[lldb] Make GetDIENamesAndRanges() allow 0-valued decl and call lines

In an upcoming patch, D142556, Clang is proposed to be changed to emit
line locations that are inlined at line 0. This clashed with the behavior of
GetDIENamesAndRanges() which used 0 as a default value to determine if
file, line or column numbers had been set. Users of that function then
checked for any non-0 values when setting up the call site:

  if (call_file != 0 || call_line != 0 || call_column != 0)
    [...]

which did not work with the Clang change since all three values then
could be 0.

This changes the function to use std::optional to catch non-set values
instead.

Reviewed By: clayborg

Differential Revision: https://reviews.llvm.org/D142552

lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp

@@ -2394,12 +2394,12 @@ DWARFASTParserClang::ParseFunctionFromDWARF(CompileUnit &comp_unit,
   DWARFRangeList func_ranges;
   const char *name = nullptr;
   const char *mangled = nullptr;
-  int decl_file = 0;
-  int decl_line = 0;
-  int decl_column = 0;
-  int call_file = 0;
-  int call_line = 0;
-  int call_column = 0;
+  std::optional<int> decl_file;
+  std::optional<int> decl_line;
+  std::optional<int> decl_column;
+  std::optional<int> call_file;
+  std::optional<int> call_line;
+  std::optional<int> call_column;
   DWARFExpressionList frame_base;
 
   const dw_tag_t tag = die.Tag();
@@ -2429,9 +2429,10 @@ DWARFASTParserClang::ParseFunctionFromDWARF(CompileUnit &comp_unit,
 
     FunctionSP func_sp;
     std::unique_ptr<Declaration> decl_up;
-    if (decl_file != 0 || decl_line != 0 || decl_column != 0)
-      decl_up = std::make_unique<Declaration>(die.GetCU()->GetFile(decl_file),
-                                              decl_line, decl_column);
+    if (decl_file || decl_line || decl_column)
+      decl_up = std::make_unique<Declaration>(
+          die.GetCU()->GetFile(decl_file ? *decl_file : 0),
+          decl_line ? *decl_line : 0, decl_column ? *decl_column : 0);
 
     SymbolFileDWARF *dwarf = die.GetDWARF();
     // Supply the type _only_ if it has already been parsed

lldb/source/Plugins/SymbolFile/DWARF/DWARFDIE.cpp

@@ -439,8 +439,9 @@ bool DWARFDIE::IsMethod() const {
 
 bool DWARFDIE::GetDIENamesAndRanges(
     const char *&name, const char *&mangled, DWARFRangeList &ranges,
-    int &decl_file, int &decl_line, int &decl_column, int &call_file,
-    int &call_line, int &call_column,
+    std::optional<int> &decl_file, std::optional<int> &decl_line,
+    std::optional<int> &decl_column, std::optional<int> &call_file,
+    std::optional<int> &call_line, std::optional<int> &call_column,
     lldb_private::DWARFExpressionList *frame_base) const {
   if (IsValid()) {
     return m_die->GetDIENamesAndRanges(

lldb/source/Plugins/SymbolFile/DWARF/DWARFDIE.h

@@ -83,12 +83,12 @@ class DWARFDIE : public DWARFBaseDIE {
   DWARFDIE
   GetAttributeValueAsReferenceDIE(const dw_attr_t attr) const;
 
-  bool
-  GetDIENamesAndRanges(const char *&name, const char *&mangled,
-                       DWARFRangeList &ranges, int &decl_file, int &decl_line,
-                       int &decl_column, int &call_file, int &call_line,
-                       int &call_column,
-                       lldb_private::DWARFExpressionList *frame_base) const;
+  bool GetDIENamesAndRanges(
+      const char *&name, const char *&mangled, DWARFRangeList &ranges,
+      std::optional<int> &decl_file, std::optional<int> &decl_line,
+      std::optional<int> &decl_column, std::optional<int> &call_file,
+      std::optional<int> &call_line, std::optional<int> &call_column,
+      lldb_private::DWARFExpressionList *frame_base) const;
 
