[cfe-commits] [PATCH] Disallow __has_include and __has_include_next outside of preprocessor directives

[Argyrios Kyrtzidis]

On Jan 16, 2013, at 9:52 AM, Aaron Ballman <aaron at aaronballman.com> wrote:

> On Wed, Jan 16, 2013 at 10:33 AM, Dmitri Gribenko <gribozavr at gmail.com> wrote:
>> On Wed, Jan 16, 2013 at 3:15 PM, Aaron Ballman <aaron at aaronballman.com> wrote:
>>> This patch moves the logic around slightly to handle macros better;
>>> instead of relying on the PP Lexer, we track the information in the PP
>>> itself so that is is always available.  I've expanded the test cases
>>> to cover macros more fully.
>> 
>> void Preprocessor::HandleIfDirective(Token &IfToken,
>>                                      bool ReadAnyTokensBeforeDirective) {
>> +  ParsingPreprocessorDirective = true;
>>   ++NumIf;
>> 
>>   // Parse and evaluate the conditional expression.
>> @@ -2101,6 +2102,7 @@
>>     SkipExcludedConditionalBlock(IfToken.getLocation(), /*Foundnonskip*/false,
>>                                  /*FoundElse*/false);
>>   }
>> +  ParsingPreprocessorDirective = false;
>> }
>> 
>> We have llvm/Support/SaveAndRestore.h to simplify this.
> 
> That's neat, I didn't notice we had that.  However, using that would
> mean I couldn't use a bit-field for the property either (due to
> requiring a reference).  So the question I have is: which is "better"?
> Given that we already have several other boolean bitfields, I am on
> the fence.

This is not specific to this patch but needing to make a choice between RAII or bitfield seems unfortunate, could we add a helper macro or something when bitfields are involved ?

> 
>> +  /// \brief Returns true if currently parsing a preprocessor directive
>> +  bool isParsingPreprocessorDirective() const {
>> +    return ParsingPreprocessorDirective;
>> +  }
>> 
>> +  /// \brief True if we are currently preprocessing a #if or #elif directive
>> +  bool ParsingPreprocessorDirective : 1;
>> 
>> Please synchronize these two comments, and maybe rename to
>> ParsingIfOrElifDirective.
> 
> Can do.
> 
> Thanks!
> 
> ~Aaron
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