[llvm] r215784 - [Support] Promote cl::StringSaver to a separate utility

Rafael Auler rafaelauler at gmail.com
Fri Aug 15 16:41:01 PDT 2014


A saveStringRef() member would be helpful.


On Fri, Aug 15, 2014 at 8:18 PM, Sean Silva <chisophugis at gmail.com> wrote:

> Author: silvas
> Date: Fri Aug 15 18:18:33 2014
> New Revision: 215784
>
> URL: http://llvm.org/viewvc/llvm-project?rev=215784&view=rev
> Log:
> [Support] Promote cl::StringSaver to a separate utility
>
> This class is generally useful.
>
> In breaking it out, the primary change is that it has been made
> non-virtual. It seems like being abstract led to there being 3 different
> (2 in llvm + 1 in clang) concrete implementations which disagreed about
> the ownership of the saved strings (see the manual call to free() in the
> unittest StrDupSaver; yes this is different from the CommandLine.cpp
> StrDupSaver which owns the stored strings; which is different from
> Clang's StringSetSaver which just holds a reference to a
> std::set<std::string> which owns the strings).
>
> I've identified 2 other places in the
> codebase that are open-coding this pattern:
>
>   memcpy(Alloc.Allocate<char>(strlen(S)+1), S, strlen(S)+1)
>
> I'll be switching them over. They are
> * llvm::sys::Process::GetArgumentVector
> * The StringAllocator member of YAMLIO's Input class
> This also will allow simplifying Clang's driver.cpp quite a bit.
>
> Let me know if there are any other places that could benefit from
> StringSaver. I'm also thinking of adding a saveStringRef member for
> getting a stable StringRef.
>
> Added:
>     llvm/trunk/include/llvm/Support/StringSaver.h
> Modified:
>     llvm/trunk/include/llvm/Support/CommandLine.h
>     llvm/trunk/lib/Support/CommandLine.cpp
>     llvm/trunk/unittests/Support/CommandLineTest.cpp
>
> Modified: llvm/trunk/include/llvm/Support/CommandLine.h
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/CommandLine.h?rev=215784&r1=215783&r2=215784&view=diff
>
> ==============================================================================
> --- llvm/trunk/include/llvm/Support/CommandLine.h (original)
> +++ llvm/trunk/include/llvm/Support/CommandLine.h Fri Aug 15 18:18:33 2014
> @@ -24,6 +24,7 @@
>  #include "llvm/ADT/StringMap.h"
>  #include "llvm/ADT/Twine.h"
>  #include "llvm/Support/Compiler.h"
> +#include "llvm/Support/StringSaver.h"
>  #include <cassert>
>  #include <climits>
>  #include <cstdarg>
> @@ -1772,15 +1773,6 @@ void getRegisteredOptions(StringMap<Opti
>  // Standalone command line processing utilities.
>  //
>
> -/// \brief Saves strings in the inheritor's stable storage and returns a
> stable
> -/// raw character pointer.
> -class StringSaver {
> -  virtual void anchor();
> -public:
> -  virtual const char *SaveString(const char *Str) = 0;
> -  virtual ~StringSaver() {};  // Pacify -Wnon-virtual-dtor.
> -};
> -
>  /// \brief Tokenizes a command line that can contain escapes and quotes.
>  //
>  /// The quoting rules match those used by GCC and other tools that use
>
> Added: llvm/trunk/include/llvm/Support/StringSaver.h
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/StringSaver.h?rev=215784&view=auto
>
> ==============================================================================
> --- llvm/trunk/include/llvm/Support/StringSaver.h (added)
> +++ llvm/trunk/include/llvm/Support/StringSaver.h Fri Aug 15 18:18:33 2014
> @@ -0,0 +1,33 @@
> +//===- llvm/Support/StringSaver.h - Stable storage for strings --*- C++
> -*-===//
> +//
> +//                     The LLVM Compiler Infrastructure
> +//
> +// This file is distributed under the University of Illinois Open Source
> +// License. See LICENSE.TXT for details.
> +//
>
> +//===----------------------------------------------------------------------===//
> +
> +#ifndef LLVM_SUPPORT_STRINGSAVER_H
> +#define LLVM_SUPPORT_STRINGSAVER_H
> +
> +#include "llvm/Support/Allocator.h"
> +#include <cstring>
> +
> +namespace llvm {
> +
> +/// \brief Saves strings in stable storage that it owns.
> +class StringSaver {
> +  BumpPtrAllocator Alloc;
> +
> +public:
> +  const char *saveCStr(const char *CStr) {
> +    auto Len = std::strlen(CStr) + 1; // Don't forget the NUL!
> +    char *Buf = Alloc.Allocate<char>(Len);
> +    std::memcpy(Buf, CStr, Len);
> +    return Buf;
> +  }
> +};
> +
> +} // end namespace llvm
> +
> +#endif
>
> Modified: llvm/trunk/lib/Support/CommandLine.cpp
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/CommandLine.cpp?rev=215784&r1=215783&r2=215784&view=diff
>
> ==============================================================================
> --- llvm/trunk/lib/Support/CommandLine.cpp (original)
> +++ llvm/trunk/lib/Support/CommandLine.cpp Fri Aug 15 18:18:33 2014
> @@ -76,7 +76,6 @@ void parser<double>::anchor() {}
>  void parser<float>::anchor() {}
