Check for invalid abbreviation operators in munged bitcode.

unittests/Bitcode/NaClMungeWriteErrorTests.cpp

 //===- llvm/unittest/Bitcode/NaClMungeWriteErrorTests.cpp -----------------===//
 //     Tests parser for PNaCl bitcode instructions.
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
@@ skipping 19 matching lines @@
   3, naclbitc::TYPE_CODE_FUNCTION, 0, 0, Terminator,
   0, naclbitc::BLK_CODE_EXIT, Terminator,
   3, naclbitc::MODULE_CODE_FUNCTION, 1, 0, 0, 0, Terminator,
   1, naclbitc::BLK_CODE_ENTER, naclbitc::FUNCTION_BLOCK_ID, 2, Terminator,
   3, naclbitc::FUNC_CODE_DECLAREBLOCKS, 1, Terminator,
   3, naclbitc::FUNC_CODE_INST_RET, Terminator,
   0, naclbitc::BLK_CODE_EXIT, Terminator,
   0, naclbitc::BLK_CODE_EXIT, Terminator
 };
 
+// Indices to records in bitcode.
+const uint64_t VoidTypeIndex = 3; // Index for "@t0 = void".
+const uint64_t RetVoidIndex = 9; // return void;
+const uint64_t LastExitBlockIndex = 11;
+
 // Expected output when bitcode records are dumped.
-const char* ExpectedDump =
+const char *ExpectedDumpedBitcode =
     "       0:0|<65532, 80, 69, 88, 69, 1, 0,|Magic Number: 'PEXE' (80, 69, "
     "88, 69)\n"
     "          | 8, 0, 17, 0, 4, 0, 2, 0, 0, |PNaCl Version: 2\n"
     "          | 0>                          |\n"
     "      16:0|1: <65535, 8, 2>             |module {  // BlockID = 8\n"
     "      24:0|  1: <65535, 17, 3>          |  types {  // BlockID = 17\n"
     "      32:0|    3: <1, 2>                |    count 2;\n"
     "      34:5|    3: <2>                   |    @t0 = void;\n"
     "      36:4|    3: <21, 0, 0>            |    @t1 = void ();\n"
     "      39:7|  0: <65534>                 |  }\n"
     "      44:0|  3: <8, 1, 0, 0, 0>         |  define external void @f0();\n"
     "      48:6|  1: <65535, 12, 2>          |  function void @f0() {  \n"
     "          |                             |                   // BlockID "
     "= 12\n"
     "      56:0|    3: <1, 1>                |    blocks 1;\n"
     "          |                             |  %b0:\n"
     "      58:4|    3: <10>                  |    ret void;\n"
     "      60:2|  0: <65534>                 |  }\n"
     "      64:0|0: <65534>                   |}\n"
     ;
 
+const char *UnableToContinue =
+      "Error: Unable to generate bitcode file due to write errors\n";
+
+const char *NoErrorRecoveryMessages = "";
+
+// Runs write munging tests on BitcodeRecords with the given Edits. It
+// then parses the written bitcode.  ErrorMessages is the expected
+// error messages logged by the write munging, when no error recovery
+// is allowed. ErrorRecoveryMessages are messages, in addition to
+// ErrorMessages, when the writer applies error recovery.
+void CheckParseEdits(const uint64_t *Edits, size_t EditsSize,
+                     std::string ErrorMessages,
+                     std::string ErrorRecoveryMessages) {
+  NaClParseBitcodeMunger Munger(ARRAY_TERM(BitcodeRecords));
+  EXPECT_FALSE(Munger.runTest(Edits, EditsSize, true));
+  std::string BadResults(ErrorMessages);
+  BadResults.append(UnableToContinue);
+  EXPECT_EQ(BadResults, Munger.getTestResults());
+
+  Munger.setTryToRecoverOnWrite(true);
+  EXPECT_TRUE(Munger.runTest(Edits, EditsSize, true));
+  std::string GoodResults(ErrorMessages);
+  GoodResults.append(ErrorRecoveryMessages);
+  GoodResults.append("Successful parse!\n");
+  EXPECT_EQ(GoodResults, Munger.getTestResults());
+}
+
+// Same as CheckParseEdits, but also runs the bitcode dumper on the
+//  written bitcode records.  DumpedBitcode is the expected dumped

[jvoung (off chromium), 2015/05/29 16:43:25]

extra space (line up comments)

[Karl, 2015/05/29 20:02:16]

Done.

+//  bitcode.
+void CheckDumpEdits(const uint64_t *Edits, size_t EditsSize,
+                    std::string ErrorMessages,
+                    std::string ErrorRecoveryMessages,
+                    std::string DumpedBitcode) {
+  NaClObjDumpMunger Munger(ARRAY_TERM(BitcodeRecords));
+  EXPECT_FALSE(Munger.runTest(Edits, EditsSize));
+  std::string BadResults(ErrorMessages);
+  BadResults.append(UnableToContinue);
+  EXPECT_EQ(BadResults, Munger.getTestResults());
+
+  Munger.setTryToRecoverOnWrite(true);
+  EXPECT_TRUE(Munger.runTest(Edits, EditsSize));
+  std::string GoodResults(ErrorMessages);
+  GoodResults.append(ErrorRecoveryMessages);
+  GoodResults.append(DumpedBitcode);
+  EXPECT_EQ(GoodResults, Munger.getTestResults());
+
+  // Verify that we can also parse the bitcode.
+  CheckParseEdits(Edits, EditsSize, ErrorMessages, ErrorRecoveryMessages);
+}
+
+// Same as ExpectedDumpedBitcode, but is just the records dumped by the
+// simplier write munger.

[jvoung (off chromium), 2015/05/29 16:43:25]

simplier -> simpler

[Karl, 2015/05/29 20:02:16]

Done.

+const char *ExpectedRecords =
+    "       1: [65535, 8, 2]\n"
+    "         1: [65535, 17, 3]\n"
+    "           3: [1, 2]\n"
+    "           3: [2]\n"
+    "           3: [21, 0, 0]\n"
+    "         0: [65534]\n"
+    "         3: [8, 1, 0, 0, 0]\n"
+    "         1: [65535, 12, 2]\n"
+    "           3: [1, 1]\n"
+    "           3: [10]\n"
+    "         0: [65534]\n"
+    "       0: [65534]\n";
+
+// Same as CheckParseEdits, but run the simplier write munger instead

[jvoung (off chromium), 2015/05/29 16:43:25]

simplier -> simpler

[Karl, 2015/05/29 20:02:16]

Done.

+// of the bitcode parser. Records is the the records dumped by the

[jvoung (off chromium), 2015/05/29 16:43:25]

the the -> the

[Karl, 2015/05/29 20:02:16]

Done.

+// write munger. This should be used in cases where the written munged
+// records is not valid bitcode.
+void CheckWriteEdits(const uint64_t *Edits, size_t EditsSize,
+                     std::string ExpectedErrorMessage,
+                     std::string ErrorRecoveryMessages,
+                     std::string Records) {
+  NaClWriteMunger Munger(ARRAY_TERM(BitcodeRecords));
+  EXPECT_FALSE(Munger.runTest(Edits, EditsSize));
+  std::string BadResults(ExpectedErrorMessage);
+  BadResults.append(UnableToContinue);
+  EXPECT_EQ(BadResults, Munger.getTestResults());
+
+  Munger.setTryToRecoverOnWrite(true);
+  EXPECT_TRUE(Munger.runTest(Edits, EditsSize));
+  std::string GoodResults(ExpectedErrorMessage);
+  GoodResults.append(ErrorRecoveryMessages);
+  GoodResults.append(Records);
+  EXPECT_EQ(GoodResults, Munger.getTestResults());
+}
+
+// Show that we can dump the bitcode records
+TEST(NaClMungeWriteErrorTests, DumpBitcodeRecords) {
+  NaClObjDumpMunger Munger(ARRAY_TERM(BitcodeRecords));
+  EXPECT_TRUE(Munger.runTest());
+  EXPECT_EQ(ExpectedDumpedBitcode, Munger.getTestResults());
+}
+
 // Edit to change void type with an illegal abbreviation index.
-const uint64_t VoidTypeIndex = 3; // Index for "@t0 = void".
 const uint64_t AbbrevIndex4VoidTypeEdit[] = {
   VoidTypeIndex, NaClMungedBitcode::Replace,
   4, naclbitc::TYPE_CODE_VOID, Terminator,
 };
 
