[cfe-dev] The need for good location info

[Chris Lattner]

This boggles the mind.  Here's my (bad) code:

      llvm::SmallPtrSet<const DirectoryEntry *, 8> SeenDirs;
      for (unsigned i = 0; i != SearchList.size(); ++i) {
        // If this isn't the first time we've seen this dir, remove it.
655:   if (!SeenDirs.insert(SearchList[i].getDir()).second) {
...

G++ emits:

clang.cpp: In function ‘void  
RemoveDuplicates(std::vector<clang::DirectoryLookup,  
std::allocator<clang::DirectoryLookup> >&)’:
clang.cpp:655: error: request for member ‘second’ in ‘SeenDirs.  
llvm::SmallPtrSet<PtrType, SmallSize>::insert [with PtrType = const  
clang::DirectoryEntry*, unsigned int SmallSize = 8u]((+(+ SearchList)- 
 >std::vector<_Tp, _Alloc>::operator[] [with _Tp =  
clang::DirectoryLookup, _Alloc =  
std::allocator<clang::DirectoryLookup>](((long unsigned int)i)))- 
 >clang::DirectoryLookup::getDir())’, which is of non-class type ‘bool’


The ".second" is invalid (because insert on smallptrset returns a  
bool).  GCC is trying to pretty print out the expression, but it's  
already prelowered stuff as it parsed.  Hopefully we'll be able to  
just do:

clang.cpp:655: error: invalid field 'second' on object of type 'bool'
    if (!SeenDirs.insert(SearchList[i].getDir()).second) {
         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^

or something.  When is C++ support in clang coming? ;-)

-Chris