Auto merge of #17259 - lnicola:sync-from-rust, r=lnicola

internal: Sync from downstream

1 files changed, 292 insertions, 0 deletions

diff --git a/compiler/rustc_llvm/llvm-wrapper/CoverageMappingWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/CoverageMappingWrapper.cpp
new file mode 100644
index 00000000000..e842f47f48c
--- /dev/null
+++ b/compiler/rustc_llvm/llvm-wrapper/CoverageMappingWrapper.cpp
@@ -0,0 +1,292 @@
+#include "LLVMWrapper.h"
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ProfileData/Coverage/CoverageMapping.h"
+#include "llvm/ProfileData/Coverage/CoverageMappingWriter.h"
+#include "llvm/ProfileData/InstrProf.h"
+
+using namespace llvm;
+
+// FFI equivalent of enum `llvm::coverage::Counter::CounterKind`
+// https://github.com/rust-lang/llvm-project/blob/ea6fa9c2/llvm/include/llvm/ProfileData/Coverage/CoverageMapping.h#L97-L99
+enum class LLVMRustCounterKind {
+  Zero = 0,
+  CounterValueReference = 1,
+  Expression = 2,
+};
+
+// FFI equivalent of struct `llvm::coverage::Counter`
+// https://github.com/rust-lang/llvm-project/blob/ea6fa9c2/llvm/include/llvm/ProfileData/Coverage/CoverageMapping.h#L94-L149
+struct LLVMRustCounter {
+  LLVMRustCounterKind CounterKind;
+  uint32_t ID;
+};
+
+static coverage::Counter fromRust(LLVMRustCounter Counter) {
+  switch (Counter.CounterKind) {
+  case LLVMRustCounterKind::Zero:
+    return coverage::Counter::getZero();
+  case LLVMRustCounterKind::CounterValueReference:
+    return coverage::Counter::getCounter(Counter.ID);
+  case LLVMRustCounterKind::Expression:
+    return coverage::Counter::getExpression(Counter.ID);
+  }
+  report_fatal_error("Bad LLVMRustCounterKind!");
+}
+
+// FFI equivalent of enum `llvm::coverage::CounterMappingRegion::RegionKind`
+// https://github.com/rust-lang/llvm-project/blob/ea6fa9c2/llvm/include/llvm/ProfileData/Coverage/CoverageMapping.h#L213-L234
+enum class LLVMRustCounterMappingRegionKind {
+  CodeRegion = 0,
+  ExpansionRegion = 1,
+  SkippedRegion = 2,
+  GapRegion = 3,
+  BranchRegion = 4,
+  MCDCDecisionRegion = 5,
+  MCDCBranchRegion = 6
+};
+
+static coverage::CounterMappingRegion::RegionKind
+fromRust(LLVMRustCounterMappingRegionKind Kind) {
+  switch (Kind) {
+  case LLVMRustCounterMappingRegionKind::CodeRegion:
+    return coverage::CounterMappingRegion::CodeRegion;
+  case LLVMRustCounterMappingRegionKind::ExpansionRegion:
+    return coverage::CounterMappingRegion::ExpansionRegion;
+  case LLVMRustCounterMappingRegionKind::SkippedRegion:
+    return coverage::CounterMappingRegion::SkippedRegion;
+  case LLVMRustCounterMappingRegionKind::GapRegion:
+    return coverage::CounterMappingRegion::GapRegion;
+  case LLVMRustCounterMappingRegionKind::BranchRegion:
+    return coverage::CounterMappingRegion::BranchRegion;
+#if LLVM_VERSION_GE(18, 0)
+  case LLVMRustCounterMappingRegionKind::MCDCDecisionRegion:
+    return coverage::CounterMappingRegion::MCDCDecisionRegion;
+  case LLVMRustCounterMappingRegionKind::MCDCBranchRegion:
+    return coverage::CounterMappingRegion::MCDCBranchRegion;
+#else
+  case LLVMRustCounterMappingRegionKind::MCDCDecisionRegion:
+    break;
+  case LLVMRustCounterMappingRegionKind::MCDCBranchRegion:
+    break;
+#endif
+  }
+  report_fatal_error("Bad LLVMRustCounterMappingRegionKind!");
+}
+
+enum LLVMRustMCDCParametersTag {
+  None = 0,
+  Decision = 1,
+  Branch = 2,
+};
+
+struct LLVMRustMCDCDecisionParameters {
+  uint32_t BitmapIdx;
+  uint16_t NumConditions;
+};
+
+struct LLVMRustMCDCBranchParameters {
+  int16_t ConditionID;
+  int16_t ConditionIDs[2];
+};
+
+struct LLVMRustMCDCParameters {
+  LLVMRustMCDCParametersTag Tag;
+  LLVMRustMCDCDecisionParameters DecisionParameters;
+  LLVMRustMCDCBranchParameters BranchParameters;
+};
+
+// LLVM representations for `MCDCParameters` evolved from LLVM 18 to 19.
