[llvm-debuginfo-analyzer] Common handling of unsigned attribute values. (#116027)

- In the DWARF reader, for those attributes that can have an unsigned
value, allow for the following cases:
  * Is an implicit constant
  * Is an optional value
- The testing is done by creating a file with generated DWARF, using
`DwarfGenerator` (generate DWARF debug info for unit tests).

Author: CarlosAlbertoEnciso

llvm/lib/DebugInfo/LogicalView/Readers/LVDWARFReader.cpp

@@ -253,15 +253,18 @@ void LVDWARFReader::processOneAttribute(const DWARFDie &Die,
   // We are processing .debug_info section, implicit_const attribute
   // values are not really stored here, but in .debug_abbrev section.
   auto GetAsUnsignedConstant = [&]() -> int64_t {
-    return AttrSpec.isImplicitConst() ? AttrSpec.getImplicitConstValue()
-                                      : *FormValue.getAsUnsignedConstant();
+    if (AttrSpec.isImplicitConst())
+      return AttrSpec.getImplicitConstValue();
+    if (std::optional<uint64_t> Val = FormValue.getAsUnsignedConstant())
+      return *Val;
+    return 0;
   };
 
   auto GetFlag = [](const DWARFFormValue &FormValue) -> bool {
     return FormValue.isFormClass(DWARFFormValue::FC_Flag);
   };
 
-  auto GetBoundValue = [](const DWARFFormValue &FormValue) -> int64_t {
+  auto GetBoundValue = [&AttrSpec](const DWARFFormValue &FormValue) -> int64_t {
     switch (FormValue.getForm()) {
     case dwarf::DW_FORM_ref_addr:
     case dwarf::DW_FORM_ref1:
@@ -282,6 +285,8 @@ void LVDWARFReader::processOneAttribute(const DWARFDie &Die,
       return *FormValue.getAsUnsignedConstant();
     case dwarf::DW_FORM_sdata:
       return *FormValue.getAsSignedConstant();
+    case dwarf::DW_FORM_implicit_const:
+      return AttrSpec.getImplicitConstValue();
     default:
       return 0;
     }
@@ -294,13 +299,13 @@ void LVDWARFReader::processOneAttribute(const DWARFDie &Die,
 
   switch (AttrSpec.Attr) {
   case dwarf::DW_AT_accessibility:
-    CurrentElement->setAccessibilityCode(*FormValue.getAsUnsignedConstant());
+    CurrentElement->setAccessibilityCode(GetAsUnsignedConstant());
     break;
   case dwarf::DW_AT_artificial:
     CurrentElement->setIsArtificial();
     break;
   case dwarf::DW_AT_bit_size:
-    CurrentElement->setBitSize(*FormValue.getAsUnsignedConstant());
+    CurrentElement->setBitSize(GetAsUnsignedConstant());
     break;
   case dwarf::DW_AT_call_file:
     CurrentElement->setCallFilenameIndex(IncrementFileIndex
@@ -332,13 +337,12 @@ void LVDWARFReader::processOneAttribute(const DWARFDie &Die,
         Stream << hexString(Value, 2);
         CurrentElement->setValue(Stream.str());
       } else
-        CurrentElement->setValue(
-            hexString(*FormValue.getAsUnsignedConstant(), 2));
+        CurrentElement->setValue(hexString(GetAsUnsignedConstant(), 2));
     } else
       CurrentElement->setValue(dwarf::toStringRef(FormValue));
     break;
   case dwarf::DW_AT_count:
-    CurrentElement->setCount(*FormValue.getAsUnsignedConstant());
+    CurrentElement->setCount(GetAsUnsignedConstant());
     break;
   case dwarf::DW_AT_decl_line:
     CurrentElement->setLineNumber(GetAsUnsignedConstant());
@@ -357,10 +361,10 @@ void LVDWARFReader::processOneAttribute(const DWARFDie &Die,
       CurrentElement->setIsExternal();
     break;
   case dwarf::DW_AT_GNU_discriminator:
-    CurrentElement->setDiscriminator(*FormValue.getAsUnsignedConstant());
+    CurrentElement->setDiscriminator(GetAsUnsignedConstant());
     break;
   case dwarf::DW_AT_inline:
-    CurrentElement->setInlineCode(*FormValue.getAsUnsignedConstant());
+    CurrentElement->setInlineCode(GetAsUnsignedConstant());
     break;
   case dwarf::DW_AT_lower_bound:
     CurrentElement->setLowerBound(GetBoundValue(FormValue));
@@ -380,7 +384,7 @@ void LVDWARFReader::processOneAttribute(const DWARFDie &Die,
     CurrentElement->setUpperBound(GetBoundValue(FormValue));
     break;
   case dwarf::DW_AT_virtuality:
-    CurrentElement->setVirtualityCode(*FormValue.getAsUnsignedConstant());
+    CurrentElement->setVirtualityCode(GetAsUnsignedConstant());
     break;
 
   case dwarf::DW_AT_abstract_origin:

llvm/test/tools/llvm-debuginfo-analyzer/DWARF/05-dwarf-incorrect-lexical-scope-variable.test

@@ -43,14 +43,14 @@
 ; ONE-EMPTY:
 ; ONE-NEXT: [001]             {CompileUnit} 'pr-43860.cpp'
 ; ONE-NEXT: [002]               {Producer} 'clang version 15.0.0 {{.*}}'
-; ONE-NEXT: [002]     2         {Function} extern not_inlined 'InlineFunction' -> 'int'
+; ONE-NEXT: [002]     2         {Function} extern inlined 'InlineFunction' -> 'int'
 ; ONE-NEXT: [003]                 {Block}
 ; ONE-NEXT: [004]     5             {Variable} 'Var_2' -> 'int'
 ; ONE-NEXT: [003]     2           {Parameter} 'Param' -> 'int'
 ; ONE-NEXT: [003]     3           {Variable} 'Var_1' -> 'int'
 ; ONE-NEXT: [002]    11         {Function} extern not_inlined 'test' -> 'int'
 ; ONE-NEXT: [003]    12           {Variable} 'A' -> 'int'
-; ONE-NEXT: [003]    13           {InlinedFunction} not_inlined 'InlineFunction' -> 'int'
+; ONE-NEXT: [003]    13           {InlinedFunction} inlined 'InlineFunction' -> 'int'
 ; ONE-NEXT: [004]                   {Block}
 ; ONE-NEXT: [005]                     {Variable} 'Var_2' -> 'int'
 ; ONE-NEXT: [004]                   {Parameter} 'Param' -> 'int'

llvm/unittests/DebugInfo/LogicalView/CMakeLists.txt

@@ -1,17 +1,22 @@
 set(LLVM_LINK_COMPONENTS
+  ${LLVM_TARGETS_TO_BUILD}
   AllTargetsDescs
   AllTargetsDisassemblers
   AllTargetsInfos
+  AsmPrinter
   DebugInfoLogicalView
   MC
   MCDisassembler
   TargetParser
   )
 
 add_llvm_unittest_with_input_files(DebugInfoLogicalViewTests
+  ../DWARF/DwarfGenerator.cpp
+  ../DWARF/DwarfUtils.cpp
   CodeViewReaderTest.cpp
   CommandLineOptionsTest.cpp
   CompareElementsTest.cpp
+  DWARFGeneratedTest.cpp
   DWARFReaderTest.cpp
   SelectElementsTest.cpp
   LocationRangesTest.cpp