[llvm] r246590 - [MC] Add support for generating COFF CRCs
David Majnemer via llvm-commits
llvm-commits at lists.llvm.org
Tue Sep 1 14:23:58 PDT 2015
Author: majnemer
Date: Tue Sep 1 16:23:58 2015
New Revision: 246590
URL: http://llvm.org/viewvc/llvm-project?rev=246590&view=rev
Log:
[MC] Add support for generating COFF CRCs
COFF sections are accompanied with an auxiliary symbol which includes a
checksum. This checksum used to be filled with just zero but this seems
to upset LINK.exe when it is processing a /INCREMENTAL link job.
Instead, fill the CheckSum field with the JamCRC of the section
contents. This matches MSVC's behavior.
This fixes PR19666.
N.B. A rather simple implementation of JamCRC is given. It implements
a byte-wise calculation using the method given by Sarwate. There are
implementations with higher throughput like slice-by-eight and making
use of PCLMULQDQ. We can switch to one of those techniques if it turns
out to be a significant use of time.
Added:
llvm/trunk/include/llvm/Support/JamCRC.h
llvm/trunk/lib/Support/JamCRC.cpp
Modified:
llvm/trunk/lib/MC/WinCOFFObjectWriter.cpp
llvm/trunk/lib/Support/CMakeLists.txt
llvm/trunk/test/MC/COFF/basic-coff-64.s
llvm/trunk/test/MC/COFF/basic-coff.s
llvm/trunk/test/MC/COFF/symbol-fragment-offset-64.s
llvm/trunk/test/MC/COFF/symbol-fragment-offset.s
Added: llvm/trunk/include/llvm/Support/JamCRC.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/JamCRC.h?rev=246590&view=auto
==============================================================================
--- llvm/trunk/include/llvm/Support/JamCRC.h (added)
+++ llvm/trunk/include/llvm/Support/JamCRC.h Tue Sep 1 16:23:58 2015
@@ -0,0 +1,48 @@
+//===-- llvm/Support/JamCRC.h - Cyclic Redundancy Check ---------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains an implementation of JamCRC.
+//
+// We will use the "Rocksoft^tm Model CRC Algorithm" to describe the properties
+// of this CRC:
+// Width : 32
+// Poly : 04C11DB7
+// Init : FFFFFFFF
+// RefIn : True
+// RefOut : True
+// XorOut : 00000000
+// Check : 340BC6D9 (result of CRC for "123456789")
+//
+// N.B. We permit flexibility of the "Init" value. Some consumers of this need
+// it to be zero.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_JAMCRC_H
+#define LLVM_SUPPORT_JAMCRC_H
+
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/Support/DataTypes.h"
+
+namespace llvm {
+class JamCRC {
+public:
+ JamCRC(uint32_t Init = 0xFFFFFFFFU) : CRC(Init) {}
+
+ // \brief Update the CRC calculation with Data.
+ void update(ArrayRef<char> Data);
+
+ uint32_t getCRC() const { return CRC; }
+
+private:
+ uint32_t CRC;
+};
+} // End of namespace llvm
+
+#endif
Modified: llvm/trunk/lib/MC/WinCOFFObjectWriter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/WinCOFFObjectWriter.cpp?rev=246590&r1=246589&r2=246590&view=diff
==============================================================================
--- llvm/trunk/lib/MC/WinCOFFObjectWriter.cpp (original)
+++ llvm/trunk/lib/MC/WinCOFFObjectWriter.cpp Tue Sep 1 16:23:58 2015
@@ -32,6 +32,7 @@
#include "llvm/Support/Debug.h"
#include "llvm/Support/Endian.h"
#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/JamCRC.h"
#include "llvm/Support/TimeValue.h"
#include <cstdio>
@@ -1029,6 +1030,7 @@ void WinCOFFObjectWriter::writeObject(MC
}
}
+ SmallVector<char, 128> SectionContents;
for (i = Sections.begin(), ie = Sections.end(), j = Asm.begin(),
je = Asm.end();
(i != ie) && (j != je); ++i, ++j) {
@@ -1047,7 +1049,33 @@ void WinCOFFObjectWriter::writeObject(MC
WriteZeros(SectionDataPadding);
+ // Save the contents of the section to a temporary buffer, we need this
+ // to CRC the data before we dump it into the object file.
