[DWARFYAML] Add helper function getDWARFEmitterByName(). NFC.

[Higuoxing]

Summary

In this patch, we add a helper function getDWARFEmitterByName(). This
function returns the proper DWARF section emitting method by the name.

[Higuoxing]

This comment was removed by Higuoxing.

[Higuoxing]

Update.

[Higuoxing]

Pull out the changes of adding emitDebug[GNU]Pub[names/types] functions.

[jhenderson]

llvm/lib/ObjectYAML/ELFEmitter.cpp

953 ↗

(On Diff #282139)

I'm not sure this check is really giving us anything. There's a check in the getDWARFEmitterByName that the name is a recognised name (the default case), so I think you can just remove this check here.

956–958 ↗

(On Diff #282139)

if (Error Err = EmitFunc(*OS, DWARF);

[Higuoxing]

Address review comments.

Thanks for reviewing!

[jhenderson]

LGTM.

llvm/lib/ObjectYAML/DWARFEmitter.cpp

DWARFYAML::emitDebugSections(StringRef YAMLString, bool IsLittleEndian) {
 
   DWARFYAML::Data DI;
   DI.IsLittleEndian = IsLittleEndian;
   YIn >> DI;
   if (YIn.error())
     return createStringError(YIn.error(), GeneratedDiag.getMessage());
 
   StringMap<std::unique_ptr<MemoryBuffer>> DebugSections;
-  Error Err = emitDebugSectionImpl(DI, &DWARFYAML::emitDebugInfo, "debug_info",
-                                   DebugSections);
-  Err = joinErrors(std::move(Err),
-                   emitDebugSectionImpl(DI, &DWARFYAML::emitDebugLine,
-                                        "debug_line", DebugSections));
-  Err = joinErrors(std::move(Err),
-                   emitDebugSectionImpl(DI, &DWARFYAML::emitDebugStr,
-                                        "debug_str", DebugSections));
+
+  Error Err = Error::success();
+  cantFail(std::move(Err));
+
+  for (StringRef SecName : DI.getNonEmptySectionNames()) {
+    if (SecName == "debug_abbrev")
       Err = joinErrors(std::move(Err),
                        emitDebugSectionImpl(DI, &DWARFYAML::emitDebugAbbrev,
-                                        "debug_abbrev", DebugSections));
+                                            SecName, DebugSections));
+    else if (SecName == "debug_aranges")
       Err = joinErrors(std::move(Err),
                        emitDebugSectionImpl(DI, &DWARFYAML::emitDebugAranges,
-                                        "debug_aranges", DebugSections));
+                                            SecName, DebugSections));
+    else if (SecName == "debug_info")
+      Err = joinErrors(std::move(Err),
+                       emitDebugSectionImpl(DI, &DWARFYAML::emitDebugInfo,
+                                            SecName, DebugSections));
+    else if (SecName == "debug_line")
+      Err = joinErrors(std::move(Err),
+                       emitDebugSectionImpl(DI, &DWARFYAML::emitDebugLine,
+                                            SecName, DebugSections));
+    else if (SecName == "debug_ranges")
       Err = joinErrors(std::move(Err),
                        emitDebugSectionImpl(DI, &DWARFYAML::emitDebugRanges,
-                                        "debug_ranges", DebugSections));
+                                            SecName, DebugSections));
+    else if (SecName == "debug_str")
+      Err = joinErrors(std::move(Err),
+                       emitDebugSectionImpl(DI, &DWARFYAML::emitDebugStr,
+                                            SecName, DebugSections));
+    else
+      Err = joinErrors(std::move(Err),
+                       createStringError(errc::not_supported,
+                                         SecName + " is not supported"));
+  }
 
   if (Err)
     return std::move(Err);
   return std::move(DebugSections);
 }

llvm/unittests/ObjectYAML/DWARFYAMLTest.cpp

debug_gnu_pubnames:
   Entries:
     - DieOffset: 0x1234
       Name:      abcd
 )";
   DWARFYAML::Data Data;
   EXPECT_THAT_ERROR(parseDWARFYAML(Yaml, Data),
                     FailedWithMessage("missing required key 'Descriptor'"));
 }
+
+TEST(EmitDebugSections, UnsupportedSection) {
+  StringRef Yaml = R"(
+debug_rnglists: []
+)";
+  auto SectionsOrErr = DWARFYAML::emitDebugSections(Yaml);
+  EXPECT_THAT_ERROR(SectionsOrErr.takeError(),
+                    FailedWithMessage("debug_rnglists is not supported"));
+}