[llvm] f98e03a - [DebugInfo] Fix misleading using of DWARF forms with DIELabel. NFCI.

[Igor Kudrin via llvm-commits]

Author: Igor Kudrin
Date: 2020-08-03T15:04:08+07:00
New Revision: f98e03a35ded30893095f71be933ffc754d71d37

URL: https://github.com/llvm/llvm-project/commit/f98e03a35ded30893095f71be933ffc754d71d37
DIFF: https://github.com/llvm/llvm-project/commit/f98e03a35ded30893095f71be933ffc754d71d37.diff

LOG: [DebugInfo] Fix misleading using of DWARF forms with DIELabel. NFCI.

DIELabel can emit only 32- or 64-bit values, while it was created in
some places with DW_FORM_udata, which implies emitting uleb128.
Nevertheless, these places also expected to emit U32 or U64, but just
used a misleading DWARF form. The patch updates those places to use more
appropriate DWARF forms and restricts DIELabel::SizeOf() to accept only
forms that are actually used in the LLVM codebase.

Differential Revision: https://reviews.llvm.org/D84094

Added: 
    

Modified: 
    llvm/lib/CodeGen/AsmPrinter/DIE.cpp
    llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
    llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/CodeGen/AsmPrinter/DIE.cpp b/llvm/lib/CodeGen/AsmPrinter/DIE.cpp
index 03219637f216..b041f94de075 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DIE.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DIE.cpp
@@ -495,19 +495,25 @@ void DIEExpr::print(raw_ostream &O) const { O << "Expr: " << *Expr; }
 /// EmitValue - Emit label value.
 ///
 void DIELabel::emitValue(const AsmPrinter *AP, dwarf::Form Form) const {
-  AP->emitLabelReference(
-      Label, SizeOf(AP, Form),
-      Form == dwarf::DW_FORM_strp || Form == dwarf::DW_FORM_sec_offset ||
-          Form == dwarf::DW_FORM_ref_addr || Form == dwarf::DW_FORM_data4);
+  bool IsSectionRelative = Form != dwarf::DW_FORM_addr;
+  AP->emitLabelReference(Label, SizeOf(AP, Form), IsSectionRelative);
 }
 
 /// SizeOf - Determine size of label value in bytes.
 ///
 unsigned DIELabel::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
-  if (Form == dwarf::DW_FORM_data4) return 4;
-  if (Form == dwarf::DW_FORM_sec_offset) return 4;
-  if (Form == dwarf::DW_FORM_strp) return 4;
-  return AP->MAI->getCodePointerSize();
+  switch (Form) {
+  case dwarf::DW_FORM_data4:
+    return 4;
+  case dwarf::DW_FORM_sec_offset:
+  case dwarf::DW_FORM_strp:
+    // FIXME: add support for DWARF64
+    return 4;
+  case dwarf::DW_FORM_addr:
+    return AP->MAI->getCodePointerSize();
+  default:
+    llvm_unreachable("DIE Value form not supported yet");
+  }
 }
 
 LLVM_DUMP_METHOD

diff  --git a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index 871977df7a2c..704fff246b6a 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -439,8 +439,8 @@ DIE &DwarfCompileUnit::updateSubprogramScopeDIE(const DISubprogram *SP) {
             true});
         DIELoc *Loc = new (DIEValueAllocator) DIELoc;
         addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_WASM_location);
-        addSInt(*Loc, dwarf::DW_FORM_sdata, FrameBase.Location.WasmLoc.Kind);
-        addLabel(*Loc, dwarf::DW_FORM_udata, SPSym);
+        addSInt(*Loc, dwarf::DW_FORM_sdata, TI_GLOBAL_RELOC);
+        addLabel(*Loc, dwarf::DW_FORM_data4, SPSym);
         DD->addArangeLabel(SymbolCU(this, SPSym));
         addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_stack_value);
         addBlock(*SPDie, dwarf::DW_AT_frame_base, Loc);

diff  --git a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
index 1ba2afe48bf4..2b45e50869ed 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -335,7 +335,7 @@ void DwarfUnit::addOpAddress(DIELoc &Die, const MCSymbol *Sym) {
   }
 
   addUInt(Die, dwarf::DW_FORM_data1, dwarf::DW_OP_addr);
-  addLabel(Die, dwarf::DW_FORM_udata, Sym);
+  addLabel(Die, dwarf::DW_FORM_addr, Sym);
 }
 
 void DwarfUnit::addLabelDelta(DIE &Die, dwarf::Attribute Attribute,