Add a version field in the bitcode for the summary

[mehdi_amini]

(update tests)

[mehdi_amini]

r267318

include/llvm/Bitcode/LLVMBitCodes.h

enum GlobalValueSummarySymtabCodes {
   // COMBINED_GLOBALVAR_INIT_REFS: [modid, linkage, n x valueid]
   FS_COMBINED_GLOBALVAR_INIT_REFS = 6,
   // ALIAS: [valueid, linkage, valueid]
   FS_ALIAS = 7,
   // COMBINED_ALIAS: [modid, linkage, offset]
   FS_COMBINED_ALIAS = 8,
   // COMBINED_ORIGINAL_NAME: [original_name_hash]
   FS_COMBINED_ORIGINAL_NAME = 9,
+  // VERSION of the summary, bumped when adding flags for instance.
+  FS_VERSION = 10,
 };
 
 enum MetadataCodes {
   METADATA_STRING_OLD = 1,       // MDSTRING:      [values]
   METADATA_VALUE = 2,            // VALUE:         [type num, value num]
   METADATA_NODE = 3,             // NODE:          [n x md num]
   METADATA_NAME = 4,             // STRING:        [values]
   METADATA_DISTINCT_NODE = 5,    // DISTINCT_NODE: [n x md num]

lib/Bitcode/Reader/BitcodeReader.cpp

std::error_code ModuleSummaryIndexBitcodeReader::parseModule() {
   }
 }
 
 // Eagerly parse the entire summary block. This populates the GlobalValueSummary
 // objects in the index.
 std::error_code ModuleSummaryIndexBitcodeReader::parseEntireSummary() {
   if (Stream.EnterSubBlock(bitc::GLOBALVAL_SUMMARY_BLOCK_ID))
     return error("Invalid record");
-
   SmallVector<uint64_t, 64> Record;
+
+  // Parse version
+  {
+    BitstreamEntry Entry = Stream.advanceSkippingSubblocks();
+    if (Entry.Kind != BitstreamEntry::Record)
+      return error("Invalid Summary Block: record for version expected");
+    if (Stream.readRecord(Entry.ID, Record) != bitc::FS_VERSION)
+      return error("Invalid Summary Block: version expected");
+  }
+  const uint64_t Version = Record[0];
+  if (Version != 1)
+    return error("Invalid summary version " + Twine(Version) + ", 1 expected");
+  Record.clear();
+
   // Keep around the last seen summary to be used when we see an optional
   // "OriginalName" attachement.
   GlobalValueSummary *LastSeenSummary = nullptr;
   bool Combined = false;
   while (1) {
     BitstreamEntry Entry = Stream.advanceSkippingSubblocks();
 
     switch (Entry.Kind) {

lib/Bitcode/Writer/BitcodeWriter.cpp

void ModuleBitcodeWriter::writeModuleLevelReferences(
   GlobalVarSummary *VS = cast<GlobalVarSummary>(Info->summary());
   for (auto Ref : VS->refs())
     NameVals.push_back(VE.getValueID(Ref.getValue()));
   Stream.EmitRecord(bitc::FS_PERMODULE_GLOBALVAR_INIT_REFS, NameVals,
                     FSModRefsAbbrev);
   NameVals.clear();
 }
 
+// Current version for the summary.
+// This is bumped whenever we introduce changes in the way some record are
+// interpreted, like flags for instance.
+static const uint64_t INDEX_VERSION = 1;
+
 /// Emit the per-module summary section alongside the rest of
 /// the module's bitcode.
 void ModuleBitcodeWriter::writePerModuleGlobalValueSummary() {
   if (M.empty())
     return;
 
   if (Index->begin() == Index->end())
     return;
 
   Stream.EnterSubblock(bitc::GLOBALVAL_SUMMARY_BLOCK_ID, 3);
 
+  Stream.EmitRecord(bitc::FS_VERSION, ArrayRef<uint64_t>{INDEX_VERSION});
+
   // Abbrev for FS_PERMODULE.
   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE));
   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 5)); // linkage
   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // instcount
   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // numrefs
   // numrefs x valueid, n x (valueid, callsitecount)
void ModuleBitcodeWriter::writePerModuleGlobalValueSummary() {
   }
 
   Stream.ExitBlock();
 }
 
 /// Emit the combined summary section into the combined index file.
 void IndexBitcodeWriter::writeCombinedGlobalValueSummary() {
   Stream.EnterSubblock(bitc::GLOBALVAL_SUMMARY_BLOCK_ID, 3);
+  Stream.EmitRecord(bitc::FS_VERSION, ArrayRef<uint64_t>{INDEX_VERSION});
 
