未解决的外部符号，即使看起来一切正常

Question

我不习惯在Windows上编码，我对VS上的这个错误感到困惑。

我正在开发一个静态库libA，另一个libB调用libA中的某些方法，以及一个程序prog调用libB中的一些方法。

libA编译没有任何问题。

与libB相同。关于libA的include和lib文件夹被提供给VS，以及作为附加依赖项的libA.lib。

对于prog，我给出了关于libA和libB的include和lib文件夹。这两个库本身作为附加依赖项给出。它进行编译，但在链接时，我得到了几个错误LNK2001类型：

unresolved external symbol "public virtual void __thiscall libA::classA1::methodA1(void)" (?methodA1@classA1@libA@@UEAXXZ) in File libB.lib(classB1.obj)

我对libB进行了转储，符号?methodA1@classA1@libA@@UEAXXZ在转储文件中多次出现。

Dump of file .libB.lib
File Type: LIBRARY
Archive member name at 8: /                
61C9303F time/date Mon Dec 27 12:17:19 2021
uid
gid
0 mode   36987E size correct header end
14630 public symbols 
...
3F43C3C ?methodA1@classA1@libA@@UEAXXZ
...
Archive member name at 3698C2: /                
61C9303F time/date Mon Dec 27 12:17:19 2021
uid
gid
0 mode   36272A size correct header end
61 offsets
...
32 ?methodA1@classA1@libA@@UEAXXZ
... 
SECTION HEADER #42 .text$mn name
0 physical address
0 virtual address
1D7 size of raw data
5FA3 file pointer to raw data (00005FA3 to 00006179)
617A file pointer to relocation table
0 file pointer to line numbers
D number of relocations
0 number of line numbers 60501020 flags
Code
COMDAT; sym= "public: virtual void __cdecl libA::classA1::methodA1(void)" (?methodA1@classA1@libA@@UEAAXXZ)
16 byte align
Execute Read
...
SECTION HEADER #92
.xdata name
0 physical address
0 virtual address
1C size of raw data
6B4E file pointer to raw data (00006B4E to 00006B69)
6B6A file pointer to relocation table
0 file pointer to line numbers
1 number of relocations
0 number of line numbers
40301040 flags
Initialized Data
COMDAT; sym= $unwind$?methodA1@classA1@libA@@UEAAXXZ
4 byte align
Read Only
...
SECTION HEADER #93
.pdata name
0 physical address
0 virtual address
C size of raw data
6B74 file pointer to raw data (00006B74 to 00006B7F)
6B80 file pointer to relocation table
0 file pointer to line numbers
3 number of relocations
0 number of line numbers
40301040 flags
Initialized Data
COMDAT; sym= $pdata$?methodA1@classA1@libA@@UEAAXXZ
4 byte align
Read Only
...
RELOCATIONS #93
Symbol    Symbol
Offset    Type              Applied To         Index     Name
--------  ----------------  -----------------  --------  ------
00000000  ADDR32NB                   00000000       124  $LN269
00000004  ADDR32NB                   000001D7       124  $LN269
00000008  ADDR32NB                   00000000       22A  $unwind$?methodA1@classA1@libA@@UEAAXXZ
...
RELOCATIONS #101
Symbol    Symbol
Offset    Type              Applied To         Index     Name
--------  ----------------  -----------------  --------  ------
00000000  ADDR64            00000000 00000000       3BA  ??_R4classA1@libA@@6B@ (const libA::classA1::`RTTI Complete Object Locator')
00000008  ADDR64            00000000 00000000        D3  ??_EclassA1@libA@@UEAAPEAXI@Z (public: virtual void * __cdecl libA::classA1::`vector deleting destructor'(unsigned int))
00000010  ADDR64            00000000 00000000        8D  _purecall
00000018  ADDR64            00000000 00000000        8D  _purecall
00000020  ADDR64            00000000 00000000        CE  ?methodA1@classA1@libA@@UEAAXXZ (public: virtual void __cdecl libA::classA1::methodA1(void))
00000028  ADDR64            00000000 00000000        CF  ?methodA2@classA1@libA@@UEAAXXZ (public: virtual void __cdecl libA::classA1::methodA2(void))
...
0CE 00000000 SECT42 notype ()    External     | ?methodA1@classA1@libA@@UEAAXXZ (public: virtual void __cdecl libA::classA1::methodA1(void))
...
22A 00000000 SECT92 notype       Static       | $unwind$?methodA1@classA1@libA@@UEAAXXZ
22B 00000000 SECT93 notype       Static       | .pdata
Section length    C, #relocs    3, #linenums    0, checksum AAAF74B1, selection    5 (pick associative Section 0x42)
22D 00000000 SECT93 notype       Static       | $pdata$?methodA1@classA1@libA@@UEAAXXZ
22E 00000000 SECT94 notype       Static       | .voltbl
Section length    4, #relocs    0, #linenums    0, checksum D5442740, selection    5 (pick associative Section 0x42)

与libA的dumplib文件相同。

如果有帮助的话，这里是prog:的链接器命令

/OUT:"C:progReleaseprog.exe" /MANIFEST /LTCG:incremental /NXCOMPAT /PDB:"C:progReleaseprog.pdb" /DYNAMICBASE "libA.lib" "libB.lib" "some_other_libs.lib" /DEBUG /MACHINE:X86 /OPT:REF /SAFESEH /INCREMENTAL:NO /PGD:"C:progReleaseprog.pgd" /SUBSYSTEM:CONSOLE /MANIFESTUAC:"level='asInvoker' uiAccess='false'" /ManifestFile:"Releaseprog.exe.intermediate.manifest" /LTCGOUT:"Releaseprog.iobj" /OPT:ICF /ERRORREPORT:PROMPT /ILK:"Releaseprog.ilk" /NOLOGO /TLBID:1

Answer 1

最后，我发现了问题。

libA和libB在Linux上正常工作，所以我不明白为什么我在Windows上遇到这个问题。

事实证明，我真的不知道为什么，但CMake生成的VS解决方案文件允许使用x86目标体系结构编译libA，但加上额外的选项"机器x64"；在命令行部分(项目属性>链接器(或静态库的库管理员(>命令行(。

我把这个"/机器x64"；选项，重新编译了libA，现在整个事情都编译并链接了。