[Lldb-commits] [lldb] r346783 - [Cocoa] Implement formatter for the new NSDate representation.

[Zachary Turner via lldb-commits]

Did this fix the bitfield problem too? I didn’t fix that one.
On Fri, Nov 16, 2018 at 11:56 AM Davide Italiano <davide at freebsd.org> wrote:

> I saw you partially fixed this.
>
> I addressed the remaining problem in:
> Davides-Mac-Pro:lldb davide$ git llvm push
> Pushing 1 commit:
>   b6fd30d9119 [Cocoa] Prefer llvm::SignExtend64. Pointed out by zturner.
> Sending        lldb/trunk/source/Plugins/Language/ObjC/Cocoa.cpp
> Transmitting file data .done
> Committing transaction...
> Committed revision 347087.
> Committed b6fd30d9119 to svn.
>
>
> --
> Davide
> On Fri, Nov 16, 2018 at 10:09 AM Davide Italiano <davide at freebsd.org>
> wrote:
> >
> > Sorry Zach, I was sick for the past few days. I'll look into this one
> now.
> >
> > --
> > Davide
> > On Wed, Nov 14, 2018 at 9:16 AM Zachary Turner <zturner at google.com>
> wrote:
> > >
> > >
> > >
> > > On Tue, Nov 13, 2018 at 11:46 AM Davide Italiano via lldb-commits <
> lldb-commits at lists.llvm.org> wrote:
> > >>
> > >> Author: davide
> > >> Date: Tue Nov 13 11:43:43 2018
> > >> New Revision: 346783
> > >>
> > >> URL: http://llvm.org/viewvc/llvm-project?rev=346783&view=rev
> > >> Log:
> > >> [Cocoa] Implement formatter for the new NSDate representation.
> > >>
> > >> <rdar://problem/46002786>
> > >>
> > >> Modified:
> > >>     lldb/trunk/source/Plugins/Language/ObjC/Cocoa.cpp
> > >>
> > >> Modified: lldb/trunk/source/Plugins/Language/ObjC/Cocoa.cpp
> > >> URL:
> http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/Language/ObjC/Cocoa.cpp?rev=346783&r1=346782&r2=346783&view=diff
> > >>
> ==============================================================================
> > >> --- lldb/trunk/source/Plugins/Language/ObjC/Cocoa.cpp (original)
> > >> +++ lldb/trunk/source/Plugins/Language/ObjC/Cocoa.cpp Tue Nov 13
> 11:43:43 2018
> > >> @@ -742,6 +742,60 @@ bool lldb_private::formatters::NSURLSumm
> > >>    return false;
> > >>  }
> > >>
> > >> +/// Bias value for tagged pointer exponents.
> > >> +/// Recommended values:
> > >> +/// 0x3e3: encodes all dates between distantPast and distantFuture
> > >> +///   except for the range within about 1e-28 second of the
> reference date.
> > >> +/// 0x3ef: encodes all dates for a few million years beyond
> distantPast and
> > >> +///   distantFuture, except within about 1e-25 second of the
> reference date.
> > >> +const int TAGGED_DATE_EXPONENT_BIAS = 0x3ef;
> > >> +
> > >> +typedef union {
> > >> +  struct {
> > >> +    uint64_t fraction:52;  // unsigned
> > >> +    uint64_t exponent:11;  // signed
> > >> +    uint64_t sign:1;
> > >> +  };
> > >> +  uint64_t i;
> > >> +  double d;
> > >> +} DoubleBits;
> > >> +typedef union {
> > >> +  struct {
> > >> +    uint64_t fraction:52;  // unsigned
> > >> +    uint64_t exponent:7;   // signed
> > >> +    uint64_t sign:1;
> > >> +    uint64_t unused:4;  // placeholder for pointer tag bits
> > >> +  };
> > >
> > > MSVC gives:
> > >
> > > warning C4201: nonstandard extension used: nameless struct/union
> > >
> > >>
> > >> +  uint64_t i;
> > >> +} TaggedDoubleBits;
> > >> +
> > >> +static uint64_t decodeExponent(uint64_t exp) {
> > >> +  int64_t exp7 = exp;
> > >> +  // Tagged exponent field is 7-bit signed. Sign-extend the value to
> 64 bits
> > >> +  // before performing arithmetic.
> > >> +  int64_t exp11 = ((exp7 << 57) >> 57) + TAGGED_DATE_EXPONENT_BIAS;
> > >> +  return exp11;
> > >> +}
> > >
> > > this should probably be:
> > >
> > > return llvm::SignExtend64<7>(exp) + TAGGED_DATE_EXPONENT_BIAS;
> > >
> > >>
> > >> +
> > >> +static uint64_t decodeTaggedTimeInterval(uint64_t
> encodedTimeInterval) {
> > >> +  if (encodedTimeInterval == 0)
> > >> +    return 0.0;
> > >> +  if (encodedTimeInterval == std::numeric_limits<uint64_t>::max())
> > >> +    return -0.0;
> > >> +
> > >> +  TaggedDoubleBits encodedBits = { .i = encodedTimeInterval };
> > >
> > > Designated initializers are C++20 which are not allowed in LLVM.
> >
> >
> >
> > --
> > Davide
> >
> > "There are no solved problems; there are only problems that are more
> > or less solved" -- Henri Poincare
>
>
>
> --
> Davide
>
> "There are no solved problems; there are only problems that are more
> or less solved" -- Henri Poincare
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/lldb-commits/attachments/20181116/138964e6/attachment.html>