[llvm-objcopy][NFC] More error propagation

Summary: Do some more error cleanup, removing some dependencies from llvm-objcopy's error/reportError in [ELF/COFF]Objcopy methods.

Reviewers: jhenderson, alexshap, jakehehrlich, mstorsjo, espindola

Subscribers: emaste, arichardson

Differential Revision: https://reviews.llvm.org/D57423

llvm-svn: 352625
diff --git a/llvm/tools/llvm-objcopy/ELF/ELFObjcopy.cpp b/llvm/tools/llvm-objcopy/ELF/ELFObjcopy.cpp
index 9259996..7ba8db6 100644
--- a/llvm/tools/llvm-objcopy/ELF/ELFObjcopy.cpp
+++ b/llvm/tools/llvm-objcopy/ELF/ELFObjcopy.cpp
@@ -178,8 +178,8 @@
   }
 }
 
-static void splitDWOToFile(const CopyConfig &Config, const Reader &Reader,
-                           StringRef File, ElfType OutputElfType) {
+static Error splitDWOToFile(const CopyConfig &Config, const Reader &Reader,
+                            StringRef File, ElfType OutputElfType) {
   auto DWOFile = Reader.create();
   DWOFile->removeSections(
       [&](const SectionBase &Sec) { return onlyKeepDWOPred(*DWOFile, Sec); });
@@ -188,9 +188,8 @@
   FileBuffer FB(File);
   auto Writer = createWriter(Config, *DWOFile, FB, OutputElfType);
   if (Error E = Writer->finalize())
-    error(std::move(E));
-  if (Error E = Writer->write())
-    error(std::move(E));
+    return E;
+  return Writer->write();
 }
 
 static Error dumpSectionToFile(StringRef SecName, StringRef Filename,
@@ -269,12 +268,14 @@
 // any previous removals. Lastly whether or not something is removed shouldn't
 // depend a) on the order the options occur in or b) on some opaque priority
 // system. The only priority is that keeps/copies overrule removes.
-static void handleArgs(const CopyConfig &Config, Object &Obj,
-                       const Reader &Reader, ElfType OutputElfType) {
+static Error handleArgs(const CopyConfig &Config, Object &Obj,
+                        const Reader &Reader, ElfType OutputElfType) {
 
-  if (!Config.SplitDWO.empty()) {
-    splitDWOToFile(Config, Reader, Config.SplitDWO, OutputElfType);
-  }
+  if (!Config.SplitDWO.empty())
+    if (Error E =
+            splitDWOToFile(Config, Reader, Config.SplitDWO, OutputElfType))
+      return E;
+
   if (Config.OutputArch)
     Obj.Machine = Config.OutputArch.getValue().EMachine;
 
@@ -520,7 +521,7 @@
       ErrorOr<std::unique_ptr<MemoryBuffer>> BufOrErr =
           MemoryBuffer::getFile(File);
       if (!BufOrErr)
-        reportError(File, BufOrErr.getError());
+        return createFileError(File, errorCodeToError(BufOrErr.getError()));
       std::unique_ptr<MemoryBuffer> Buf = std::move(*BufOrErr);
       ArrayRef<uint8_t> Data(
           reinterpret_cast<const uint8_t *>(Buf->getBufferStart()),
@@ -538,16 +539,18 @@
       StringRef SecName = SecPair.first;
       StringRef File = SecPair.second;
       if (Error E = dumpSectionToFile(SecName, File, Obj))
-        reportError(Config.InputFilename, std::move(E));
+        return createFileError(Config.InputFilename, std::move(E));
     }
   }
 
   if (!Config.AddGnuDebugLink.empty())
     Obj.addSection<GnuDebugLinkSection>(Config.AddGnuDebugLink);
+
+  return Error::success();
 }
 
-void executeObjcopyOnRawBinary(const CopyConfig &Config, MemoryBuffer &In,
-                               Buffer &Out) {
+Error executeObjcopyOnRawBinary(const CopyConfig &Config, MemoryBuffer &In,
+                                Buffer &Out) {
   BinaryReader Reader(Config.BinaryArch, &In);
   std::unique_ptr<Object> Obj = Reader.create();
 
@@ -555,17 +558,17 @@
   // (-B<arch>).
   const ElfType OutputElfType = getOutputElfType(
       Config.OutputArch ? Config.OutputArch.getValue() : Config.BinaryArch);
-  handleArgs(Config, *Obj, Reader, OutputElfType);
+  if (Error E = handleArgs(Config, *Obj, Reader, OutputElfType))
+    return E;
   std::unique_ptr<Writer> Writer =
       createWriter(Config, *Obj, Out, OutputElfType);
   if (Error E = Writer->finalize())
-    error(std::move(E));
-  if (Error E = Writer->write())
-    error(std::move(E));
+    return E;
+  return Writer->write();
 }
 
-void executeObjcopyOnBinary(const CopyConfig &Config,
-                            object::ELFObjectFileBase &In, Buffer &Out) {
+Error executeObjcopyOnBinary(const CopyConfig &Config,
+                             object::ELFObjectFileBase &In, Buffer &Out) {
   ELFReader Reader(&In);
   std::unique_ptr<Object> Obj = Reader.create();
   // Prefer OutputArch (-O<format>) if set, otherwise infer it from the input.
@@ -577,25 +580,29 @@
   if (!Config.BuildIdLinkDir.empty()) {
     BuildIdBytes = unwrapOrError(findBuildID(In));
     if (BuildIdBytes.size() < 2)
-      error("build ID in file '" + Config.InputFilename +
-            "' is smaller than two bytes");
+      return createFileError(
+          Config.InputFilename,
+          createStringError(object_error::parse_failed,
+                            "build ID is smaller than two bytes."));
   }
 
   if (!Config.BuildIdLinkDir.empty() && Config.BuildIdLinkInput) {
     linkToBuildIdDir(Config, Config.InputFilename,
                      Config.BuildIdLinkInput.getValue(), BuildIdBytes);
   }
-  handleArgs(Config, *Obj, Reader, OutputElfType);
+  if (Error E = handleArgs(Config, *Obj, Reader, OutputElfType))
+    return E;
   std::unique_ptr<Writer> Writer =
       createWriter(Config, *Obj, Out, OutputElfType);
   if (Error E = Writer->finalize())
-    error(std::move(E));
+    return E;
   if (Error E = Writer->write())
-    error(std::move(E));
+    return E;
   if (!Config.BuildIdLinkDir.empty() && Config.BuildIdLinkOutput) {
     linkToBuildIdDir(Config, Config.OutputFilename,
                      Config.BuildIdLinkOutput.getValue(), BuildIdBytes);
   }
+  return Error::success();
 }
 
 } // end namespace elf