r198461 - Debug info: Ensure that the last stop point in a function is still within

[Adrian Prantl]

On Jan 5, 2014, at 8:22 PM, dblaikie at gmail.com wrote:

> 
> 
> On Fri Jan 03 2014 at 4:00:30 PM, Adrian Prantl <aprantl at apple.com> wrote:
> 
> On Jan 3, 2014, at 15:53, Eric Christopher <echristo at gmail.com> wrote:
> 
>> There's not enough information in the commit message, the comments, or the test cases to know what's broken or fixed here. Why is forcing the block the correct solution here? What is it working around?
>> 
>> 
> 
> Let’s use this as an example:
> 
>> ==============================================================================
>> --- cfe/trunk/test/CodeGenObjC/arc-linetable.m (original)
>> +++ cfe/trunk/test/CodeGenObjC/arc-linetable.m Fri Jan  3 17:34:30 2014
> 
> - (int)testNoSideEffect:(NSString *)foo {
> int x = 1;
> return 1; // Return expression
> }
> 
> Before this fix, a user would set a breakpoint at the return expression and then attempt to print x and it would fail, because the instruction that is at that line would be in the DW_TAG_subprogram lexical scope (instead of the lexical scope of the function body compound statement which contains x).
> 
> I'm confused by this - Clang doesn't emit a separate lexical scope for the top level compound statement of a function... 
> 

At least for Objective C this is not true. From CGObjcC.cpp:

/// Generate an Objective-C method.  An Objective-C method is a C function with
/// its pointer, name, and types registered in the class struture.
void CodeGenFunction::GenerateObjCMethod(const ObjCMethodDecl *OMD) {
StartObjCMethod(OMD, OMD->getClassInterface(), OMD->getLocStart());
EmitStmt(OMD->getBody());
FinishFunction(OMD->getBodyRBrace());
}

-- adrian

> 
> Since the compound statement is ended before we emit the cleanups and return block those instructions end up in the wrong scope.
> 
> -- adrian
> 
> 
> 
> _______________________________________________
> cfe-commits mailing list
> cfe-commits at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits