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llvm-project/lld/test/ELF/linkerscript/linkorder2.s

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[ELF] - Stop setting OutSecOff too early. Currently LLD sets OutSecOff in addSection for input sections. That is a fake offset (just a rude approximation to remember the order), used for sorting SHF_LINK_ORDER sections (see resolveShfLinkOrder, compareByFilePosition). There are 2 problems with such approach: 1. We currently change and reuse Size field as a value assigned. Changing size is not good because leads to bugs. Currently, SIZEOF(.bss) for empty .bss returns 2 because we add two empty synthetic sections and increase size twice by 1. (See PR37011: https://bugs.llvm.org/show_bug.cgi?id=37011) 2. Such approach simply does not work when --symbol-ordering-file is involved, because processing of the ordering file might break the initial section order. This fixes PR37011. Differential revision: https://reviews.llvm.org/D45368 llvm-svn: 329560
2018-04-09 21:01:50 +08:00
# REQUIRES: x86
# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o
[ELF] Keep orphan section names (.rodata.foo .text.foo) unchanged if !hasSectionsCommand This behavior matches GNU ld and seems reasonable. ``` // If a SECTIONS command is not specified .text.* -> .text .rodata.* -> .rodata .init_array.* -> .init_array ``` A proposed Linux feature CONFIG_FG_KASLR may depend on the GNU ld behavior. Reword a comment about -z keep-text-section-prefix and a comment about CommonSection (deleted by rL286234). Reviewed By: grimar Differential Revision: https://reviews.llvm.org/D75225
2020-02-26 10:00:13 +08:00
# RUN: echo 'SECTIONS { .rodata : {*(.rodata.*)} .text : {*(.text.*)} }' > %t.script
[ELF] - Stop setting OutSecOff too early. Currently LLD sets OutSecOff in addSection for input sections. That is a fake offset (just a rude approximation to remember the order), used for sorting SHF_LINK_ORDER sections (see resolveShfLinkOrder, compareByFilePosition). There are 2 problems with such approach: 1. We currently change and reuse Size field as a value assigned. Changing size is not good because leads to bugs. Currently, SIZEOF(.bss) for empty .bss returns 2 because we add two empty synthetic sections and increase size twice by 1. (See PR37011: https://bugs.llvm.org/show_bug.cgi?id=37011) 2. Such approach simply does not work when --symbol-ordering-file is involved, because processing of the ordering file might break the initial section order. This fixes PR37011. Differential revision: https://reviews.llvm.org/D45368 llvm-svn: 329560
2018-04-09 21:01:50 +08:00
# RUN: echo "_bar" > %t.ord
# RUN: echo "_foo" >> %t.ord
# RUN: ld.lld --symbol-ordering-file %t.ord -o %t --script %t.script %t.o
# RUN: llvm-objdump -s %t | FileCheck %s
# CHECK: Contents of section .rodata:
# CHECK-NEXT: 02000000 00000000 01000000 00000000
[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: Contents of section .text:
# CHECK-NEXT: 02000000 00000000 01000000 00000000
[ELF] - Stop setting OutSecOff too early. Currently LLD sets OutSecOff in addSection for input sections. That is a fake offset (just a rude approximation to remember the order), used for sorting SHF_LINK_ORDER sections (see resolveShfLinkOrder, compareByFilePosition). There are 2 problems with such approach: 1. We currently change and reuse Size field as a value assigned. Changing size is not good because leads to bugs. Currently, SIZEOF(.bss) for empty .bss returns 2 because we add two empty synthetic sections and increase size twice by 1. (See PR37011: https://bugs.llvm.org/show_bug.cgi?id=37011) 2. Such approach simply does not work when --symbol-ordering-file is involved, because processing of the ordering file might break the initial section order. This fixes PR37011. Differential revision: https://reviews.llvm.org/D45368 llvm-svn: 329560
2018-04-09 21:01:50 +08:00
# RUN: echo "_foo" > %t.ord
# RUN: echo "_bar" >> %t.ord
# RUN: ld.lld --symbol-ordering-file %t.ord -o %t --script %t.script %t.o
# RUN: llvm-objdump -s %t | FileCheck %s --check-prefix=INV
# INV: Contents of section .rodata:
# INV-NEXT: 01000000 00000000 02000000 00000000
[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
# INV: Contents of section .text:
# INV-NEXT: 01000000 00000000 02000000 00000000
[ELF] - Stop setting OutSecOff too early. Currently LLD sets OutSecOff in addSection for input sections. That is a fake offset (just a rude approximation to remember the order), used for sorting SHF_LINK_ORDER sections (see resolveShfLinkOrder, compareByFilePosition). There are 2 problems with such approach: 1. We currently change and reuse Size field as a value assigned. Changing size is not good because leads to bugs. Currently, SIZEOF(.bss) for empty .bss returns 2 because we add two empty synthetic sections and increase size twice by 1. (See PR37011: https://bugs.llvm.org/show_bug.cgi?id=37011) 2. Such approach simply does not work when --symbol-ordering-file is involved, because processing of the ordering file might break the initial section order. This fixes PR37011. Differential revision: https://reviews.llvm.org/D45368 llvm-svn: 329560
2018-04-09 21:01:50 +08:00
.section .text.foo,"a",@progbits
_foo:
.quad 1
.section .text.bar,"a",@progbits
_bar:
.quad 2
.section .rodata.foo,"ao",@progbits,.text.foo
.quad 1
.section .rodata.bar,"ao",@progbits,.text.bar
.quad 2