[DWARF] Modification of code for the verification of .debug_info section.

Summary:
This patch modifies the handleDebugInfo() function so that we verify the contents of each unit
in the .debug_info section only if its header has been successfully verified.

This change will allow for more/different verification checks depending on the type of the unit since from
dwarf5, the .debug_info section may consist of different types of units.

Subscribers: aprantl

Differential Revision: https://reviews.llvm.org/D35521

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@308245 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 17 insertions, 13 deletions

diff --git a/include/llvm/DebugInfo/DWARF/DWARFVerifier.h b/include/llvm/DebugInfo/DWARF/DWARFVerifier.h
index d9e0e3aaa65e..c0291a83ed97 100644
--- a/include/llvm/DebugInfo/DWARF/DWARFVerifier.h
+++ b/include/llvm/DebugInfo/DWARF/DWARFVerifier.h
@@ -31,7 +31,6 @@ class DWARFVerifier {
   /// can verify each reference points to a valid DIE and not an offset that
   /// lies between to valid DIEs.
   std::map<uint64_t, std::set<uint32_t>> ReferenceToDIEOffsets;
-  uint32_t NumDebugInfoErrors = 0;
   uint32_t NumDebugLineErrors = 0;
   uint32_t NumAppleNamesErrors = 0;
 
@@ -50,14 +49,17 @@ class DWARFVerifier {
   /// \param Offset A reference to the offset start of the unit. The offset will
   /// be updated to point to the next unit in .debug_info
   /// \param UnitIndex The index of the unit to be verified
+  /// \param UnitType A reference to the type of the unit
   /// \param isUnitDWARF64 A reference to a flag that shows whether the unit is
   /// in 64-bit format.
   ///
   /// \returns true if the header is verified successfully, false otherwise.
   bool verifyUnitHeader(const DWARFDataExtractor DebugInfoData,
-                        uint32_t *Offset, unsigned UnitIndex,
+                        uint32_t *Offset, unsigned UnitIndex, uint8_t &UnitType,
                         bool &isUnitDWARF64);
 
+
+  bool verifyUnitContents(DWARFUnit Unit);
   /// Verifies the attribute's DWARF attribute and its value.
   ///
   /// This function currently checks for:
@@ -66,7 +68,11 @@ class DWARFVerifier {
   ///
   /// \param Die          The DWARF DIE that owns the attribute value
   /// \param AttrValue    The DWARF attribute value to check
-  void verifyDebugInfoAttribute(const DWARFDie &Die, DWARFAttribute &AttrValue);
+  ///
+  /// \returns NumErrors The number of errors occured during verification of
+  /// attributes' values in a .debug_info section unit
+  unsigned verifyDebugInfoAttribute(const DWARFDie &Die,
+                                    DWARFAttribute &AttrValue);
 
   /// Verifies the attribute's DWARF form.
   ///
@@ -77,7 +83,10 @@ class DWARFVerifier {
   ///
   /// \param Die          The DWARF DIE that owns the attribute value
   /// \param AttrValue    The DWARF attribute value to check
-  void verifyDebugInfoForm(const DWARFDie &Die, DWARFAttribute &AttrValue);
+  ///
+  /// \returns NumErrors The number of errors occured during verification of
+  /// attributes' forms in a .debug_info section unit
+  unsigned verifyDebugInfoForm(const DWARFDie &Die, DWARFAttribute &AttrValue);
 
   /// Verifies the all valid references that were found when iterating through
   /// all of the DIE attributes.
@@ -86,7 +95,10 @@ class DWARFVerifier {
   /// offset matches. This helps to ensure if a DWARF link phase moved things
   /// around, that it doesn't create invalid references by failing to relocate
   /// CU relative and absolute references.
-  void verifyDebugInfoReferences();
+  ///
+  /// \returns NumErrors The number of errors occured during verification of
+  /// references for the .debug_info section
+  unsigned verifyDebugInfoReferences();
 
   /// Verify the the DW_AT_stmt_list encoding and value and ensure that no
   /// compile units that have the same DW_AT_stmt_list value.
@@ -102,14 +114,6 @@ class DWARFVerifier {
 public:
   DWARFVerifier(raw_ostream &S, DWARFContext &D)
       : OS(S), DCtx(D) {}
-  /// Verify the unit header chain in the .debug_info section.
-  ///
-  /// Any errors are reported to the stream that this object was
-  /// constructed with.
-  ///
-  /// \returns true if the unit header chain verifies successfully, false
-  /// otherwise.
-  bool handleDebugInfoUnitHeaderChain();
   /// Verify the information in the .debug_info section.
   ///
   /// Any errors are reported to the stream that was this object was