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[MC][MachO]Do not emit DWARF for no-personality case
Detail: Follow up to D144999, where we emitted DWARF for non-canonical personality. Reviewed By: jyknight Differential Revision: https://reviews.llvm.org/D152540
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3 files changed

+154
-8
lines changed

3 files changed

+154
-8
lines changed

‎llvm/lib/MC/MCAsmBackend.cpp

Lines changed: 13 additions & 8 deletions
Original file line numberDiff line numberDiff line change
@@ -117,12 +117,17 @@ bool MCAsmBackend::fixupNeedsRelaxationAdvanced(
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}
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bool MCAsmBackend::isDarwinCanonicalPersonality(const MCSymbol *Sym) const {
120-
if (Sym && Sym->isMachO()) {
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StringRef name = Sym->getName();
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// XXX: We intentionally leave out "___gcc_personality_v0" because, despite
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// being system-defined like these two, it is not very commonly-used.
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// Reserving an empty slot for it seems silly.
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return name == "___gxx_personality_v0" || name == "___objc_personality_v0";
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}
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return false;
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// Consider a NULL personality (ie., no personality encoding) to be canonical
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// because it's always at 0.
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if (!Sym)
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return true;
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if (!Sym->isMachO())
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llvm_unreachable("Expected MachO symbols only");
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StringRef name = Sym->getName();
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// XXX: We intentionally leave out "___gcc_personality_v0" because, despite
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// being system-defined like these two, it is not very commonly-used.
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// Reserving an empty slot for it seems silly.
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return name == "___gxx_personality_v0" || name == "___objc_personality_v0";
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}

‎llvm/test/MC/MachO/AArch64/darwin-ARM64-no-personality.s

Lines changed: 73 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,73 @@
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# RUN: llvm-mc -filetype=obj -triple=arm64-apple-macos11.0 %s | llvm-objdump --unwind-info - | FileCheck %s
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# Check that we emit the right encoding for the no-personality case.
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# CHECK: Contents of __compact_unwind section:
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# CHECK: Entry at offset {{.+}}
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# CHECK: start: {{.+}} ltmp0
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# CHECK: length: {{.+}}
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# CHECK: compact encoding: 0x02001000
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# CHECK: Entry at offset {{.+}}
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# CHECK: start: {{.+}} __Z3foov
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# CHECK: length: {{.+}}
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# CHECK: compact encoding: 0x04000000
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# CHECK: Entry at offset {{.+}}
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# CHECK: start: {{.+}} _main
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# CHECK: length: {{.+}}
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# CHECK: compact encoding: 0x04000000
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.section __TEXT,__text,regular,pure_instructions
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.build_version macos, 11, 0
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.globl __Z3barPi
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.p2align 2
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__Z3barPi:
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.cfi_startproc
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sub sp, sp, #16
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.cfi_def_cfa_offset 16
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str x0, [sp, #8]
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add sp, sp, #16
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ret
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.cfi_endproc
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.globl __Z3foov
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.p2align 2
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__Z3foov:
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.cfi_startproc
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sub sp, sp, #32
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.cfi_def_cfa_offset 32
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stp x29, x30, [sp, #16]
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add x29, sp, #16
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.cfi_def_cfa w29, 16
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.cfi_offset w30, -8
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.cfi_offset w29, -16
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sub x0, x29, #4
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bl __Z3barPi
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ldp x29, x30, [sp, #16]
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add sp, sp, #32
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ret
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.cfi_endproc
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.globl _main
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.p2align 2
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_main:
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.cfi_startproc
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sub sp, sp, #32
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.cfi_def_cfa_offset 32
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stp x29, x30, [sp, #16]
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add x29, sp, #16
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.cfi_def_cfa w29, 16
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.cfi_offset w30, -8
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.cfi_offset w29, -16
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mov w8, #0
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str w8, [sp, #8]
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stur wzr, [x29, #-4]
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bl __Z3foov
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ldr w0, [sp, #8]
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ldp x29, x30, [sp, #16]
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add sp, sp, #32
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ret
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.cfi_endproc
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.subsections_via_symbols

‎llvm/test/MC/MachO/darwin-x86_64-no-personality.s

Lines changed: 68 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,68 @@
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# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin10.0 %s | llvm-objdump --unwind-info - | FileCheck %s
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# Check that we emit the right encoding for the no-personality case.
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# CHECK: Contents of __compact_unwind section:
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# CHECK: Entry at offset {{.+}}
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# CHECK: start: {{.+}} __Z3barPi
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# CHECK: length: {{.+}}
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# CHECK: compact encoding: 0x01000000
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# CHECK: Entry at offset {{.+}}
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# CHECK: start: {{.+}} __Z3foov
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# CHECK: length: {{.+}}
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# CHECK: compact encoding: 0x01000000
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# CHECK: Entry at offset {{.+}}
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# CHECK: start: {{.+}} _main
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# CHECK: length: 0x1c
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.section __TEXT,__text,regular,pure_instructions
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.globl __Z3barPi
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.p2align 4, 0x90
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__Z3barPi:
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.cfi_startproc
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pushq %rbp
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.cfi_def_cfa_offset 16
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.cfi_offset %rbp, -16
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movq %rsp, %rbp
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.cfi_def_cfa_register %rbp
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movq %rdi, -8(%rbp)
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popq %rbp
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retq
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.cfi_endproc
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.globl __Z3foov
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.p2align 4, 0x90
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__Z3foov:
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.cfi_startproc
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pushq %rbp
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.cfi_def_cfa_offset 16
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.cfi_offset %rbp, -16
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movq %rsp, %rbp
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.cfi_def_cfa_register %rbp
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subq $16, %rsp
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leaq -4(%rbp), %rdi
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callq __Z3barPi
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addq $16, %rsp
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popq %rbp
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retq
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.cfi_endproc
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.globl _main
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.p2align 4, 0x90
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_main:
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.cfi_startproc
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pushq %rbp
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.cfi_def_cfa_offset 16
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.cfi_offset %rbp, -16
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movq %rsp, %rbp
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.cfi_def_cfa_register %rbp
59+
subq $16, %rsp
60+
movl $0, -4(%rbp)
61+
callq __Z3foov
62+
xorl %eax, %eax
63+
addq $16, %rsp
64+
popq %rbp
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retq
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.cfi_endproc
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.subsections_via_symbols

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