+ SectionContents.clear();
+ raw_svector_ostream VecOS(SectionContents);
+ raw_pwrite_stream &OldStream = getStream();
+ // Redirect the output stream to our buffer.
+ setStream(VecOS);
+ // Fill our buffer with the section data.
Asm.writeSectionData(&*j, Layout);
+ // Reset the stream back to what it was before.
+ setStream(OldStream);
+
+ // Calculate our CRC with an initial value of '0', this is not how
+ // JamCRC is specified but it aligns with the expected output.
+ JamCRC JC(/*Init=*/0x00000000U);
+ JC.update(SectionContents);
+
+ // Write the section contents to the object file.
+ getStream() << SectionContents;
+
+ // Update the section definition auxiliary symbol to record the CRC.
+ COFFSection *Sec = SectionMap[&*j];
+ COFFSymbol::AuxiliarySymbols &AuxSyms = Sec->Symbol->Aux;
+ assert(AuxSyms.size() == 1 &&
+ AuxSyms[0].AuxType == ATSectionDefinition);
+ AuxSymbol &SecDef = AuxSyms[0];
+ SecDef.Aux.SectionDefinition.CheckSum = JC.getCRC();
}
if ((*i)->Relocations.size() > 0) {
Modified: llvm/trunk/lib/Support/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/CMakeLists.txt?rev=246590&r1=246589&r2=246590&view=diff
==============================================================================
--- llvm/trunk/lib/Support/CMakeLists.txt (original)
+++ llvm/trunk/lib/Support/CMakeLists.txt Tue Sep 1 16:23:58 2015
@@ -59,6 +59,7 @@ add_llvm_library(LLVMSupport
IntEqClasses.cpp
IntervalMap.cpp
IntrusiveRefCntPtr.cpp
+ JamCRC.cpp
LEB128.cpp
LineIterator.cpp
Locale.cpp
Added: llvm/trunk/lib/Support/JamCRC.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/JamCRC.cpp?rev=246590&view=auto
==============================================================================
--- llvm/trunk/lib/Support/JamCRC.cpp (added)
+++ llvm/trunk/lib/Support/JamCRC.cpp Tue Sep 1 16:23:58 2015
@@ -0,0 +1,96 @@
+//===-- JamCRC.cpp - Cyclic Redundancy Check --------------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains an implementation of JamCRC.
+//
+//===----------------------------------------------------------------------===//
+//
+// The implementation technique is the one mentioned in:
+// D. V. Sarwate. 1988. Computation of cyclic redundancy checks via table
+// look-up. Commun. ACM 31, 8 (August 1988)
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/JamCRC.h"
+
+using namespace llvm;
+
+static const uint32_t CRCTable[256] = {
+ 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba,
+ 0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3,
+ 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
+ 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91,
+ 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de,
+ 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
+ 0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec,
+ 0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5,
+ 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
+ 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
+ 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940,
+ 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
+ 0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116,
+ 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f,
+ 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
+ 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d,
+ 0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a,
+ 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
+ 0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818,
+ 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
+ 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
+ 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457,
+ 0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c,
+ 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
+ 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2,
+ 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb,
+ 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
+ 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9,
+ 0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086,
+ 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
+ 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4,
+ 0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad,
+ 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
+ 0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683,
+ 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8,
+ 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
+ 0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe,
+ 0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7,
+ 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
+ 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
+ 0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252,
+ 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
