Modify DWARFFormValue to remember the DWARFUnit that it was decoded with.

Modifying DWARFFormValue to remember the DWARFUnit that it was encoded with can simplify the usage of instances of this class. Previously users would have to try and pass in the same DWARFUnit that was used to decode the form value and there was a possibility that a different DWARFUnit might be supplied to the functions that extract values (strings, CU relative references, addresses) and cause problems. This fixes this potential issue by storing the DWARFUnit inside the DWARFFormValue so that this mistake can't be made. Instances of DWARFFormValue are not stored permanently and are used as temporary values, so the increase in size of an instance of DWARFFormValue isn't a big deal. This makes decoding form values more bullet proof and is a change that will be used by future modifications.

https://reviews.llvm.org/D26052

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285594 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/DebugInfo/DWARF/DWARFFormValue.h b/include/llvm/DebugInfo/DWARF/DWARFFormValue.h
index 19efd933d726396601a6c12c436ccc3bd0308580..c3dc4691913192960c83ff8aa9225389a1275dda 100644 (file)
--- a/include/llvm/DebugInfo/DWARF/DWARFFormValue.h
+++ b/include/llvm/DebugInfo/DWARF/DWARFFormValue.h
@@ -49,15 +49,16 @@ private:
     const uint8_t* data;
   };
 
-  dwarf::Form Form;   // Form for this value.
+  dwarf::Form Form; // Form for this value.
   ValueType Value; // Contains all data for the form.
+  const DWARFUnit *U; // Remember the DWARFUnit at extract time.
 
 public:
-  DWARFFormValue(dwarf::Form F = dwarf::Form(0)) : Form(F) {}
+  DWARFFormValue(dwarf::Form F = dwarf::Form(0)) : Form(F), U(nullptr) {}
   dwarf::Form getForm() const { return Form; }
   bool isFormClass(FormClass FC) const;
-
-  void dump(raw_ostream &OS, const DWARFUnit *U) const;
+  const DWARFUnit *getUnit() const { return U; }
+  void dump(raw_ostream &OS) const;
 
   /// \brief extracts a value in data at offset *offset_ptr.
   ///
@@ -65,24 +66,24 @@ public:
   /// case no relocation processing will be performed and some
   /// kind of forms that depend on Unit information are disallowed.
   /// \returns whether the extraction succeeded.
-  bool extractValue(DataExtractor data, uint32_t *offset_ptr,
-                    const DWARFUnit *u);
+  bool extractValue(const DataExtractor &Data, uint32_t *OffsetPtr,
+                    const DWARFUnit *U);
   bool isInlinedCStr() const {
     return Value.data != nullptr && Value.data == (const uint8_t*)Value.cstr;
   }
 
   /// getAsFoo functions below return the extracted value as Foo if only
   /// DWARFFormValue has form class is suitable for representing Foo.
-  Optional<uint64_t> getAsReference(const DWARFUnit *U) const;
+  Optional<uint64_t> getAsReference() const;
   Optional<uint64_t> getAsUnsignedConstant() const;
   Optional<int64_t> getAsSignedConstant() const;
-  Optional<const char *> getAsCString(const DWARFUnit *U) const;
-  Optional<uint64_t> getAsAddress(const DWARFUnit *U) const;
+  Optional<const char *> getAsCString() const;
+  Optional<uint64_t> getAsAddress() const;
   Optional<uint64_t> getAsSectionOffset() const;
   Optional<ArrayRef<uint8_t>> getAsBlock() const;
 
   bool skipValue(DataExtractor debug_info_data, uint32_t *offset_ptr,
-                 const DWARFUnit *u) const;
+                 const DWARFUnit *U) const;
   static bool skipValue(dwarf::Form form, DataExtractor debug_info_data,
                         uint32_t *offset_ptr, const DWARFUnit *u);
   static bool skipValue(dwarf::Form form, DataExtractor debug_info_data,
@@ -92,7 +93,7 @@ public:
   static ArrayRef<uint8_t> getFixedFormSizes(uint8_t AddrSize,
                                              uint16_t Version);
 private:
-  void dumpString(raw_ostream &OS, const DWARFUnit *U) const;
+  void dumpString(raw_ostream &OS) const;
 };
 
