[NFC][DebugInfo] Wrap DILineInfo return type with std::optional to handle missing debug info. (#129792)

ZequanWu · web-flow · commit 6dbe82f061bf · 2025-03-17T17:01:06.000-04:00
Currently, `DIContext::getLineInfoForAddress` and
`DIContext::getLineInfoForDataAddress` returns empty DILineInfo when the
debug info is missing for the given address. This is not differentiable
with the case when debug info is found for the given address but the
debug info is default value (filename:linenum is &lt;invalid&gt;:0).

This change wraps the return types of `DIContext::getLineInfoForAddress`
and `DIContext::getLineInfoForDataAddress` with `std::optional`.
diff --git a/llvm/include/llvm/DebugInfo/BTF/BTFContext.h b/llvm/include/llvm/DebugInfo/BTF/BTFContext.h
@@ -30,11 +30,11 @@ class BTFContext final : public DIContext {
     // BTF is no DWARF, so ignore this operation for now.
   }
 
-  DILineInfo getLineInfoForAddress(
+  std::optional<DILineInfo> getLineInfoForAddress(
       object::SectionedAddress Address,
       DILineInfoSpecifier Specifier = DILineInfoSpecifier()) override;
 
-  DILineInfo
+  std::optional<DILineInfo>
   getLineInfoForDataAddress(object::SectionedAddress Address) override;
 
   DILineInfoTable getLineInfoForAddressRange(
diff --git a/llvm/include/llvm/DebugInfo/DIContext.h b/llvm/include/llvm/DebugInfo/DIContext.h
@@ -252,10 +252,12 @@ class DIContext {
     return true;
   }
 
-  virtual DILineInfo getLineInfoForAddress(
+  // For getLineInfoForAddress and getLineInfoForDataAddress, std::nullopt is
+  // returned when debug info is missing for the given address.
+  virtual std::optional<DILineInfo> getLineInfoForAddress(
       object::SectionedAddress Address,
       DILineInfoSpecifier Specifier = DILineInfoSpecifier()) = 0;
-  virtual DILineInfo
+  virtual std::optional<DILineInfo>
   getLineInfoForDataAddress(object::SectionedAddress Address) = 0;
   virtual DILineInfoTable getLineInfoForAddressRange(
       object::SectionedAddress Address, uint64_t Size,
diff --git a/llvm/include/llvm/DebugInfo/DWARF/DWARFContext.h b/llvm/include/llvm/DebugInfo/DWARF/DWARFContext.h
@@ -386,10 +386,10 @@ class DWARFContext : public DIContext {
   ///            executable's debug info.
   DIEsForAddress getDIEsForAddress(uint64_t Address, bool CheckDWO = false);
 
-  DILineInfo getLineInfoForAddress(
+  std::optional<DILineInfo> getLineInfoForAddress(
       object::SectionedAddress Address,
       DILineInfoSpecifier Specifier = DILineInfoSpecifier()) override;
-  DILineInfo
+  std::optional<DILineInfo>
   getLineInfoForDataAddress(object::SectionedAddress Address) override;
   DILineInfoTable getLineInfoForAddressRange(
       object::SectionedAddress Address, uint64_t Size,
diff --git a/llvm/include/llvm/DebugInfo/PDB/PDBContext.h b/llvm/include/llvm/DebugInfo/PDB/PDBContext.h
@@ -42,10 +42,10 @@ namespace pdb {
 
     void dump(raw_ostream &OS, DIDumpOptions DIDumpOpts) override;
 
-    DILineInfo getLineInfoForAddress(
+    std::optional<DILineInfo> getLineInfoForAddress(
         object::SectionedAddress Address,
         DILineInfoSpecifier Specifier = DILineInfoSpecifier()) override;
-    DILineInfo
+    std::optional<DILineInfo>
     getLineInfoForDataAddress(object::SectionedAddress Address) override;
     DILineInfoTable getLineInfoForAddressRange(
         object::SectionedAddress Address, uint64_t Size,
diff --git a/llvm/lib/DebugInfo/BTF/BTFContext.cpp b/llvm/lib/DebugInfo/BTF/BTFContext.cpp
@@ -20,12 +20,13 @@ using namespace llvm;
 using object::ObjectFile;
 using object::SectionedAddress;
 
-DILineInfo BTFContext::getLineInfoForAddress(SectionedAddress Address,
-                                             DILineInfoSpecifier Specifier) {
+std::optional<DILineInfo>
+BTFContext::getLineInfoForAddress(SectionedAddress Address,
+                                  DILineInfoSpecifier Specifier) {
   const BTF::BPFLineInfo *LineInfo = BTF.findLineInfo(Address);
   DILineInfo Result;
   if (!LineInfo)
-    return Result;
+    return std::nullopt;
 
   Result.LineSource = BTF.findString(LineInfo->LineOff);
   Result.FileName = BTF.findString(LineInfo->FileNameOff);
@@ -34,9 +35,10 @@ DILineInfo BTFContext::getLineInfoForAddress(SectionedAddress Address,
   return Result;
 }
 
-DILineInfo BTFContext::getLineInfoForDataAddress(SectionedAddress Address) {
+std::optional<DILineInfo>
+BTFContext::getLineInfoForDataAddress(SectionedAddress Address) {
   // BTF does not convey such information.
-  return {};
+  return std::nullopt;
 }
 
 DILineInfoTable
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp b/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
@@ -1730,8 +1730,9 @@ DWARFContext::getLocalsForAddress(object::SectionedAddress Address) {
   return Result;
 }
 
-DILineInfo DWARFContext::getLineInfoForAddress(object::SectionedAddress Address,
-                                               DILineInfoSpecifier Spec) {
+std::optional<DILineInfo>
+DWARFContext::getLineInfoForAddress(object::SectionedAddress Address,
+                                    DILineInfoSpecifier Spec) {
   DILineInfo Result;
   DWARFCompileUnit *CU = getCompileUnitForCodeAddress(Address.Address);
   if (!CU)
@@ -1751,7 +1752,7 @@ DILineInfo DWARFContext::getLineInfoForAddress(object::SectionedAddress Address,
   return Result;
 }
 
-DILineInfo
+std::optional<DILineInfo>
 DWARFContext::getLineInfoForDataAddress(object::SectionedAddress Address) {
   DILineInfo Result;
   DWARFCompileUnit *CU = getCompileUnitForDataAddress(Address.Address);
diff --git a/llvm/lib/DebugInfo/GSYM/DwarfTransformer.cpp b/llvm/lib/DebugInfo/GSYM/DwarfTransformer.cpp
@@ -741,7 +741,7 @@ llvm::Error DwarfTransformer::verify(StringRef GsymPath,
       uint32_t NumDwarfInlineInfos = DwarfInlineInfos.getNumberOfFrames();
       if (NumDwarfInlineInfos == 0) {
         DwarfInlineInfos.addFrame(
-            DICtx.getLineInfoForAddress(SectAddr, DLIS));
+            DICtx.getLineInfoForAddress(SectAddr, DLIS).value_or(DILineInfo()));
       }
 
       // Check for 1 entry that has no file and line info
diff --git a/llvm/lib/DebugInfo/PDB/PDBContext.cpp b/llvm/lib/DebugInfo/PDB/PDBContext.cpp
@@ -32,8 +32,9 @@ PDBContext::PDBContext(const COFFObjectFile &Object,
 
 void PDBContext::dump(raw_ostream &OS, DIDumpOptions DumpOpts){}
 
-DILineInfo PDBContext::getLineInfoForAddress(object::SectionedAddress Address,
-                                             DILineInfoSpecifier Specifier) {
+std::optional<DILineInfo>
+PDBContext::getLineInfoForAddress(object::SectionedAddress Address,
+                                  DILineInfoSpecifier Specifier) {
   DILineInfo Result;
   Result.FunctionName = getFunctionName(Address.Address, Specifier.FNKind);
 
@@ -64,7 +65,7 @@ DILineInfo PDBContext::getLineInfoForAddress(object::SectionedAddress Address,
   return Result;
 }
 