+// Look at representations in 18
+// https://github.com/rust-lang/llvm-project/blob/66a2881a/llvm/include/llvm/ProfileData/Coverage/CoverageMapping.h#L253-L263
+// and representations in 19
+// https://github.com/llvm/llvm-project/blob/843cc474faefad1d639f4c44c1cf3ad7dbda76c8/llvm/include/llvm/ProfileData/Coverage/MCDCTypes.h
+#if LLVM_VERSION_GE(18, 0) && LLVM_VERSION_LT(19, 0)
+static coverage::CounterMappingRegion::MCDCParameters
+fromRust(LLVMRustMCDCParameters Params) {
+  auto parameter = coverage::CounterMappingRegion::MCDCParameters{};
+  switch (Params.Tag) {
+  case LLVMRustMCDCParametersTag::None:
+    return parameter;
+  case LLVMRustMCDCParametersTag::Decision:
+    parameter.BitmapIdx =
+        static_cast<unsigned>(Params.DecisionParameters.BitmapIdx),
+    parameter.NumConditions =
+        static_cast<unsigned>(Params.DecisionParameters.NumConditions);
+    return parameter;
+  case LLVMRustMCDCParametersTag::Branch:
+    parameter.ID = static_cast<coverage::CounterMappingRegion::MCDCConditionID>(
+        Params.BranchParameters.ConditionID),
+    parameter.FalseID =
+        static_cast<coverage::CounterMappingRegion::MCDCConditionID>(
+            Params.BranchParameters.ConditionIDs[0]),
+    parameter.TrueID =
+        static_cast<coverage::CounterMappingRegion::MCDCConditionID>(
+            Params.BranchParameters.ConditionIDs[1]);
+    return parameter;
+  }
+  report_fatal_error("Bad LLVMRustMCDCParametersTag!");
+}
+#elif LLVM_VERSION_GE(19, 0)
+static coverage::mcdc::Parameters fromRust(LLVMRustMCDCParameters Params) {
+  switch (Params.Tag) {
+  case LLVMRustMCDCParametersTag::None:
+    return std::monostate();
+  case LLVMRustMCDCParametersTag::Decision:
+    return coverage::mcdc::DecisionParameters(
+        Params.DecisionParameters.BitmapIdx,
+        Params.DecisionParameters.NumConditions);
+  case LLVMRustMCDCParametersTag::Branch:
+    return coverage::mcdc::BranchParameters(
+        static_cast<coverage::mcdc::ConditionID>(
+            Params.BranchParameters.ConditionID),
+        {static_cast<coverage::mcdc::ConditionID>(
+             Params.BranchParameters.ConditionIDs[0]),
+         static_cast<coverage::mcdc::ConditionID>(
+             Params.BranchParameters.ConditionIDs[1])});
+  }
+  report_fatal_error("Bad LLVMRustMCDCParametersTag!");
+}
+#endif
+
+// FFI equivalent of struct `llvm::coverage::CounterMappingRegion`
+// https://github.com/rust-lang/llvm-project/blob/ea6fa9c2/llvm/include/llvm/ProfileData/Coverage/CoverageMapping.h#L211-L304
+struct LLVMRustCounterMappingRegion {
+  LLVMRustCounter Count;
+  LLVMRustCounter FalseCount;
+  LLVMRustMCDCParameters MCDCParameters;
+  uint32_t FileID;
+  uint32_t ExpandedFileID;
+  uint32_t LineStart;
+  uint32_t ColumnStart;
+  uint32_t LineEnd;
+  uint32_t ColumnEnd;
+  LLVMRustCounterMappingRegionKind Kind;
+};
+
+// FFI equivalent of enum `llvm::coverage::CounterExpression::ExprKind`
+// https://github.com/rust-lang/llvm-project/blob/ea6fa9c2/llvm/include/llvm/ProfileData/Coverage/CoverageMapping.h#L154
+enum class LLVMRustCounterExprKind {
+  Subtract = 0,
+  Add = 1,
+};
+
+// FFI equivalent of struct `llvm::coverage::CounterExpression`
+// https://github.com/rust-lang/llvm-project/blob/ea6fa9c2/llvm/include/llvm/ProfileData/Coverage/CoverageMapping.h#L151-L160
+struct LLVMRustCounterExpression {
+  LLVMRustCounterExprKind Kind;
+  LLVMRustCounter LHS;
+  LLVMRustCounter RHS;
+};
+
+static coverage::CounterExpression::ExprKind
+fromRust(LLVMRustCounterExprKind Kind) {
+  switch (Kind) {
+  case LLVMRustCounterExprKind::Subtract:
+    return coverage::CounterExpression::Subtract;
+  case LLVMRustCounterExprKind::Add:
+    return coverage::CounterExpression::Add;
+  }
+  report_fatal_error("Bad LLVMRustCounterExprKind!");
+}
+
+extern "C" void LLVMRustCoverageWriteFilenamesSectionToBuffer(
+    const char *const Filenames[], size_t FilenamesLen, // String start pointers
+    const size_t *const Lengths, size_t LengthsLen,     // Corresponding lengths
+    RustStringRef BufferOut) {
+  if (FilenamesLen != LengthsLen) {
+    report_fatal_error(
+        "Mismatched lengths in LLVMRustCoverageWriteFilenamesSectionToBuffer");
+  }
+
+  SmallVector<std::string, 32> FilenameRefs;
+  FilenameRefs.reserve(FilenamesLen);
+  for (size_t i = 0; i < FilenamesLen; i++) {
+    FilenameRefs.emplace_back(Filenames[i], Lengths[i]);
+  }
+  auto FilenamesWriter = coverage::CoverageFilenamesSectionWriter(
+      ArrayRef<std::string>(FilenameRefs));
+  auto OS = RawRustStringOstream(BufferOut);
+  FilenamesWriter.write(OS);
+}
+
+extern "C" void LLVMRustCoverageWriteMappingToBuffer(
+    const unsigned *VirtualFileMappingIDs, unsigned NumVirtualFileMappingIDs,
+    const LLVMRustCounterExpression *RustExpressions, unsigned NumExpressions,
+    const LLVMRustCounterMappingRegion *RustMappingRegions,
+    unsigned NumMappingRegions, RustStringRef BufferOut) {
+  // Convert from FFI representation to LLVM representation.