-// Edit to add local abbreviation for "ret void", and then use on that
-// instruction.
-const uint64_t RetVoidIndex = 9; // return void;
-const uint64_t UseLocalRetVoidAbbrevEdits[] = {
-  RetVoidIndex, NaClMungedBitcode::AddBefore,
-    2, naclbitc::BLK_CODE_DEFINE_ABBREV, 1, 1,
-       naclbitc::FUNC_CODE_INST_RET, Terminator,
-  RetVoidIndex, NaClMungedBitcode::Replace,
-    4, naclbitc::FUNC_CODE_INST_RET, Terminator
-};
-
-// Show that we can dump the bitcode records
-TEST(NaClMungeWriteErrorTests, DumpBitcodeRecords) {
-  NaClObjDumpMunger Munger(ARRAY_TERM(BitcodeRecords));
-  EXPECT_TRUE(Munger.runTest());
-  EXPECT_EQ(ExpectedDump, Munger.getTestResults());
-}
-
 // Show that by default, one can't write a bad abbreviation index.
 TEST(NaClMungeWriteErrorTests, CantWriteBadAbbrevIndex) {
+  CheckDumpEdits(
+      ARRAY(AbbrevIndex4VoidTypeEdit),
+      "Error (Block 17): Uses illegal abbreviation index: 4: [2]\n",
+      NoErrorRecoveryMessages,
+      ExpectedDumpedBitcode);
+}
+
+// Show that writing out an illegal abbreviation index, causes the
+// parser to fail.
+TEST(MyNaClMungerWriteErrorTests, DieOnWriteBadAbbreviationIndex) {
   NaClWriteMunger Munger(ARRAY_TERM(BitcodeRecords));
-  EXPECT_FALSE(Munger.runTest(ARRAY(AbbrevIndex4VoidTypeEdit)));
-  EXPECT_EQ(
-      "Error (Block 17): Uses illegal abbreviation index: 4: [2]\n"
-      "Error: Unable to generate bitcode file due to write errors\n",
-      Munger.getTestResults());
-}
-
-// Show that we use more local abbreviations than specified in the
+  Munger.setWriteBadAbbrevIndex(true);
+  Munger.setRunAsDeathTest(true);
+  EXPECT_DEATH(
+      Munger.runTest(ARRAY(AbbrevIndex4VoidTypeEdit)),
+      ".*"
+      // Report problem while writing.
+      "Error \\(Block 17\\)\\: Uses illegal abbreviation index\\: 4\\: \\[2\\]"
+      ".*"
+      // Corresponding error while parsing.
+      "Fatal\\(35\\:0)\\: Invalid abbreviation \\# 4 defined for record"
+      ".*"
+      // Output of report_fatal_error.
+      "LLVM ERROR\\: Unable to continue"
+      ".*");
+}
+
+// Show what happens when we use more local abbreviations than specified in the
 // corresponding enclosing block.
 TEST(NaClMungeWriteErrorTests, CantWriteTooManyLocalAbbreviations) {
-  NaClWriteMunger Munger(ARRAY_TERM(BitcodeRecords));
-  Munger.munge(ARRAY(UseLocalRetVoidAbbrevEdits));
-  EXPECT_EQ(
-      "       1: [65535, 8, 2]\n"
-      "         1: [65535, 17, 3]\n"
-      "           3: [1, 2]\n"
-      "           3: [2]\n"
-      "           3: [21, 0, 0]\n"
-      "         0: [65534]\n"
-      "         3: [8, 1, 0, 0, 0]\n"
-      "         1: [65535, 12, 2]\n"      // Only allows 2 bits for abbrevs.
-      "           3: [1, 1]\n"
-      "           2: [65533, 1, 1, 10]\n" // defines abbev 4:
-      "           4: [10]\n"              // can't use, 4 can't fit in two bits.
-      "         0: [65534]\n"
-      "       0: [65534]\n",
-      stringify(Munger));
-
-  EXPECT_FALSE(Munger.runTest());
-  EXPECT_EQ(
-      "Error (Block 12): Uses illegal abbreviation index: 4: [10]\n"
-      "Error: Unable to generate bitcode file due to write errors\n",
-      Munger.getTestResults());
+  // Edit to add local abbreviation for "ret void", and then use on that
+  // instruction.
+  const uint64_t UseLocalRetVoidAbbrevEdits[] = {
+    RetVoidIndex, NaClMungedBitcode::AddBefore,
+    2, naclbitc::BLK_CODE_DEFINE_ABBREV, 1, 1,
+    naclbitc::FUNC_CODE_INST_RET, Terminator,
+    RetVoidIndex, NaClMungedBitcode::Replace,
+    4, naclbitc::FUNC_CODE_INST_RET, Terminator
+  };
+
+  CheckDumpEdits(
+      ARRAY(UseLocalRetVoidAbbrevEdits),
+      "Error (Block 12): Uses illegal abbreviation index: 4: [10]\n",
+      NoErrorRecoveryMessages,
+      "       0:0|<65532, 80, 69, 88, 69, 1, 0,|Magic Number: 'PEXE'"
+      " (80, 69, 88, 69)\n"
+      "          | 8, 0, 17, 0, 4, 0, 2, 0, 0, |PNaCl Version: 2\n"
+      "          | 0>                          |\n"
+      "      16:0|1: <65535, 8, 2>             |module {  // BlockID = 8\n"
+      "      24:0|  1: <65535, 17, 3>          |  types {  // BlockID = 17\n"
+      "      32:0|    3: <1, 2>                |    count 2;\n"
+      "      34:5|    3: <2>                   |    @t0 = void;\n"
+      "      36:4|    3: <21, 0, 0>            |    @t1 = void ();\n"
+      "      39:7|  0: <65534>                 |  }\n"
+      "      44:0|  3: <8, 1, 0, 0, 0>         |  define external void @f0();\n"
+      // Block only specifies 2 bits for abbreviations (i.e. limit = 3).
+      "      48:6|  1: <65535, 12, 2>          |  function void @f0() {  \n"
+      "          |                             |                   // BlockID"
+      " = 12\n"
+      "      56:0|    3: <1, 1>                |    blocks 1;\n"
+      // Added abbreviation. Defines abbreviation index 4.
+      "      58:4|    2: <65533, 1, 1, 10>     |    %a0 = abbrev <10>;\n"
+      "          |                             |  %b0:\n"
+      // Repaired abbreviation index of 4 (now 3).
+      "      60:4|    3: <10>                  |    ret void;\n"
+      "      62:2|  0: <65534>                 |  }\n"
+      "      64:0|0: <65534>                   |}\n");
 }
 
