[llvm-commits] [llvm] r82348 - /llvm/trunk/lib/Support/CommandLine.cpp

[Jeffrey Yasskin]

FYI, this change introduced an infinite loop by failing to shrink
WorkStr when it copies a word. I've rolled it back in r82675 and added
a small part of the unittest that ought to be there to protect
refactorings like this.

On Sat, Sep 19, 2009 at 6:33 PM, Chris Lattner <sabre at nondot.org> wrote:
> Author: lattner
> Date: Sat Sep 19 20:33:46 2009
> New Revision: 82348
>
> URL: http://llvm.org/viewvc/llvm-project?rev=82348&view=rev
> Log:
> rewrite ParseCStringVector in terms of stringref.
>
> Modified:
>    llvm/trunk/lib/Support/CommandLine.cpp
>
> Modified: llvm/trunk/lib/Support/CommandLine.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/CommandLine.cpp?rev=82348&r1=82347&r2=82348&view=diff
>
> ==============================================================================
> --- llvm/trunk/lib/Support/CommandLine.cpp (original)
> +++ llvm/trunk/lib/Support/CommandLine.cpp Sat Sep 19 20:33:46 2009
> @@ -296,42 +296,31 @@
>  /// using strdup(), so it is the caller's responsibility to free()
>  /// them later.
>  ///
> -static void ParseCStringVector(std::vector<char *> &output,
> -                               const char *input) {
> +static void ParseCStringVector(std::vector<char *> &OutputVector,
> +                               const char *Input) {
>   // Characters which will be treated as token separators:
> -  static const char *const delims = " \v\f\t\r\n";
> +  StringRef Delims = " \v\f\t\r\n";
>
> -  std::string work(input);
> -  // Skip past any delims at head of input string.
> -  size_t pos = work.find_first_not_of(delims);
> -  // If the string consists entirely of delims, then exit early.
> -  if (pos == std::string::npos) return;
> -  // Otherwise, jump forward to beginning of first word.
> -  work = work.substr(pos);
> -  // Find position of first delimiter.
> -  pos = work.find_first_of(delims);
> -
> -  while (!work.empty() && pos != std::string::npos) {
> -    // Everything from 0 to POS is the next word to copy.
> -    output.push_back(strdup(work.substr(0,pos).c_str()));
> -    // Is there another word in the string?
> -    size_t nextpos = work.find_first_not_of(delims, pos + 1);
> -    if (nextpos != std::string::npos) {
> -      // Yes? Then remove delims from beginning ...
> -      work = work.substr(work.find_first_not_of(delims, pos + 1));
> -      // and find the end of the word.
> -      pos = work.find_first_of(delims);
> -    } else {
> -      // No? (Remainder of string is delims.) End the loop.
> -      work = "";
> -      pos = std::string::npos;
> +  StringRef WorkStr(Input);
> +  while (!WorkStr.empty()) {
> +    // If the first character is a delimiter, strip them off.
> +    if (Delims.find(WorkStr[0]) != StringRef::npos) {
> +      size_t Pos = WorkStr.find_first_not_of(Delims);
> +      if (Pos == StringRef::npos) Pos = WorkStr.size();
> +      WorkStr = WorkStr.substr(Pos);
> +      continue;
>     }
> +
> +    // Find position of first delimiter.
> +    size_t Pos = WorkStr.find_first_of(Delims);
> +    if (Pos == StringRef::npos) Pos = WorkStr.size();
> +
> +    // Everything from 0 to Pos is the next word to copy.
> +    char *NewStr = (char*)malloc(Pos+1);
> +    memcpy(NewStr, WorkStr.data(), Pos);
> +    NewStr[Pos] = 0;
> +    OutputVector.push_back(NewStr);
>   }
> -
> -  // If `input' ended with non-delim char, then we'll get here with
> -  // the last word of `input' in `work'; copy it now.
> -  if (!work.empty())
> -    output.push_back(strdup(work.c_str()));
>  }
>
>  /// ParseEnvironmentOptions - An alternative entry point to the
>
>
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