+  SmallVector<coverage::CounterMappingRegion, 0> MappingRegions;
+  MappingRegions.reserve(NumMappingRegions);
+  for (const auto &Region : ArrayRef<LLVMRustCounterMappingRegion>(
+           RustMappingRegions, NumMappingRegions)) {
+    MappingRegions.emplace_back(
+        fromRust(Region.Count), fromRust(Region.FalseCount),
+#if LLVM_VERSION_GE(18, 0) && LLVM_VERSION_LT(19, 0)
+        // LLVM 19 may move this argument to last.
+        fromRust(Region.MCDCParameters),
+#endif
+        Region.FileID, Region.ExpandedFileID, // File IDs, then region info.
+        Region.LineStart, Region.ColumnStart, Region.LineEnd, Region.ColumnEnd,
+        fromRust(Region.Kind));
+  }
+
+  std::vector<coverage::CounterExpression> Expressions;
+  Expressions.reserve(NumExpressions);
+  for (const auto &Expression :
+       ArrayRef<LLVMRustCounterExpression>(RustExpressions, NumExpressions)) {
+    Expressions.emplace_back(fromRust(Expression.Kind),
+                             fromRust(Expression.LHS),
+                             fromRust(Expression.RHS));
+  }
+
+  auto CoverageMappingWriter = coverage::CoverageMappingWriter(
+      ArrayRef<unsigned>(VirtualFileMappingIDs, NumVirtualFileMappingIDs),
+      Expressions, MappingRegions);
+  auto OS = RawRustStringOstream(BufferOut);
+  CoverageMappingWriter.write(OS);
+}
+
+extern "C" LLVMValueRef
+LLVMRustCoverageCreatePGOFuncNameVar(LLVMValueRef F, const char *FuncName,
+                                     size_t FuncNameLen) {
+  auto FuncNameRef = StringRef(FuncName, FuncNameLen);
+  return wrap(createPGOFuncNameVar(*cast<Function>(unwrap(F)), FuncNameRef));
+}
+
+extern "C" uint64_t LLVMRustCoverageHashByteArray(const char *Bytes,
+                                                  size_t NumBytes) {
+  auto StrRef = StringRef(Bytes, NumBytes);
+  return IndexedInstrProf::ComputeHash(StrRef);
+}
+
+static void WriteSectionNameToString(LLVMModuleRef M, InstrProfSectKind SK,
+                                     RustStringRef Str) {
+  auto TargetTriple = Triple(unwrap(M)->getTargetTriple());
+  auto name = getInstrProfSectionName(SK, TargetTriple.getObjectFormat());
+  auto OS = RawRustStringOstream(Str);
+  OS << name;
+}
+
+extern "C" void LLVMRustCoverageWriteMapSectionNameToString(LLVMModuleRef M,
+                                                            RustStringRef Str) {
+  WriteSectionNameToString(M, IPSK_covmap, Str);
+}
+
+extern "C" void
+LLVMRustCoverageWriteFuncSectionNameToString(LLVMModuleRef M,
+                                             RustStringRef Str) {
+  WriteSectionNameToString(M, IPSK_covfun, Str);
+}
+
+extern "C" void LLVMRustCoverageWriteMappingVarNameToString(RustStringRef Str) {
+  auto name = getCoverageMappingVarName();
+  auto OS = RawRustStringOstream(Str);
+  OS << name;
+}
+
+extern "C" uint32_t LLVMRustCoverageMappingVersion() {
+  // This should always be `CurrentVersion`, because that's the version LLVM
+  // will use when encoding the data we give it. If for some reason we ever
+  // want to override the version number we _emit_, do it on the Rust side.
+  return coverage::CovMapVersion::CurrentVersion;
+}