-DILineInfo
+std::optional<DILineInfo>
 PDBContext::getLineInfoForDataAddress(object::SectionedAddress Address) {
   // Unimplemented. S_GDATA and S_LDATA in CodeView (used to describe global
   // variables) aren't capable of carrying line information.
@@ -84,9 +85,10 @@ PDBContext::getLineInfoForAddressRange(object::SectionedAddress Address,
     return Table;
 
   while (auto LineInfo = LineNumbers->getNext()) {
-    DILineInfo LineEntry = getLineInfoForAddress(
-        {LineInfo->getVirtualAddress(), Address.SectionIndex}, Specifier);
-    Table.push_back(std::make_pair(LineInfo->getVirtualAddress(), LineEntry));
+    if (std::optional<DILineInfo> LineEntry = getLineInfoForAddress(
+            {LineInfo->getVirtualAddress(), Address.SectionIndex}, Specifier))
+      Table.push_back(
+          std::make_pair(LineInfo->getVirtualAddress(), *LineEntry));
   }
   return Table;
 }
@@ -95,7 +97,8 @@ DIInliningInfo
 PDBContext::getInliningInfoForAddress(object::SectionedAddress Address,
                                       DILineInfoSpecifier Specifier) {
   DIInliningInfo InlineInfo;
-  DILineInfo CurrentLine = getLineInfoForAddress(Address, Specifier);
+  DILineInfo CurrentLine =
+      getLineInfoForAddress(Address, Specifier).value_or(DILineInfo());
 
   // Find the function at this address.
   std::unique_ptr<PDBSymbol> ParentFunc =
diff --git a/llvm/lib/DebugInfo/Symbolize/SymbolizableObjectFile.cpp b/llvm/lib/DebugInfo/Symbolize/SymbolizableObjectFile.cpp
@@ -276,8 +276,11 @@ SymbolizableObjectFile::symbolizeCode(object::SectionedAddress ModuleOffset,
   if (ModuleOffset.SectionIndex == object::SectionedAddress::UndefSection)
     ModuleOffset.SectionIndex =
         getModuleSectionIndexForAddress(ModuleOffset.Address);
-  DILineInfo LineInfo =
-      DebugInfoContext->getLineInfoForAddress(ModuleOffset, LineInfoSpecifier);
+  DILineInfo LineInfo;
+  if (std::optional<DILineInfo> DBGLineInfo =
+          DebugInfoContext->getLineInfoForAddress(ModuleOffset,
+                                                  LineInfoSpecifier))
+    LineInfo = *DBGLineInfo;
 
   // Override function name from symbol table if necessary.
   if (shouldOverrideWithSymbolTable(LineInfoSpecifier.FNKind, UseSymbolTable)) {
@@ -334,10 +337,11 @@ DIGlobal SymbolizableObjectFile::symbolizeData(
   Res.DeclFile = FileName;
 
   // Try and get a better filename:lineno pair from the debuginfo, if present.
-  DILineInfo DL = DebugInfoContext->getLineInfoForDataAddress(ModuleOffset);
-  if (DL.Line != 0) {
-    Res.DeclFile = DL.FileName;
-    Res.DeclLine = DL.Line;
+  std::optional<DILineInfo> DL =
+      DebugInfoContext->getLineInfoForDataAddress(ModuleOffset);
+  if (DL && DL->Line != 0) {
+    Res.DeclFile = DL->FileName;
+    Res.DeclLine = DL->Line;
   }
   return Res;
 }
diff --git a/llvm/lib/ExecutionEngine/Orc/Debugging/VTuneSupportPlugin.cpp b/llvm/lib/ExecutionEngine/Orc/Debugging/VTuneSupportPlugin.cpp
@@ -71,7 +71,8 @@ static VTuneMethodBatch getMethodBatch(LinkGraph &G, bool EmitDebugInfo) {
         SAddr, Sym->getSize(),
         DILineInfoSpecifier::FileLineInfoKind::AbsoluteFilePath);
     Method.SourceFileSI = Batch.Strings.size();
-    Batch.Strings.push_back(DC->getLineInfoForAddress(SAddr).FileName);
+    Batch.Strings.push_back(
+        DC->getLineInfoForAddress(SAddr).value_or(DILineInfo()).FileName);
     for (auto &LInfo : LinesInfo) {
       Method.LineTable.push_back(
           std::pair<unsigned, unsigned>{/*unsigned*/ Sym->getOffset(),
diff --git a/llvm/tools/llvm-dwarfdump/llvm-dwarfdump.cpp b/llvm/tools/llvm-dwarfdump/llvm-dwarfdump.cpp
@@ -565,9 +565,13 @@ static bool lookup(ObjectFile &Obj, DWARFContext &DICtx, uint64_t Address,
 
