[DWARFYAML][debug_info] Add support for error handling.

This patch helps add support for error handling in `DWARFYAML::emitDebugInfo()`.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D82275

llvm/lib/ObjectYAML/DWARFEmitter.cpp

@@ -267,9 +267,7 @@ public:
 
 Error DWARFYAML::emitDebugInfo(raw_ostream &OS, const DWARFYAML::Data &DI) {
   DumpVisitor Visitor(DI, OS);
-  Visitor.traverseDebugInfo();
-
-  return Error::success();
+  return Visitor.traverseDebugInfo();
 }
 
 static void emitFileEntry(raw_ostream &OS, const DWARFYAML::File &File) {
@@ -483,7 +481,8 @@ DWARFYAML::emitDebugSections(StringRef YAMLString, bool ApplyFixups,
 
   if (ApplyFixups) {
     DIEFixupVisitor DIFixer(DI);
-    DIFixer.traverseDebugInfo();
+    if (Error Err = DIFixer.traverseDebugInfo())
+      return std::move(Err);
   }
 
   StringMap<std::unique_ptr<MemoryBuffer>> DebugSections;

llvm/lib/ObjectYAML/DWARFVisitor.cpp

@@ -10,7 +10,8 @@
 
 #include "DWARFVisitor.h"
 #include "llvm/ObjectYAML/DWARFYAML.h"
-#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/Errc.h"
+#include "llvm/Support/Error.h"
 
 using namespace llvm;
 
@@ -44,7 +45,7 @@ static unsigned getRefSize(const DWARFYAML::Unit &Unit) {
   return getOffsetSize(Unit);
 }
 
-template <typename T> void DWARFYAML::VisitorImpl<T>::traverseDebugInfo() {
+template <typename T> Error DWARFYAML::VisitorImpl<T>::traverseDebugInfo() {
   for (auto &Unit : DebugInfo.CompileUnits) {
     onStartCompileUnit(Unit);
     if (Unit.Entries.empty())
@@ -57,8 +58,8 @@ template <typename T> void DWARFYAML::VisitorImpl<T>::traverseDebugInfo() {
         continue;
 
       if (AbbrCode > DebugInfo.AbbrevDecls.size())
-        // TODO: Handle and test this error.
-        report_fatal_error(
+        return createStringError(
+            errc::invalid_argument,
             "abbrev code must be less than or equal to the number of "
             "entries in abbreviation table");
       const DWARFYAML::Abbrev &Abbrev = DebugInfo.AbbrevDecls[AbbrCode - 1];
@@ -179,6 +180,8 @@ template <typename T> void DWARFYAML::VisitorImpl<T>::traverseDebugInfo() {
     }
     onEndCompileUnit(Unit);
   }
+
+  return Error::success();
 }
 
 // Explicitly instantiate the two template expansions.

llvm/lib/ObjectYAML/DWARFVisitor.h

@@ -16,6 +16,7 @@
 #include "llvm/Support/MemoryBuffer.h"
 
 namespace llvm {
+class Error;
 
 namespace DWARFYAML {
 
@@ -68,7 +69,7 @@ public:
 
   virtual ~VisitorImpl() {}
 
-  void traverseDebugInfo();
+  Error traverseDebugInfo();
 
 private:
   void onVariableSizeValue(uint64_t U, unsigned Size);

llvm/test/tools/yaml2obj/ELF/DWARF/debug-info.yaml

@@ -643,13 +643,13 @@ DWARF:
           Values:
             - Value: 0x1234
 
-## i) Test that yaml2obj reports a fatal error when 'debug_info' has values in its
+## i) Test that yaml2obj reports an error when 'debug_info' has values in its
 ## entries but 'debug_abbrev' doesn't have enough attributes for them.
 
-# RUN: not --crash yaml2obj --docnum=10 %s -o %t10.o 2>&1 | \
-# RUN:   FileCheck %s --check-prefixes=FATAL
+# RUN: not yaml2obj --docnum=10 %s -o %t10.o 2>&1 | \
+# RUN:   FileCheck %s --check-prefixes=ERROR
 
-# FATAL: LLVM ERROR: abbrev code must be less than or equal to the number of entries in abbreviation table
+# ERROR: yaml2obj: error: abbrev code must be less than or equal to the number of entries in abbreviation table
 
 --- !ELF
 FileHeader: