[lldb] Add Function::GetAddress and redirect some uses (#115836)

Many calls to Function::GetAddressRange() were not interested in the
range itself. Instead they wanted to find the address of the function
(its entry point) or the base address for relocation of function-scoped
entities (technically, the two don't need to be the same, but there's
isn't good reason for them not to be). This PR creates a separate
function for retrieving this, and changes the existing
(non-controversial) uses to call that instead.

Author: labath

lldb/include/lldb/Symbol/Function.h

@@ -449,6 +449,11 @@ class Function : public UserID, public SymbolContextScope {
 
   AddressRanges GetAddressRanges() { return m_block.GetRanges(); }
 
+  /// Return the address of the function (its entry point). This address is also
+  /// used as a base address for relocation of function-scope entities (blocks
+  /// and variables).
+  const Address &GetAddress() const { return m_address; }
+
   lldb::LanguageType GetLanguage() const;
   /// Find the file and line number of the source location of the start of the
   /// function.  This will use the declaration if present and fall back on the
@@ -658,6 +663,9 @@ class Function : public UserID, public SymbolContextScope {
   /// include addresses belonging to other functions.
   AddressRange m_range;
 
+  /// The address (entry point) of the function.
+  Address m_address;
+
   /// The frame base expression for variables that are relative to the frame
   /// pointer.
   DWARFExpressionList m_frame_base;

lldb/source/API/SBBlock.cpp

@@ -176,8 +176,7 @@ bool SBBlock::GetDescription(SBStream &description) {
     m_opaque_ptr->CalculateSymbolContext(&sc);
     if (sc.function) {
       m_opaque_ptr->DumpAddressRanges(
-          &strm,
-          sc.function->GetAddressRange().GetBaseAddress().GetFileAddress());
+          &strm, sc.function->GetAddress().GetFileAddress());
     }
   } else
     strm.PutCString("No value");

lldb/source/API/SBFunction.cpp

@@ -120,8 +120,7 @@ SBInstructionList SBFunction::GetInstructions(SBTarget target,
   if (m_opaque_ptr) {
     TargetSP target_sp(target.GetSP());
     std::unique_lock<std::recursive_mutex> lock;
-    ModuleSP module_sp(
-        m_opaque_ptr->GetAddressRange().GetBaseAddress().GetModule());
+    ModuleSP module_sp(m_opaque_ptr->GetAddress().GetModule());
     if (target_sp && module_sp) {
       lock = std::unique_lock<std::recursive_mutex>(target_sp->GetAPIMutex());
       const bool force_live_memory = true;

lldb/source/Breakpoint/BreakpointResolver.cpp

@@ -325,7 +325,7 @@ void BreakpointResolver::AddLocation(SearchFilter &filter,
   // If the line number is before the prologue end, move it there...
   bool skipped_prologue = false;
   if (skip_prologue && sc.function) {
-    Address prologue_addr(sc.function->GetAddressRange().GetBaseAddress());
+    Address prologue_addr = sc.function->GetAddress();
     if (prologue_addr.IsValid() && (line_start == prologue_addr)) {
       const uint32_t prologue_byte_size = sc.function->GetPrologueByteSize();
       if (prologue_byte_size) {

lldb/source/Breakpoint/BreakpointResolverName.cpp

@@ -339,7 +339,7 @@ BreakpointResolverName::SearchCallback(SearchFilter &filter,
       if (!sc.block->GetStartAddress(break_addr))
         break_addr.Clear();
     } else if (sc.function) {
-      break_addr = sc.function->GetAddressRange().GetBaseAddress();
+      break_addr = sc.function->GetAddress();
       if (m_skip_prologue && break_addr.IsValid()) {
         const uint32_t prologue_byte_size = sc.function->GetPrologueByteSize();
         if (prologue_byte_size)

lldb/source/Core/SearchFilter.cpp

@@ -152,7 +152,7 @@ bool SearchFilter::FunctionPasses(Function &function) {
   // This is a slightly cheesy job, but since we don't have finer grained 
   // filters yet, just checking that the start address passes is probably
   // good enough for the base class behavior.
-  Address addr = function.GetAddressRange().GetBaseAddress();
+  Address addr = function.GetAddress();
   return AddressPasses(addr);
 }
 

lldb/source/Expression/DWARFExpressionList.cpp

@@ -126,8 +126,7 @@ bool DWARFExpressionList::MatchesOperand(
     if (!sc.function)
       return false;
 
-    addr_t load_function_start =
-        sc.function->GetAddressRange().GetBaseAddress().GetFileAddress();
+    addr_t load_function_start = sc.function->GetAddress().GetFileAddress();
     if (load_function_start == LLDB_INVALID_ADDRESS)
       return false;
 

lldb/source/Expression/IRExecutionUnit.cpp

@@ -731,8 +731,7 @@ class LoadAddressResolver {
 
       // If that didn't work, try the function.
       if (load_address == LLDB_INVALID_ADDRESS && candidate_sc.function) {
-        Address addr =
-            candidate_sc.function->GetAddressRange().GetBaseAddress();
+        Address addr = candidate_sc.function->GetAddress();
         load_address = m_target->GetProcessSP() ? addr.GetLoadAddress(m_target)
                                                 : addr.GetFileAddress();
       }

lldb/source/Plugins/Architecture/Mips/ArchitectureMips.cpp

@@ -97,7 +97,7 @@ lldb::addr_t ArchitectureMips::GetBreakableLoadAddress(lldb::addr_t addr,
       resolve_scope, sc);
     Address sym_addr;
     if (sc.function)
-      sym_addr = sc.function->GetAddressRange().GetBaseAddress();
+      sym_addr = sc.function->GetAddress();
     else if (sc.symbol)
       sym_addr = sc.symbol->GetAddress();
 

lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderDarwin.cpp

@@ -796,10 +796,8 @@ bool DynamicLoaderDarwin::AlwaysRelyOnEHUnwindInfo(SymbolContext &sym_ctx) {
   if (sym_ctx.symbol) {
     module_sp = sym_ctx.symbol->GetAddressRef().GetModule();
   }
-  if (module_sp.get() == nullptr && sym_ctx.function) {
-    module_sp =
-        sym_ctx.function->GetAddressRange().GetBaseAddress().GetModule();
-  }
+  if (module_sp.get() == nullptr && sym_ctx.function)
+    module_sp = sym_ctx.function->GetAddress().GetModule();
   if (module_sp.get() == nullptr)
     return false;