maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity
llvm-project/lld/test/ELF/partition-icf.s

Ignoring revisions in .git-blame-ignore-revs. Click here to bypass and see the normal blame view.

52 lines
913 B
ArmAsm
Raw Normal View History

ELF: Add basic partition data structures and behaviours. This change causes us to read partition specifications from partition specification sections and split output sections into partitions according to their reachability from partition entry points. This is only the first step towards a full implementation of partitions. Later changes will add additional synthetic sections to each partition so that they can be loaded independently. Differential Revision: https://reviews.llvm.org/D60353 llvm-svn: 361925
2019-05-29 11:55:20 +08:00
// REQUIRES: x86
// RUN: llvm-mc %s -o %t.o -filetype=obj --triple=x86_64-unknown-linux
// RUN: ld.lld %t.o -o %t --export-dynamic --gc-sections --icf=all
// RUN: llvm-readelf -S -s %t | FileCheck %s
Reland D66717 [ELF] Do not ICF two sections with different output sections (by SECTIONS commands) Recommit r370635 (reverted by r371202), with one change: move addOrphanSections() before ICF. Before, orphan sections in two different partitions may be folded and moved to the main partition. Now, InputSection->OutputSection assignment for orphans happens before ICF. ICF does not fold input sections with different output sections. With the PR43241 reproduce, `llvm-objcopy --extract-partition libvr.so libchrome__combined.so libvr.so` => no error Updated description: Fixes PR39418. Complements D47241 (the non-linker-script case). processSectionCommands() assigns input sections to output sections. ICF is called before it, so .text.foo and .text.bar may be folded even if their output sections are made different by SECTIONS commands. ``` markLive<ELFT>() doIcf<ELFT>() // During ICF, we don't know the output sections writeResult() combineEhSections<ELFT>() script->processSectionCommands() // InputSection -> OutputSection assignment ``` This patch splits processSectionCommands() into processSectionCommands() and processSymbolAssignments(), and moves processSectionCommands()/addOrphanSections() before ICF: ``` markLive<ELFT>() combineEhSections<ELFT>() script->processSectionCommands() script->addOrphanSections(); doIcf<ELFT>() // should remove folded input sections writeResult() script->processSymbolAssignments() ``` An alternative approach is to unfold a section `sec` in processSectionCommands() when we find `sec` and `sec->repl` belong to different output sections. I feel this patch is superior because this can fold more sections and the decouple of SectionCommand/SymbolAssignment gives flexibility: * An ExprValue can't be evaluated before its section is assigned to an output section -> we can delete getOutputSectionVA and simplify another place where we had to check if the output section is null. Moreover, a case in linkerscript/early-assign-symbol.s can be handled now. * processSectionCommands/processSymbolAssignments can be freely moved around. llvm-svn: 371216
2019-09-06 23:57:44 +08:00
// CHECK: part1
ELF: Add basic partition data structures and behaviours. This change causes us to read partition specifications from partition specification sections and split output sections into partitions according to their reachability from partition entry points. This is only the first step towards a full implementation of partitions. Later changes will add additional synthetic sections to each partition so that they can be loaded independently. Differential Revision: https://reviews.llvm.org/D60353 llvm-svn: 361925
2019-05-29 11:55:20 +08:00
// CHECK: [[P1:[0-9]+]]] .text
Reland D66717 [ELF] Do not ICF two sections with different output sections (by SECTIONS commands) Recommit r370635 (reverted by r371202), with one change: move addOrphanSections() before ICF. Before, orphan sections in two different partitions may be folded and moved to the main partition. Now, InputSection->OutputSection assignment for orphans happens before ICF. ICF does not fold input sections with different output sections. With the PR43241 reproduce, `llvm-objcopy --extract-partition libvr.so libchrome__combined.so libvr.so` => no error Updated description: Fixes PR39418. Complements D47241 (the non-linker-script case). processSectionCommands() assigns input sections to output sections. ICF is called before it, so .text.foo and .text.bar may be folded even if their output sections are made different by SECTIONS commands. ``` markLive<ELFT>() doIcf<ELFT>() // During ICF, we don't know the output sections writeResult() combineEhSections<ELFT>() script->processSectionCommands() // InputSection -> OutputSection assignment ``` This patch splits processSectionCommands() into processSectionCommands() and