[lld] r277680 - Make filler expression compatible with gold.

[Rui Ueyama via llvm-commits]

My observation is different; gold handles numbers starting with 0x as a
binary of arbitrary size in hexstring. How did you test it?

On Thu, Aug 4, 2016 at 6:35 AM, Rafael Espíndola <rafael.espindola at gmail.com
> wrote:

> Note that gold also parses the hex string as a 32 bit value.
>
> Cheers,
> Rafael
>
>
> On 3 August 2016 at 19:25, Rui Ueyama via llvm-commits
> <llvm-commits at lists.llvm.org> wrote:
> > Author: ruiu
> > Date: Wed Aug  3 18:25:15 2016
> > New Revision: 277680
> >
> > URL: http://llvm.org/viewvc/llvm-project?rev=277680&view=rev
> > Log:
> > Make filler expression compatible with gold.
> >
> > Previously, a decimal filler expression is interpreted as a byte value.
> > Gold on the other hand use it as a 32-bit big-endian value.
> > This patch fixes the compatibility issue.
> >
> > Differential Revision: https://reviews.llvm.org/D23142
> >
> > Modified:
> >     lld/trunk/ELF/LinkerScript.cpp
> >     lld/trunk/test/ELF/linkerscript/linkerscript-sections-padding.s
> >
> > Modified: lld/trunk/ELF/LinkerScript.cpp
> > URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/
> LinkerScript.cpp?rev=277680&r1=277679&r2=277680&view=diff
> > ============================================================
> ==================
> > --- lld/trunk/ELF/LinkerScript.cpp (original)
> > +++ lld/trunk/ELF/LinkerScript.cpp Wed Aug  3 18:25:15 2016
> > @@ -843,18 +843,19 @@ std::vector<uint8_t> ScriptParser::readO
> >    if (!Tok.startswith("="))
> >      return {};
> >    next();
> > +
> > +  // Read a hexstring of arbitrary length.
> >    if (Tok.startswith("=0x"))
> >      return parseHex(Tok.substr(3));
> >
> > -  // This must be a decimal.
> > -  unsigned int Value;
> > -  if (Tok.substr(1).getAsInteger(10, Value)) {
> > -    setError("filler should be a decimal/hexadecimal value");
> > +  // Read a decimal or octal value as a big-endian 32 bit value.
> > +  // Why do this? I don't know, but that's what gold does.
> > +  uint32_t V;
> > +  if (Tok.substr(1).getAsInteger(0, V)) {
> > +    setError("invalid filler expression: " + Tok);
> >      return {};
> >    }
> > -  if (Value > 255)
> > -    setError("only single bytes decimal are supported for the filler
> now");
> > -  return {static_cast<unsigned char>(Value)};
> > +  return { uint8_t(V >> 24), uint8_t(V >> 16), uint8_t(V >> 8),
> uint8_t(V) };
> >  }
> >
> >  void ScriptParser::readProvide(bool Hidden) {
> >
> > Modified: lld/trunk/test/ELF/linkerscript/linkerscript-
> sections-padding.s
> > URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/
> linkerscript/linkerscript-sections-padding.s?rev=277680&
> r1=277679&r2=277680&view=diff
> > ============================================================
> ==================
> > --- lld/trunk/test/ELF/linkerscript/linkerscript-sections-padding.s
> (original)
> > +++ lld/trunk/test/ELF/linkerscript/linkerscript-sections-padding.s Wed
> Aug  3 18:25:15 2016
> > @@ -20,10 +20,10 @@
> >  # NO: 00000120  66 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> >
> >  ## Decimal value.
> > -# RUN: echo "SECTIONS { .mysec : { *(.mysec*) } =99 }" > %t.script
> > +# RUN: echo "SECTIONS { .mysec : { *(.mysec*) } =777 }" > %t.script
> >  # RUN: ld.lld -o %t.out --script %t.script %t
> >  # RUN: hexdump -C %t.out | FileCheck -check-prefix=DEC %s
> > -# DEC: 00000120  66 63 63 63 63 63 63 63  63 63 63 63 63 63 63 63
> > +# DEC: 00000120  66 00 03 09 00 00 03 09 00 00 03 09 00 00 03 09
> >
> >  ## Invalid hex value:
> >  # RUN: echo "SECTIONS { .mysec : { *(.mysec*) } =0x99XX }" > %t.script
> >
> >
> > _______________________________________________
> > llvm-commits mailing list
> > llvm-commits at lists.llvm.org
> > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits
>
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