 // Show what happens when there are more enter blocks then exit blocks.
 TEST(NaClMungeWriteErrorTests, CantWriteTooManyEnterBlocks) {
-  NaClWriteMunger Munger(ARRAY_TERM(BitcodeRecords));
-  // Remove all but first two records (i.e. two enter blocks).
-  NaClMungedBitcode &MungedBitcode = Munger.getMungedBitcode();
-  for (size_t i = 2; i < MungedBitcode.getBaseRecords().size(); ++i) {
-    MungedBitcode.remove(i);
-  }
-
-  EXPECT_FALSE(Munger.runTest());
-  EXPECT_EQ(
+  // Remove all records except the first two records in BitcodeRecords.
+  const uint64_t Edits[] = {
+    2, NaClMungedBitcode::Remove,
+    3, NaClMungedBitcode::Remove,
+    4, NaClMungedBitcode::Remove,
+    5, NaClMungedBitcode::Remove,
+    6, NaClMungedBitcode::Remove,
+    7, NaClMungedBitcode::Remove,
+    8, NaClMungedBitcode::Remove,
+    9, NaClMungedBitcode::Remove,
+    10, NaClMungedBitcode::Remove,
+    11, NaClMungedBitcode::Remove
+  };
+  CheckDumpEdits(
+      ARRAY(Edits),
       "Error (Block 17): Missing close block.\n"
-      "Error (Block 8): Missing close block.\n"
-      "Error: Unable to generate bitcode file due to write errors\n",
-      Munger.getTestResults());
+      "Error (Block 8): Missing close block.\n",
+      NoErrorRecoveryMessages,
+      "       0:0|<65532, 80, 69, 88, 69, 1, 0,|Magic Number: 'PEXE' (80, 69,"
+      " 88, 69)\n"
+      "          | 8, 0, 17, 0, 4, 0, 2, 0, 0, |PNaCl Version: 2\n"
+      "          | 0>                          |\n"
+      "      16:0|1: <65535, 8, 2>             |module {  // BlockID = 8\n"
+      "      24:0|  1: <65535, 17, 3>          |  types {  // BlockID = 17\n"
+      "      32:0|  0: <65534>                 |  }\n"
+      "      36:0|0: <65534>                   |}\n");
 }
 