>  void parser<std::string>::anchor() {}
>  void parser<char>::anchor() {}
> -void StringSaver::anchor() {}
>
>
>  //===----------------------------------------------------------------------===//
>
> @@ -509,7 +508,7 @@ void cl::TokenizeGNUCommandLine(StringRe
>      // End the token if this is whitespace.
>      if (isWhitespace(Src[I])) {
>        if (!Token.empty())
> -        NewArgv.push_back(Saver.SaveString(Token.c_str()));
> +        NewArgv.push_back(Saver.saveCStr(Token.c_str()));
>        Token.clear();
>        continue;
>      }
> @@ -520,7 +519,7 @@ void cl::TokenizeGNUCommandLine(StringRe
>
>    // Append the last token after hitting EOF with no whitespace.
>    if (!Token.empty())
> -    NewArgv.push_back(Saver.SaveString(Token.c_str()));
> +    NewArgv.push_back(Saver.saveCStr(Token.c_str()));
>  }
>
>  /// Backslashes are interpreted in a rather complicated way in the
> Windows-style
> @@ -593,7 +592,7 @@ void cl::TokenizeWindowsCommandLine(Stri
>      if (State == UNQUOTED) {
>        // Whitespace means the end of the token.
>        if (isWhitespace(Src[I])) {
> -        NewArgv.push_back(Saver.SaveString(Token.c_str()));
> +        NewArgv.push_back(Saver.saveCStr(Token.c_str()));
>          Token.clear();
>          State = INIT;
>          continue;
> @@ -625,7 +624,7 @@ void cl::TokenizeWindowsCommandLine(Stri
>    }
>    // Append the last token after hitting EOF with no whitespace.
>    if (!Token.empty())
> -    NewArgv.push_back(Saver.SaveString(Token.c_str()));
> +    NewArgv.push_back(Saver.saveCStr(Token.c_str()));
>  }
>
>  static bool ExpandResponseFile(const char *FName, StringSaver &Saver,
> @@ -691,25 +690,6 @@ bool cl::ExpandResponseFiles(StringSaver
>    return AllExpanded;
>  }
>
> -namespace {
> -  class StrDupSaver : public StringSaver {
> -    std::vector<char*> Dups;
> -  public:
> -    ~StrDupSaver() {
> -      for (std::vector<char *>::iterator I = Dups.begin(), E = Dups.end();
> -           I != E; ++I) {
> -        char *Dup = *I;
> -        free(Dup);
> -      }
> -    }
> -    const char *SaveString(const char *Str) override {
> -      char *Dup = strdup(Str);
> -      Dups.push_back(Dup);
> -      return Dup;
> -    }
> -  };
> -}
> -
>  /// ParseEnvironmentOptions - An alternative entry point to the
>  /// CommandLine library, which allows you to read the program's name
>  /// from the caller (as PROGNAME) and its command-line arguments from
> @@ -729,8 +709,8 @@ void cl::ParseEnvironmentOptions(const c
>    // Get program's "name", which we wouldn't know without the caller
>    // telling us.
>    SmallVector<const char *, 20> newArgv;
> -  StrDupSaver Saver;
> -  newArgv.push_back(Saver.SaveString(progName));
> +  StringSaver Saver;
> +  newArgv.push_back(Saver.saveCStr(progName));
>
>    // Parse the value of the environment variable into a "command line"
>    // and hand it off to ParseCommandLineOptions().
> @@ -754,7 +734,7 @@ void cl::ParseCommandLineOptions(int arg
>    SmallVector<const char *, 20> newArgv;
>    for (int i = 0; i != argc; ++i)
>      newArgv.push_back(argv[i]);
> -  StrDupSaver Saver;
> +  StringSaver Saver;
>    ExpandResponseFiles(Saver, TokenizeGNUCommandLine, newArgv);
>    argv = &newArgv[0];
>    argc = static_cast<int>(newArgv.size());
>
> Modified: llvm/trunk/unittests/Support/CommandLineTest.cpp
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/Support/CommandLineTest.cpp?rev=215784&r1=215783&r2=215784&view=diff
>
> ==============================================================================
> --- llvm/trunk/unittests/Support/CommandLineTest.cpp (original)
> +++ llvm/trunk/unittests/Support/CommandLineTest.cpp Fri Aug 15 18:18:33
> 2014
> @@ -146,26 +146,19 @@ TEST(CommandLineTest, UseOptionCategory)
>                                                    "Category.";
>  }
>
> -class StrDupSaver : public cl::StringSaver {
> -  const char *SaveString(const char *Str) override {
> -    return strdup(Str);
> -  }
> -};
> -
> -typedef void ParserFunction(StringRef Source, llvm::cl::StringSaver
> &Saver,
> +typedef void ParserFunction(StringRef Source, StringSaver &Saver,
>                              SmallVectorImpl<const char *> &NewArgv);
>
>
>  void testCommandLineTokenizer(ParserFunction *parse, const char *Input,
>                                const char *const Output[], size_t
> OutputSize) {
>    SmallVector<const char *, 0> Actual;
> -  StrDupSaver Saver;
> +  StringSaver Saver;
>    parse(Input, Saver, Actual);
>    EXPECT_EQ(OutputSize, Actual.size());
>    for (unsigned I = 0, E = Actual.size(); I != E; ++I) {
>      if (I < OutputSize)
>        EXPECT_STREQ(Output[I], Actual[I]);
> -    free(const_cast<char *>(Actual[I]));
>    }
>  }
>
>
>
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