[llvm] r219804 - Use 'auto' for easier reading; no functional change intended.

[David Blaikie]

On Wed, Oct 15, 2014 at 10:06 AM, Aaron Ballman <aaron at aaronballman.com>
wrote:

> On Wed, Oct 15, 2014 at 12:47 PM, David Blaikie <dblaikie at gmail.com>
> wrote:
> > I /think/ we generally like to still specify the 'const' when using auto
> > (like we specify the '*') - though this probably isn't a hard-and-fast
> rule,
> > just a thought.
>
> I thought it was a hard-and-fast rule?


I was mostly going off actual usage, rather than the style guide wording.


> We sort of suggest it, but not
> very explicitly, in our coding guidelines
> (
> http://llvm.org/docs/CodingStandards.html#use-auto-type-deduction-to-make-code-more-readable
> )
>

But that sounds about consistent with usage/habits I've seen. Maybe we
could call it out separately from for loops (and explicitly mention the
'const' part of it) as useful general auto guidance.

Sometimes I think it's reasonable to not worry about the 'const' if I'm
actually /adding/ const (eg: if a function returns a non-const pointer that
I'm going to stuff in an "auto *" for a few lines as simple
common-subexpression reuse, adding const to it isn't particularly
important) and if I can't tell if I'm adding const or not, I probably don't
care much... until I get a compilation error because I tried to call a
non-const function on an "auto *" not realizing that it was actually
pointer-to-const.


>
> ~Aaron
>
> >
> > On Wed, Oct 15, 2014 at 9:21 AM, Sanjay Patel <spatel at rotateright.com>
> > wrote:
> >>
> >> Author: spatel
> >> Date: Wed Oct 15 11:21:37 2014
> >> New Revision: 219804
> >>
> >> URL: http://llvm.org/viewvc/llvm-project?rev=219804&view=rev
> >> Log:
> >> Use 'auto' for easier reading; no functional change intended.
> >>
> >> Modified:
> >>     llvm/trunk/lib/Bitcode/Writer/BitcodeWriter.cpp
> >>
> >> Modified: llvm/trunk/lib/Bitcode/Writer/BitcodeWriter.cpp
> >> URL:
> >>
> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Bitcode/Writer/BitcodeWriter.cpp?rev=219804&r1=219803&r2=219804&view=diff
> >>
> >>
> ==============================================================================
> >> --- llvm/trunk/lib/Bitcode/Writer/BitcodeWriter.cpp (original)
> >> +++ llvm/trunk/lib/Bitcode/Writer/BitcodeWriter.cpp Wed Oct 15 11:21:37
> >> 2014
> >> @@ -710,18 +710,15 @@ static void WriteModuleInfo(const Module
> >>  static uint64_t GetOptimizationFlags(const Value *V) {
> >>    uint64_t Flags = 0;
> >>
> >> -  if (const OverflowingBinaryOperator *OBO =
> >> -        dyn_cast<OverflowingBinaryOperator>(V)) {
> >> +  if (auto *OBO = dyn_cast<OverflowingBinaryOperator>(V)) {
> >>      if (OBO->hasNoSignedWrap())
> >>        Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
> >>      if (OBO->hasNoUnsignedWrap())
> >>        Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
> >> -  } else if (const PossiblyExactOperator *PEO =
> >> -               dyn_cast<PossiblyExactOperator>(V)) {
> >> +  } else if (auto *PEO = dyn_cast<PossiblyExactOperator>(V)) {
> >>      if (PEO->isExact())
> >>        Flags |= 1 << bitc::PEO_EXACT;
> >> -  } else if (const FPMathOperator *FPMO =
> >> -             dyn_cast<const FPMathOperator>(V)) {
> >> +  } else if (auto *FPMO = dyn_cast<const FPMathOperator>(V)) {
> >>      if (FPMO->hasUnsafeAlgebra())
> >>        Flags |= FastMathFlags::UnsafeAlgebra;
> >>      if (FPMO->hasNoNaNs())
> >>
> >>
> >> _______________________________________________
> >> 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
> >
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20141015/eb479dfa/attachment.html>