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llvm-project/lld/test/ELF/arm-exidx-canunwind.s

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[ELF][ARM] Initial implentation of ARM exceptions support The .ARM.exidx sections contain a table. Each entry has two fields: - PREL31 offset to the function the table entry describes - Action to take, either cantunwind, inline unwind, or PREL31 offset to .ARM.extab section The table entries must be sorted in order of the virtual addresses the first entry of the table describes. Traditionally this is implemented by the SHF_LINK_ORDER dependency. Instead of implementing this directly we sort the table entries post relocation. The .ARM.exidx OutputSection is described by the PT_ARM_EXIDX program header Differential revision: https://reviews.llvm.org/D25127 llvm-svn: 283730
2016-10-10 17:39:26 +08:00
// RUN: llvm-mc -filetype=obj -triple=armv7a-none-linux-gnueabi %s -o %t
// RUN: ld.lld %t -o %t2 2>&1
// RUN: llvm-objdump -d -triple=armv7a-none-linux-gnueabi %t2 | FileCheck %s
// RUN: llvm-objdump -s -triple=armv7a-none-linux-gnueabi %t2 | FileCheck -check-prefix=CHECK-EXIDX %s
// RUN: llvm-readobj --program-headers --sections %t2 | FileCheck -check-prefix=CHECK-PT %s
// REQUIRES: arm
// Test that inline unwinding table entries and references to .ARM.extab
// entries survive the re-ordering of the .ARM.exidx section
.syntax unified
// Will produce an ARM.exidx entry with inline unwinding instructions
.section .text.func1, "ax",%progbits
.global func1
func1:
.fnstart
bx lr
.save {r7, lr}
.setfp r7, sp, #0
.fnend
// Unwinding instructions for .text2 too large for an inline entry ARM.exidx
// entry. A separate .ARM.extab section is created to hold the unwind entries
// The .ARM.exidx table entry has a reference to the .ARM.extab section.
.section .text.func2, "ax",%progbits
.global func2
func2:
.fnstart
bx lr
.personality __gxx_personality_v0
.handlerdata
.long 0
.section .text.func2
.fnend
// Dummy implementation of personality routines to satisfy reference from
// exception tables
.section .text.__gcc_personality_v0, "ax", %progbits
.global __gxx_personality_v0
__gxx_personality_v0:
bx lr
.section .text.__aeabi_unwind_cpp_pr0, "ax", %progbits
.global __aeabi_unwind_cpp_pr0
__aeabi_unwind_cpp_pr0:
bx lr
.text
.global _start
_start:
bl func1
bl func2
bx lr
// CHECK: Disassembly of section .text:
// CHECK-NEXT: _start:
// CHECK-NEXT: 11000: 01 00 00 eb bl #4 <func1>
// CHECK-NEXT: 11004: 01 00 00 eb bl #4 <func2>
// CHECK-NEXT: 11008: 1e ff 2f e1 bx lr
// CHECK: func1:
// CHECK-NEXT: 1100c: 1e ff 2f e1 bx lr
// CHECK: func2:
// CHECK-NEXT: 11010: 1e ff 2f e1 bx lr
// CHECK: __gxx_personality_v0:
// CHECK-NEXT: 11014: 1e ff 2f e1 bx lr
// CHECK: __aeabi_unwind_cpp_pr0:
// CHECK-NEXT: 11018: 1e ff 2f e1 bx lr
// CHECK-EXIDX: Contents of section .ARM.exidx:
// 100d4 + f38 = 1100c = func1 (inline unwinding data)
[ELF] Add terminating sentinel .ARM.exidx table entry The .ARM.exidx table has an entry for each function with the first entry giving the start address of the function, the table is sorted in ascending order of function address. Given a PC value, the unwinder will search the table for the entry that contains the PC value. If the table entry happens to be the last, the range of the addresses that the final unwinding table describes will extend to the end of the address space. To prevent an incorrect address outside the address range of the program matching the last entry we follow ld.bfd's example and add a sentinel EXIDX_CANTUNWIND entry at the end of the table. This gives the final real table entry an upper bound. In addition the llvm libunwind unwinder currently depends on the presence of a sentinel entry (PR31091). Differential revision: https://reviews.llvm.org/D26977 llvm-svn: 287869
2016-11-24 19:43:55 +08:00