   // Abbrev for FS_COMBINED.
   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED));
   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // modid
   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 5)); // linkage
   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // instcount
   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // numrefs

test/Bitcode/summary_version.ll

+; Check summary versioning
+; RUN: opt  -module-summary  %s -o - | llvm-bcanalyzer -dump | FileCheck %s
+
+; CHECK: <GLOBALVAL_SUMMARY_BLOCK
+; CHECK: <VERSION op0=1/>
+
+
+
+; Need a function for the summary to be populated.
+define void @foo() {
+    ret void
+}

test/Bitcode/thinlto-alias.ll

 ; Test to check the callgraph in summary
 ; RUN: opt -module-summary %s -o %t.o
 ; RUN: llvm-bcanalyzer -dump %t.o | FileCheck %s
 ; RUN: opt -module-summary %p/Inputs/thinlto-alias.ll -o %t2.o
 ; RUN: llvm-lto -thinlto -o %t3 %t.o %t2.o
 ; RUN: llvm-bcanalyzer -dump %t3.thinlto.bc | FileCheck %s --check-prefix=COMBINED
 
 ; CHECK:       <GLOBALVAL_SUMMARY_BLOCK
+; CHECK-NEXT:    <VERSION
 ; See if the call to func is registered, using the expected callsite count
 ; and value id matching the subsequent value symbol table.
 ; CHECK-NEXT:    <PERMODULE {{.*}} op4=[[FUNCID:[0-9]+]] op5=1/>
 ; CHECK-NEXT:  </GLOBALVAL_SUMMARY_BLOCK>
 ; CHECK-NEXT:  <VALUE_SYMTAB
 ; CHECK-NEXT:    <FNENTRY {{.*}} record string = 'main'
 ; External function analias should have entry with value id FUNCID
 ; CHECK-NEXT:    <ENTRY {{.*}} op0=[[FUNCID]] {{.*}} record string = 'analias'
 ; CHECK-NEXT:  </VALUE_SYMTAB>
 
 ; COMBINED:       <GLOBALVAL_SUMMARY_BLOCK
+; COMBINED-NEXT:    <VERSION
 ; See if the call to analias is registered, using the expected callsite count
 ; and value id matching the subsequent value symbol table.
 ; COMBINED-NEXT:    <COMBINED {{.*}} op4=[[ALIASID:[0-9]+]] op5=1/>
 ; Followed by the alias and aliasee
 ; COMBINED-NEXT:    <COMBINED {{.*}}
 ; COMBINED-NEXT:    <COMBINED_ALIAS  {{.*}} op2=[[ALIASEEOFFSET:[0-9]+]]
 ; COMBINED-NEXT:  </GLOBALVAL_SUMMARY_BLOCK
 ; COMBINED-NEXT:  <VALUE_SYMTAB

test/Bitcode/thinlto-function-summary-callgraph-pgo.ll

 ; Test to check the callgraph in summary when there is PGO
 ; RUN: opt -module-summary %s -o %t.o
 ; RUN: llvm-bcanalyzer -dump %t.o | FileCheck %s
 ; RUN: opt -module-summary %p/Inputs/thinlto-function-summary-callgraph.ll -o %t2.o
 ; RUN: llvm-lto -thinlto -o %t3 %t.o %t2.o
 ; RUN: llvm-bcanalyzer -dump %t3.thinlto.bc | FileCheck %s --check-prefix=COMBINED
 
 ; CHECK:       <GLOBALVAL_SUMMARY_BLOCK
+; CHECK-NEXT:    <VERSION
 ; See if the call to func is registered, using the expected callsite count
 ; and profile count, with value id matching the subsequent value symbol table.
 ; CHECK-NEXT:    <PERMODULE_PROFILE {{.*}} op4=[[FUNCID:[0-9]+]] op5=1 op6=1/>
 ; CHECK-NEXT:  </GLOBALVAL_SUMMARY_BLOCK>
 ; CHECK-NEXT:  <VALUE_SYMTAB
 ; CHECK-NEXT:    <FNENTRY {{.*}} record string = 'main'
 ; External function func should have entry with value id FUNCID
 ; CHECK-NEXT:    <ENTRY {{.*}} op0=[[FUNCID]] {{.*}} record string = 'func'
 ; CHECK-NEXT:  </VALUE_SYMTAB>
 