+ 0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60,
+ 0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79,
+ 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
+ 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f,
+ 0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04,
+ 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
+ 0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a,
+ 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
+ 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
+ 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21,
+ 0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e,
+ 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
+ 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c,
+ 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45,
+ 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
+ 0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db,
+ 0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0,
+ 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
+ 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6,
+ 0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf,
+ 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
+ 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
+};
+
+void JamCRC::update(ArrayRef<char> Data) {
+ for (char Byte : Data) {
+ int TableIdx = (CRC ^ Byte) & 0xff;
+ CRC = CRCTable[TableIdx] ^ (CRC >> 8);
+ }
+}
Modified: llvm/trunk/test/MC/COFF/basic-coff-64.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/COFF/basic-coff-64.s?rev=246590&r1=246589&r2=246590&view=diff
==============================================================================
--- llvm/trunk/test/MC/COFF/basic-coff-64.s (original)
+++ llvm/trunk/test/MC/COFF/basic-coff-64.s Tue Sep 1 16:23:58 2015
@@ -93,7 +93,7 @@ _main:
// CHECK: Length: [[TextSize]]
// CHECK: RelocationCount: 2
// CHECK: LineNumberCount: 0
-// CHECK: Checksum: 0x0
+// CHECK: Checksum: 0x8E1B6D20
// CHECK: Number: [[TextNum]]
// CHECK: Selection: 0x0
// CHECK: }
@@ -110,7 +110,7 @@ _main:
// CHECK: Length: [[DataSize]]
// CHECK: RelocationCount: 0
// CHECK: LineNumberCount: 0
-// CHECK: Checksum: 0x0
+// CHECK: Checksum: 0x2B95CA92
// CHECK: Number: [[DataNum]]
// CHECK: Selection: 0x0
// CHECK: }
Modified: llvm/trunk/test/MC/COFF/basic-coff.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/COFF/basic-coff.s?rev=246590&r1=246589&r2=246590&view=diff
==============================================================================
--- llvm/trunk/test/MC/COFF/basic-coff.s (original)
+++ llvm/trunk/test/MC/COFF/basic-coff.s Tue Sep 1 16:23:58 2015
@@ -93,7 +93,7 @@ L_.str:
// CHECK: Length: 21
// CHECK: RelocationCount: 2
// CHECK: LineNumberCount: 0
-// CHECK: Checksum: 0x0
+// CHECK: Checksum: 0xC6461CBE
// CHECK: Number: 1
// CHECK: Selection: 0x0
// CHECK: }
@@ -110,7 +110,7 @@ L_.str:
// CHECK: Length: 12
// CHECK: RelocationCount: 0
// CHECK: LineNumberCount: 0
-// CHECK: Checksum: 0x0
+// CHECK: Checksum: 0x2B95CA92
// CHECK: Number: 2
// CHECK: Selection: 0x0
// CHECK: }
Modified: llvm/trunk/test/MC/COFF/symbol-fragment-offset-64.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/COFF/symbol-fragment-offset-64.s?rev=246590&r1=246589&r2=246590&view=diff
==============================================================================
--- llvm/trunk/test/MC/COFF/symbol-fragment-offset-64.s (original)
+++ llvm/trunk/test/MC/COFF/symbol-fragment-offset-64.s Tue Sep 1 16:23:58 2015
@@ -114,7 +114,7 @@ _main:
// CHECK: Length: 48
// CHECK: RelocationCount: 6
// CHECK: LineNumberCount: 0
-// CHECK: Checksum: 0x0
+// CHECK: Checksum: 0x7BD396E3
// CHECK: Number: 1
// CHECK: Selection: 0x0
// CHECK: }
@@ -131,7 +131,7 @@ _main:
// CHECK: Length: 35
// CHECK: RelocationCount: 0
// CHECK: LineNumberCount: 0
-// CHECK: Checksum: 0x0
+// CHECK: Checksum: 0xB0A4C21
// CHECK: Number: 2
// CHECK: Selection: 0x0
// CHECK: }
Modified: llvm/trunk/test/MC/COFF/symbol-fragment-offset.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/COFF/symbol-fragment-offset.s?rev=246590&r1=246589&r2=246590&view=diff
==============================================================================
--- llvm/trunk/test/MC/COFF/symbol-fragment-offset.s (original)
+++ llvm/trunk/test/MC/COFF/symbol-fragment-offset.s Tue Sep 1 16:23:58 2015
@@ -114,7 +114,7 @@ L_.str2:
// CHECK: Length: 45
// CHECK: RelocationCount: 6
// CHECK: LineNumberCount: 0
-// CHECK: Checksum: 0x0
+// CHECK: Checksum: 0xDED1DC2
// CHECK: Number: 1
// CHECK: Selection: 0x0
// CHECK: }
@@ -131,7 +131,7 @@ L_.str2:
// CHECK: Length: 35
// CHECK: RelocationCount: 0
// CHECK: LineNumberCount: 0
-// CHECK: Checksum: 0x0
+// CHECK: Checksum: 0xB0A4C21
// CHECK: Number: 2
// CHECK: Selection: 0x0
// CHECK: }
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