// 100dc + f34 = 11010 = func2 (100e0 + c = 100ec = .ARM.extab entry)
// CHECK-EXIDX-NEXT: 100d4 380f0000 08849780 340f0000 0c000000
// 100e4 + f30 = 11014 = terminate = func2 + sizeof(func2)
// CHECK-EXIDX-NEXT: 100e4 300f0000 01000000
[ELF] Consolidate .ARM.extab.* sections into .ARM.extab When -ffunction-sections and ARM C++ exceptions are used each .text.suffix section will have at least one .ARM.exidx.suffix section and may have an additional .ARM.extab.suffix section if the unwinding instructions are too large to inline into the .ARM.exidx table entry. For a large program without a linker script this can lead to a large number of section header table entries that can increase the size of the ELF file. This change introduces a default rule for .ARM.extab.* to be placed in a single output section called .ARM.extab . This follows the behavior of ld.gold and ld.bfd. fixes pr33407 Differential Revision: https://reviews.llvm.org/D34678 llvm-svn: 306522
2017-06-28 17:12:38 +08:00
// CHECK-EXIDX-NEXT: Contents of section .ARM.extab:
[ELF] Add terminating sentinel .ARM.exidx table entry The .ARM.exidx table has an entry for each function with the first entry giving the start address of the function, the table is sorted in ascending order of function address. Given a PC value, the unwinder will search the table for the entry that contains the PC value. If the table entry happens to be the last, the range of the addresses that the final unwinding table describes will extend to the end of the address space. To prevent an incorrect address outside the address range of the program matching the last entry we follow ld.bfd's example and add a sentinel EXIDX_CANTUNWIND entry at the end of the table. This gives the final real table entry an upper bound. In addition the llvm libunwind unwinder currently depends on the presence of a sentinel entry (PR31091). Differential revision: https://reviews.llvm.org/D26977 llvm-svn: 287869
2016-11-24 19:43:55 +08:00
// 100ec + f28 = 11014 = __gxx_personality_v0
// CHECK-EXIDX-NEXT: 100ec 280f0000 b0b0b000 00000000
[ELF][ARM] Initial implentation of ARM exceptions support The .ARM.exidx sections contain a table. Each entry has two fields: - PREL31 offset to the function the table entry describes - Action to take, either cantunwind, inline unwind, or PREL31 offset to .ARM.extab section The table entries must be sorted in order of the virtual addresses the first entry of the table describes. Traditionally this is implemented by the SHF_LINK_ORDER dependency. Instead of implementing this directly we sort the table entries post relocation. The .ARM.exidx OutputSection is described by the PT_ARM_EXIDX program header Differential revision: https://reviews.llvm.org/D25127 llvm-svn: 283730
2016-10-10 17:39:26 +08:00
// CHECK-PT: Name: .ARM.exidx
// CHECK-PT-NEXT: Type: SHT_ARM_EXIDX (0x70000001)
Always compute sh_link for SHF_LINK_ORDER sections. Since the output has a section table too, it is meaningful to compute the sh_link. In a more practical note, the binutils' strip crashes if sh_link is not set for SHT_ARM_EXIDX. llvm-svn: 287280
2016-11-18 07:16:39 +08:00
// CHECK-PT-NEXT: Flags [
// CHECK-PT-NEXT: SHF_ALLOC
// CHECK-PT-NEXT: SHF_LINK_ORDER
[ELF][ARM] Initial implentation of ARM exceptions support The .ARM.exidx sections contain a table. Each entry has two fields: - PREL31 offset to the function the table entry describes - Action to take, either cantunwind, inline unwind, or PREL31 offset to .ARM.extab section The table entries must be sorted in order of the virtual addresses the first entry of the table describes. Traditionally this is implemented by the SHF_LINK_ORDER dependency. Instead of implementing this directly we sort the table entries post relocation. The .ARM.exidx OutputSection is described by the PT_ARM_EXIDX program header Differential revision: https://reviews.llvm.org/D25127 llvm-svn: 283730
