[DWARFYAML] Pull out common helper functions for rnglist and loclist tables. NFC.

[Higuoxing]

Summary

This patch helps pull out some common helper functions for range list
and location list tables. NFC.

[grimar]

llvm/lib/ObjectYAML/DWARFEmitter.cpp

454

nit: you do not need curly braces around return createStringError....

481

It looks like you could pass const DWARFYAML::RnglistEntry &Entry directly to checkListEntryOperands

i.e.:

static Error checkListEntryOperands(const DWARFYAML::RnglistEntry &Entry, uint64_t ExpectedOpsNum) {
  StringRef EncodingName = dwarf::RangeListEncodingString(Entry.Operator);
...
}

and then avoid having the CheckOperands helper? (inline checkListEntryOperands)

[Higuoxing]

llvm/lib/ObjectYAML/DWARFEmitter.cpp

481

Yeah, but I want to use checkListEntryOperands() to check operands for both the range list table and the location list table. The .debug_loclists section is implemented in D84234

[Higuoxing]

llvm/lib/ObjectYAML/DWARFEmitter.cpp

481

My idea is having

StringRef EncodingName = dwarf::RangeListEncodingString(Entry.Operator);
auto CheckOperands = [&](uint64_t ExpectedOperands) -> Error {
  return checkListEntryOperands(EncodingName, Entry.Values, ExpectedOperands);
};

for the range list table and

StringRef EncodingName = dwarf::LocListEncodingString(Entry.Operator);
auto CheckOperands = [&](uint64_t ExpectedOperands) -> Error {
  return checkListEntryOperands(EncodingName, Entry.Values, ExpectedOperands);
};

for the location list table.

[jhenderson]

LGTM, personally, barring @grimar's first nit.

[grimar]

llvm/lib/ObjectYAML/DWARFEmitter.cpp

481

Ah, OK.

[Higuoxing]

Thanks for reviewing!

llvm/lib/ObjectYAML/DWARFEmitter.cpp

454

Oh, thanks for pointing this out!

llvm/lib/ObjectYAML/DWARFEmitter.cpp

for (uint64_t Offset : Table.Offsets) {
                                          Table.Format == dwarf::DWARF64 ? 8 : 4,
                                          OS, DI.IsLittleEndian));
     }
   }
 
   return Error::success();
 }
 
+static Error checkListEntryOperands(StringRef EncodingString,
+                                    ArrayRef<yaml::Hex64> Values,
+                                    uint64_t ExpectedOperands) {
+  if (Values.size() != ExpectedOperands)
+    return createStringError(
+        errc::invalid_argument,
+        "invalid number (%zu) of operands for the operator: %s, %" PRIu64
+        " expected",
+        Values.size(), EncodingString.str().c_str(), ExpectedOperands);
+
+  return Error::success();
+}
+
+static Error writeListEntryAddress(StringRef EncodingName, raw_ostream &OS,
+                                   uint64_t Addr, uint8_t AddrSize,
+                                   bool IsLittleEndian) {
+  if (Error Err = writeVariableSizedInteger(Addr, AddrSize, OS, IsLittleEndian))
+    return createStringError(errc::invalid_argument,
+                             "unable to write address for the operator %s: %s",
+                             EncodingName.str().c_str(),
+                             toString(std::move(Err)).c_str());
+
+  return Error::success();
+}
+
 static Expected<uint64_t> writeListEntry(raw_ostream &OS,
                                          const DWARFYAML::RnglistEntry &Entry,
                                          uint8_t AddrSize,
                                          bool IsLittleEndian) {
   uint64_t BeginOffset = OS.tell();
   writeInteger((uint8_t)Entry.Operator, OS, IsLittleEndian);
 
-  auto CheckOperands = [&](uint64_t ExpectedOperands) -> Error {
-    if (Entry.Values.size() != ExpectedOperands) {
-      return createStringError(
-          errc::invalid_argument,
-          "invalid number (%zu) of operands for the operator: %s, %" PRIu64
-          " expected",
-          Entry.Values.size(),
-          dwarf::RangeListEncodingString(Entry.Operator).str().c_str(),
-          ExpectedOperands);
-    }
+  StringRef EncodingName = dwarf::RangeListEncodingString(Entry.Operator);
 
-    return Error::success();
+  auto CheckOperands = [&](uint64_t ExpectedOperands) -> Error {
+    return checkListEntryOperands(EncodingName, Entry.Values, ExpectedOperands);
   };
 
   auto WriteAddress = [&](uint64_t Addr) -> Error {
-    if (Error Err =
-            writeVariableSizedInteger(Addr, AddrSize, OS, IsLittleEndian))
-      return createStringError(
-          errc::not_supported,
-          "unable to write address for the operator %s: %s",
-          dwarf::RangeListEncodingString(Entry.Operator).str().c_str(),
-          toString(std::move(Err)).c_str());
-    return Error::success();
+    return writeListEntryAddress(EncodingName, OS, Addr, AddrSize,
+                                 IsLittleEndian);
   };
 
   switch (Entry.Operator) {
   case dwarf::DW_RLE_end_of_list:
     if (Error Err = CheckOperands(0))
       return std::move(Err);
     break;
   case dwarf::DW_RLE_base_addressx: