[llvm] r306488 - Object: Teach irsymtab::read() to try to use the irsymtab that we wrote to disk.
Peter Collingbourne via llvm-commits
llvm-commits at lists.llvm.org
Tue Jun 27 16:50:24 PDT 2017
Author: pcc
Date: Tue Jun 27 16:50:24 2017
New Revision: 306488
URL: http://llvm.org/viewvc/llvm-project?rev=306488&view=rev
Log:
Object: Teach irsymtab::read() to try to use the irsymtab that we wrote to disk.
Fixes PR27551.
Differential Revision: https://reviews.llvm.org/D33974
Modified:
llvm/trunk/include/llvm/Bitcode/BitcodeReader.h
llvm/trunk/include/llvm/Object/IRSymtab.h
llvm/trunk/lib/Bitcode/Reader/BitcodeReader.cpp
llvm/trunk/lib/Object/IRSymtab.cpp
llvm/trunk/test/Object/X86/irsymtab.ll
llvm/trunk/tools/llvm-lto2/llvm-lto2.cpp
Modified: llvm/trunk/include/llvm/Bitcode/BitcodeReader.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Bitcode/BitcodeReader.h?rev=306488&r1=306487&r2=306488&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Bitcode/BitcodeReader.h (original)
+++ llvm/trunk/include/llvm/Bitcode/BitcodeReader.h Tue Jun 27 16:50:24 2017
@@ -111,9 +111,14 @@ namespace llvm {
struct BitcodeFileContents {
std::vector<BitcodeModule> Mods;
+ StringRef Symtab, StrtabForSymtab;
};
- /// Returns the contents of a bitcode file.
+ /// Returns the contents of a bitcode file. This includes the raw contents of
+ /// the symbol table embedded in the bitcode file. Clients which require a
+ /// symbol table should prefer to use irsymtab::read instead of this function
+ /// because it creates a reader for the irsymtab and handles upgrading bitcode
+ /// files without a symbol table or with an old symbol table.
Expected<BitcodeFileContents> getBitcodeFileContents(MemoryBufferRef Buffer);
/// Returns a list of modules in the specified bitcode buffer.
Modified: llvm/trunk/include/llvm/Object/IRSymtab.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Object/IRSymtab.h?rev=306488&r1=306487&r2=306488&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Object/IRSymtab.h (original)
+++ llvm/trunk/include/llvm/Object/IRSymtab.h Tue Jun 27 16:50:24 2017
@@ -255,6 +255,8 @@ public:
/// copied into an irsymtab::Symbol object.
symbol_range symbols() const;
+ size_t getNumModules() const { return Modules.size(); }
+
/// Returns a slice of the symbol table for the I'th module in the file.
/// The symbols enumerated by this method are ephemeral, but they can be
/// copied into an irsymtab::Symbol object.
Modified: llvm/trunk/lib/Bitcode/Reader/BitcodeReader.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Bitcode/Reader/BitcodeReader.cpp?rev=306488&r1=306487&r2=306488&view=diff
==============================================================================
--- llvm/trunk/lib/Bitcode/Reader/BitcodeReader.cpp (original)
+++ llvm/trunk/lib/Bitcode/Reader/BitcodeReader.cpp Tue Jun 27 16:50:24 2017
@@ -5360,8 +5360,9 @@ const std::error_category &llvm::Bitcode
return *ErrorCategory;
}
-static Expected<StringRef> readStrtab(BitstreamCursor &Stream) {
- if (Stream.EnterSubBlock(bitc::STRTAB_BLOCK_ID))
+static Expected<StringRef> readBlobInRecord(BitstreamCursor &Stream,
+ unsigned Block, unsigned RecordID) {
+ if (Stream.EnterSubBlock(Block))
return error("Invalid record");
StringRef Strtab;
@@ -5382,7 +5383,7 @@ static Expected<StringRef> readStrtab(Bi
case BitstreamEntry::Record:
StringRef Blob;
SmallVector<uint64_t, 1> Record;
- if (Stream.readRecord(Entry.ID, Record, &Blob) == bitc::STRTAB_BLOB)
+ if (Stream.readRecord(Entry.ID, Record, &Blob) == RecordID)
Strtab = Blob;
break;
}
@@ -5450,7 +5451,8 @@ llvm::getBitcodeFileContents(MemoryBuffe
}
if (Entry.ID == bitc::STRTAB_BLOCK_ID) {
- Expected<StringRef> Strtab = readStrtab(Stream);
+ Expected<StringRef> Strtab =
+ readBlobInRecord(Stream, bitc::STRTAB_BLOCK_ID, bitc::STRTAB_BLOB);
if (!Strtab)
return Strtab.takeError();
// This string table is used by every preceding bitcode module that does
@@ -5462,6 +5464,28 @@ llvm::getBitcodeFileContents(MemoryBuffe
break;
I->Strtab = *Strtab;
}
+ // Similarly, the string table is used by every preceding symbol table;
+ // normally there will be just one unless the bitcode file was created
+ // by binary concatenation.
