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cranelift: refactor unwind logic to accommodate multiple backends (#2357)

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*    Make cranelift_codegen::isa::unwind::input public
*    Move UnwindCode's common offset field out of the structure
*    Make MachCompileResult::unwind_info more generic
*    Record initial stack pointer offset
This commit is contained in:
Yury Delendik
2020-11-05 16:57:40 -06:00
committed by GitHub
parent df59ffb1b6
commit f60c0f3ec3
15 changed files with 396 additions and 351 deletions
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282
cranelift/codegen/src/isa/x86/unwind.rs
View File

@@ -81,7 +81,7 @@ pub(crate) fn create_unwind_info(
unwind_codes = epilogues_unwind_codes.last_mut().unwrap();
if !is_last_block {
unwind_codes.push(UnwindCode::RememberState { offset });
unwind_codes.push((offset, UnwindCode::RememberState));
}
} else if in_epilogue {
unwind_codes = epilogues_unwind_codes.last_mut().unwrap();
@@ -95,15 +95,19 @@ pub(crate) fn create_unwind_info(
match opcode {
Opcode::X86Push => {
let reg = func.locations[arg].unwrap_reg();
unwind_codes.push(UnwindCode::StackAlloc {
unwind_codes.push((
offset,
size: word_size.into(),
});
unwind_codes.push(UnwindCode::SaveRegister {
UnwindCode::StackAlloc {
size: word_size.into(),
},
));
unwind_codes.push((
offset,
reg,
stack_offset: 0,
});
UnwindCode::SaveRegister {
reg,
stack_offset: 0,
},
));
}
Opcode::AdjustSpDown => {
let stack_size =
@@ -111,10 +115,8 @@ pub(crate) fn create_unwind_info(
// This is used when calling a stack check function
// We need to track the assignment to RAX which has the size of the stack
unwind_codes.push(UnwindCode::StackAlloc {
offset,
size: stack_size,
});
unwind_codes
.push((offset, UnwindCode::StackAlloc { size: stack_size }));
}
_ => {}
}
@@ -138,10 +140,8 @@ pub(crate) fn create_unwind_info(
stack_size = Some(imm as u32);
unwind_codes.push(UnwindCode::StackAlloc {
offset,
size: imm as u32,
});
unwind_codes
.push((offset, UnwindCode::StackAlloc { size: imm as u32 }));
}
Opcode::AdjustSpUpImm => {
let imm: i64 = imm.into();
@@ -149,10 +149,8 @@ pub(crate) fn create_unwind_info(
stack_size = Some(imm as u32);
unwind_codes.push(UnwindCode::StackDealloc {
offset,
size: imm as u32,
});
unwind_codes
.push((offset, UnwindCode::StackDealloc { size: imm as u32 }));
}
_ => {}
}
@@ -170,18 +168,20 @@ pub(crate) fn create_unwind_info(
// Note: the stack_offset here is relative to an adjusted SP
if dst == (RU::rsp as RegUnit) && FPR.contains(src) {
let stack_offset: i32 = stack_offset.into();
unwind_codes.push(UnwindCode::SaveRegister {
unwind_codes.push((
offset,
reg: src,
stack_offset: stack_offset as u32,
});
UnwindCode::SaveRegister {
reg: src,
stack_offset: stack_offset as u32,
},
));
}
}
}
InstructionData::CopySpecial { src, dst, .. } if frame_register.is_none() => {
// Check for change in CFA register (RSP is always the starting CFA)
if src == (RU::rsp as RegUnit) {
unwind_codes.push(UnwindCode::SetFramePointer { offset, reg: dst });
unwind_codes.push((offset, UnwindCode::SetFramePointer { reg: dst }));
frame_register = Some(dst);
}
}
@@ -203,18 +203,25 @@ pub(crate) fn create_unwind_info(
let offset = epilogue_pop_offsets[i];
let reg = func.locations[*arg].unwrap_reg();
unwind_codes.push(UnwindCode::RestoreRegister { offset, reg });
unwind_codes.push(UnwindCode::StackDealloc {
unwind_codes.push((offset, UnwindCode::RestoreRegister { reg }));
unwind_codes.push((
offset,
size: word_size.into(),
});
UnwindCode::StackDealloc {
size: word_size.into(),
},
));
if Some(reg) == frame_register {
unwind_codes.push((offset, UnwindCode::RestoreFramePointer));
// Keep frame_register assigned for next epilogue.
