[lldb] (Begin to) support discontinuous lldb_private::Functions (#115730)

This is the beginning of a different, more fundamental approach to
handling. This PR tries to tries to minimize functional changes. It only
makes sure that we store the true set of ranges inside the function
object, so that subsequent patches can make use of it.

1 files changed, 29 insertions, 10 deletions

diff --git a/lldb/source/Symbol/Function.cpp b/lldb/source/Symbol/Function.cpp
index 04766e26674c..f590cf4632bc 100644
--- a/lldb/source/Symbol/Function.cpp
+++ b/lldb/source/Symbol/Function.cpp
@@ -254,12 +254,32 @@ Function *IndirectCallEdge::GetCallee(ModuleList &images,
 
 /// @}
 
+AddressRange CollapseRanges(llvm::ArrayRef<AddressRange> ranges) {
+  if (ranges.empty())
+    return AddressRange();
+  if (ranges.size() == 1)
+    return ranges[0];
+
+  Address lowest_addr = ranges[0].GetBaseAddress();
+  addr_t highest_addr = lowest_addr.GetFileAddress() + ranges[0].GetByteSize();
+  for (const AddressRange &range : ranges.drop_front()) {
+    Address range_begin = range.GetBaseAddress();
+    addr_t range_end = range_begin.GetFileAddress() + range.GetByteSize();
+    if (range_begin.GetFileAddress() < lowest_addr.GetFileAddress())
+      lowest_addr = range_begin;
+    if (range_end > highest_addr)
+      highest_addr = range_end;
+  }
+  return AddressRange(lowest_addr, highest_addr - lowest_addr.GetFileAddress());
+}
+
 //
 Function::Function(CompileUnit *comp_unit, lldb::user_id_t func_uid,
                    lldb::user_id_t type_uid, const Mangled &mangled, Type *type,
-                   const AddressRange &range)
+                   AddressRanges ranges)
     : UserID(func_uid), m_comp_unit(comp_unit), m_type_uid(type_uid),
-      m_type(type), m_mangled(mangled), m_block(func_uid), m_range(range),
+      m_type(type), m_mangled(mangled), m_block(func_uid),
+      m_ranges(std::move(ranges)), m_range(CollapseRanges(m_ranges)),
       m_frame_base(), m_flags(), m_prologue_byte_size(0) {
   m_block.SetParentScope(this);
   assert(comp_unit != nullptr);
@@ -406,14 +426,13 @@ void Function::GetDescription(Stream *s, lldb::DescriptionLevel level,
     llvm::interleaveComma(decl_context, *s, [&](auto &ctx) { ctx.Dump(*s); });
     *s << "}";
   }
-  *s << ", range = ";
-  Address::DumpStyle fallback_style;
-  if (level == eDescriptionLevelVerbose)
-    fallback_style = Address::DumpStyleModuleWithFileAddress;
-  else
-    fallback_style = Address::DumpStyleFileAddress;
-  GetAddressRange().Dump(s, target, Address::DumpStyleLoadAddress,
-                         fallback_style);
+  *s << ", range" << (m_ranges.size() > 1 ? "s" : "") << " = ";
+  Address::DumpStyle fallback_style =
+      level == eDescriptionLevelVerbose
+          ? Address::DumpStyleModuleWithFileAddress
+          : Address::DumpStyleFileAddress;
+  for (const AddressRange &range : m_ranges)
+    range.Dump(s, target, Address::DumpStyleLoadAddress, fallback_style);
 }
 
 void Function::Dump(Stream *s, bool show_context) const {