   /// The range of all the children of this DIE.
   llvm::iterator_range<child_iterator> children() const;

lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.cpp

@@ -234,9 +234,10 @@ static DWARFRangeList GetRangesOrReportError(DWARFUnit &unit,
 // DW_AT_low_pc/DW_AT_high_pc pair, DW_AT_entry_pc, or DW_AT_ranges attributes.
 bool DWARFDebugInfoEntry::GetDIENamesAndRanges(
     DWARFUnit *cu, const char *&name, const char *&mangled,
-    DWARFRangeList &ranges, int &decl_file, int &decl_line, int &decl_column,
-    int &call_file, int &call_line, int &call_column,
-    DWARFExpressionList *frame_base) const {
+    DWARFRangeList &ranges, std::optional<int> &decl_file,
+    std::optional<int> &decl_line, std::optional<int> &decl_column,
+    std::optional<int> &call_file, std::optional<int> &call_line,
+    std::optional<int> &call_column, DWARFExpressionList *frame_base) const {
   dw_addr_t lo_pc = LLDB_INVALID_ADDRESS;
   dw_addr_t hi_pc = LLDB_INVALID_ADDRESS;
   std::vector<DWARFDIE> dies;
@@ -315,32 +316,32 @@ bool DWARFDebugInfoEntry::GetDIENamesAndRanges(
           break;
 
         case DW_AT_decl_file:
-          if (decl_file == 0)
+          if (!decl_file)
             decl_file = form_value.Unsigned();
           break;
 
         case DW_AT_decl_line:
-          if (decl_line == 0)
+          if (!decl_line)
             decl_line = form_value.Unsigned();
           break;
 
         case DW_AT_decl_column:
-          if (decl_column == 0)
+          if (!decl_column)
             decl_column = form_value.Unsigned();
           break;
 
         case DW_AT_call_file:
-          if (call_file == 0)
+          if (!call_file)
             call_file = form_value.Unsigned();
           break;
 
         case DW_AT_call_line:
-          if (call_line == 0)
+          if (!call_line)
             call_line = form_value.Unsigned();
           break;
 
         case DW_AT_call_column:
-          if (call_column == 0)
+          if (!call_column)
             call_column = form_value.Unsigned();
           break;
 

lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.h

@@ -103,8 +103,10 @@ class DWARFDebugInfoEntry {
 
   bool GetDIENamesAndRanges(
       DWARFUnit *cu, const char *&name, const char *&mangled,
-      DWARFRangeList &rangeList, int &decl_file, int &decl_line,
-      int &decl_column, int &call_file, int &call_line, int &call_column,
+      DWARFRangeList &rangeList, std::optional<int> &decl_file,
+      std::optional<int> &decl_line, std::optional<int> &decl_column,
+      std::optional<int> &call_file, std::optional<int> &call_line,
+      std::optional<int> &call_column,
       lldb_private::DWARFExpressionList *frame_base = nullptr) const;
 
   const DWARFAbbreviationDeclaration *

lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp

@@ -1284,12 +1284,12 @@ size_t SymbolFileDWARF::ParseBlocksRecursive(
       const char *name = nullptr;
       const char *mangled_name = nullptr;
 
-      int decl_file = 0;
-      int decl_line = 0;
-      int decl_column = 0;
-      int call_file = 0;
-      int call_line = 0;
-      int call_column = 0;
+      std::optional<int> decl_file;
+      std::optional<int> decl_line;
+      std::optional<int> decl_column;
+      std::optional<int> call_file;
+      std::optional<int> call_line;
+      std::optional<int> call_column;
       if (die.GetDIENamesAndRanges(name, mangled_name, ranges, decl_file,
                                    decl_line, decl_column, call_file, call_line,
                                    call_column, nullptr)) {
@@ -1332,16 +1332,18 @@ size_t SymbolFileDWARF::ParseBlocksRecursive(
         if (tag != DW_TAG_subprogram &&
             (name != nullptr || mangled_name != nullptr)) {
           std::unique_ptr<Declaration> decl_up;
-          if (decl_file != 0 || decl_line != 0 || decl_column != 0)
+          if (decl_file || decl_line || decl_column)
             decl_up = std::make_unique<Declaration>(
-                comp_unit.GetSupportFiles().GetFileSpecAtIndex(decl_file),
-                decl_line, decl_column);
+                comp_unit.GetSupportFiles().GetFileSpecAtIndex(
+                    decl_file ? *decl_file : 0),
+                decl_line ? *decl_line : 0, decl_column ? *decl_column : 0);
 
           std::unique_ptr<Declaration> call_up;
-          if (call_file != 0 || call_line != 0 || call_column != 0)
+          if (call_file || call_line || call_column)
             call_up = std::make_unique<Declaration>(
-                comp_unit.GetSupportFiles().GetFileSpecAtIndex(call_file),
-                call_line, call_column);
+                comp_unit.GetSupportFiles().GetFileSpecAtIndex(
+                    call_file ? *call_file : 0),
+                call_line ? *call_line : 0, call_column ? *call_column : 0);
 
           block->SetInlinedFunctionInfo(name, mangled_name, decl_up.get(),
                                         call_up.get());