[cfe-commits] r149973 - /cfe/trunk/lib/CodeGen/BackendUtil.cpp

[Bill Wendling]

On Feb 7, 2012, at 10:22 AM, David Blaikie <dblaikie at gmail.com> wrote:

> On Tue, Feb 7, 2012 at 1:05 AM, Bill Wendling <isanbard at gmail.com> wrote:
>> Author: void
>> Date: Tue Feb  7 03:05:34 2012
>> New Revision: 149973
>> 
>> URL: http://llvm.org/viewvc/llvm-project?rev=149973&view=rev
>> Log:
>> Reserve a moderate amount of space for the back-end arguments.
>> 
>> Modified:
>>    cfe/trunk/lib/CodeGen/BackendUtil.cpp
>> 
>> Modified: cfe/trunk/lib/CodeGen/BackendUtil.cpp
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/BackendUtil.cpp?rev=149973&r1=149972&r2=149973&view=diff
>> ==============================================================================
>> --- cfe/trunk/lib/CodeGen/BackendUtil.cpp (original)
>> +++ cfe/trunk/lib/CodeGen/BackendUtil.cpp Tue Feb  7 03:05:34 2012
>> @@ -247,6 +247,7 @@
>>   }
>> 
>>   std::vector<const char *> BackendArgs;
>> +  BackendArgs.reserve(16);
> 
> Would a SmallVector be a better fit, then? (see attached patches - I
> also went down a small rabbit hole when I discovered that
> ParseCommandLineOptions couldn't be passed a buffer of const char*s -
> by fixing the const down in LLVM's command line support I was able to
> enable this & remove a few const_casts from clang's various drivers
> too. (another thing to do down there might be to change CommandLine's
> internal buffering to SmallVector rather than std::vector (see newArgv
> in CommandLine.cpp:479 - though I only discovered this when I realized
> I couldn't change line 486 to use data() because vector::data()
> doesn't exist in C++98))
> 
Hi David,

I thought about SmallVector as well, but I didn't want to make anything but cosmetic changes (which would hopefully result in compile time improvements). These patches look good to me. (Yay! for getting rid of const_casts!) Please go ahead and apply them. Thanks! :-)

-bw