[SPIRV] Encode CodeView checksum information in SPIR-V (KhronosGroup#936

)

* [SPIRV] Encode CodeView checksum information in SPIR-V

This is a workaround to keep CodeView checksum information throughout the
translation. The idea is to store checksum kind and value to Ops[TextIdx]
and then parse this string while creating DIFile.

lib/SPIRV/LLVMToSPIRVDbgTran.cpp

@@ -939,7 +939,15 @@ SPIRVExtInst *LLVMToSPIRVDbgTran::getSource(const T *DIEntry) {
   using namespace SPIRVDebug::Operand::Source;
   SPIRVWordVec Ops(OperandCount);
   Ops[FileIdx] = BM->getString(FileName)->getId();
-  Ops[TextIdx] = getDebugInfoNone()->getId();
+  DIFile *F = DIEntry ? DIEntry->getFile() : nullptr;
+  if (F && F->getRawChecksum()) {
+    const auto &CheckSum = F->getChecksum().getValue();
+    Ops[TextIdx] = BM->getString("//__" + CheckSum.getKindAsString().str() +
+                                 ":" + CheckSum.Value.str())
+                       ->getId();
+  } else {
+    Ops[TextIdx] = getDebugInfoNone()->getId();
+  }
   SPIRVExtInst *Source = static_cast<SPIRVExtInst *>(
       BM->addDebugInfo(SPIRVDebug::Source, getVoidTy(), Ops));
   FileMap[FileName] = Source;

lib/SPIRV/SPIRVToLLVMDbgTran.cpp

@@ -46,6 +46,7 @@
 
 #include "llvm/IR/DIBuilder.h"
 #include "llvm/IR/Module.h"
+#include "llvm/ADT/StringExtras.h"
 
 using namespace std;
 using namespace SPIRVDebug::Operand;
@@ -65,11 +66,13 @@ void SPIRVToLLVMDbgTran::addDbgInfoVersion() {
                    DEBUG_METADATA_VERSION);
 }
 
-DIFile *SPIRVToLLVMDbgTran::getDIFile(const string &FileName) {
+DIFile *
+SPIRVToLLVMDbgTran::getDIFile(const std::string &FileName,
+                              Optional<DIFile::ChecksumInfo<StringRef>> CS) {
   return getOrInsert(FileMap, FileName, [=]() {
     SplitFileName Split(FileName);
     if (!Split.BaseName.empty())
-      return Builder.createFile(Split.BaseName, Split.Path);
+      return Builder.createFile(Split.BaseName, Split.Path, CS);
     return static_cast<DIFile *>(nullptr);
   });
 }
@@ -987,7 +990,8 @@ DIFile *SPIRVToLLVMDbgTran::getFile(const SPIRVId SourceId) {
          "DebugSource instruction is expected");
   SPIRVWordVec SourceArgs = Source->getArguments();
   assert(SourceArgs.size() == OperandCount && "Invalid number of operands");
-  return getDIFile(getString(SourceArgs[FileIdx]));
+  StringRef Checksum(getString(SourceArgs[TextIdx]));
+  return getDIFile(getString(SourceArgs[FileIdx]), ParseChecksum(Checksum));
 }
 
 SPIRVToLLVMDbgTran::SplitFileName::SplitFileName(const string &FileName) {
@@ -1011,4 +1015,23 @@ std::string SPIRVToLLVMDbgTran::findModuleProducer() {
   return "spirv";
 }
 
+Optional<DIFile::ChecksumInfo<StringRef>>
+SPIRVToLLVMDbgTran::ParseChecksum(StringRef Text) {
+  // Example of "Text" variable:
+  // "SomeInfo//__CSK_MD5:7bb56387968a9caa6e9e35fff94eaf7b:OtherInfo"
+  Optional<DIFile::ChecksumInfo<StringRef>> CS;
+  auto KindPos = Text.find(SPIRVDebug::ChecksumKindPrefx);
+  if (KindPos != StringRef::npos) {
+    auto ColonPos = Text.find(":", KindPos);
+    KindPos += string("//__").size();
+    auto KindStr = Text.substr(KindPos, ColonPos - KindPos);
+    auto Checksum = Text.substr(ColonPos).ltrim(':');
+    if (auto Kind = DIFile::getChecksumKind(KindStr)) {
+      size_t ChecksumEndPos = Checksum.find_if_not(llvm::isHexDigit);
+      CS.emplace(Kind.getValue(), Checksum.substr(0, ChecksumEndPos));
+    }
+  }
+  return CS;
+}
+
 } // namespace SPIRV

lib/SPIRV/SPIRVToLLVMDbgTran.h

@@ -85,7 +85,8 @@ class SPIRVToLLVMDbgTran {
 
 private:
   DIFile *getFile(const SPIRVId SourceId);
-  DIFile *getDIFile(const std::string &FileName);
+  DIFile *getDIFile(const std::string &FileName,
+                    Optional<DIFile::ChecksumInfo<StringRef>> CS = None);
   DIFile *getDIFile(const SPIRVEntry *E);
   unsigned getLineNo(const SPIRVEntry *E);
 
