[llvm] [NFC][DWARF] Prefer addSectionLabel (PR #214239)

[via llvm-commits]

llvmorg-github-actions[bot] wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-debuginfo

Author: Aiden Grossman (boomanaiden154)

<details>
<summary>Changes</summary>

This is a follow-up to a comment on #<!-- -->213128.

addSectionDelta was only called in sites within if statements that would branch on whether or not split DWARF is enabled and then branching to either addSectionDelta or addSectionLabel. Instead we can just make addSectionLabel call addSectionDelta internally if we're in a DwoUnit to make things simpler.

This is obviously NFC for most cases. For macro info, we were previously branching on useSplitDWARF which can differ, but only in the case we are emitting into the skeleton compile unit, which we should not be doing for macro info.

---
Full diff: https://github.com/llvm/llvm-project/pull/214239.diff


4 Files Affected:

- (modified) llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp (+3-13) 
- (modified) llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp (+9-20) 
- (modified) llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp (+1-1) 
- (modified) llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h (+4-4) 


``````````diff
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index 7072fc9c8d2fb..752dc69b3971e 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -526,13 +526,8 @@ DIE &DwarfCompileUnit::updateSubprogramScopeDIE(const DISubprogram *SP,
   if (emitFuncLineTableOffsets() && LineTableSym) {
     MCSymbol *Symbol =
         Asm->getObjFileLowering().getDwarfLineSection()->getBeginSymbol();
-    if (isDwoUnit()) {
-      addSectionDelta(*SPDie, dwarf::DW_AT_LLVM_stmt_sequence, LineTableSym,
-                      Symbol);
-    } else {
-      addSectionLabel(*SPDie, dwarf::DW_AT_LLVM_stmt_sequence, LineTableSym,
-                      Symbol);
-    }
+    addSectionLabel(*SPDie, dwarf::DW_AT_LLVM_stmt_sequence, LineTableSym,
+                    Symbol);
   }
 
   // Only include DW_AT_frame_base in full debug info
@@ -648,12 +643,7 @@ void DwarfCompileUnit::addScopeRangeList(DIE &ScopeDIE,
     const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
     const MCSymbol *RangeSectionSym =
         TLOF.getDwarfRangesSection()->getBeginSymbol();
-    if (isDwoUnit())
-      addSectionDelta(ScopeDIE, dwarf::DW_AT_ranges, List.Label,
-                      RangeSectionSym);
-    else
-      addSectionLabel(ScopeDIE, dwarf::DW_AT_ranges, List.Label,
-                      RangeSectionSym);
+    addSectionLabel(ScopeDIE, dwarf::DW_AT_ranges, List.Label, RangeSectionSym);
   }
 }
 
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 0b21819cb7bdf..7260b0b7ced38 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -1428,28 +1428,17 @@ void DwarfDebug::finalizeModuleInfo() {
     // If compile Unit has macros, emit "DW_AT_macro_info/DW_AT_macros"
     // attribute.
     if (CUNode->getMacros()) {
+      DIE &InfoEntry = useSplitDwarf() ? TheCU.getUnitDie() : U.getUnitDie();
       if (UseDebugMacroSection) {
-        if (useSplitDwarf())
-          TheCU.addSectionDelta(
-              TheCU.getUnitDie(), dwarf::DW_AT_macros, U.getMacroLabelBegin(),
-              TLOF.getDwarfMacroDWOSection()->getBeginSymbol());
-        else {
-          dwarf::Attribute MacrosAttr = getDwarfVersion() >= 5
-                                            ? dwarf::DW_AT_macros
-                                            : dwarf::DW_AT_GNU_macros;
-          U.addSectionLabel(U.getUnitDie(), MacrosAttr, U.getMacroLabelBegin(),
-                            TLOF.getDwarfMacroSection()->getBeginSymbol());
-        }
+        dwarf::Attribute MacrosAttr = getDwarfVersion() >= 5 || useSplitDwarf()
+                                          ? dwarf::DW_AT_macros
+                                          : dwarf::DW_AT_GNU_macros;
+        U.addSectionLabel(InfoEntry, MacrosAttr, U.getMacroLabelBegin(),
+                          TLOF.getDwarfMacroSection()->getBeginSymbol());
       } else {
-        if (useSplitDwarf())
-          TheCU.addSectionDelta(
-              TheCU.getUnitDie(), dwarf::DW_AT_macro_info,
-              U.getMacroLabelBegin(),
-              TLOF.getDwarfMacinfoDWOSection()->getBeginSymbol());
-        else
-          U.addSectionLabel(U.getUnitDie(), dwarf::DW_AT_macro_info,
-                            U.getMacroLabelBegin(),
-                            TLOF.getDwarfMacinfoSection()->getBeginSymbol());
+        U.addSectionLabel(InfoEntry, dwarf::DW_AT_macro_info,
+                          U.getMacroLabelBegin(),
+                          TLOF.getDwarfMacinfoSection()->getBeginSymbol());
       }
     }
   }
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
index 78c0769e49161..f69bf09d81694 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -2129,7 +2129,7 @@ void DwarfUnit::addSectionDelta(DIE &Die, dwarf::Attribute Attribute,
 
 void DwarfUnit::addSectionLabel(DIE &Die, dwarf::Attribute Attribute,
                                 const MCSymbol *Label, const MCSymbol *Sec) {
-  if (Asm->doesDwarfUseRelocationsAcrossSections())
+  if (Asm->doesDwarfUseRelocationsAcrossSections() && !isDwoUnit())
     addLabel(Die, Attribute, DD->getDwarfSectionOffsetForm(), Label);
   else
     addSectionDelta(Die, Attribute, Label, Sec);
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h
index 139fae5621940..8397445b710a5 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h
@@ -317,10 +317,6 @@ class DwarfUnit : public DIEUnit {
 
   void constructTypeDIE(DIE &Buffer, const DICompositeType *CTy);
 
-  /// addSectionDelta - Add a label delta attribute data and value.
-  void addSectionDelta(DIE &Die, dwarf::Attribute Attribute, const MCSymbol *Hi,
-                       const MCSymbol *Lo);
-
   /// Add a Dwarf section label attribute data and value.
   void addSectionLabel(DIE &Die, dwarf::Attribute Attribute,
                        const MCSymbol *Label, const MCSymbol *Sec);
@@ -413,6 +409,10 @@ class DwarfUnit : public DIEUnit {
   /// Returns 'true' if the current DwarfVersion is compatible
   /// with the specified \p Version.
   bool isCompatibleWithVersion(uint16_t Version) const;
+
+  /// addSectionDelta - Add a label delta attribute data and value.
+  void addSectionDelta(DIE &Die, dwarf::Attribute Attribute, const MCSymbol *Hi,
+                       const MCSymbol *Lo);
 };
 
 class DwarfTypeUnit final : public DwarfUnit {

``````````

</details>


https://github.com/llvm/llvm-project/pull/214239