[PATCH] D148384: [Demangle] replace use of llvm::StringView w/ std::string_view

[Nick Desaulniers via Phabricator via llvm-commits]

nickdesaulniers added a comment.

In D148384#4270106 <https://reviews.llvm.org/D148384#4270106>, @nickdesaulniers wrote:

> These windows buildbot failures are tough to make out: https://lab.llvm.org/buildbot/#/builders/127/builds/46749/steps/4/logs/stdio
>
>   [2/1778] Building CXX object lib\Demangle\CMakeFiles\LLVMDemangle.dir\DLangDemangle.cpp.obj
>   FAILED: lib/Demangle/CMakeFiles/LLVMDemangle.dir/DLangDemangle.cpp.obj 
>   C:\PROGRA~2\MIB055~1\2019\PROFES~1\VC\Tools\MSVC\1429~1.301\bin\Hostx64\x64\cl.exe  /nologo /TP -DGTEST_HAS_RTTI=0 -DUNICODE -D_CRT_NONSTDC_NO_DEPRECATE -D_CRT_NONSTDC_NO_WARNINGS -D_CRT_SECURE_NO_DEPRECATE -D_CRT_SECURE_NO_WARNINGS -D_GLIBCXX_ASSERTIONS -D_HAS_EXCEPTIONS=0 -D_LIBCPP_ENABLE_ASSERTIONS -D_SCL_SECURE_NO_DEPRECATE -D_SCL_SECURE_NO_WARNINGS -D_UNICODE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -Ilib\Demangle -IC:\b\slave\sanitizer-windows\llvm-project\llvm\lib\Demangle -Iinclude -IC:\b\slave\sanitizer-windows\llvm-project\llvm\include /DWIN32 /D_WINDOWS   /Zc:inline /Zc:preprocessor /Zc:__cplusplus /Zi /Oi /bigobj /permissive- /W4 -wd4141 -wd4146 -wd4244 -wd4267 -wd4291 -wd4351 -wd4456 -wd4457 -wd4458 -wd4459 -wd4503 -wd4624 -wd4722 -wd4100 -wd4127 -wd4512 -wd4505 -wd4610 -wd4510 -wd4702 -wd4245 -wd4706 -wd4310 -wd4701 -wd4703 -wd4389 -wd4611 -wd4805 -wd4204 -wd4577 -wd4091 -wd4592 -wd4319 -wd4709 -wd5105 -wd4324 -w14062 -we4238 /Gw /MD /O2 /Ob2  /EHs-c- /GR- -UNDEBUG -std:c++17 /showIncludes /Folib\Demangle\CMakeFiles\LLVMDemangle.dir\DLangDemangle.cpp.obj /Fdlib\Demangle\CMakeFiles\LLVMDemangle.dir\LLVMDemangle.pdb /FS -c C:\b\slave\sanitizer-windows\llvm-project\llvm\lib\Demangle\DLangDemangle.cpp
>   C:\b\slave\sanitizer-windows\llvm-project\llvm\include\llvm/Demangle/Utility.h(111): error C2664: 'void *memcpy(void *,const void *,size_t)': cannot convert argument 2 from 'std::_String_view_iterator<_Traits>' to 'const void *'
>           with
>           [
>               _Traits=std::char_traits<char>
>           ]
>   C:\b\slave\sanitizer-windows\llvm-project\llvm\include\llvm/Demangle/Utility.h(111): note: No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called
>   C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\VC\Tools\MSVC\14.29.30133\include\vcruntime_string.h(43): note: see declaration of 'memcpy'
>
> So something crazy is going on with `std::string_view::iterator` and implicit conversion to `void*`? Is this an issue in Windows C++17 support?
>
> EDIT: also:
>
>   C:\b\slave\sanitizer-windows\llvm-project\llvm\lib\Demangle\MicrosoftDemangle.cpp(2403): error C2678: binary '-': no operator found which takes a left-hand operand of type 'std::_String_view_iterator<_Traits>' (or there is no acceptable conversion)
>   
>   C:\b\slave\sanitizer-windows\llvm-project\llvm\lib\Demangle\MicrosoftDemangle.cpp(2380): warning C4477: 'printf' : format string '%.*s' requires an argument of type 'char *', but variadic argument 3 has type 'std::_String_view_iterator<_Traits>'
>   
>   C:\b\slave\sanitizer-windows\llvm-project\llvm\lib\Demangle\MicrosoftDemangle.cpp(2388): warning C4477: 'printf' : format string '%.*s' requires an argument of type 'char *', but variadic argument 3 has type 'std::_String_view_iterator<_Traits>'
>   
>   C:\b\slave\sanitizer-windows\llvm-project\llvm\lib\Demangle\ItaniumDemangle.cpp(82): warning C4477: 'fprintf' : format string '%.*s' requires an argument of type 'char *', but variadic argument 2 has type 'std::_String_view_iterator<_Traits>'

Perhaps:

  diff --git a/llvm/lib/Demangle/ItaniumDemangle.cpp b/llvm/lib/Demangle/ItaniumDemangle.cpp
  index 4bc00c5144a4..7a7bcd36fc68 100644
  --- a/llvm/lib/Demangle/ItaniumDemangle.cpp
  +++ b/llvm/lib/Demangle/ItaniumDemangle.cpp
  @@ -79,7 +79,7 @@ struct DumpVisitor {
   
     void printStr(const char *S) { fprintf(stderr, "%s", S); }
     void print(std::string_view SV) {
  -    fprintf(stderr, "\"%.*s\"", (int)SV.size(), SV.begin());
  +    fprintf(stderr, "\"%.*s\"", (int)SV.size(), &*SV.begin());
     }
     void print(const Node *N) {
       if (N)
  diff --git a/llvm/lib/Demangle/MicrosoftDemangle.cpp b/llvm/lib/Demangle/MicrosoftDemangle.cpp
  index 15cb0e7d8864..5204c24164d6 100644
  --- a/llvm/lib/Demangle/MicrosoftDemangle.cpp
  +++ b/llvm/lib/Demangle/MicrosoftDemangle.cpp
  @@ -2377,7 +2377,7 @@ void Demangler::dumpBackReferences() {
       T->output(OB, OF_Default);
   
       std::string_view B = OB;
  -    std::printf("  [%d] - %.*s\n", (int)I, (int)B.size(), B.begin());
  +    std::printf("  [%d] - %.*s\n", (int)I, (int)B.size(), &*B.begin());
     }
     std::free(OB.getBuffer());
   
  @@ -2386,7 +2386,7 @@ void Demangler::dumpBackReferences() {
     std::printf("%d name backreferences\n", (int)Backrefs.NamesCount);
     for (size_t I = 0; I < Backrefs.NamesCount; ++I) {
       std::printf("  [%d] - %.*s\n", (int)I, (int)Backrefs.Names[I]->Name.size(),
  -                Backrefs.Names[I]->Name.begin());
  +                &*Backrefs.Names[I]->Name.begin());
     }
     if (Backrefs.NamesCount > 0)
       std::printf("\n");
  @@ -2400,7 +2400,7 @@ char *llvm::microsoftDemangle(const char *MangledName, size_t *NMangled,
     std::string_view Name{MangledName};
     SymbolNode *AST = D.parse(Name);
     if (!D.Error && NMangled)
  -    *NMangled = Name.begin() - MangledName;
  +    *NMangled = Name.begin() - &*MangledName;
   
     if (Flags & MSDF_DumpBackrefs)
       D.dumpBackReferences();

?


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  https://reviews.llvm.org/D148384/new/

https://reviews.llvm.org/D148384