[clang-doc] Remove uses of consumeErrorusers/ilovepi/remove-consume-error

In BitcodeReader, we were using consumeError(), which drops the error
and hides it from normal usage. To avoid that, we can just slightly
tweak the API to return an Expected<T>, and propagate the error
accordingly.

2 files changed, 21 insertions, 27 deletions

diff --git a/clang-tools-extra/clang-doc/BitcodeReader.cpp b/clang-tools-extra/clang-doc/BitcodeReader.cpp
index 4efbbd34730c..0af7aeb1d350 100644
--- a/clang-tools-extra/clang-doc/BitcodeReader.cpp
+++ b/clang-tools-extra/clang-doc/BitcodeReader.cpp
@@ -847,9 +847,11 @@ llvm::Error ClangDocBitcodeReader::readBlock(unsigned ID, T I) {
 
   while (true) {
     unsigned BlockOrCode = 0;
-    Cursor Res = skipUntilRecordOrBlock(BlockOrCode);
+    llvm::Expected<Cursor> C = skipUntilRecordOrBlock(BlockOrCode);
+    if (!C)
+      return C.takeError();
 
-    switch (Res) {
+    switch (*C) {
     case Cursor::BadBlock:
       return llvm::createStringError(llvm::inconvertibleErrorCode(),
                                      "bad block found");
@@ -985,45 +987,39 @@ llvm::Error ClangDocBitcodeReader::readSubBlock(unsigned ID, T I) {
   }
 }
 
-ClangDocBitcodeReader::Cursor
+llvm::Expected<ClangDocBitcodeReader::Cursor>
 ClangDocBitcodeReader::skipUntilRecordOrBlock(unsigned &BlockOrRecordID) {
   llvm::TimeTraceScope("Reducing infos", "skipUntilRecordOrBlock");
   BlockOrRecordID = 0;
 
   while (!Stream.AtEndOfStream()) {
-    Expected<unsigned> MaybeCode = Stream.ReadCode();
-    if (!MaybeCode) {
-      // FIXME this drops the error on the floor.
-      consumeError(MaybeCode.takeError());
-      return Cursor::BadBlock;
-    }
+    Expected<unsigned> Code = Stream.ReadCode();
+    if (!Code)
+      return Code.takeError();
 
-    unsigned Code = MaybeCode.get();
-    if (Code >= static_cast<unsigned>(llvm::bitc::FIRST_APPLICATION_ABBREV)) {
+    if (*Code >= static_cast<unsigned>(llvm::bitc::FIRST_APPLICATION_ABBREV)) {
       BlockOrRecordID = Code;
       return Cursor::Record;
     }
-    switch (static_cast<llvm::bitc::FixedAbbrevIDs>(Code)) {
+    switch (static_cast<llvm::bitc::FixedAbbrevIDs>(*Code)) {
     case llvm::bitc::ENTER_SUBBLOCK:
       if (Expected<unsigned> MaybeID = Stream.ReadSubBlockID())
         BlockOrRecordID = MaybeID.get();
-      else {
-        // FIXME this drops the error on the floor.
-        consumeError(MaybeID.takeError());
-      }
+      else
+        return MaybeID.takeError();
       return Cursor::BlockBegin;
     case llvm::bitc::END_BLOCK:
       if (Stream.ReadBlockEnd())
-        return Cursor::BadBlock;
+        return llvm::createStringError(llvm::inconvertibleErrorCode(),
+                                       "error at end of block");
       return Cursor::BlockEnd;
     case llvm::bitc::DEFINE_ABBREV:
-      if (llvm::Error Err = Stream.ReadAbbrevRecord()) {
-        // FIXME this drops the error on the floor.
-        consumeError(std::move(Err));
-      }
+      if (llvm::Error Err = Stream.ReadAbbrevRecord())
+        return std::move(Err);
       continue;
     case llvm::bitc::UNABBREV_RECORD:
-      return Cursor::BadBlock;
+      return llvm::createStringError(llvm::inconvertibleErrorCode(),
+                                     "found unabbreviated record");
     case llvm::bitc::FIRST_APPLICATION_ABBREV:
       llvm_unreachable("Unexpected abbrev id.");
     }
@@ -1149,10 +1145,8 @@ ClangDocBitcodeReader::readBitcode() {
         return std::move(Err);
       continue;
     default:
-      if (llvm::Error Err = Stream.SkipBlock()) {
-        // FIXME this drops the error on the floor.
-        consumeError(std::move(Err));
-      }
+      if (llvm::Error Err = Stream.SkipBlock())
+        return std::move(Err);
       continue;
     }
   }
diff --git a/clang-tools-extra/clang-doc/BitcodeReader.h b/clang-tools-extra/clang-doc/BitcodeReader.h
index 4947721f0a06..0f7f4f256f15 100644
--- a/clang-tools-extra/clang-doc/BitcodeReader.h
+++ b/clang-tools-extra/clang-doc/BitcodeReader.h
@@ -59,7 +59,7 @@ private:
 
   // Helper function to step through blocks to find and dispatch the next record
   // or block to be read.
-  Cursor skipUntilRecordOrBlock(unsigned &BlockOrRecordID);
+  llvm::Expected<Cursor> skipUntilRecordOrBlock(unsigned &BlockOrRecordID);
 
   // Helper function to set up the appropriate type of Info.
   llvm::Expected<std::unique_ptr<Info>> readBlockToInfo(unsigned ID);