[llvm] r292949 - [CodeView] Fix off-by-one error in def range gap emission
Hans Wennborg via llvm-commits
llvm-commits at lists.llvm.org
Wed Feb 8 09:26:17 PST 2017
Merged to 4.0 in r294479.
On Tue, Jan 24, 2017 at 8:57 AM, Reid Kleckner via llvm-commits
<llvm-commits at lists.llvm.org> wrote:
> Author: rnk
> Date: Tue Jan 24 10:57:55 2017
> New Revision: 292949
>
> URL: http://llvm.org/viewvc/llvm-project?rev=292949&view=rev
> Log:
> [CodeView] Fix off-by-one error in def range gap emission
>
> Also fixes a much worse bug where we emitted the wrong gap size for the
> def range uncovered by the test for this issue.
>
> Fixes PR31726.
>
> Modified:
> llvm/trunk/lib/MC/MCCodeView.cpp
> llvm/trunk/test/MC/COFF/cv-def-range-gap.s
>
> Modified: llvm/trunk/lib/MC/MCCodeView.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCCodeView.cpp?rev=292949&r1=292948&r2=292949&view=diff
> ==============================================================================
> --- llvm/trunk/lib/MC/MCCodeView.cpp (original)
> +++ llvm/trunk/lib/MC/MCCodeView.cpp Tue Jan 24 10:57:55 2017
> @@ -509,17 +509,17 @@ void CodeViewContext::encodeDefRange(MCA
> // are artificially constructing.
> size_t RecordSize = FixedSizePortion.size() +
> sizeof(LocalVariableAddrRange) + 4 * NumGaps;
> - // Write out the recrod size.
> - support::endian::Writer<support::little>(OS).write<uint16_t>(RecordSize);
> + // Write out the record size.
> + LEWriter.write<uint16_t>(RecordSize);
> // Write out the fixed size prefix.
> OS << FixedSizePortion;
> // Make space for a fixup that will eventually have a section relative
> // relocation pointing at the offset where the variable becomes live.
> Fixups.push_back(MCFixup::create(Contents.size(), BE, FK_SecRel_4));
> - Contents.resize(Contents.size() + 4); // Fixup for code start.
> + LEWriter.write<uint32_t>(0); // Fixup for code start.
> // Make space for a fixup that will record the section index for the code.
> Fixups.push_back(MCFixup::create(Contents.size(), BE, FK_SecRel_2));
> - Contents.resize(Contents.size() + 2); // Fixup for section index.
> + LEWriter.write<uint16_t>(0); // Fixup for section index.
> // Write down the range's extent.
> LEWriter.write<uint16_t>(Chunk);
>
> @@ -529,7 +529,7 @@ void CodeViewContext::encodeDefRange(MCA
> } while (RangeSize > 0);
>
> // Emit the gaps afterwards.
> - assert((NumGaps == 0 || Bias < MaxDefRange) &&
> + assert((NumGaps == 0 || Bias <= MaxDefRange) &&
> "large ranges should not have gaps");
> unsigned GapStartOffset = GapAndRangeSizes[I].second;
> for (++I; I != J; ++I) {
> @@ -537,7 +537,7 @@ void CodeViewContext::encodeDefRange(MCA
> assert(I < GapAndRangeSizes.size());
> std::tie(GapSize, RangeSize) = GapAndRangeSizes[I];
> LEWriter.write<uint16_t>(GapStartOffset);
> - LEWriter.write<uint16_t>(RangeSize);
> + LEWriter.write<uint16_t>(GapSize);
> GapStartOffset += GapSize + RangeSize;
> }
> }
>
> Modified: llvm/trunk/test/MC/COFF/cv-def-range-gap.s
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/COFF/cv-def-range-gap.s?rev=292949&r1=292948&r2=292949&view=diff
> ==============================================================================
> --- llvm/trunk/test/MC/COFF/cv-def-range-gap.s (original)
> +++ llvm/trunk/test/MC/COFF/cv-def-range-gap.s Tue Jan 24 10:57:55 2017
> @@ -38,6 +38,19 @@
> # CHECK-NEXT: Range: 0x1
> # CHECK-NEXT: }
> # CHECK-NEXT: }
> +# CHECK-NEXT: DefRangeRegister {
> +# CHECK-NEXT: Register: 23
> +# CHECK-NEXT: MayHaveNoName: 0
> +# CHECK-NEXT: LocalVariableAddrRange {
> +# CHECK-NEXT: OffsetStart: .text+0x2001C
> +# CHECK-NEXT: ISectStart: 0x0
> +# CHECK-NEXT: Range: 0xF000
> +# CHECK-NEXT: }
> +# CHECK-NEXT: LocalVariableAddrGap [
> +# CHECK-NEXT: GapStartOffset: 0x1
> +# CHECK-NEXT: Range: 0xEFFE
> +# CHECK-NEXT: ]
> +# CHECK-NEXT: }
>
> .text
> f: # @f
> @@ -62,6 +75,16 @@ f:
> .Lbegin3:
> nop
> .Lend3:
> +
> + # Create a range that is exactly 0xF000 bytes long with a gap in the
> + # middle.
> +.Lbegin4:
> + nop
> +.Lend4:
> + .fill 0xeffe, 1, 0x90
> +.Lbegin5:
> + nop
> +.Lend5:
> ret
> .Lfunc_end0:
>
> @@ -94,6 +117,7 @@ f:
> .asciz "p"
> .Ltmp19:
> .cv_def_range .Lbegin0 .Lend0 .Lbegin1 .Lend1 .Lbegin2 .Lend2 .Lbegin3 .Lend3, "A\021\027\000\000\000"
> + .cv_def_range .Lbegin4 .Lend4 .Lbegin5 .Lend5, "A\021\027\000\000\000"
> .short 2 # Record length
> .short 4431 # Record kind: S_PROC_ID_END
> .Ltmp15:
>
>
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