2016-10-10 17:39:26 +08:00
// CHECK-PT-NEXT: ]
// CHECK-PT-NEXT: Address: 0x100D4
// CHECK-PT-NEXT: Offset: 0xD4
[ELF] Add terminating sentinel .ARM.exidx table entry The .ARM.exidx table has an entry for each function with the first entry giving the start address of the function, the table is sorted in ascending order of function address. Given a PC value, the unwinder will search the table for the entry that contains the PC value. If the table entry happens to be the last, the range of the addresses that the final unwinding table describes will extend to the end of the address space. To prevent an incorrect address outside the address range of the program matching the last entry we follow ld.bfd's example and add a sentinel EXIDX_CANTUNWIND entry at the end of the table. This gives the final real table entry an upper bound. In addition the llvm libunwind unwinder currently depends on the presence of a sentinel entry (PR31091). Differential revision: https://reviews.llvm.org/D26977 llvm-svn: 287869
2016-11-24 19:43:55 +08:00
// CHECK-PT-NEXT: Size: 24
[ELF][ARM] Initial implentation of ARM exceptions support The .ARM.exidx sections contain a table. Each entry has two fields: - PREL31 offset to the function the table entry describes - Action to take, either cantunwind, inline unwind, or PREL31 offset to .ARM.extab section The table entries must be sorted in order of the virtual addresses the first entry of the table describes. Traditionally this is implemented by the SHF_LINK_ORDER dependency. Instead of implementing this directly we sort the table entries post relocation. The .ARM.exidx OutputSection is described by the PT_ARM_EXIDX program header Differential revision: https://reviews.llvm.org/D25127 llvm-svn: 283730
2016-10-10 17:39:26 +08:00
// CHECK-PT: Type: PT_ARM_EXIDX (0x70000001)
// CHECK-PT-NEXT: Offset: 0xD4
// CHECK-PT-NEXT: VirtualAddress: 0x100D4
// CHECK-PT-NEXT: PhysicalAddress: 0x100D4
[ELF] Add terminating sentinel .ARM.exidx table entry The .ARM.exidx table has an entry for each function with the first entry giving the start address of the function, the table is sorted in ascending order of function address. Given a PC value, the unwinder will search the table for the entry that contains the PC value. If the table entry happens to be the last, the range of the addresses that the final unwinding table describes will extend to the end of the address space. To prevent an incorrect address outside the address range of the program matching the last entry we follow ld.bfd's example and add a sentinel EXIDX_CANTUNWIND entry at the end of the table. This gives the final real table entry an upper bound. In addition the llvm libunwind unwinder currently depends on the presence of a sentinel entry (PR31091). Differential revision: https://reviews.llvm.org/D26977 llvm-svn: 287869
2016-11-24 19:43:55 +08:00
// CHECK-PT-NEXT: FileSize: 24
// CHECK-PT-NEXT: MemSize: 24
[ELF][ARM] Initial implentation of ARM exceptions support The .ARM.exidx sections contain a table. Each entry has two fields: - PREL31 offset to the function the table entry describes - Action to take, either cantunwind, inline unwind, or PREL31 offset to .ARM.extab section The table entries must be sorted in order of the virtual addresses the first entry of the table describes. Traditionally this is implemented by the SHF_LINK_ORDER dependency. Instead of implementing this directly we sort the table entries post relocation. The .ARM.exidx OutputSection is described by the PT_ARM_EXIDX program header Differential revision: https://reviews.llvm.org/D25127 llvm-svn: 283730
2016-10-10 17:39:26 +08:00
// CHECK-PT-NEXT: Flags [ (0x4)
// CHECK-PT-NEXT: PF_R (0x4)
// CHECK-PT-NEXT: ]
// CHECK-PT-NEXT: Alignment: 4
// CHECK-PT-NEXT: }