@@ -173,6 +174,7 @@ class SPIRVToLLVMDbgTran {
   }
   const std::string &getString(const SPIRVId Id);
   std::string findModuleProducer();
+  Optional<DIFile::ChecksumInfo<StringRef>> ParseChecksum(StringRef Text);
 };
 } // namespace SPIRV
 

lib/SPIRV/libSPIRV/SPIRV.debug.h

@@ -7,6 +7,7 @@ namespace SPIRVDebug {
 
 const unsigned int DebugInfoVersion = 0x00010000;
 static const std::string ProducerPrefix = {"Debug info producer: "};
+static const std::string ChecksumKindPrefx = {"//__CSK_"};
 
 // clang-format off
 

test/DebugInfo/DebugInfoChecksum.ll

@@ -0,0 +1,63 @@
+; Test checks debug info of Checksumkind & Checksum is preserved from LLVM IR to
+; SPIR-V and SPIR-V to LLVM IR translation.
+
+; Original .cpp source:
+;
+;  int main() {
+;    return 0;
+;  }
+
+; Command line:
+; ./clang -cc1 -debug-info-kind=standalone -S -emit-llvm -triple spir -gcodeview -gcodeview-ghash main.cpp
+
+; RUN: llvm-as %s -o %t.bc
+; RUN: llvm-spirv %t.bc -spirv-text -o - | FileCheck %s --check-prefix CHECK-SPIRV
+; RUN: llvm-spirv %t.bc -o %t.spv
+; RUN: llvm-spirv -r %t.spv -o %t.rev.bc
+; RUN: llvm-dis %t.rev.bc -o %t.rev.ll
+; RUN: FileCheck %s --input-file %t.rev.ll --check-prefix CHECK-LLVM
+
+; ModuleID = 'source.bc'
+source_filename = "main.cpp"
+target datalayout = "e-p:32:32-i64:64-v16:16-v24:32-v32:32-v48:64-v96:128-v192:256-v256:256-v512:512-v1024:1024-n8:16:32:64"
+target triple = "spir"
+
+; Function Attrs: noinline norecurse nounwind optnone
+define i32 @main() #0 !dbg !10 {
+entry:
+  %retval = alloca i32, align 4
+  store i32 0, i32* %retval, align 4
+  ret i32 0, !dbg !15
+}
+
+attributes #0 = { noinline norecurse nounwind optnone "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="none" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5, !6, !7, !8}
+!opencl.used.extensions = !{!2}
+!opencl.used.optional.core.features = !{!2}
+!opencl.compiler.options = !{!2}
+!llvm.ident = !{!9}
+
+; CHECK-LLVM: !DIFile(filename: "main.cpp"
+; CHECK-LLVM-SAME: checksumkind: CSK_MD5, checksum: "7bb56387968a9caa6e9e35fff94eaf7b"
+; CHECK-SPIRV: String [[#REG:]] "//__CSK_MD5:7bb56387968a9caa6e9e35fff94eaf7b"
+; CHECK-SPIRV: DebugSource
+; CHECK-SPIRV-SAME: [[#REG]]
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "clang version 13.0.0 (https://github.com/llvm/llvm-project.git 7d09e1d7cf27ce781e83f9d388a7a3e1e6487ead)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
+!1 = !DIFile(filename: "<stdin>", directory: "oneAPI", checksumkind: CSK_MD5, checksum: "7bb56387968a9caa6e9e35fff94eaf7b")
+!2 = !{}
+!3 = !{i32 2, !"CodeView", i32 1}
+!4 = !{i32 2, !"CodeViewGHash", i32 1}
+!5 = !{i32 2, !"Debug Info Version", i32 3}
+!6 = !{i32 1, !"wchar_size", i32 4}
+!7 = !{i32 1, !"ThinLTO", i32 0}
+!8 = !{i32 1, !"EnableSplitLTOUnit", i32 1}
+!9 = !{!"clang version 13.0.0 (https://github.com/llvm/llvm-project.git 7d09e1d7cf27ce781e83f9d388a7a3e1e6487ead)"}
+!10 = distinct !DISubprogram(name: "main", scope: !11, file: !11, line: 1, type: !12, scopeLine: 1, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !2)
+!11 = !DIFile(filename: "main.cpp", directory: "C:\\", checksumkind: CSK_MD5, checksum: "7bb56387968a9caa6e9e35fff94eaf7b")
+!12 = !DISubroutineType(types: !13)
+!13 = !{!14}
+!14 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!15 = !DILocation(line: 2, column: 3, scope: !10)