+ if (!F.Symtab.empty() && F.StrtabForSymtab.empty())
+ F.StrtabForSymtab = *Strtab;
+ continue;
+ }
+
+ if (Entry.ID == bitc::SYMTAB_BLOCK_ID) {
+ Expected<StringRef> SymtabOrErr =
+ readBlobInRecord(Stream, bitc::SYMTAB_BLOCK_ID, bitc::SYMTAB_BLOB);
+ if (!SymtabOrErr)
+ return SymtabOrErr.takeError();
+
+ // We can expect the bitcode file to have multiple symbol tables if it
+ // was created by binary concatenation. In that case we silently
+ // ignore any subsequent symbol tables, which is fine because this is a
+ // low level function. The client is expected to notice that the number
+ // of modules in the symbol table does not match the number of modules
+ // in the input file and regenerate the symbol table.
+ if (F.Symtab.empty())
+ F.Symtab = *SymtabOrErr;
continue;
}
Modified: llvm/trunk/lib/Object/IRSymtab.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Object/IRSymtab.cpp?rev=306488&r1=306487&r2=306488&view=diff
==============================================================================
--- llvm/trunk/lib/Object/IRSymtab.cpp (original)
+++ llvm/trunk/lib/Object/IRSymtab.cpp Tue Jun 27 16:50:24 2017
@@ -318,7 +318,31 @@ Expected<FileContents> irsymtab::readBit
return make_error<StringError>("Bitcode file does not contain any modules",
inconvertibleErrorCode());
- // Right now we have no on-disk representation of symbol tables, so we always
- // upgrade.
- return upgrade(BFC.Mods);
+ if (BFC.StrtabForSymtab.empty() ||
+ BFC.Symtab.size() < sizeof(storage::Header))
+ return upgrade(BFC.Mods);
+
+ // We cannot use the regular reader to read the version and producer, because
+ // it will expect the header to be in the current format. The only thing we
+ // can rely on is that the version and producer will be present as the first
+ // struct elements.
+ auto *Hdr = reinterpret_cast<const storage::Header *>(BFC.Symtab.data());
+ unsigned Version = Hdr->Version;
+ StringRef Producer = Hdr->Producer.get(BFC.StrtabForSymtab);
+ if (Version != storage::Header::kCurrentVersion ||
+ Producer != kExpectedProducerName)
+ return upgrade(BFC.Mods);
+
+ FileContents FC;
+ FC.TheReader = {{BFC.Symtab.data(), BFC.Symtab.size()},
+ {BFC.StrtabForSymtab.data(), BFC.StrtabForSymtab.size()}};
+
+ // Finally, make sure that the number of modules in the symbol table matches
+ // the number of modules in the bitcode file. If they differ, it may mean that
+ // the bitcode file was created by binary concatenation, so we need to create
+ // a new symbol table from scratch.
+ if (FC.TheReader.getNumModules() != BFC.Mods.size())
+ return upgrade(std::move(BFC.Mods));
+
+ return std::move(FC);
}
Modified: llvm/trunk/test/Object/X86/irsymtab.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Object/X86/irsymtab.ll?rev=306488&r1=306487&r2=306488&view=diff
==============================================================================
--- llvm/trunk/test/Object/X86/irsymtab.ll (original)
+++ llvm/trunk/test/Object/X86/irsymtab.ll Tue Jun 27 16:50:24 2017
@@ -1,6 +1,12 @@
; RUN: env LLVM_OVERRIDE_PRODUCER=producer opt -o %t %s
; RUN: llvm-bcanalyzer -dump -show-binary-blobs %t | FileCheck --check-prefix=BCA %s
+; Same producer, does not require upgrade.
