions { mcount: "\u{1}_mcount".into(), ..base },
+        options: TargetOptions {
+            // the AAPCS64 expects use of non-leaf frame pointers per
+            // https://github.com/ARM-software/abi-aa/blob/4492d1570eb70c8fd146623e0db65b2d241f12e7/aapcs64/aapcs64.rst#the-frame-pointer
+            // and we tend to encounter interesting bugs in AArch64 unwinding code if we do not
+            frame_pointer: FramePointer::NonLeaf,
+             mcount: "\u{1}_mcount".into(), ..base
+         },
     }
 }
diff --git a/compiler/rustc_target/src/spec/targets/aarch64_unknown_linux_ohos.rs b/compiler/rustc_target/src/spec/targets/aarch64_unknown_linux_ohos.rs
index f2994b1232e..51cdebf22db 100644
--- a/compiler/rustc_target/src/spec/targets/aarch64_unknown_linux_ohos.rs
+++ b/compiler/rustc_target/src/spec/targets/aarch64_unknown_linux_ohos.rs
@@ -1,4 +1,6 @@
-use crate::spec::{SanitizerSet, StackProbeType, Target, TargetMetadata, TargetOptions, base};
+use crate::spec::{
+    FramePointer, SanitizerSet, StackProbeType, Target, TargetMetadata, TargetOptions, base,
+};
 
 pub(crate) fn target() -> Target {
     let mut base = base::linux_ohos::opts();
@@ -16,6 +18,10 @@ pub(crate) fn target() -> Target {
         data_layout: "e-m:e-p270:32:32-p271:32:32-p272:64:64-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128-Fn32".into(),
         arch: "aarch64".into(),
         options: TargetOptions {
+            // the AAPCS64 expects use of non-leaf frame pointers per
+            // https://github.com/ARM-software/abi-aa/blob/4492d1570eb70c8fd146623e0db65b2d241f12e7/aapcs64/aapcs64.rst#the-frame-pointer
+            // and we tend to encounter interesting bugs in AArch64 unwinding code if we do not
+            frame_pointer: FramePointer::NonLeaf,
             mcount: "\u{1}_mcount".into(),
             stack_probes: StackProbeType::Inline,
             supported_sanitizers: SanitizerSet::ADDRESS