[Lldb-commits] [PATCH] D70517: [lldb][DataFormatters] Support pretty printing std::string when built with -funsigned-char.

[Jordan Rupprecht via Phabricator via lldb-commits]

rupprecht created this revision.
rupprecht added reviewers: labath, JDevlieghere, shafik.
Herald added subscribers: lldb-commits, christof.
Herald added a project: LLDB.

When built w/ `-funsigned-char`, `std::string` becomes equivalent to `std::basic_string<unsigned char>`, causing these formatters to not match. This patch adds overloads for both libstdc++ and libc++ string formatters that accepts unsigned char.

Motivated by the following example:

  $ cat pretty_print.cc
  
  template <typename T>
  void print_val(T s) {
    std::cerr << s << '\n';  // Set a breakpoint here!
  }
  
  int main() {
    std::string val = "hello";
    print_val(val);
    return 0;
  }
  $ clang++ -stdlib=libc++ -funsigned-char -fstandalone-debug -g pretty_print.cc
  $ lldb ./a.out -b -o 'b pretty_print.cc:6' -o r -o 'fr v'
  ...
  (lldb) fr v
  (std::__1::basic_string<unsigned char, std::__1::char_traits<unsigned char>, std::__1::allocator<unsigned char> >) s = {
    __r_ = {
      std::__1::__compressed_pair_elem<std::__1::basic_string<unsigned char, std::__1::char_traits<unsigned char>, std::__1::allocator<unsigned char> >::__rep, 0, false> = {
        __value_ = {
           = {
            __l = (__cap_ = 122511465736202, __size_ = 0, __data_ = 0x0000000000000000)
            __s = {
               = (__size_ = '\n', __lx = '\n')
              __data_ = {
                [0] = 'h'
                [1] = 'e'
                [2] = 'l'
                [3] = 'l'
                [4] = 'o'
                [5] = '\0'
  ...


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D70517

Files:
  lldb/packages/Python/lldbsuite/test/functionalities/data-formatter/data-formatter-stl/libcxx/string/TestDataFormatterLibcxxString.py
  lldb/packages/Python/lldbsuite/test/functionalities/data-formatter/data-formatter-stl/libcxx/string/main.cpp
  lldb/packages/Python/lldbsuite/test/functionalities/data-formatter/data-formatter-stl/libstdcpp/string/TestDataFormatterStdString.py
  lldb/packages/Python/lldbsuite/test/functionalities/data-formatter/data-formatter-stl/libstdcpp/string/main.cpp
  lldb/source/Plugins/Language/CPlusPlus/CPlusPlusLanguage.cpp

-------------- next part --------------
A non-text attachment was scrubbed...
Name: D70517.230348.patch
Type: text/x-patch
Size: 7030 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/lldb-commits/attachments/20191121/84e6053d/attachment.bin>