 }

diff --git a/include/llvm/DebugInfo/DWARF/DWARFUnit.h b/include/llvm/DebugInfo/DWARF/DWARFUnit.h
index fc2875cb28f1cd621ed641c29a75351c6f25c9ad..f8ce95fbbeabffea1e00b2d8316181dbc8a5997a 100644 (file)
--- a/include/llvm/DebugInfo/DWARF/DWARFUnit.h
+++ b/include/llvm/DebugInfo/DWARF/DWARFUnit.h
@@ -195,6 +195,10 @@ public:
     return Abbrevs;
   }
   uint8_t getAddressByteSize() const { return AddrSize; }
+  uint8_t getRefAddrByteSize() const {
+    // FIXME: Support DWARF64.
+    return (Version == 2) ? AddrSize : 4;
+  }
   uint64_t getBaseAddress() const { return BaseAddr; }
 
   void setBaseAddress(uint64_t base_addr) {

diff --git a/lib/DebugInfo/DWARF/DWARFAcceleratorTable.cpp b/lib/DebugInfo/DWARF/DWARFAcceleratorTable.cpp
index cef4eab296bb0d8146861ba31828b27e8ec5406e..7111ad3f9fc7f5f6a04c356c5b2ed55950a72809 100644 (file)
--- a/lib/DebugInfo/DWARF/DWARFAcceleratorTable.cpp
+++ b/lib/DebugInfo/DWARF/DWARFAcceleratorTable.cpp
@@ -120,7 +120,7 @@ void DWARFAcceleratorTable::dump(raw_ostream &OS) const {
           for (auto &Atom : AtomForms) {
             OS << format("{Atom[%d]: ", i++);
             if (Atom.extractValue(AccelSection, &DataOffset, nullptr))
-              Atom.dump(OS, nullptr);
+              Atom.dump(OS);
             else
               OS << "Error extracting the value";
             OS << "} ";

diff --git a/lib/DebugInfo/DWARF/DWARFDebugInfoEntry.cpp b/lib/DebugInfo/DWARF/DWARFDebugInfoEntry.cpp
index 880fc5c3fa2007b7fdf2cb6988a7576cd9fd2c96..55378e59b3cb6469a2f757de98c88f2d41e94ccf 100644 (file)
--- a/lib/DebugInfo/DWARF/DWARFDebugInfoEntry.cpp
+++ b/lib/DebugInfo/DWARF/DWARFDebugInfoEntry.cpp
@@ -158,13 +158,13 @@ void DWARFDebugInfoEntryMinimal::dumpAttribute(raw_ostream &OS,
   else if (attr == DW_AT_decl_line || attr == DW_AT_call_line)
     OS << *formValue.getAsUnsignedConstant();
   else
-    formValue.dump(OS, u);
+    formValue.dump(OS);
 
   // We have dumped the attribute raw value. For some attributes
   // having both the raw value and the pretty-printed value is
   // interesting. These attributes are handled below.
   if (attr == DW_AT_specification || attr == DW_AT_abstract_origin) {
-    Optional<uint64_t> Ref = formValue.getAsReference(u);
+    Optional<uint64_t> Ref = formValue.getAsReference();
     if (Ref.hasValue()) {
       uint32_t RefOffset = Ref.getValue();
       DWARFDebugInfoEntryMinimal DIE;
@@ -264,7 +264,7 @@ const char *DWARFDebugInfoEntryMinimal::getAttributeValueAsString(
   DWARFFormValue FormValue;
   if (!getAttributeValue(U, Attr, FormValue))
     return FailValue;
-  Optional<const char *> Result = FormValue.getAsCString(U);
+  Optional<const char *> Result = FormValue.getAsCString();
   return Result.hasValue() ? Result.getValue() : FailValue;
 }
 
@@ -274,7 +274,7 @@ uint64_t DWARFDebugInfoEntryMinimal::getAttributeValueAsAddress(
   DWARFFormValue FormValue;
   if (!getAttributeValue(U, Attr, FormValue))
     return FailValue;
-  Optional<uint64_t> Result = FormValue.getAsAddress(U);
+  Optional<uint64_t> Result = FormValue.getAsAddress();
   return Result.hasValue() ? Result.getValue() : FailValue;
 }
 
@@ -294,7 +294,7 @@ uint64_t DWARFDebugInfoEntryMinimal::getAttributeValueAsReference(
   DWARFFormValue FormValue;
   if (!getAttributeValue(U, Attr, FormValue))
     return FailValue;
-  Optional<uint64_t> Result = FormValue.getAsReference(U);
+  Optional<uint64_t> Result = FormValue.getAsReference();
   return Result.hasValue() ? Result.getValue() : FailValue;
 }
 

diff --git a/lib/DebugInfo/DWARF/DWARFFormValue.cpp b/lib/DebugInfo/DWARF/DWARFFormValue.cpp
index a2d625a06de23b4609c58e909029e3bc26facf8a..5d9c118473a8a517fef65fd517838966f37d3754 100644 (file)
--- a/lib/DebugInfo/DWARF/DWARFFormValue.cpp
+++ b/lib/DebugInfo/DWARF/DWARFFormValue.cpp
@@ -133,8 +133,10 @@ bool DWARFFormValue::isFormClass(DWARFFormValue::FormClass FC) const {
          FC == FC_SectionOffset;
 }
 
-bool DWARFFormValue::extractValue(DataExtractor data, uint32_t *offset_ptr,
+bool DWARFFormValue::extractValue(const DataExtractor &data, 
+                                  uint32_t *offset_ptr,
                                   const DWARFUnit *cu) {
+  U = cu;
   bool indirect = false;
   bool is_block = false;
   Value.data = nullptr;
@@ -145,14 +147,14 @@ bool DWARFFormValue::extractValue(DataExtractor data, uint32_t *offset_ptr,
     switch (Form) {
     case DW_FORM_addr:
     case DW_FORM_ref_addr: {
-      if (!cu)
+      if (!U)
         return false;
       uint16_t AddrSize =
           (Form == DW_FORM_addr)
-              ? cu->getAddressByteSize()
-              : getRefAddrSize(cu->getAddressByteSize(), cu->getVersion());
-      RelocAddrMap::const_iterator AI = cu->getRelocMap()->find(*offset_ptr);
-      if (AI != cu->getRelocMap()->end()) {
+              ? U->getAddressByteSize()
+              : U->getRefAddrByteSize();
+      RelocAddrMap::const_iterator AI = U->getRelocMap()->find(*offset_ptr);
+      if (AI != U->getRelocMap()->end()) {
         const std::pair<uint8_t, int64_t> &R = AI->second;
         Value.uval = data.getUnsigned(offset_ptr, AddrSize) + R.second;
       } else
@@ -188,10 +190,10 @@ bool DWARFFormValue::extractValue(DataExtractor data, uint32_t *offset_ptr,
     case DW_FORM_data4:
     case DW_FORM_ref4: {
       Value.uval = data.getU32(offset_ptr);
-      if (!cu)
+      if (!U)
         break;
-      RelocAddrMap::const_iterator AI = cu->getRelocMap()->find(*offset_ptr-4);
-      if (AI != cu->getRelocMap()->end())
+      RelocAddrMap::const_iterator AI = U->getRelocMap()->find(*offset_ptr-4);
+      if (AI != U->getRelocMap()->end())
         Value.uval += AI->second.second;
       break;
     }
@@ -219,11 +221,11 @@ bool DWARFFormValue::extractValue(DataExtractor data, uint32_t *offset_ptr,
     case DW_FORM_GNU_strp_alt: {
       // FIXME: This is 64-bit for DWARF64.
       Value.uval = data.getU32(offset_ptr);
-      if (!cu)
+      if (!U)
         break;
       RelocAddrMap::const_iterator AI =
-          cu->getRelocMap()->find(*offset_ptr - 4);
-      if (AI != cu->getRelocMap()->end())
+          U->getRelocMap()->find(*offset_ptr - 4);
+      if (AI != U->getRelocMap()->end())
         Value.uval += AI->second.second;
       break;
     }
@@ -256,8 +258,8 @@ bool DWARFFormValue::extractValue(DataExtractor data, uint32_t *offset_ptr,
 
 bool
 DWARFFormValue::skipValue(DataExtractor debug_info_data, uint32_t* offset_ptr,
-                          const DWARFUnit *cu) const {
-  return DWARFFormValue::skipValue(Form, debug_info_data, offset_ptr, cu);
+                          const DWARFUnit *U) const {
+  return DWARFFormValue::skipValue(Form, debug_info_data, offset_ptr, U);
 }
 
 bool
@@ -371,7 +373,7 @@ DWARFFormValue::skipValue(dwarf::Form form, DataExtractor debug_info_data,
 }
 
 void
-DWARFFormValue::dump(raw_ostream &OS, const DWARFUnit *cu) const {
+DWARFFormValue::dump(raw_ostream &OS) const {
   uint64_t uvalue = Value.uval;
   bool cu_relative_offset = false;
 
@@ -380,7 +382,9 @@ DWARFFormValue::dump(raw_ostream &OS, const DWARFUnit *cu) const {
   case DW_FORM_GNU_addr_index: {
     OS << format(" indexed (%8.8x) address = ", (uint32_t)uvalue);
     uint64_t Address;
-    if (cu->getAddrOffsetSectionItem(uvalue, Address))
+    if (U == nullptr)
+      OS << "<invalid dwarf unit>";
+    else if (U->getAddrOffsetSectionItem(uvalue, Address))
       OS << format("0x%016" PRIx64, Address);
     else
       OS << "<no .debug_addr section>";
@@ -431,17 +435,17 @@ DWARFFormValue::dump(raw_ostream &OS, const DWARFUnit *cu) const {
   case DW_FORM_udata:     OS << Value.uval; break;
   case DW_FORM_strp: {
     OS << format(" .debug_str[0x%8.8x] = ", (uint32_t)uvalue);
-    dumpString(OS, cu);
+    dumpString(OS);
     break;
   }
   case DW_FORM_GNU_str_index: {
     OS << format(" indexed (%8.8x) string = ", (uint32_t)uvalue);
-    dumpString(OS, cu);
+    dumpString(OS);
     break;
   }
   case DW_FORM_GNU_strp_alt: {
     OS << format("alt indirect string, offset: 0x%" PRIx64 "", uvalue);
-    dumpString(OS, cu);
+    dumpString(OS);
     break;
   }
   case DW_FORM_ref_addr:
@@ -490,13 +494,13 @@ DWARFFormValue::dump(raw_ostream &OS, const DWARFUnit *cu) const {
   if (cu_relative_offset) {
     OS << " => {";
     WithColor(OS, syntax::Address).get()
-      << format("0x%8.8" PRIx64, uvalue + (cu ? cu->getOffset() : 0));
+      << format("0x%8.8" PRIx64, uvalue + (U ? U->getOffset() : 0));
     OS << "}";
   }
 }
 
-void DWARFFormValue::dumpString(raw_ostream &OS, const DWARFUnit *U) const {
-  Optional<const char *> DbgStr = getAsCString(U);
+void DWARFFormValue::dumpString(raw_ostream &OS) const {
+  Optional<const char *> DbgStr = getAsCString();
   if (DbgStr.hasValue()) {
     raw_ostream &COS = WithColor(OS, syntax::String);
     COS << '"';
@@ -505,7 +509,7 @@ void DWARFFormValue::dumpString(raw_ostream &OS, const DWARFUnit *U) const {
   }
 }
 
-Optional<const char *> DWARFFormValue::getAsCString(const DWARFUnit *U) const {
+Optional<const char *> DWARFFormValue::getAsCString() const {
   if (!isFormClass(FC_String))
     return None;
   if (Form == DW_FORM_string)
@@ -526,7 +530,7 @@ Optional<const char *> DWARFFormValue::getAsCString(const DWARFUnit *U) const {
   return None;
 }
 
-Optional<uint64_t> DWARFFormValue::getAsAddress(const DWARFUnit *U) const {
+Optional<uint64_t> DWARFFormValue::getAsAddress() const {
   if (!isFormClass(FC_Address))
     return None;
   if (Form == DW_FORM_GNU_addr_index) {
@@ -539,7 +543,7 @@ Optional<uint64_t> DWARFFormValue::getAsAddress(const DWARFUnit *U) const {
   return Value.uval;
 }
 
-Optional<uint64_t> DWARFFormValue::getAsReference(const DWARFUnit *U) const {
+Optional<uint64_t> DWARFFormValue::getAsReference() const {
   if (!isFormClass(FC_Reference))
     return None;
   switch (Form) {

diff --git a/lib/DebugInfo/DWARF/DWARFTypeUnit.cpp b/lib/DebugInfo/DWARF/DWARFTypeUnit.cpp
index 38ed3aeaaf3117f0248d9a9361bd995f2056be55..fa3f1d4d2b8d335ee59cf42fbda3b33032326eaa 100644 (file)
--- a/lib/DebugInfo/DWARF/DWARFTypeUnit.cpp
+++ b/lib/DebugInfo/DWARF/DWARFTypeUnit.cpp
@@ -30,7 +30,7 @@ void DWARFTypeUnit::dump(raw_ostream &OS, bool SummarizeTypes) {
   DWARFFormValue NameVal;
   const char *Name = "";
   if (TD->getAttributeValue(this, llvm::dwarf::DW_AT_name, NameVal))
-    if (auto ON = NameVal.getAsCString(this))
+    if (auto ON = NameVal.getAsCString())
       Name = *ON;
 
   if (SummarizeTypes) {

diff --git a/tools/dsymutil/DwarfLinker.cpp b/tools/dsymutil/DwarfLinker.cpp
index cb8bb7eeca837fa00607a176b2ab4e0aa6acafd1..778c76043ae48f43a5ae876437803961dc82c43b 100644 (file)
--- a/tools/dsymutil/DwarfLinker.cpp
+++ b/tools/dsymutil/DwarfLinker.cpp
@@ -1487,7 +1487,7 @@ static const DWARFDebugInfoEntryMinimal *resolveDIEReference(
     const DWARFFormValue &RefValue, const DWARFUnit &Unit,
     const DWARFDebugInfoEntryMinimal &DIE, CompileUnit *&RefCU) {
   assert(RefValue.isFormClass(DWARFFormValue::FC_Reference));
-  uint64_t RefOffset = *RefValue.getAsReference(&Unit);
+  uint64_t RefOffset = *RefValue.getAsReference();
 
   if ((RefCU = getUnitForOffset(Units, RefOffset)))
     if (const auto *RefDie = RefCU->getOrigUnit().getDIEForOffset(RefOffset))
@@ -1838,12 +1838,6 @@ static bool dieNeedsChildrenToBeMeaningful(uint32_t Tag) {
   llvm_unreachable("Invalid Tag");
 }
 
-static unsigned getRefAddrSize(const DWARFUnit &U) {
-  if (U.getVersion() == 2)
-    return U.getAddressByteSize();
-  return 4;
-}
-
 void DwarfLinker::startDebugObject(DWARFContext &Dwarf, DebugMapObject &Obj) {
   Units.reserve(Dwarf.getNumCompileUnits());
   // Iterate over the debug map entries and put all the ones that are
@@ -2159,7 +2153,7 @@ unsigned DwarfLinker::shouldKeepSubprogramDIE(
 
   uint64_t HighPc;
   if (HighPcValue.isFormClass(DWARFFormValue::FC_Address)) {
-    HighPc = *HighPcValue.getAsAddress(&OrigUnit);
+    HighPc = *HighPcValue.getAsAddress();
   } else {
     assert(HighPcValue.isFormClass(DWARFFormValue::FC_Constant));
     HighPc = LowPc + *HighPcValue.getAsUnsignedConstant();
@@ -2357,7 +2351,7 @@ unsigned DwarfLinker::DIECloner::cloneStringAttribute(DIE &Die,
                                                       const DWARFFormValue &Val,
                                                       const DWARFUnit &U) {
   // Switch everything to out of line strings.
-  const char *String = *Val.getAsCString(&U);
+  const char *String = *Val.getAsCString();
   unsigned Offset = Linker.StringPool.getStringOffset(String);
   Die.addValue(DIEAlloc, dwarf::Attribute(AttrSpec.Attr), dwarf::DW_FORM_strp,
                DIEInteger(Offset));
@@ -2369,7 +2363,7 @@ unsigned DwarfLinker::DIECloner::cloneDieReferenceAttribute(
     AttributeSpec AttrSpec, unsigned AttrSize, const DWARFFormValue &Val,
     CompileUnit &Unit) {
   const DWARFUnit &U = Unit.getOrigUnit();
-  uint32_t Ref = *Val.getAsReference(&U);
+  uint32_t Ref = *Val.getAsReference();
   DIE *NewRefDie = nullptr;
   CompileUnit *RefUnit = nullptr;
   DeclContext *Ctxt = nullptr;
@@ -2392,7 +2386,7 @@ unsigned DwarfLinker::DIECloner::cloneDieReferenceAttribute(
       DIEInteger Attr(Ctxt->getCanonicalDIEOffset());
       Die.addValue(DIEAlloc, dwarf::Attribute(AttrSpec.Attr),
                    dwarf::DW_FORM_ref_addr, Attr);
-      return getRefAddrSize(U);
+      return U.getRefAddrByteSize();
     }
   }
 
@@ -2427,7 +2421,7 @@ unsigned DwarfLinker::DIECloner::cloneDieReferenceAttribute(
           Die.addValue(DIEAlloc, dwarf::Attribute(AttrSpec.Attr),
                        dwarf::DW_FORM_ref_addr, DIEInteger(Attr)));
     }
-    return getRefAddrSize(U);
+    return U.getRefAddrByteSize();
   }
 
   Die.addValue(DIEAlloc, dwarf::Attribute(AttrSpec.Attr),
@@ -2481,7 +2475,7 @@ unsigned DwarfLinker::DIECloner::cloneBlockAttribute(DIE &Die,
 unsigned DwarfLinker::DIECloner::cloneAddressAttribute(
     DIE &Die, AttributeSpec AttrSpec, const DWARFFormValue &Val,
     const CompileUnit &Unit, AttributesInfo &Info) {
-  uint64_t Addr = *Val.getAsAddress(&Unit.getOrigUnit());
+  uint64_t Addr = *Val.getAsAddress();
   if (AttrSpec.Attr == dwarf::DW_AT_low_pc) {
     if (Die.getTag() == dwarf::DW_TAG_inlined_subroutine ||
         Die.getTag() == dwarf::DW_TAG_lexical_block)