[cfe-commits] Add cpp frontend

[Douglas Gregor]

On Mar 6, 2011, at 9:51 AM, Joerg Sonnenberger wrote:

> Anyone for review? This would be quite useful to have in 2.9 as a
> standalone cpp (even in "modern" mode) is used by a number of programs.
> 
> Joerg
> 
> On Sat, Mar 05, 2011 at 01:19:59PM +0100, Joerg Sonnenberger wrote:
>> Hi all,
>> the attached patch recognizes getting called as cpp and act accordingly.
>> This differs from clang -E in the handling of missing input files. cpp
>> assumes that stdin is used in that case. Patch is based on an earlier
>> version from rdivacky.
>> 
>> Joerg
> 
>> Index: include/clang/Driver/Driver.h
>> ===================================================================
>> --- include/clang/Driver/Driver.h	(revision 126955)
>> +++ include/clang/Driver/Driver.h	(working copy)
>> @@ -102,6 +102,9 @@
>>   /// Whether the driver should follow g++ like behavior.
>>   unsigned CCCIsCXX : 1;
>> 
>> +  /// Whether the driver is just the preprocessor
>> +  unsigned CCCIsCPP : 1;
>> +
>>   /// Echo commands while executing (in -v style).
>>   unsigned CCCEcho : 1;
>> 
>> @@ -221,7 +224,7 @@
>>   /// \param TC - The default host tool chain.
>>   /// \param Args - The input arguments.
>>   /// \param Actions - The list to store the resulting actions onto.
>> -  void BuildActions(const ToolChain &TC, const ArgList &Args,
>> +  void BuildActions(const ToolChain &TC, const InputArgList &Args,
>>                     ActionList &Actions) const;
>> 
>>   /// BuildUniversalActions - Construct the list of actions to perform
>> @@ -230,7 +233,7 @@
>>   /// \param TC - The default host tool chain.
>>   /// \param Args - The input arguments.
>>   /// \param Actions - The list to store the resulting actions onto.
>> -  void BuildUniversalActions(const ToolChain &TC, const ArgList &Args,
>> +  void BuildUniversalActions(const ToolChain &TC, const InputArgList &Args,
>>                              ActionList &Actions) const;
>> 
>>   /// BuildJobs - Bind actions to concrete tools and translate
>> Index: tools/driver/driver.cpp
>> ===================================================================
>> --- tools/driver/driver.cpp	(revision 126955)
>> +++ tools/driver/driver.cpp	(working copy)
>> @@ -342,6 +342,11 @@
>>     TheDriver.CCCIsCXX = true;
>>   }
>> 
>> +  if (llvm::StringRef(ProgName).endswith("cpp") ||
>> +      llvm::StringRef(ProgName).rsplit('-').first.endswith("cpp")) {
>> +    TheDriver.CCCIsCPP = true;
>> +  }

Why is this an "endswith" check rather than equality comparison? I suspect that we just want to match "cpp" or "cpp-version".

Even as "cpp", we're still going to outright reject "-traditional". Is that still the right thing to do?

Anyway, this looks okay to me, but I'd love to hear Daniel's opinion on this.

  - Doug