processSymbolAssignments(), and moves processSectionCommands()/addOrphanSections() before ICF: ``` markLive<ELFT>() combineEhSections<ELFT>() script->processSectionCommands() script->addOrphanSections(); doIcf<ELFT>() // should remove folded input sections writeResult() script->processSymbolAssignments() ``` An alternative approach is to unfold a section `sec` in processSectionCommands() when we find `sec` and `sec->repl` belong to different output sections. I feel this patch is superior because this can fold more sections and the decouple of SectionCommand/SymbolAssignment gives flexibility: * An ExprValue can't be evaluated before its section is assigned to an output section -> we can delete getOutputSectionVA and simplify another place where we had to check if the output section is null. Moreover, a case in linkerscript/early-assign-symbol.s can be handled now. * processSectionCommands/processSymbolAssignments can be freely moved around. llvm-svn: 371216
2019-09-06 23:57:44 +08:00
// CHECK: part2
ELF: Add basic partition data structures and behaviours. This change causes us to read partition specifications from partition specification sections and split output sections into partitions according to their reachability from partition entry points. This is only the first step towards a full implementation of partitions. Later changes will add additional synthetic sections to each partition so that they can be loaded independently. Differential Revision: https://reviews.llvm.org/D60353 llvm-svn: 361925
2019-05-29 11:55:20 +08:00
// CHECK: [[P2:[0-9]+]]] .text
// CHECK: Symbol table '.symtab'
// CHECK: [[P1]] f1
// CHECK: [[P2]] f2
Reland D66717 [ELF] Do not ICF two sections with different output sections (by SECTIONS commands) Recommit r370635 (reverted by r371202), with one change: move addOrphanSections() before ICF. Before, orphan sections in two different partitions may be folded and moved to the main partition. Now, InputSection->OutputSection assignment for orphans happens before ICF. ICF does not fold input sections with different output sections. With the PR43241 reproduce, `llvm-objcopy --extract-partition libvr.so libchrome__combined.so libvr.so` => no error Updated description: Fixes PR39418. Complements D47241 (the non-linker-script case). processSectionCommands() assigns input sections to output sections. ICF is called before it, so .text.foo and .text.bar may be folded even if their output sections are made different by SECTIONS commands. ``` markLive<ELFT>() doIcf<ELFT>() // During ICF, we don't know the output sections writeResult() combineEhSections<ELFT>() script->processSectionCommands() // InputSection -> OutputSection assignment ``` This patch splits processSectionCommands() into processSectionCommands() and processSymbolAssignments(), and moves processSectionCommands()/addOrphanSections() before ICF: ``` markLive<ELFT>() combineEhSections<ELFT>() script->processSectionCommands() script->addOrphanSections(); doIcf<ELFT>() // should remove folded input sections writeResult() script->processSymbolAssignments() ``` An alternative approach is to unfold a section `sec` in processSectionCommands() when we find `sec` and `sec->repl` belong to different output sections. I feel this patch is superior because this can fold more sections and the decouple of SectionCommand/SymbolAssignment gives flexibility: * An ExprValue can't be evaluated before its section is assigned to an output section -> we can delete getOutputSectionVA and simplify another place where we had to check if the output section is null. Moreover, a case in linkerscript/early-assign-symbol.s can be handled now. * processSectionCommands/processSymbolAssignments can be freely moved around. llvm-svn: 371216
2019-09-06 23:57:44 +08:00
// CHECK: [[P1]] g1
// CHECK: [[P2]] g2
ELF: Add basic partition data structures and behaviours. This change causes us to read partition specifications from partition specification sections and split output sections into partitions according to their reachability from partition entry points. This is only the first step towards a full implementation of partitions. Later changes will add additional synthetic sections to each partition so that they can be loaded independently. Differential Revision: https://reviews.llvm.org/D60353 llvm-svn: 361925
2019-05-29 11:55:20 +08:00
.section .llvm_sympart.f1,"",@llvm_sympart
.asciz "part1"
.quad f1
.section .llvm_sympart.f2,"",@llvm_sympart
.asciz "part2"
.quad f2
.section .llvm_sympart.g1,"",@llvm_sympart
.asciz "part1"
.quad g1
.section .llvm_sympart.g2,"",@llvm_sympart
.asciz "part2"
.quad g2
.section .text.f1,"ax",@progbits
.globl f1
f1:
.byte 1
.section .text.f2,"ax",@progbits
.globl f2
f2:
.byte 2
.section .text.g1,"ax",@progbits
.globl g1
g1:
.byte 3
.section .text.g2,"ax",@progbits
.globl g2
g2:
.byte 3