   // TODO: it is neccessary to set proper SectionIndex here.
   // object::SectionedAddress::UndefSection works for only absolute addresses.
-  if (DILineInfo LineInfo = DICtx.getLineInfoForAddress(
-          {Lookup, object::SectionedAddress::UndefSection}))
+  if (DILineInfo LineInfo =
+          DICtx
+              .getLineInfoForAddress(
+                  {Lookup, object::SectionedAddress::UndefSection})
+              .value_or(DILineInfo())) {
     LineInfo.dump(OS);
+  }
 
   return true;
 }
diff --git a/llvm/tools/llvm-objdump/MachODump.cpp b/llvm/tools/llvm-objdump/MachODump.cpp
@@ -7646,7 +7646,8 @@ static void DisassembleMachO(StringRef Filename, MachOObjectFile *MachOOF,
 
           // Print debug info.
           if (diContext) {
-            DILineInfo dli = diContext->getLineInfoForAddress({PC, SectIdx});
+            DILineInfo dli = diContext->getLineInfoForAddress({PC, SectIdx})
+                                 .value_or(DILineInfo());
             // Print valid line info if it changed.
             if (dli != lastLine && dli.Line != 0)
               outs() << "\t## " << dli.FileName << ':' << dli.Line << ':'
diff --git a/llvm/unittests/DebugInfo/BTF/BTFParserTest.cpp b/llvm/unittests/DebugInfo/BTF/BTFParserTest.cpp
@@ -343,17 +343,15 @@ TEST(BTFParserTest, btfContext) {
   BTFParser BTF;
   std::unique_ptr<BTFContext> Ctx = BTFContext::create(Mock.makeObj());
 
-  DILineInfo I1 = Ctx->getLineInfoForAddress({16, 1});
-  EXPECT_EQ(I1.Line, 7u);
-  EXPECT_EQ(I1.Column, 1u);
-  EXPECT_EQ(I1.FileName, "a.c");
-  EXPECT_EQ(I1.LineSource, "first line");
-
-  DILineInfo I2 = Ctx->getLineInfoForAddress({24, 1});
-  EXPECT_EQ(I2.Line, 0u);
-  EXPECT_EQ(I2.Column, 0u);
-  EXPECT_EQ(I2.FileName, DILineInfo::BadString);
-  EXPECT_EQ(I2.LineSource, std::nullopt);
+  std::optional<DILineInfo> I1 = Ctx->getLineInfoForAddress({16, 1});
+  EXPECT_TRUE(I1.has_value());
+  EXPECT_EQ(I1->Line, 7u);
+  EXPECT_EQ(I1->Column, 1u);
+  EXPECT_EQ(I1->FileName, "a.c");
+  EXPECT_EQ(I1->LineSource, "first line");
+
+  std::optional<DILineInfo> I2 = Ctx->getLineInfoForAddress({24, 1});
+  EXPECT_FALSE(I2.has_value());
 }
 
 static uint32_t mkInfo(uint32_t Kind) { return Kind << 24; }

Original file line number	Diff line number	Diff line change
`@@ -741,7 +741,7 @@ llvm::Error DwarfTransformer::verify(StringRef GsymPath,`
`741`	`741`	`uint32_t NumDwarfInlineInfos = DwarfInlineInfos.getNumberOfFrames();`
`742`	`742`	`if (NumDwarfInlineInfos == 0) {`
`743`	`743`	`DwarfInlineInfos.addFrame(`
`744`		`- DICtx.getLineInfoForAddress(SectAddr, DLIS));`
	`744`	`+ DICtx.getLineInfoForAddress(SectAddr, DLIS).value_or(DILineInfo()));`
`745`	`745`	`}`
`746`	`746`
`747`	`747`	`// Check for 1 entry that has no file and line info`