r305600 - [Driver] Do a PATH lookup if needed when using -no-canonical-prefixes

[Joerg Sonnenberger via cfe-commits]

On Fri, Jun 16, 2017 at 10:40:18PM -0000, Petr Hosek via cfe-commits wrote:
> @@ -53,8 +53,15 @@ using namespace clang::driver;
>  using namespace llvm::opt;
>  
>  std::string GetExecutablePath(const char *Argv0, bool CanonicalPrefixes) {
> -  if (!CanonicalPrefixes)
> -    return Argv0;
> +  if (!CanonicalPrefixes) {
> +    SmallString<128> ExecutablePath(Argv0);
> +    // Do a PATH lookup if Argv0 isn't a valid path.
> +    if (!llvm::sys::fs::exists(ExecutablePath))
> +      if (llvm::ErrorOr<std::string> P =
> +              llvm::sys::findProgramByName(ExecutablePath))
> +        ExecutablePath = *P;
> +    return ExecutablePath.str();
> +  }
>  
>    // This just needs to be some symbol in the binary; C++ doesn't
>    // allow taking the address of ::main however.

This will fail if the current directory contains a file with the name of
the program, won't it? I think the correct order here would be to check
if ExecutablePath contains a path separator and if it doesn't, call
findProgramByName.

Joerg