[lld] r332952 - [ELF] Simplify. NFC

[Fāng-ruì Sòng via llvm-commits]

OK.

if (Name.startswith(Prefix))
  DoSomethingWith(Name.substr(Prefix.size())))

should be acceptable. What if an integer constant is used?

if (Name.startswith("__start_"))
  DoSomethingWith(Name.substr(8)))



On Tue, May 22, 2018 at 9:02 AM Rui Ueyama <ruiu at google.com> wrote:

> This is somewhat arguable whether this simplifies the code or not because
> in most (perhaps all?) places in lld, StringRefs are handled as an
> immutable (or initialize-once) object. We don't usually use StringRef's
> member functions that mutates the internal state of the object. If you read
> lld's code, I think you'd notice that we usually create a new StringRef
> object when we need a substring, even if it seems a bit inefficient. I
> believe that makes the code easier to understand as mutating an object
> sometimes creates confusion.
>
> On Mon, May 21, 2018 at 11:31 PM Fangrui Song via llvm-commits <
> llvm-commits at lists.llvm.org> wrote:
>
>> Author: maskray
>> Date: Mon May 21 23:28:00 2018
>> New Revision: 332952
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=332952&view=rev
>> Log:
>> [ELF] Simplify. NFC
>>
>> Modified:
>>     lld/trunk/ELF/LTO.cpp
>>
>> Modified: lld/trunk/ELF/LTO.cpp
>> URL:
>> http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/LTO.cpp?rev=332952&r1=332951&r2=332952&view=diff
>>
>> ==============================================================================
>> --- lld/trunk/ELF/LTO.cpp (original)
>> +++ lld/trunk/ELF/LTO.cpp Mon May 21 23:28:00 2018
>> @@ -155,8 +155,8 @@ BitcodeCompiler::BitcodeCompiler() {
>>    for (Symbol *Sym : Symtab->getSymbols()) {
>>      StringRef Name = Sym->getName();
>>      for (StringRef Prefix : {"__start_", "__stop_"})
>> -      if (Name.startswith(Prefix))
>> -        UsedStartStop.insert(Name.substr(Prefix.size()));
>> +      if (Name.consume_front(Prefix))
>> +        UsedStartStop.insert(Name);
>>    }
>>  }
>>
>>
>>
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>>
>

-- 
宋方睿
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