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llvm-project/lld/test/ELF/linkerscript/unused-synthetic.s

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[ELF] Remove unused synthetic sections from script commands Script commands are processed before unused synthetic sections are removed. Therefore, if a linker script matches one of these sections it'll get emitted as an empty output section because the logic for removing unused synthetic sections ignores script commands which could have already matched and captured one of these sections. This patch fixes that by also removing the unused synthetic sections from the script commands. Differential Revision: https://reviews.llvm.org/D34800 llvm-svn: 307037
2017-07-03 23:49:25 +08:00
# REQUIRES: x86
# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
# RUN: echo "SECTIONS { \
[ELF] - Remove unused synthetic sections correctly. This is PR35740 which now crashes because we remove unused synthetic sections incorrectly. We can keep input section description and corresponding output section live even if it must be empty and dead. This results in a crash because SHF_LINK_ORDER handling code tries to access first section which is nullptr in this case. Patch fixes the issue. Differential revision: https://reviews.llvm.org/D42681 llvm-svn: 324463
2018-02-07 17:11:07 +08:00
# RUN: .got : { *(.got) *(.got) } \
[ELF] Remove unused synthetic sections from script commands Script commands are processed before unused synthetic sections are removed. Therefore, if a linker script matches one of these sections it'll get emitted as an empty output section because the logic for removing unused synthetic sections ignores script commands which could have already matched and captured one of these sections. This patch fixes that by also removing the unused synthetic sections from the script commands. Differential Revision: https://reviews.llvm.org/D34800 llvm-svn: 307037
2017-07-03 23:49:25 +08:00
# RUN: .plt : { *(.plt) } \
# RUN: .text : { *(.text) } \
# RUN: }" > %t.script
# RUN: ld.lld -shared -o %t.so --script %t.script %t.o
[lld][NFC] Update tests to use -S instead of -s when using llvm-readelf. Summary: llvm-readobj/readelf accepts both -s and -S as aliases for --sections. However with GNU readelf only -S means --section, and -s means --symbols. I would like to make llvm-readelf more compatible. Reviewers: MaskRay, espindola Reviewed By: MaskRay Subscribers: emaste, arichardson, steven_wu, dexonsmith, llvm-commits Differential Revision: https://reviews.llvm.org/D54118 llvm-svn: 346164
2018-11-06 04:39:06 +08:00
# RUN: llvm-readelf -S %t.so | FileCheck %s
[ELF] Remove unused synthetic sections from script commands Script commands are processed before unused synthetic sections are removed. Therefore, if a linker script matches one of these sections it'll get emitted as an empty output section because the logic for removing unused synthetic sections ignores script commands which could have already matched and captured one of these sections. This patch fixes that by also removing the unused synthetic sections from the script commands. Differential Revision: https://reviews.llvm.org/D34800 llvm-svn: 307037
2017-07-03 23:49:25 +08:00
# CHECK-NOT: .got
# CHECK-NOT: .plt
[lld] Mitigate relocation overflow [part 1 of 2]. This CL places .dynsym and .dynstr at the beginning of SHF_ALLOC sections. We do this to mitigate the possibility that huge .dynsym and .dynstr sections placed between ro-data and text sections cause relocation overflow. Differential Revision: https://reviews.llvm.org/D45788 llvm-svn: 332374
2018-05-16 01:02:35 +08:00
# CHECK: .dynsym
[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: .text
[ELF] Remove unused synthetic sections from script commands Script commands are processed before unused synthetic sections are removed. Therefore, if a linker script matches one of these sections it'll get emitted as an empty output section because the logic for removing unused synthetic sections ignores script commands which could have already matched and captured one of these sections. This patch fixes that by also removing the unused synthetic sections from the script commands. Differential Revision: https://reviews.llvm.org/D34800 llvm-svn: 307037
2017-07-03 23:49:25 +08:00
[ELF] Reset OutputSection size prior to processing linker script commands The size of an OutputSection is calculated early, to aid handling of compressed debug sections. However, subsequent to this point, unused synthetic sections are removed. In the event that an OutputSection, from which such an InputSection is removed, is still required (e.g. because it has a symbol assignment), and no longer has any InputSections, dot assignments, or BYTE()-family directives, the size member is never updated when processing the commands. If the removed InputSection had a non-zero size (such as a .got.plt section), the section ends up with the wrong size in the output. The fix is to reset the OutputSection size prior to processing the linker script commands relating to that OutputSection. This ensures that the size is correct even in the above situation. Additionally, to reduce the risk of developers misusing OutputSection Size and InputSection OutSecOff, they are set to simply the number of InputSections in an OutputSection, and the corresponding index respectively. We cannot completely stop using them, due to SHF_LINK_ORDER sections requiring them. Compressed debug sections also require the full size. This is now calculated in maybeCompress for these kinds of sections. Reviewers: ruiu, rafael Differential Revision: https://reviews.llvm.org/D38361 llvm-svn: 320472
2017-12-12 19:51:13 +08:00
# Test that the size of a removed unused synthetic input section is not added
# to the output section size. Adding a symbol assignment prevents removal of
# the output section, but does not cause the section size to be recomputed.
# RUN: echo "SECTIONS { \
# RUN: .got.plt : { a_sym = .; *(.got.plt) } \
# RUN: }" > %t2.script
# RUN: ld.lld -shared -o %t2.so --script %t2.script %t.o
[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 --section-headers %t2.so | FileCheck %s --check-prefix=CHECK2
[ELF] Reset OutputSection size prior to processing linker script commands The size of an OutputSection is calculated early, to aid handling of compressed debug sections. However, subsequent to this point, unused synthetic sections are removed. In the event that an OutputSection, from which such an InputSection is removed, is still required (e.g. because it has a symbol assignment), and no longer has any InputSections, dot assignments, or BYTE()-family directives, the size member is never updated when processing the commands. If the removed InputSection had a non-zero size (such as a .got.plt section), the section ends up with the wrong size in the output. The fix is to reset the OutputSection size prior to processing the linker script commands relating to that OutputSection. This ensures that the size is correct even in the above situation. Additionally, to reduce the risk of developers misusing OutputSection Size and InputSection OutSecOff, they are set to simply the number of InputSections in an OutputSection, and the corresponding index respectively. We cannot completely stop using them, due to SHF_LINK_ORDER sections requiring them. Compressed debug sections also require the full size. This is now calculated in maybeCompress for these kinds of sections. Reviewers: ruiu, rafael Differential Revision: https://reviews.llvm.org/D38361 llvm-svn: 320472
2017-12-12 19:51:13 +08:00
# CHECK2: .got.plt 00000000
[ELF] Remove unused synthetic sections from script commands Script commands are processed before unused synthetic sections are removed. Therefore, if a linker script matches one of these sections it'll get emitted as an empty output section because the logic for removing unused synthetic sections ignores script commands which could have already matched and captured one of these sections. This patch fixes that by also removing the unused synthetic sections from the script commands. Differential Revision: https://reviews.llvm.org/D34800 llvm-svn: 307037
2017-07-03 23:49:25 +08:00
.global _start
_start:
nop