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/entry-inference4.test

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

69 lines
2.7 KiB
Plaintext
Raw Normal View History

lld-link: Take /SUBSYSTEM into account for automatic /ENTRY detection. If /subsystem:windows is passed, link.exe only looks for WinMain and wWinMain, and if /subsystem:console is passed it only looks for main and wmain. lld-link used to look for all 4 in both cases. This patch makes lld-link match link.exe's behavior. This requires that the subsystem is known by the time findDefaultEntry() gets called. findDefaultEntry() is called before the main link loop, so that the loop can mark the entry point as undefined. That means inferSubsystem() has to be called above the main loop as well. This in turn means /subsystem: from .drectve sections only has an effect on entry point inference for obj files passed to lld-link directly (and not in obj files found later in .lib files). link.exe seems to ignore /subsystem: for obj files from lib files completely (while in lld it's ignored only for entry point detection but it still overrides /subsystem: flags passed on the command line for the value that gets written in the output file). Also, if the subsytem isn't needed (e.g. when only writing a /def: lib file and not writing a coff file), link.exe doesn't complain if the subsystem isn't known, so both subsystem and entry point handling should be below the early return lld has for that case. Fixes PR36523. https://reviews.llvm.org/D50316 llvm-svn: 339165
2018-08-08 03:10:28 +08:00
# RUN: sed 's/ENTRY1/WinMain/;s/ENTRY2/main/' %s | yaml2obj > %t.obj
# RUN: not lld-link /subsystem:windows /out:%t.exe %t.obj > %t.log 2>&1
# RUN: FileCheck -check-prefix=WINMAIN %s < %t.log
# RUN: sed 's/ENTRY1/wWinMain/;s/ENTRY2/main/' %s | yaml2obj > %t.obj
# RUN: not lld-link /subsystem:windows /out:%t.exe %t.obj > %t.log 2>&1
# RUN: FileCheck -check-prefix=WWINMAIN %s < %t.log
# RUN: sed 's/ENTRY1/WinMain/;s/ENTRY2/main/' %s | yaml2obj > %t.obj
# RUN: not lld-link /subsystem:console /out:%t.exe %t.obj > %t.log 2>&1
# RUN: FileCheck -check-prefix=MAIN %s < %t.log
# RUN: sed 's/ENTRY1/WinMain/;s/ENTRY2/wmain/' %s | yaml2obj > %t.obj
# RUN: not lld-link /subsystem:console /out:%t.exe %t.obj > %t.log 2>&1
# RUN: FileCheck -check-prefix=WMAIN %s < %t.log
lld-link: Several tweaks to default entry point selection. Three related changes: 1. link.exe uses the presence of main and wmain to decide if it should call mainCRTStartup or wmainCRTStartup, even if /nodefaultlib is passed. For compatibility, remove FindMain logic. 2. Default to the non-wide entrypoint if main is not found. This has two effects: 2a. In normal links, lld-link now prints lld-link: error: undefined symbol: _main >>> referenced by f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:78 >>> libcmt.lib(exe_main.obj):("int __cdecl invoke_main(void)" (?invoke_main@@YAHXZ)) >>> referenced by f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:283 >>> libcmt.lib(exe_main.obj):("int __cdecl __scrt_common_main_seh(void)" (?__scrt_common_main_seh@@YAHXZ)) instead of lld-link: error: entry point must be defined This is arguably a better error message, since it now mentions that _main is missing. (This matches link.exe's diagnostic in this case.) 2b. With /nodefautlib, we now default to mainCRTStartup if no main() is present, again matching link.exe. This makes r337407 obsolete. This means if you have a cc file containing both mainCRTStartup and wmainCRTStartup and you pass /nodefaultlib /subsystem:console, lld-link will now call mainCRTStartup, matching link.exe 3. Print a warning if both main and wmain are present, similar to link.exe's LNK4067. Differential Revision: https://reviews.llvm.org/D52832 llvm-svn: 343698
2018-10-04 01:01:39 +08:00
# RUN: sed 's/ENTRY1/wmain/;s/ENTRY2/main/' %s | yaml2obj > %t.obj
# RUN: not lld-link /out:%t.exe %t.obj > %t.log 2>&1
# RUN: FileCheck -check-prefix=MAINWMAIN %s < %t.log
# RUN: sed 's/ENTRY1/wWinMain/;s/ENTRY2/WinMain/' %s | yaml2obj > %t.obj
# RUN: not lld-link /out:%t.exe %t.obj > %t.log 2>&1
# RUN: FileCheck -check-prefix=WINMAINWWINMAIN %s < %t.log
# MAIN: error: <root>: undefined symbol: mainCRTStartup
# WMAIN: error: <root>: undefined symbol: wmainCRTStartup
# MAINWMAIN: warning: found both wmain and main; using latter
# MAINWMAIN: error: <root>: undefined symbol: mainCRTStartup
# WINMAIN: error: <root>: undefined symbol: WinMainCRTStartup
# WWINMAIN: error: <root>: undefined symbol: wWinMainCRTStartup
# WINMAINWWINMAIN: warning: found both wWinMain and WinMain; using latter
# WINMAINWWINMAIN: error: <root>: undefined symbol: WinMainCRTStartup
lld-link: Take /SUBSYSTEM into account for automatic /ENTRY detection. If /subsystem:windows is passed, link.exe only looks for WinMain and wWinMain, and if /subsystem:console is passed it only looks for main and wmain. lld-link used to look for all 4 in both cases. This patch makes lld-link match link.exe's behavior. This requires that the subsystem is known by the time findDefaultEntry() gets called. findDefaultEntry() is called before the main link loop, so that the loop can mark the entry point as undefined. That means inferSubsystem() has to be called above the main loop as well. This in turn means /subsystem: from .drectve sections only has an effect on entry point inference for obj files passed to lld-link directly (and not in obj files found later in .lib files). link.exe seems to ignore /subsystem: for obj files from lib files completely (while in lld it's ignored only for entry point detection but it still overrides /subsystem: flags passed on the command line for the value that gets written in the output file). Also, if the subsytem isn't needed (e.g. when only writing a /def: lib file and not writing a coff file), link.exe doesn't complain if the subsystem isn't known, so both subsystem and entry point handling should be below the early return lld has for that case. Fixes PR36523. https://reviews.llvm.org/D50316 llvm-svn: 339165
2018-08-08 03:10:28 +08:00
--- !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: B82A000000C3
symbols:
- Name: .text
Value: 0
SectionNumber: 1
SimpleType: IMAGE_SYM_TYPE_NULL
ComplexType: IMAGE_SYM_DTYPE_NULL
StorageClass: IMAGE_SYM_CLASS_STATIC
SectionDefinition:
Length: 6
NumberOfRelocations: 0
NumberOfLinenumbers: 0
CheckSum: 0
Number: 0
- Name: ENTRY1
Value: 0
SectionNumber: 1
SimpleType: IMAGE_SYM_TYPE_NULL
ComplexType: IMAGE_SYM_DTYPE_NULL
StorageClass: IMAGE_SYM_CLASS_EXTERNAL
- Name: ENTRY2
Value: 0
SectionNumber: 1
SimpleType: IMAGE_SYM_TYPE_NULL
ComplexType: IMAGE_SYM_DTYPE_NULL
StorageClass: IMAGE_SYM_CLASS_EXTERNAL
...