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llvm-project/lld/test/ELF/arm-exidx-sentinel-orphan.s

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[ELF] Change test files for style consistency. NFC * Move `REQUIRES:` line to the top * llvm-mc ... -o %t -> llvm-mc ... -o %t.o * Don't check "TEXT" "DATA" columns (they are bfd-style names that do not fit into llvm well) in llvm-objdump output llvm-svn: 335498
2018-06-26 01:07:40 +08:00
// REQUIRES: arm
[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
// RUN: llvm-mc -filetype=obj -triple=armv7a-none-linux-gnueabi %s -o %t
// Use Linker script without .ARM.exidx Output Section so it is treated as
// an orphan. We must still add the sentinel table entry
// RUN: echo "SECTIONS { \
// RUN: .text 0x11000 : { *(.text*) } \
// RUN: } " > %t.script
[ELF] Remove Duplicate .ARM.exidx sections The ARM.exidx section contains a table of 8-byte entries with the first word of each entry an offset to the function it describes and the second word instructions for unwinding if an exception is thrown from that function. The SHF_LINK_ORDER processing will order the table in ascending order of the functions described by the exception table entries. As the address range of an exception table entry is terminated by the next table entry, it is possible to merge consecutive table entries that have identical unwind instructions. For this implementation we define a table entry to be identical if: - Both entries are the special EXIDX_CANTUNWIND. - Both entries have the same inline unwind instructions. We do not attempt to establish if table entries that are references to .ARM.extab sections are identical. This implementation works at a granularity of a single .ARM.exidx InputSection. If all entries in the InputSection are identical to the previous table entry we can remove the InputSection. A more sophisticated but more complex implementation would rewrite InputSection contents so that duplicates within a .ARM.exidx InputSection can be merged. Differential Revision: https://reviews.llvm.org/D40967 llvm-svn: 320803
2017-12-15 19:09:41 +08:00
// RUN: ld.lld --no-merge-exidx-entries --script %t.script %t -o %t2
[test] lld/test/: change llvm-objdump single-dash long options to double-dash options
2020-03-16 08:47:44 +08:00
// RUN: llvm-objdump -s --triple=armv7a-none-linux-gnueabi %t2 | FileCheck %s
[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
.syntax unified
.text
.global _start
_start:
.fnstart
.cantunwind
bx lr
.fnend
// CHECK: Contents of section .ARM.exidx:
// 11004 - 4 = 0x11000 = _start
// 1100c - 8 = 0x11004 = _start + sizeof(_start)
[ELF] Assign RF_EXEC rank even if --no-rosegment or SECTIONS command is used Summary: Currently when --no-rosegment is specified or a linker script with SECTIONS command is used, .rodata (A) .text (AX) are assigned the same rank and .rodata may be placed after .text . This increases the gap between .text and .bss and can cause pc-relative relocation overflow (e.g. gcc crtbegin.o crtbegin.S have R_X86_64_PC32 relocation from .text to .bss). This patch makes SingleRoRx affect only segment layout, not section layout. As a consequence, .rodata will be placed before .text regardless of SingleRoRx. Reviewers: espindola, ruiu, grimar, echristo, javed.absar Subscribers: emaste, arichardson, llvm-commits Differential Revision: https://reviews.llvm.org/D48405 llvm-svn: 335627
2018-06-27 01:04:47 +08:00
// CHECK-NEXT: 0000 00100100 01000000 fc0f0100 01000000