maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity
llvm-project/lld/test/COFF/dllimport-gc.test

57 lines
1.8 KiB
Plaintext
Raw Normal View History

Garbage collect dllimported symbols. This is a different implementation than r303225 (which was reverted in r303270, re-submitted in r303304 and then re-reverted in r303527). In the previous patch, I tried to add Live bit to each dllimported symbol. It turned out that it didn't work with "oldnames.lib" which contains a lot of weak aliases to dllimported symbols. The way we handle weak aliases is to check if undefined symbols can be resolved using weak aliases, and if so, memcpy the Defined symbols to weak Undefined symbols, so that any references to weak aliases automatically see defined symbols instead of undefined ones. This memcpy happens before MarkLive kicks in. That means we may have multiple copies of dllimported symbols. So turning on one instance's Live bit is not enough. This patch moves the Live bit to dllimport file. Since multiple copies of dllsymbols still point to the same file, we can use it as the central repository to keep track of liveness. Differential Revision: https://reviews.llvm.org/D33520 llvm-svn: 303814
2017-05-25 06:30:06 +08:00
# RUN: yaml2obj < %p/Inputs/export.yaml > %t-lib.obj
# RUN: lld-link /out:%t.dll /dll %t-lib.obj /implib:%t.lib /export:exportfn1
# RUN: yaml2obj < %p/Inputs/oldname.yaml > %t-oldname.obj
# RUN: yaml2obj < %s > %t.obj
# RUN: lld-link /out:%t1.exe /entry:main %t.obj %t-oldname.obj %t.lib
# RUN: llvm-readobj -coff-imports %t1.exe | FileCheck -check-prefix=REF %s
# REF-NOT: Symbol: exportfn1
# RUN: lld-link /out:%t2.exe /entry:main %t.obj %t-oldname.obj %t.lib /opt:noref
# RUN: llvm-readobj -coff-imports %t2.exe | FileCheck -check-prefix=NOREF %s
# NOREF: Symbol: exportfn1
--- !COFF
header:
Machine: IMAGE_FILE_MACHINE_AMD64
Characteristics: []
sections:
- Name: .text
Characteristics: [ IMAGE_SCN_CNT_CODE, IMAGE_SCN_MEM_EXECUTE, IMAGE_SCN_MEM_READ ]
Alignment: 4
SectionData: 0000000000000000
symbols:
- Name: .text
Value: 0
SectionNumber: 1
SimpleType: IMAGE_SYM_TYPE_NULL
ComplexType: IMAGE_SYM_DTYPE_NULL
StorageClass: IMAGE_SYM_CLASS_STATIC
SectionDefinition:
Length: 8
NumberOfRelocations: 0
NumberOfLinenumbers: 0
CheckSum: 0
Number: 0
- Name: main
Value: 0
SectionNumber: 1
SimpleType: IMAGE_SYM_TYPE_NULL
ComplexType: IMAGE_SYM_DTYPE_FUNCTION
StorageClass: IMAGE_SYM_CLASS_EXTERNAL
- Name: exportfn1
Value: 0
SectionNumber: 0
SimpleType: IMAGE_SYM_TYPE_NULL
ComplexType: IMAGE_SYM_DTYPE_NULL
StorageClass: IMAGE_SYM_CLASS_EXTERNAL
- Name: exportfn1_alias
Value: 0
SectionNumber: 0
SimpleType: IMAGE_SYM_TYPE_NULL
ComplexType: IMAGE_SYM_DTYPE_NULL
StorageClass: IMAGE_SYM_CLASS_EXTERNAL
...