 ; COMBINED:       <GLOBALVAL_SUMMARY_BLOCK
+; COMBINED-NEXT:    <VERSION
 ; COMBINED-NEXT:    <COMBINED
 ; See if the call to func is registered, using the expected callsite count
 ; and profile count, with value id matching the subsequent value symbol table.
 ; COMBINED-NEXT:    <COMBINED_PROFILE {{.*}} op4=[[FUNCID:[0-9]+]] op5=1 op6=1/>
 ; COMBINED-NEXT:  </GLOBALVAL_SUMMARY_BLOCK>
 ; COMBINED-NEXT:  <VALUE_SYMTAB
 ; Entry for function func should have entry with value id FUNCID
 ; COMBINED-NEXT:    <COMBINED_GVDEFENTRY {{.*}} op0=[[FUNCID]] {{.*}} op2=7289175272376759421/>

test/Bitcode/thinlto-function-summary-callgraph.ll

 ; Test to check the callgraph in summary
 ; RUN: opt -module-summary %s -o %t.o
 ; RUN: llvm-bcanalyzer -dump %t.o | FileCheck %s
 ; RUN: opt -module-summary %p/Inputs/thinlto-function-summary-callgraph.ll -o %t2.o
 ; RUN: llvm-lto -thinlto -o %t3 %t.o %t2.o
 ; RUN: llvm-bcanalyzer -dump %t3.thinlto.bc | FileCheck %s --check-prefix=COMBINED
 
 ; CHECK:       <GLOBALVAL_SUMMARY_BLOCK
+; CHECK-NEXT:    <VERSION
 ; See if the call to func is registered, using the expected callsite count
 ; and value id matching the subsequent value symbol table.
 ; CHECK-NEXT:    <PERMODULE {{.*}} op4=[[FUNCID:[0-9]+]] op5=1/>
 ; CHECK-NEXT:  </GLOBALVAL_SUMMARY_BLOCK>
 ; CHECK-NEXT:  <VALUE_SYMTAB
 ; CHECK-NEXT:    <FNENTRY {{.*}} record string = 'main'
 ; External function func should have entry with value id FUNCID
 ; CHECK-NEXT:    <ENTRY {{.*}} op0=[[FUNCID]] {{.*}} record string = 'func'
 ; CHECK-NEXT:  </VALUE_SYMTAB>
 
 ; COMBINED:       <GLOBALVAL_SUMMARY_BLOCK
+; COMBINED-NEXT:    <VERSION
 ; COMBINED-NEXT:    <COMBINED
 ; See if the call to func is registered, using the expected callsite count
 ; and value id matching the subsequent value symbol table.
 ; COMBINED-NEXT:    <COMBINED {{.*}} op4=[[FUNCID:[0-9]+]] op5=1/>
 ; COMBINED-NEXT:  </GLOBALVAL_SUMMARY_BLOCK>
 ; COMBINED-NEXT:  <VALUE_SYMTAB
 ; Entry for function func should have entry with value id FUNCID
 ; COMBINED-NEXT:    <COMBINED_GVDEFENTRY {{.*}} op0=[[FUNCID]] {{.*}} op2=7289175272376759421/>

test/Bitcode/thinlto-function-summary-originalnames.ll

 ; Test to check the callgraph in summary
 ; RUN: opt -module-summary %s -o %t.o
 ; RUN: llvm-lto -thinlto-action=thinlink -o %t.index.bc %t.o
 ; RUN: llvm-bcanalyzer -dump %t.index.bc | FileCheck %s --check-prefix=COMBINED
 
 ; COMBINED:       <GLOBALVAL_SUMMARY_BLOCK
+; COMBINED-NEXT:    <VERSION
 ; COMBINED-NEXT:    <COMBINED
 ; COMBINED-NEXT:    <COMBINED_ORIGINAL_NAME op0=6699318081062747564/>
 ; COMBINED-NEXT:  </GLOBALVAL_SUMMARY_BLOCK>
 ; COMBINED-NEXT:  <VALUE_SYMTAB
 ; COMBINED-NEXT:    <COMBINED_GVDEFENTRY {{.*}} op2=-8709959634447057722/>
 ; COMBINED-NEXT:  </VALUE_SYMTAB>
 
 ; ModuleID = 'thinlto-function-summary-callgraph.ll'
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-unknown-linux-gnu"
 
 define internal void @foo() {
     ret void
 }
 No newline at end of file

test/Bitcode/thinlto-function-summary.ll

 ; RUN: opt -name-anon-functions -module-summary < %s | llvm-bcanalyzer -dump | FileCheck %s -check-prefix=BC
 ; Check for summary block/records.
 
