From 0c157b51d339fbfe51b6ef21acd4b21452c76f2c Mon Sep 17 00:00:00 2001 From: Jubilee Young Date: Thu, 8 May 2025 14:30:33 -0700 Subject: 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. --- tests/codegen/frame-pointer.rs | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'tests/codegen/frame-pointer.rs') diff --git a/tests/codegen/frame-pointer.rs b/tests/codegen/frame-pointer.rs index 1f7c9a59c98..23989653fa8 100644 --- a/tests/codegen/frame-pointer.rs +++ b/tests/codegen/frame-pointer.rs @@ -26,8 +26,10 @@ pub fn peach(x: u32) -> u32 { // 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" +// +// AAPCS64 demands frame pointers: +// aarch64-linux-SAME: {{.*}}"frame-pointer"="non-leaf" // aarch64-apple-SAME: {{.*}}"frame-pointer"="non-leaf" // CHECK-SAME: } -- cgit 1.4.1-3-g733a5