+; RUN: env LLVM_OVERRIDE_PRODUCER=producer llvm-lto2 dump-symtab %t | FileCheck --check-prefix=SYMTAB %s
+
+; Different producer, requires upgrade.
+; RUN: env LLVM_OVERRIDE_PRODUCER=consumer llvm-lto2 dump-symtab %t | FileCheck --check-prefix=SYMTAB %s
+
; BCA: <SYMTAB_BLOCK
; Version stored at offset 0.
; BCA-NEXT: <BLOB abbrevid=4/> blob data = '\x00\x00\x00\x00\x06\x00\x00\x00\x08\x00\x00\x00D\x00\x00\x00\x01\x00\x00\x00P\x00\x00\x00\x00\x00\x00\x00P\x00\x00\x00\x02\x00\x00\x00\x80\x00\x00\x00\x00\x00\x00\x00\x0E\x00\x00\x00\x18\x00\x00\x00&\x00\x00\x00\x0B\x00\x00\x001\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x03\x00\x00\x00\x00\x00\x00\x00\x03\x00\x00\x00\xFF\xFF\xFF\xFF\x00$\x00\x00\x03\x00\x00\x00\x03\x00\x00\x00\x03\x00\x00\x00\x03\x00\x00\x00\xFF\xFF\xFF\xFF\x08$\x00\x00'
@@ -9,6 +15,13 @@
; BCA-NEXT: <BLOB abbrevid=4/> blob data = 'foobarproducerx86_64-unknown-linux-gnuirsymtab.ll'
; BCA-NEXT: </STRTAB_BLOCK>
+; SYMTAB: version: 0
+; SYMTAB-NEXT: producer: producer
+; SYMTAB-NEXT: target triple: x86_64-unknown-linux-gnu
+; SYMTAB-NEXT: source filename: irsymtab.ll
+; SYMTAB-NEXT: D------X foo
+; SYMTAB-NEXT: DU-----X bar
+
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
source_filename = "irsymtab.ll"
Modified: llvm/trunk/tools/llvm-lto2/llvm-lto2.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-lto2/llvm-lto2.cpp?rev=306488&r1=306487&r2=306488&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-lto2/llvm-lto2.cpp (original)
+++ llvm/trunk/tools/llvm-lto2/llvm-lto2.cpp Tue Jun 27 16:50:24 2017
@@ -16,9 +16,10 @@
//
//===----------------------------------------------------------------------===//
-#include "llvm/LTO/Caching.h"
+#include "llvm/Bitcode/BitcodeReader.h"
#include "llvm/CodeGen/CommandFlags.h"
#include "llvm/IR/DiagnosticPrinter.h"
+#include "llvm/LTO/Caching.h"
#include "llvm/LTO/LTO.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/FileSystem.h"
@@ -298,6 +299,17 @@ static int run(int argc, char **argv) {
static int dumpSymtab(int argc, char **argv) {
for (StringRef F : make_range(argv + 1, argv + argc)) {
std::unique_ptr<MemoryBuffer> MB = check(MemoryBuffer::getFile(F), F);
+ BitcodeFileContents BFC = check(getBitcodeFileContents(*MB), F);
+
+ if (BFC.Symtab.size() >= sizeof(irsymtab::storage::Header)) {
+ auto *Hdr = reinterpret_cast<const irsymtab::storage::Header *>(
+ BFC.Symtab.data());
+ outs() << "version: " << Hdr->Version << '\n';
+ if (Hdr->Version == irsymtab::storage::Header::kCurrentVersion)
+ outs() << "producer: " << Hdr->Producer.get(BFC.StrtabForSymtab)
+ << '\n';
+ }
+
std::unique_ptr<InputFile> Input =
check(InputFile::create(MB->getMemBufferRef()), F);
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