Fix record layout when synthesizing class types.

Prior to this patch, we would try to synthesize class types by
iterating over a DenseMap of FieldDecls and adding each one to
a CXXRecordDecl.  Since a DenseMap doesn't provide a deterministic
ordering of the elements, this would not add the fields in
FieldOffset order, but rather in some random order determined by
the memory layout of the DenseMap.

This patch fixes the issue by changing DenseMaps to vectors.  The
ability to lookup a value in the DenseMap was hardly being used,
and where it is sufficient to do a vector lookup.

Differential Revision: http://reviews.llvm.org/D8512

llvm-svn: 233090

1 files changed, 42 insertions, 53 deletions

diff --git a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
index 3323bded4f4..6984c86afd7 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
@@ -2073,8 +2073,9 @@ SymbolFileDWARF::ParseChildMembers
                                                                                                                              GetClangASTContext().GetBuiltinTypeForEncodingAndBitSize(eEncodingSint, word_width),
                                                                                                                              accessibility,
                                                                                                                              anon_field_info.bit_size);
-                                            
-                                            layout_info.field_offsets.insert(std::make_pair(unnamed_bitfield_decl, anon_field_info.bit_offset));
+
+                                            layout_info.field_offsets.push_back(
+                                                std::make_pair(unnamed_bitfield_decl, anon_field_info.bit_offset));
                                         }
                                     }
                                     last_field_info = this_field_info;
@@ -2124,9 +2125,8 @@ SymbolFileDWARF::ParseChildMembers
                                                                                     bit_size);
                                 
                                 GetClangASTContext().SetMetadataAsUserID (field_decl, MakeUserID(die->GetOffset()));
-                                
-                                layout_info.field_offsets.insert(std::make_pair(field_decl, field_bit_offset));
 
+                                layout_info.field_offsets.push_back(std::make_pair(field_decl, field_bit_offset));
                             }
                             else
                             {
@@ -2287,8 +2287,9 @@ SymbolFileDWARF::ParseChildMembers
                         }
                         else
                         {
-                            layout_info.base_offsets.insert(std::make_pair(base_class_clang_type.GetAsCXXRecordDecl(),
-                                                                           clang::CharUnits::fromQuantity(member_byte_offset)));
+                            layout_info.base_offsets.push_back(
+                                std::make_pair(base_class_clang_type.GetAsCXXRecordDecl(),
+                                               clang::CharUnits::fromQuantity(member_byte_offset)));
                         }
                     }
                 }
@@ -2669,43 +2670,36 @@ SymbolFileDWARF::ResolveClangOpaqueTypeDefinition (ClangASTType &clang_type)
                                                                   static_cast<uint32_t>(layout_info.base_offsets.size()),
                                                                   static_cast<uint32_t>(layout_info.vbase_offsets.size()));
 
-                        uint32_t idx;
-                        {
-                        llvm::DenseMap <const clang::FieldDecl *, uint64_t>::const_iterator pos, end = layout_info.field_offsets.end();
-                        for (idx = 0, pos = layout_info.field_offsets.begin(); pos != end; ++pos, ++idx)
+                        for (const auto &entry : layout_info.field_offsets)
                         {
-                            GetObjectFile()->GetModule()->LogMessage (log,
-                                                                      "SymbolFileDWARF::ResolveClangOpaqueTypeDefinition (clang_type = %p) field[%u] = { bit_offset=%u, name='%s' }",
-                                                                      static_cast<void*>(clang_type.GetOpaqueQualType()),
-                                                                      idx,
-                                                                      static_cast<uint32_t>(pos->second),
-                                                                      pos->first->getNameAsString().c_str());
-                        }
+                            GetObjectFile()->GetModule()->LogMessage(
+                                log, "SymbolFileDWARF::ResolveClangOpaqueTypeDefinition (clang_type = %p) field[%u] = "
+                                     "{ bit_offset=%u, name='%s' }",
+                                static_cast<void *>(clang_type.GetOpaqueQualType()), entry.first->getFieldIndex(),
+                                static_cast<uint32_t>(entry.second), entry.first->getNameAsString().c_str());
                         }
 
+                        uint32_t idx = 0;
+                        for (const auto &entry : layout_info.base_offsets)
                         {
-                        llvm::DenseMap <const clang::CXXRecordDecl *, clang::CharUnits>::const_iterator base_pos, base_end = layout_info.base_offsets.end();
-                        for (idx = 0, base_pos = layout_info.base_offsets.begin(); base_pos != base_end; ++base_pos, ++idx)
-                        {
-                            GetObjectFile()->GetModule()->LogMessage (log,
-                                                                      "SymbolFileDWARF::ResolveClangOpaqueTypeDefinition (clang_type = %p) base[%u] = { byte_offset=%u, name='%s' }",
-                                                                      clang_type.GetOpaqueQualType(),
-                                                                      idx,
-                                                                      (uint32_t)base_pos->second.getQuantity(),
-                                                                      base_pos->first->getNameAsString().c_str());
+                            GetObjectFile()->GetModule()->LogMessage(
+                                log, "SymbolFileDWARF::ResolveClangOpaqueTypeDefinition (clang_type = %p) base[%u] = { "
+                                     "byte_offset=%u, name='%s' }",
+                                clang_type.GetOpaqueQualType(), idx, (uint32_t)entry.second.getQuantity(),
+                                entry.first->getNameAsString().c_str());
+                            ++idx;
                         }
-                        }
-                        {
-                        llvm::DenseMap <const clang::CXXRecordDecl *, clang::CharUnits>::const_iterator vbase_pos, vbase_end = layout_info.vbase_offsets.end();
-                        for (idx = 0, vbase_pos = layout_info.vbase_offsets.begin(); vbase_pos != vbase_end; ++vbase_pos, ++idx)
+
+                        idx = 0;
+                        for (const auto &entry : layout_info.vbase_offsets)
                         {
-                            GetObjectFile()->GetModule()->LogMessage (log,
-                                                                      "SymbolFileDWARF::ResolveClangOpaqueTypeDefinition (clang_type = %p) vbase[%u] = { byte_offset=%u, name='%s' }",
-                                                                      static_cast<void*>(clang_type.GetOpaqueQualType()),
-                                                                      idx,
-                                                                      static_cast<uint32_t>(vbase_pos->second.getQuantity()),
-                                                                      vbase_pos->first->getNameAsString().c_str());
-                        }
+                            GetObjectFile()->GetModule()->LogMessage(
+                                log, "SymbolFileDWARF::ResolveClangOpaqueTypeDefinition (clang_type = %p) vbase[%u] = "
+                                     "{ byte_offset=%u, name='%s' }",
+                                static_cast<void *>(clang_type.GetOpaqueQualType()), idx,
+                                static_cast<uint32_t>(entry.second.getQuantity()),
+                                entry.first->getNameAsString().c_str());
+                            ++idx;
                         }
                     }
                     m_record_decl_to_layout_map.insert(std::make_pair(record_decl, layout_info));
@@ -7918,27 +7912,22 @@ SymbolFileDWARF::FindExternalVisibleDeclsByName (void *baton,
     }
 }
 
-bool 
-SymbolFileDWARF::LayoutRecordType (void *baton, 
-                                   const clang::RecordDecl *record_decl,
-                                   uint64_t &size, 
-                                   uint64_t &alignment,
-                                   llvm::DenseMap <const clang::FieldDecl *, uint64_t> &field_offsets,
-                                   llvm::DenseMap <const clang::CXXRecordDecl *, clang::CharUnits> &base_offsets,
-                                   llvm::DenseMap <const clang::CXXRecordDecl *, clang::CharUnits> &vbase_offsets)
+bool
+SymbolFileDWARF::LayoutRecordType(void *baton, const clang::RecordDecl *record_decl, uint64_t &size,
+                                  uint64_t &alignment,
+                                  std::vector<std::pair<const clang::FieldDecl *, uint64_t>> &field_offsets,
+                                  std::vector<std::pair<const clang::CXXRecordDecl *, clang::CharUnits>> &base_offsets,
+                                  std::vector<std::pair<const clang::CXXRecordDecl *, clang::CharUnits>> &vbase_offsets)
 {
     SymbolFileDWARF *symbol_file_dwarf = (SymbolFileDWARF *)baton;
     return symbol_file_dwarf->LayoutRecordType (record_decl, size, alignment, field_offsets, base_offsets, vbase_offsets);
 }
 
-
-bool 
-SymbolFileDWARF::LayoutRecordType (const clang::RecordDecl *record_decl,
-                                   uint64_t &bit_size, 
-                                   uint64_t &alignment,
-                                   llvm::DenseMap <const clang::FieldDecl *, uint64_t> &field_offsets,
-                                   llvm::DenseMap <const clang::CXXRecordDecl *, clang::CharUnits> &base_offsets,
-                                   llvm::DenseMap <const clang::CXXRecordDecl *, clang::CharUnits> &vbase_offsets)
+bool
+SymbolFileDWARF::LayoutRecordType(const clang::RecordDecl *record_decl, uint64_t &bit_size, uint64_t &alignment,
+                                  std::vector<std::pair<const clang::FieldDecl *, uint64_t>> &field_offsets,
+                                  std::vector<std::pair<const clang::CXXRecordDecl *, clang::CharUnits>> &base_offsets,
+                                  std::vector<std::pair<const clang::CXXRecordDecl *, clang::CharUnits>> &vbase_offsets)
 {
     Log *log (LogChannelDWARF::GetLogIfAll(DWARF_LOG_DEBUG_INFO));
     RecordDeclToLayoutMap::iterator pos = m_record_decl_to_layout_map.find (record_decl);