 // Show what happens when there are fewer enter blocks than exit
 // blocks.
 TEST(NaClMungeWriteErrorTests, CantWriteTooManyExitBlocks) {
-  NaClWriteMunger Munger(ARRAY_TERM(BitcodeRecords));
-  // Add two exit blocks.
-  NaClMungedBitcode &MungedBitcode = Munger.getMungedBitcode();
-  NaClRecordVector Values;
-  NaClBitcodeAbbrevRecord Record(0, naclbitc::BLK_CODE_EXIT, Values);
-  for (size_t i = 0; i < 2; ++i)
-    MungedBitcode.addAfter(MungedBitcode.getBaseRecords().size() - 1, Record);
-
-  EXPECT_FALSE(Munger.runTest());
-  EXPECT_EQ(
-      "Error (Block unknown): Extraneous exit block: 0: [65534]\n"
-      "Error: Unable to generate bitcode file due to write errors\n",
-      Munger.getTestResults());
+  // Add two blocks to the end of BitcodeRecords.
+  const uint64_t Edits[] = {
+    LastExitBlockIndex, NaClMungedBitcode::AddAfter,
+    naclbitc::END_BLOCK, naclbitc::BLK_CODE_EXIT, Terminator,
+    LastExitBlockIndex, NaClMungedBitcode::AddAfter,
+    naclbitc::END_BLOCK, naclbitc::BLK_CODE_EXIT, Terminator
+  };
+  CheckDumpEdits(
+      ARRAY(Edits),
+      "Error (Block unknown): Extraneous exit block: 0: [65534]\n",
+      "Error (Block unknown): Extraneous exit block: 0: [65534]\n",
+      ExpectedDumpedBitcode);
 }
 
 // Show that an error occurs when writing a bitcode record that isn't
 // in any block.
 TEST(NaClMungeWriteErrorTests, CantWriteRecordOutsideBlock) {
-  NaClWriteMunger Munger(ARRAY_TERM(BitcodeRecords));
-  NaClMungedBitcode &MungedBitcode = Munger.getMungedBitcode();
-  NaClRecordVector Values;
-  Values.push_back(4);
-  NaClBitcodeAbbrevRecord Record(naclbitc::UNABBREV_RECORD,
-                                 naclbitc::MODULE_CODE_VERSION,
-                                 Values);
-
-  MungedBitcode.addAfter(MungedBitcode.getBaseRecords().size() - 1, Record);
-  EXPECT_FALSE(Munger.runTest());
-  EXPECT_EQ(
-      "Error (Block unknown): Record outside block: 3: [1, 4]\n"
-      "Error: Unable to generate bitcode file due to write errors\n",
-      Munger.getTestResults());
+  const uint64_t Edit[] = {
+    LastExitBlockIndex, NaClMungedBitcode::AddAfter,
+    naclbitc::UNABBREV_RECORD, naclbitc::MODULE_CODE_VERSION,  4, Terminator
+  };
+  std::string Records(ExpectedRecords);
+  Records.append(
+      "       1: [65535, 4294967295, 3]\n"
+      "         3: [1, 4]\n"
+      "       0: [65534]\n");
+  CheckWriteEdits(
+      ARRAY(Edit),
+      "Error (Block unknown): Record outside block: 3: [1, 4]\n",
+      "Error (Block unknown): Missing close block.\n",
+      Records);
 }
 