}
}
epilogue_pop_offsets.clear();
// TODO ensure unwind codes sorted by offsets ?
if !is_last_block {
unwind_codes.push(UnwindCode::RestoreState { offset });
unwind_codes.push((offset, UnwindCode::RestoreState));
}
in_epilogue = false;
@@ -232,6 +239,7 @@ pub(crate) fn create_unwind_info(
epilogues_unwind_codes,
function_size,
word_size,
initial_sp_offset: word_size,
}))
}
@@ -271,37 +279,36 @@ mod tests {
UnwindInfo {
prologue_size: 9,
prologue_unwind_codes: vec![
UnwindCode::StackAlloc { offset: 2, size: 8 },
UnwindCode::SaveRegister {
offset: 2,
reg: RU::rbp.into(),
stack_offset: 0,
},
UnwindCode::SetFramePointer {
offset: 5,
reg: RU::rbp.into(),
},
UnwindCode::StackAlloc {
offset: 9,
size: 64
}
(2, UnwindCode::StackAlloc { size: 8 }),
(
2,
UnwindCode::SaveRegister {
reg: RU::rbp.into(),
stack_offset: 0,
}
),
(
5,
UnwindCode::SetFramePointer {
reg: RU::rbp.into(),
}
),
(9, UnwindCode::StackAlloc { size: 64 })
],
epilogues_unwind_codes: vec![vec![
UnwindCode::StackDealloc {
offset: 13,
size: 64
},
UnwindCode::RestoreRegister {
offset: 15,
reg: RU::rbp.into()
},
UnwindCode::StackDealloc {
offset: 15,
size: 8
}
(13, UnwindCode::StackDealloc { size: 64 }),
(
15,
UnwindCode::RestoreRegister {
reg: RU::rbp.into()
}
),
(15, UnwindCode::StackDealloc { size: 8 }),
(15, UnwindCode::RestoreFramePointer)
]],
function_size: 16,
word_size: 8,
initial_sp_offset: 8,
}
);
}
@@ -329,37 +336,36 @@ mod tests {
UnwindInfo {
prologue_size: 27,
prologue_unwind_codes: vec![
UnwindCode::StackAlloc { offset: 2, size: 8 },
UnwindCode::SaveRegister {
offset: 2,
reg: RU::rbp.into(),
stack_offset: 0,
},
UnwindCode::SetFramePointer {
offset: 5,
reg: RU::rbp.into(),
},
UnwindCode::StackAlloc {
offset: 27,
size: 10000
}
(2, UnwindCode::StackAlloc { size: 8 }),
(
2,
UnwindCode::SaveRegister {
reg: RU::rbp.into(),
stack_offset: 0,
}
),
(
5,
UnwindCode::SetFramePointer {
reg: RU::rbp.into(),
}
),
(27, UnwindCode::StackAlloc { size: 10000 })
],
epilogues_unwind_codes: vec![vec![
UnwindCode::StackDealloc {
offset: 34,
size: 10000
},
UnwindCode::RestoreRegister {
offset: 36,
reg: RU::rbp.into()
},
UnwindCode::StackDealloc {
offset: 36,
size: 8
}
(34, UnwindCode::StackDealloc { size: 10000 }),
(
36,
UnwindCode::RestoreRegister {
reg: RU::rbp.into()
}
),
(36, UnwindCode::StackDealloc { size: 8 }),
(36, UnwindCode::RestoreFramePointer)
]],
function_size: 37,
word_size: 8,
initial_sp_offset: 8,
}
);
}
@@ -387,37 +393,36 @@ mod tests {
UnwindInfo {
prologue_size: 27,
prologue_unwind_codes: vec![
UnwindCode::StackAlloc { offset: 2, size: 8 },
UnwindCode::SaveRegister {
offset: 2,
reg: RU::rbp.into(),
stack_offset: 0,
},
UnwindCode::SetFramePointer {
offset: 5,
reg: RU::rbp.into(),
},
UnwindCode::StackAlloc {
offset: 27,
size: 1000000
}
(2, UnwindCode::StackAlloc { size: 8 }),
(
2,
UnwindCode::SaveRegister {
reg: RU::rbp.into(),
stack_offset: 0,
}
),
(
5,
UnwindCode::SetFramePointer {
reg: RU::rbp.into(),
}
),
(27, UnwindCode::StackAlloc { size: 1000000 })
],
epilogues_unwind_codes: vec![vec![
UnwindCode::StackDealloc {
offset: 34,
size: 1000000
},
UnwindCode::RestoreRegister {
offset: 36,
reg: RU::rbp.into()
},
UnwindCode::StackDealloc {
offset: 36,
size: 8
}
(34, UnwindCode::StackDealloc { size: 1000000 }),
(
36,
UnwindCode::RestoreRegister {
