[llvm] r174345 - Add code to GlobalVariable.h so that global variables marked as

[Michael Gottesman]

r174433.

On Feb 5, 2013, at 11:32 AM, Michael Gottesman <mgottesman at apple.com> wrote:

> You got it.
> 
> On Feb 5, 2013, at 11:34 AM, Chad Rosier <mcrosier at apple.com> wrote:
> 
>> 
>> On Feb 4, 2013, at 10:53 PM, Michael Gottesman <mgottesman at apple.com> wrote:
>> 
>>> Author: mgottesman
>>> Date: Tue Feb  5 00:53:26 2013
>>> New Revision: 174345
>>> 
>>> URL: http://llvm.org/viewvc/llvm-project?rev=174345&view=rev
>>> Log:
>>> Add code to GlobalVariable.h so that global variables marked as
>>> externally_initialized return false for hasDefiniteInitializer and
>>> hasUniqueInitializer.
>>> 
>>> rdar://12580965.
>>> 
>>> Added:
>>>  llvm/trunk/test/Transforms/GlobalOpt/externally-initialized-global-ctr.ll
>>> Modified:
>>>  llvm/trunk/include/llvm/IR/GlobalVariable.h
>>> 
>>> Modified: llvm/trunk/include/llvm/IR/GlobalVariable.h
>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/IR/GlobalVariable.h?rev=174345&r1=174344&r2=174345&view=diff
>>> ==============================================================================
>>> --- llvm/trunk/include/llvm/IR/GlobalVariable.h (original)
>>> +++ llvm/trunk/include/llvm/IR/GlobalVariable.h Tue Feb  5 00:53:26 2013
>>> @@ -110,7 +110,10 @@ public:
>>>   return hasInitializer() &&
>>>     // The initializer of a global variable with weak linkage may change at
>>>     // link time.
>>> -      !mayBeOverridden();
>>> +      !mayBeOverridden() &&
>>> +      // The initializer of a global variable with the externally_initialized
>>> +      // marker may change at runtime before cxx initializers are evaluated.
>>> +      !isExternallyInitialized();
>>> }
>>> 
>>> /// hasUniqueInitializer - Whether the global variable has an initializer, and
>>> @@ -123,7 +126,11 @@ public:
>>>     // instead. It is wrong to modify the initializer of a global variable
>>>     // with *_odr linkage because then different instances of the global may
>>>     // have different initializers, breaking the One Definition Rule.
>>> -      !isWeakForLinker();
>>> +      !isWeakForLinker() &&
>>> +      // It is not safe to modify initializers of global variables with the
>>> +      // external_initializer marker since the value may be changed at runtime
>>> +      // before cxx initializers are evaluated.
>>> +      !isExternallyInitialized();
>>> }
>>> 
>>> /// getInitializer - Return the initializer for this global variable.  It is
>>> 
>>> Added: llvm/trunk/test/Transforms/GlobalOpt/externally-initialized-global-ctr.ll
>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/GlobalOpt/externally-initialized-global-ctr.ll?rev=174345&view=auto
>>> ==============================================================================
>>> --- llvm/trunk/test/Transforms/GlobalOpt/externally-initialized-global-ctr.ll (added)
>>> +++ llvm/trunk/test/Transforms/GlobalOpt/externally-initialized-global-ctr.ll Tue Feb  5 00:53:26 2013
>>> @@ -0,0 +1,35 @@
>>> +; RUN: opt < %s -globalopt -S | FileCheck %s
>>> +; rdar://12580965.
>>> +; ObjC++ test case.
>>> +
>>> +%struct.ButtonInitData = type { i8* }
>>> +
>>> + at _ZL14buttonInitData = internal global [1 x %struct.ButtonInitData] zeroinitializer, align 4
>>> +
>>> +@"\01L_OBJC_METH_VAR_NAME_40" = internal global [7 x i8] c"print:\00", section "__TEXT,__objc_methname,cstring_literals", align 1
>>> +@"\01L_OBJC_SELECTOR_REFERENCES_41" = internal externally_initialized  global i8* getelementptr inbounds ([7 x i8]* @"\01L_OBJC_METH_VAR_NAME_40", i32 0, i32 0), section "__DATA, __objc_selrefs, literal_pointers, no_dead_strip"
>>> +
>>> + at llvm.global_ctors = appending global [1 x { i32, void ()* }] [{ i32, void ()* } { i32 65535, void ()* @_GLOBAL__I_a }]
>>> + at llvm.used = appending global [2 x i8*] [i8* getelementptr inbounds ([7 x i8]* @"\01L_OBJC_METH_VAR_NAME_40", i32 0, i32 0),  i8* bitcast (i8** @"\01L_OBJC_SELECTOR_REFERENCES_41" to i8*)]
>>> +
>>> +define internal void @__cxx_global_var_init() section "__TEXT,__StaticInit,regular,pure_instructions" {
>>> +  %1 = load i8** @"\01L_OBJC_SELECTOR_REFERENCES_41", !invariant.load !2009
>>> +  store i8* %1, i8** getelementptr inbounds ([1 x %struct.ButtonInitData]* @_ZL14buttonInitData, i32 0, i32 0, i32 0), align 4
>>> +  ret void
>>> +}
>>> +
>>> +define internal void @_GLOBAL__I_a() section "__TEXT,__StaticInit,regular,pure_instructions" {
>>> +  call void @__cxx_global_var_init()
>>> +  ret void
>>> +}
>>> +
>>> +declare void @test(i8*)
>>> +
>>> +define void @print() {
>>> +; CHECK: %1 = load i8** getelementptr inbounds ([1 x %struct.ButtonInitData]* @_ZL14buttonInitData, i32 0, i32 0, i32 0), align 4
>>> +  %1 = load i8** getelementptr inbounds ([1 x %struct.ButtonInitData]* @_ZL14buttonInitData, i32 0, i32 0, i32 0), align 4
>>> +  call void @test(i8* %1)
>>> +  ret void
>>> +}
>>> +
>>> +!2009 = metadata !{}
>>> \ No newline at end of file
>> 
>> Please add a newline at the end of the file.
>> 
>> Chad
>> 
>>> 
>>> _______________________________________________
>>> llvm-commits mailing list
>>> llvm-commits at cs.uiuc.edu
>>> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>> 
> 
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits