DWARF: Unify form size handling code

Summary:
This patch replaces the two switches which are deducing the size of
various forms with a single implementation. I have put the new
implementation into BinaryFormat, to avoid introducing dependencies
between the two independent libraries (DebugInfo and CodeGen) that need
this functionality.

Reviewers: aprantl, JDevlieghere, dblaikie

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D44418

llvm-svn: 327486

5 files changed, 14 insertions, 104 deletions

diff --git a/llvm/lib/DebugInfo/DWARF/DWARFAbbreviationDeclaration.cpp b/llvm/lib/DebugInfo/DWARF/DWARFAbbreviationDeclaration.cpp
index f593953c62f..688a85c9da3 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFAbbreviationDeclaration.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFAbbreviationDeclaration.cpp
@@ -96,8 +96,7 @@ DWARFAbbreviationDeclaration::extract(DataExtractor Data,
       default:
         // The form has a byte size that doesn't depend on Params.
         // If it's a fixed size, keep track of it.
-        if ((ByteSize =
-                 DWARFFormValue::getFixedByteSize(F, DWARFFormParams()))) {
+        if ((ByteSize = dwarf::getFixedFormByteSize(F, dwarf::FormParams()))) {
           if (FixedAttributeSize)
             FixedAttributeSize->NumBytes += *ByteSize;
           break;
@@ -217,8 +216,7 @@ Optional<int64_t> DWARFAbbreviationDeclaration::AttributeSpec::getByteSize(
   if (ByteSize.HasByteSize)
     return ByteSize.ByteSize;
   Optional<int64_t> S;
-  auto FixedByteSize =
-      DWARFFormValue::getFixedByteSize(Form, U.getFormParams());
+  auto FixedByteSize = dwarf::getFixedFormByteSize(Form, U.getFormParams());
   if (FixedByteSize)
     S = *FixedByteSize;
   return S;
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFAcceleratorTable.cpp b/llvm/lib/DebugInfo/DWARF/DWARFAcceleratorTable.cpp
index 4771d213741..2bde3d6d034 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFAcceleratorTable.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFAcceleratorTable.cpp
@@ -130,7 +130,7 @@ std::pair<uint32_t, dwarf::Tag>
 AppleAcceleratorTable::readAtoms(uint32_t &HashDataOffset) {
   uint32_t DieOffset = dwarf::DW_INVALID_OFFSET;
   dwarf::Tag DieTag = dwarf::DW_TAG_null;
-  DWARFFormParams FormParams = {Hdr.Version, 0, dwarf::DwarfFormat::DWARF32};
+  dwarf::FormParams FormParams = {Hdr.Version, 0, dwarf::DwarfFormat::DWARF32};
 
   for (auto Atom : getAtomsDesc()) {
     DWARFFormValue FormValue(Atom.second);
@@ -179,7 +179,7 @@ Optional<uint64_t> AppleAcceleratorTable::HeaderData::extractOffset(
 bool AppleAcceleratorTable::dumpName(ScopedPrinter &W,
                                      SmallVectorImpl<DWARFFormValue> &AtomForms,
                                      uint32_t *DataOffset) const {
-  DWARFFormParams FormParams = {Hdr.Version, 0, dwarf::DwarfFormat::DWARF32};
+  dwarf::FormParams FormParams = {Hdr.Version, 0, dwarf::DwarfFormat::DWARF32};
   uint32_t NameOffset = *DataOffset;
   if (!AccelSection.isValidOffsetForDataOfSize(*DataOffset, 4)) {
     W.printString("Incorrectly terminated list.");
@@ -276,8 +276,8 @@ AppleAcceleratorTable::Entry::Entry(
 void AppleAcceleratorTable::Entry::extract(
     const AppleAcceleratorTable &AccelTable, uint32_t *Offset) {
 
-  DWARFFormParams FormParams = {AccelTable.Hdr.Version, 0,
-                                dwarf::DwarfFormat::DWARF32};
+  dwarf::FormParams FormParams = {AccelTable.Hdr.Version, 0,
+                                  dwarf::DwarfFormat::DWARF32};
   for (auto &Atom : Values)
     Atom.extractValue(AccelTable.AccelSection, Offset, FormParams);
 }
@@ -634,7 +634,7 @@ DWARFDebugNames::NameIndex::getEntry(uint32_t *Offset) const {
 
   Entry E(*this, *AbbrevIt);
 
-  DWARFFormParams FormParams = {Hdr.Version, 0, dwarf::DwarfFormat::DWARF32};
+  dwarf::FormParams FormParams = {Hdr.Version, 0, dwarf::DwarfFormat::DWARF32};
   for (auto &Value : E.Values) {
     if (!Value.extractValue(AS, Offset, FormParams))
       return make_error<StringError>("Error extracting index attribute values",
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFDebugLine.cpp b/llvm/lib/DebugInfo/DWARF/DWARFDebugLine.cpp
index c91b95cbc11..69a6e7f4a94 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFDebugLine.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFDebugLine.cpp
@@ -70,7 +70,7 @@ void DWARFDebugLine::Prologue::clear() {
   SegSelectorSize = 0;
   MinInstLength = MaxOpsPerInst = DefaultIsStmt = LineBase = LineRange = 0;
   OpcodeBase = 0;
-  FormParams = DWARFFormParams({0, 0, DWARF32});
+  FormParams = dwarf::FormParams({0, 0, DWARF32});
   ContentTypes = ContentTypeTracker();
   StandardOpcodeLengths.clear();
   IncludeDirectories.clear();
@@ -194,8 +194,8 @@ parseV5EntryFormat(const DWARFDataExtractor &DebugLineData, uint32_t
 static bool
 parseV5DirFileTables(const DWARFDataExtractor &DebugLineData,
                      uint32_t *OffsetPtr, uint64_t EndPrologueOffset,
-                     const DWARFFormParams &FormParams, const DWARFContext
-                     &Ctx, const DWARFUnit *U,
+                     const dwarf::FormParams &FormParams,
+                     const DWARFContext &Ctx, const DWARFUnit *U,
                      DWARFDebugLine::ContentTypeTracker &ContentTypes,
                      std::vector<DWARFFormValue> &IncludeDirectories,
                      std::vector<DWARFDebugLine::FileNameEntry> &FileNames) {
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFFormValue.cpp b/llvm/lib/DebugInfo/DWARF/DWARFFormValue.cpp
index ff3f880cdbb..b3ecf8e2dab 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFFormValue.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFFormValue.cpp
@@ -78,97 +78,9 @@ static const DWARFFormValue::FormClass DWARF5FormClasses[] = {
 
 };
 
-Optional<uint8_t>
-DWARFFormValue::getFixedByteSize(dwarf::Form Form,
-                                 const DWARFFormParams Params) {
-  switch (Form) {
-  case DW_FORM_addr:
-    if (Params)
-      return Params.AddrSize;
-    return None;
-
-  case DW_FORM_block:          // ULEB128 length L followed by L bytes.
-  case DW_FORM_block1:         // 1 byte length L followed by L bytes.
-  case DW_FORM_block2:         // 2 byte length L followed by L bytes.
-  case DW_FORM_block4:         // 4 byte length L followed by L bytes.
-  case DW_FORM_string:         // C-string with null terminator.
-  case DW_FORM_sdata:          // SLEB128.
-  case DW_FORM_udata:          // ULEB128.
-  case DW_FORM_ref_udata:      // ULEB128.
-  case DW_FORM_indirect:       // ULEB128.
-  case DW_FORM_exprloc:        // ULEB128 length L followed by L bytes.
-  case DW_FORM_strx:           // ULEB128.
-  case DW_FORM_addrx:          // ULEB128.
-  case DW_FORM_loclistx:       // ULEB128.
-  case DW_FORM_rnglistx:       // ULEB128.
-  case DW_FORM_GNU_addr_index: // ULEB128.
-  case DW_FORM_GNU_str_index:  // ULEB128.
-    return None;
-
-  case DW_FORM_ref_addr:
-    if (Params)
-      return Params.getRefAddrByteSize();
-    return None;
-
-  case DW_FORM_flag:
-  case DW_FORM_data1:
-  case DW_FORM_ref1:
-  case DW_FORM_strx1:
-  case DW_FORM_addrx1:
-    return 1;
-
-  case DW_FORM_data2:
-  case DW_FORM_ref2:
-  case DW_FORM_strx2:
-  case DW_FORM_addrx2:
-    return 2;
-
-  case DW_FORM_strx3:
-    return 3;
-
-  case DW_FORM_data4:
-  case DW_FORM_ref4:
-  case DW_FORM_ref_sup4:
-  case DW_FORM_strx4:
-  case DW_FORM_addrx4:
-    return 4;
-
-  case DW_FORM_strp:
-  case DW_FORM_GNU_ref_alt:
-  case DW_FORM_GNU_strp_alt:
-  case DW_FORM_line_strp:
-  case DW_FORM_sec_offset:
-  case DW_FORM_strp_sup:
-    if (Params)
-      return Params.getDwarfOffsetByteSize();
-    return None;
-
-  case DW_FORM_data8:
-  case DW_FORM_ref8:
-  case DW_FORM_ref_sig8:
-  case DW_FORM_ref_sup8:
-    return 8;
-
-  case DW_FORM_flag_present:
-    return 0;
-
-  case DW_FORM_data16:
-    return 16;
-
-  case DW_FORM_implicit_const:
-    // The implicit value is stored in the abbreviation as a SLEB128, and
-    // there no data in debug info.
-    return 0;
-
-  default:
-    break;
-  }
-  return None;
-}
-
 bool DWARFFormValue::skipValue(dwarf::Form Form, DataExtractor DebugInfoData,
                                uint32_t *OffsetPtr,
-                               const DWARFFormParams Params) {
+                               const dwarf::FormParams Params) {
   bool Indirect = false;
   do {
     switch (Form) {
@@ -230,7 +142,7 @@ bool DWARFFormValue::skipValue(dwarf::Form Form, DataExtractor DebugInfoData,
     case DW_FORM_GNU_ref_alt:
     case DW_FORM_GNU_strp_alt:
       if (Optional<uint8_t> FixedSize =
-              DWARFFormValue::getFixedByteSize(Form, Params)) {
+              dwarf::getFixedFormByteSize(Form, Params)) {
         *OffsetPtr += *FixedSize;
         return true;
       }
@@ -291,7 +203,7 @@ bool DWARFFormValue::isFormClass(DWARFFormValue::FormClass FC) const {
 }
 
 bool DWARFFormValue::extractValue(const DWARFDataExtractor &Data,
-                                  uint32_t *OffsetPtr, DWARFFormParams FP,
+                                  uint32_t *OffsetPtr, dwarf::FormParams FP,
                                   const DWARFContext *Ctx,
                                   const DWARFUnit *CU) {
   if (!Ctx && CU)
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp b/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
index e24ef90dd52..f85c0946f8d 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
@@ -158,7 +158,7 @@ void DWARFUnit::clear() {
   Offset = 0;
   Length = 0;
   Abbrevs = nullptr;
-  FormParams = DWARFFormParams({0, 0, DWARF32});
+  FormParams = dwarf::FormParams({0, 0, DWARF32});
   BaseAddr.reset();
   RangeSectionBase = 0;
   AddrOffsetSectionBase = 0;