reg: RU::rbp.into()
}
),
(36, UnwindCode::StackDealloc { size: 8 }),
(36, UnwindCode::RestoreFramePointer)
]],
function_size: 37,
word_size: 8,
initial_sp_offset: 8,
}
);
}
@@ -458,43 +463,48 @@ mod tests {
UnwindInfo {
prologue_size: 5,
prologue_unwind_codes: vec![
UnwindCode::StackAlloc { offset: 2, size: 8 },
UnwindCode::SaveRegister {
offset: 2,
reg: RU::rbp.into(),
stack_offset: 0,
},
UnwindCode::SetFramePointer {
offset: 5,
reg: RU::rbp.into()
}
(2, UnwindCode::StackAlloc { size: 8 }),
(
2,
UnwindCode::SaveRegister {
reg: RU::rbp.into(),
stack_offset: 0,
}
),
(
5,
UnwindCode::SetFramePointer {
reg: RU::rbp.into()
}
)
],
epilogues_unwind_codes: vec![
vec![
UnwindCode::RememberState { offset: 12 },
UnwindCode::RestoreRegister {
offset: 12,
reg: RU::rbp.into()
},
UnwindCode::StackDealloc {
offset: 12,
size: 8
},
UnwindCode::RestoreState { offset: 13 }
(12, UnwindCode::RememberState),
(
12,
UnwindCode::RestoreRegister {
reg: RU::rbp.into()
}
),
(12, UnwindCode::StackDealloc { size: 8 }),
(12, UnwindCode::RestoreFramePointer),
(13, UnwindCode::RestoreState)
],
vec![
UnwindCode::RestoreRegister {
offset: 15,
reg: RU::rbp.into()
},
UnwindCode::StackDealloc {
offset: 15,
size: 8
}
(
15,
UnwindCode::RestoreRegister {
reg: RU::rbp.into()
}
),
(15, UnwindCode::StackDealloc { size: 8 }),
(15, UnwindCode::RestoreFramePointer)
]
],
function_size: 16,
word_size: 8,
initial_sp_offset: 8,
}
);
}

6
cranelift/codegen/src/isa/x86/unwind/systemv.rs
View File

@@ -118,7 +118,7 @@ pub(crate) fn create_unwind_info(
fn map(&self, reg: RegUnit) -> Result<u16, RegisterMappingError> {
Ok(map_reg(self.0, reg)?.0)
}
fn rsp(&self) -> u16 {
fn sp(&self) -> u16 {
X86_64::RSP.0
}
}
@@ -165,7 +165,7 @@ mod tests {
_ => panic!("expected unwind information"),
};
assert_eq!(format!("{:?}", fde), "FrameDescriptionEntry { address: Constant(1234), length: 16, lsda: None, instructions: [(2, CfaOffset(16)), (2, Offset(Register(6), -16)), (5, CfaRegister(Register(6))), (15, Cfa(Register(7), 8)), (15, SameValue(Register(6)))] }");
assert_eq!(format!("{:?}", fde), "FrameDescriptionEntry { address: Constant(1234), length: 16, lsda: None, instructions: [(2, CfaOffset(16)), (2, Offset(Register(6), -16)), (5, CfaRegister(Register(6))), (15, SameValue(Register(6))), (15, Cfa(Register(7), 8))] }");
}
fn create_function(call_conv: CallConv, stack_slot: Option<StackSlotData>) -> Function {
@@ -205,7 +205,7 @@ mod tests {
_ => panic!("expected unwind information"),
};
assert_eq!(format!("{:?}", fde), "FrameDescriptionEntry { address: Constant(4321), length: 16, lsda: None, instructions: [(2, CfaOffset(16)), (2, Offset(Register(6), -16)), (5, CfaRegister(Register(6))), (12, RememberState), (12, Cfa(Register(7), 8)), (12, SameValue(Register(6))), (13, RestoreState), (15, Cfa(Register(7), 8)), (15, SameValue(Register(6)))] }");
assert_eq!(format!("{:?}", fde), "FrameDescriptionEntry { address: Constant(4321), length: 16, lsda: None, instructions: [(2, CfaOffset(16)), (2, Offset(Register(6), -16)), (5, CfaRegister(Register(6))), (12, RememberState), (12, SameValue(Register(6))), (12, Cfa(Register(7), 8)), (13, RestoreState), (15, SameValue(Register(6))), (15, Cfa(Register(7), 8))] }");
}
fn create_multi_return_function(call_conv: CallConv) -> Function {