 ; Check the value ids in the summary entries against the
 ; same in the ValueSumbolTable, to ensure the ordering is stable.
 ; Also check the linkage field on the summary entries.
 ; BC: <GLOBALVAL_SUMMARY_BLOCK
+; BC-NEXT: <VERSION
 ; BC-NEXT: <PERMODULE {{.*}} op0=1 op1=0
 ; BC-NEXT: <PERMODULE {{.*}} op0=2 op1=0
 ; BC-NEXT: <PERMODULE {{.*}} op0=3 op1=3
 ; BC-NEXT: <ALIAS {{.*}} op0=4 op1=0 op2=3
 ; BC-NEXT: </GLOBALVAL_SUMMARY_BLOCK
 ; BC-NEXT: <VALUE_SYMTAB
 ; BC-NEXT: <FNENTRY {{.*}} op0=3 {{.*}}> record string = 'anon.
 ; BC-NEXT: <FNENTRY {{.*}} op0=1 {{.*}}> record string = 'foo'

test/tools/llvm-lto/thinlto.ll

 ; Test combined function index generation for ThinLTO via llvm-lto.
 ; RUN: opt -module-summary %s -o %t.o
 ; RUN: opt -module-summary %p/Inputs/thinlto.ll -o %t2.o
 ; RUN: llvm-lto -thinlto -o %t3 %t.o %t2.o
 ; RUN: llvm-bcanalyzer -dump %t3.thinlto.bc | FileCheck %s --check-prefix=COMBINED
 ; RUN: not test -e %t3
 
 ; COMBINED: <MODULE_STRTAB_BLOCK
 ; COMBINED-NEXT: <ENTRY {{.*}} record string = '{{.*}}thinlto.ll.tmp{{.*}}.o'
 ; COMBINED-NEXT: <ENTRY {{.*}} record string = '{{.*}}thinlto.ll.tmp{{.*}}.o'
 ; COMBINED-NEXT: </MODULE_STRTAB_BLOCK
 ; COMBINED-NEXT: <GLOBALVAL_SUMMARY_BLOCK
+; COMBINED-NEXT: <VERSION
 ; COMBINED-NEXT: <COMBINED
 ; COMBINED-NEXT: <COMBINED
 ; COMBINED-NEXT: </GLOBALVAL_SUMMARY_BLOCK
 ; COMBINED-NEXT: <VALUE_SYMTAB
 ; Check that the format is: op0=valueid, op1=offset, op2=funcguid,
 ; where funcguid is the lower 64 bits of the function name MD5.
 ; COMBINED-NEXT: <COMBINED_GVDEFENTRY abbrevid={{[0-9]+}} op0={{1|2}} op1={{[0-9]+}} op2={{-3706093650706652785|-5300342847281564238}}
 ; COMBINED-NEXT: <COMBINED_GVDEFENTRY abbrevid={{[0-9]+}} op0={{1|2}} op1={{[0-9]+}} op2={{-3706093650706652785|-5300342847281564238}}
 ; COMBINED-NEXT: </VALUE_SYMTAB
 
 define void @f() {
 entry:
   ret void
 }

tools/llvm-bcanalyzer/llvm-bcanalyzer.cpp

default:
       STRINGIFY_CODE(FS, PERMODULE_PROFILE)
       STRINGIFY_CODE(FS, PERMODULE_GLOBALVAR_INIT_REFS)
       STRINGIFY_CODE(FS, COMBINED)
       STRINGIFY_CODE(FS, COMBINED_PROFILE)
       STRINGIFY_CODE(FS, COMBINED_GLOBALVAR_INIT_REFS)
       STRINGIFY_CODE(FS, ALIAS)
       STRINGIFY_CODE(FS, COMBINED_ALIAS)
       STRINGIFY_CODE(FS, COMBINED_ORIGINAL_NAME)
+      STRINGIFY_CODE(FS, VERSION)
     }
   case bitc::METADATA_ATTACHMENT_ID:
     switch(CodeID) {
     default:return nullptr;
       STRINGIFY_CODE(METADATA, ATTACHMENT)
     }
   case bitc::METADATA_BLOCK_ID:
     switch(CodeID) {