[cfe-dev] SourceRange for a macro-expanded function definition?

Manuel Klimek klimek at google.com
Mon Apr 7 02:22:10 PDT 2014


+argyrios

On Sat, Apr 5, 2014 at 1:40 AM, Michael Bolin <bolinfest at gmail.com> wrote:

> Also, I just tried the following on the FunctionDecl that corresponds to
> `extern NSString *someFunction1(void) NS_RETURNS_NOT_RETAINED;`:
>
> // const FunctionDecl *decl;
> CharSourceRange range =
> CharSourceRange::getCharRange(decl->getSourceRange());
> LangOptions *opts = new LangOptions();
> StringRef sourceText = Lexer::getSourceText(range, *sourceManager, *opts);
>
> The sourceText that I get back is an empty string. For other, non-macro
> FunctionDecl nodes that I tried (specifically ones with bodies), I seem to
> get the right thing, though the closing curly braces often appears to be
> missing.
>

I think if that's true, that's a bug in getSourceText() / makeFileCharRange.
Argyrios, any ideas?

Cheers,
/Manuel


> On Fri, Apr 4, 2014 at 3:28 PM, Michael Bolin <bolinfest at gmail.com> wrote:
>
>> Here is a better example:
>>
>> https://gist.github.com/bolinfest/9984257
>>
>> Here are the key lines in the output:
>>
>>
>> |-FunctionDecl 0x10450ca90 <./example.h:15:1, /System/Library/Frameworks/Foundation.framework/Headers/NSObjCRuntime.h:137:72> someFunction1 'NSString *(void)' extern
>>
>> |-FunctionDecl 0x10450cc00 <./example.h:16:1, /System/Library/Frameworks/Foundation.framework/Headers/NSObjCRuntime.h:137:72> someFunction2 'NSString *(void)' extern
>>
>> Ideally, I would like to be able to get the following instead:
>>
>>
>> |-FunctionDecl 0x10450ca90 <./example.h:15:1, ./example.h:15:61> someFunction1 'NSString *(void)' extern
>> |-FunctionDecl 0x10450cc00 <./example.h:16:1, ./example.h:16:61> someFunction2 'NSString *(void)' extern
>>
>>
>> That is, I would like to be able to extract a SourceRange from a single
>> file that I could delete (or comment out) to remove the definition or
>> someFunction1 or someFunction2. Obviously the existing SourceRange that I
>> get from the AST makes that hard to do.
>>
>> Is it possible to get my desired SourceRange?
>>
>> Thank you,
>> Michael
>>
>>
>>
>> On Wed, Apr 2, 2014 at 1:51 AM, Manuel Klimek <klimek at google.com> wrote:
>>
>>> On Wed, Apr 2, 2014 at 2:31 AM, Michael Bolin <bolinfest at gmail.com>wrote:
>>>
>>>> Hi, I am traversing the AST for an obj-c file using a clang plugin. I
>>>> have a code snippet like the following:
>>>>
>>>> #define JK_ATTRIBUTES(attr, ...)        __attribute__((attr,
>>>> ##__VA_ARGS__))
>>>> #define JK_STATIC_INLINE static __inline__ JK_ATTRIBUTES(always_inline)
>>>>
>>>> JK_STATIC_INLINE int jk_parse_skip_newline();
>>>>
>>>> @implementation Hello
>>>> - (void)say:(int)i {
>>>>   if (i > 0) {
>>>>     NSLog(@"Hello, world! (%d)", i);
>>>>   }
>>>>
>>>>   // Example of selector with unknown method declaration.
>>>>   [(id)@"Anything" length];
>>>> }
>>>> @end
>>>>
>>>> JK_STATIC_INLINE int jk_parse_skip_newline() {
>>>>   return 0;
>>>> }
>>>>
>>>> so while traversing the AST, I am trying to find the SourceRange of the
>>>> jk_parse_skip_newline() definition at the bottom of the file. For non-macro
>>>> expanded functions, this is very straightforward. But due to the macro
>>>> expansion, I get a SourceRange that spans from the start of the macro to
>>>> the end of my code snippet.
>>>>
>>>
>>> How do you get that? If you only use functions that handle SourceRanges
>>> (and never combine locations you get from getBegin() getEnd()) that should
>>> not be possible.
>>> Take a look at Lexer::makeFileCharRange and Lexer::getSourceText for how
>>> to deal with macro-ized ranges.
>>>
>>>
>>>> That means that it also includes the Hello class, which has nothing to
>>>> do with jk_parse_skip_newline(). This is a problem because I am trying to
>>>> use the AST to determine where jk_parse_skip_newline is defined so I can
>>>> comment it out of the source file.
>>>>
>>>> Is it possible for me to get the necessary SourceRange from the clang
>>>> API? Ideally, I would get a SourceRange that identifies only the last three
>>>> lines of my code sample.
>>>>
>>>> Thank you,
>>>> Michael
>>>>
>>>> _______________________________________________
>>>> cfe-dev mailing list
>>>> cfe-dev at cs.uiuc.edu
>>>> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev
>>>>
>>>>
>>>
>>
>
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