 // Show that no error occurs if we write out the maximum allowable
 // block abbreviation index bit limit.
 TEST(NaClMungerWriteErrorTests, CanWriteBlockWithMaxLimit) {
   // Replace initial block enter with maximum bit size.
   const uint64_t Edit[] = {
     0, NaClMungedBitcode::Replace,
     1, naclbitc::BLK_CODE_ENTER, naclbitc::MODULE_BLOCK_ID,
        naclbitc::MaxAbbrevWidth, Terminator
   };
   NaClWriteMunger Munger(ARRAY_TERM(BitcodeRecords));
   EXPECT_TRUE(Munger.runTest(ARRAY(Edit)));
   EXPECT_EQ(
-      "       1: [65535, 8, 32]\n"
+      "       1: [65535, 8, 32]\n" // Max abbreviation bit limit (32).
       "         1: [65535, 17, 3]\n"
       "           3: [1, 2]\n"
       "           3: [2]\n"
       "           3: [21, 0, 0]\n"
       "         0: [65534]\n"
       "         3: [8, 1, 0, 0, 0]\n"
       "         1: [65535, 12, 2]\n"
       "           3: [1, 1]\n"
       "           3: [10]\n"
       "         0: [65534]\n"
       "       0: [65534]\n",
       Munger.getTestResults());
 }
 
 // Show that an error occurs if the block abbreviation index bit limit is
 // greater than the maximum allowable.
 TEST(NaClMungerWriteErrorTests, CantWriteBlockWithBadBitLimit) {
   // Replace initial block enter with value out of range.
   const uint64_t Edit[] = {
     0, NaClMungedBitcode::Replace,
     1, naclbitc::BLK_CODE_ENTER, naclbitc::MODULE_BLOCK_ID,
        naclbitc::MaxAbbrevWidth + 1, Terminator
   };
-  NaClWriteMunger Munger(ARRAY_TERM(BitcodeRecords));
-  EXPECT_FALSE(Munger.runTest(ARRAY(Edit)));
-  EXPECT_EQ(
+  CheckDumpEdits(
+      ARRAY(Edit),
       "Error (Block unknown): Block index bit limit 33 invalid. Must be in"
-      " [2..32]: 1: [65535, 8, 33]\n"
-      "Error: Unable to generate bitcode file due to write errors\n",
-      Munger.getTestResults());
+      " [2..32]: 1: [65535, 8, 33]\n",
+      "",
+      "       0:0|<65532, 80, 69, 88, 69, 1, 0,|Magic Number: 'PEXE' (80, 69,"
+      " 88, 69)\n"
+      "          | 8, 0, 17, 0, 4, 0, 2, 0, 0, |PNaCl Version: 2\n"
+      "          | 0>                          |\n"
+      // Corrected bitsize from 33 to 32.
+      "      16:0|1: <65535, 8, 32>            |module {  // BlockID = 8\n"
+      "      24:0|  1: <65535, 17, 3>          |  types {  // BlockID = 17\n"
+      "      36:0|    3: <1, 2>                |    count 2;\n"
+      "      38:5|    3: <2>                   |    @t0 = void;\n"
+      "      40:4|    3: <21, 0, 0>            |    @t1 = void ();\n"
+      "      43:7|  0: <65534>                 |  }\n"
+      "      48:0|  3: <8, 1, 0, 0, 0>         |  define external void @f0();\n"
+      "      56:4|  1: <65535, 12, 2>          |  function void @f0() {  \n"
+      "          |                             |                   // BlockID"
+      " = 12\n"
+      "      68:0|    3: <1, 1>                |    blocks 1;\n"
+      "          |                             |  %b0:\n"
+      "      70:4|    3: <10>                  |    ret void;\n"
+      "      72:2|  0: <65534>                 |  }\n"
+      "      76:0|0: <65534>                   |}\n");
 }
 
 // Show that we can't write an enter block with a very large block id.
 TEST(NaClMungerWriteErrorTests, CantWriteBlockWithLargeBlockID) {
   // Replace initial block enter with value out of range.
   const uint64_t Edit[] = {
     0, NaClMungedBitcode::Replace,
     1, naclbitc::BLK_CODE_ENTER, (uint64_t)1 << 33, 2, Terminator
   };
-  NaClWriteMunger Munger(ARRAY_TERM(BitcodeRecords));
-  EXPECT_FALSE(Munger.runTest(ARRAY(Edit)));
-  EXPECT_EQ(
+  CheckWriteEdits(
+      ARRAY(Edit),
       "Error (Block unknown): Block id must be <= 4294967295: 1:"
-      " [65535, 8589934592, 2]\n"
-      "Error: Unable to generate bitcode file due to write errors\n",
-      Munger.getTestResults());
-}
-
-// Show that writing successfully writes out an illegal abbreviation
-// index, and then the parser fails to parse that illegal abbreviation.
-TEST(MyNaClMungerWriteErrorTests, DieOnWriteBadAbbreviationIndex) {
-  NaClWriteMunger Munger(ARRAY_TERM(BitcodeRecords));
-  Munger.setWriteBadAbbrevIndex(true);
-  Munger.setRunAsDeathTest(true);
-  EXPECT_DEATH(
-      Munger.runTest(ARRAY(AbbrevIndex4VoidTypeEdit)),
-      ".*"
-      // Report problem while writing.
-      "Error \\(Block 17\\)\\: Uses illegal abbreviation index\\: 4\\: \\[2\\]"
-      ".*"
-      // Corresponding error while parsing.
-      "Fatal\\(35\\:0)\\: Invalid abbreviation \\# 4 defined for record"
-      ".*"
-      // Output of report_fatal_error.
-      "LLVM ERROR\\: Unable to continue"
-      ".*");
+      " [65535, 8589934592, 2]\n",
+      "",
+      // Note that the maximum block ID is used for recovery.
+      "       1: [65535, 4294967295, 2]\n"
+      "         1: [65535, 17, 3]\n"
+      "           3: [1, 2]\n"
+      "           3: [2]\n"
+      "           3: [21, 0, 0]\n"
+      "         0: [65534]\n"
+      "         3: [8, 1, 0, 0, 0]\n"
+      "         1: [65535, 12, 2]\n"
+      "           3: [1, 1]\n"
+      "           3: [10]\n"
+      "         0: [65534]\n"
+      "       0: [65534]\n");
 }
 
 // Show that we check that the abbreviation actually applies to the
 // record associated with that abbreviation. Also shows that we repair
 // the problem by applying the default abbreviation instead.
 TEST(NaClMungeWriteErrorsTests, TestMismatchedAbbreviation) {
   // Create edits to:
   // 1) Expand the number of abbreviation index bits for the block from 2 to 3.
   // 2) Introduce the incorrect abbreviation for the return instruction.
   //    i.e. [9] instead of [10].
   // 3) Apply the bad abbreviation to record "ret"
   const uint64_t FunctionEnterIndex = 7;
   const uint64_t Edits[] {
+    // Upped abbreviation index bits to 3
     FunctionEnterIndex, NaClMungedBitcode::Replace,
         1, naclbitc::BLK_CODE_ENTER, naclbitc::FUNCTION_BLOCK_ID, 3, Terminator,
+    // abbrev 4: [9]
     RetVoidIndex, NaClMungedBitcode::AddBefore,
         2, naclbitc::BLK_CODE_DEFINE_ABBREV, 1, 1,
         naclbitc::FUNC_CODE_INST_RET - 1, Terminator,
+    // "ret" with bad abbreviation (4).
     RetVoidIndex, NaClMungedBitcode::Replace,
         4, naclbitc::FUNC_CODE_INST_RET, Terminator
         };
 
-  NaClWriteMunger Munger(ARRAY_TERM(BitcodeRecords));
-  Munger.munge(ARRAY(Edits));
-  EXPECT_EQ(
-      "       1: [65535, 8, 2]\n"
-      "         1: [65535, 17, 3]\n"
-      "           3: [1, 2]\n"
-      "           3: [2]\n"
-      "           3: [21, 0, 0]\n"
-      "         0: [65534]\n"
-      "         3: [8, 1, 0, 0, 0]\n"
-      "         1: [65535, 12, 3]\n"     // Upped abbreviation index bits to 3
-      "           3: [1, 1]\n"
-      "           2: [65533, 1, 1, 9]\n" // added abbrev 4: [9]
-      "           4: [10]\n"             // "ret" with bad abbreviation.
-      "         0: [65534]\n"
-      "       0: [65534]\n",
-      stringify(Munger));
-
-  // Show detected error
-  EXPECT_FALSE(Munger.runTest());
-  EXPECT_EQ(
-      "Error (Block 12): Abbreviation doesn't apply to record: 4: [10]\n"
-      "Error: Unable to generate bitcode file due to write errors\n",
-      Munger.getTestResults());
-
-  // Show that the writer can recover.
-  Munger.setTryToRecoverOnWrite(true);
-  EXPECT_TRUE(Munger.runTest(ARRAY(Edits)));
-  EXPECT_EQ(
-      "Error (Block 12): Abbreviation doesn't apply to record: 4: [10]\n"
-      "       1: [65535, 8, 2]\n"
-      "         1: [65535, 17, 3]\n"
-      "           3: [1, 2]\n"
-      "           3: [2]\n"
-      "           3: [21, 0, 0]\n"
-      "         0: [65534]\n"
-      "         3: [8, 1, 0, 0, 0]\n"
-      "         1: [65535, 12, 3]\n"
-      "           3: [1, 1]\n"
-      "           2: [65533, 1, 1, 9]\n"
-      "           3: [10]\n"              // Implicit repair here.
-      "         0: [65534]\n"
-      "       0: [65534]\n",
-      Munger.getTestResults());
+  CheckDumpEdits(
+      ARRAY(Edits),
+      "Error (Block 12): Abbreviation doesn't apply to record: 4: [10]\n",
+      "",
+      "       0:0|<65532, 80, 69, 88, 69, 1, 0,|Magic Number: 'PEXE' (80, 69,"
+      " 88, 69)\n"
+      "          | 8, 0, 17, 0, 4, 0, 2, 0, 0, |PNaCl Version: 2\n"
+      "          | 0>                          |\n"
+      "      16:0|1: <65535, 8, 2>             |module {  // BlockID = 8\n"
+      "      24:0|  1: <65535, 17, 3>          |  types {  // BlockID = 17\n"
+      "      32:0|    3: <1, 2>                |    count 2;\n"
+      "      34:5|    3: <2>                   |    @t0 = void;\n"
+      "      36:4|    3: <21, 0, 0>            |    @t1 = void ();\n"
+      "      39:7|  0: <65534>                 |  }\n"
+      "      44:0|  3: <8, 1, 0, 0, 0>         |  define external void @f0();\n"
+      // Upped abbreviation index bits to 3
+      "      48:6|  1: <65535, 12, 3>          |  function void @f0() {  \n"
+      "          |                             |                   // BlockID"
+      " = 12\n"
+      "      56:0|    3: <1, 1>                |    blocks 1;\n"
+      // added abbrev 4: [9]
+      "      58:5|    2: <65533, 1, 1, 9>      |    %a0 = abbrev <9>;\n"
+      "          |                             |  %b0:\n"
+      // Implicit repair of abbreviation index (from 4 to 3: the default abbrev)
+      "      60:6|    3: <10>                  |    ret void;\n"
+      "      62:5|  0: <65534>                 |  }\n"
+      "      64:0|0: <65534>                   |}\n");
 }
 
 // Show that we recognize when an abbreviation definition record is
 // malformed.  Also show that we repair the problem by removing the
 // definition.
 TEST(NaClMungeWriteErrorsTests, TestWritingMalformedAbbreviation) {
   // Create edits to:
   // 1) Expand the number of abbreviation index bits for the block from 2 to 3.
   // 2) Leave out the "literal" operand encoding out.
   const uint64_t FunctionEnterIndex = 7;
   const uint64_t Edits[] {
     FunctionEnterIndex, NaClMungedBitcode::Replace,   // Set Abbrev bits = 3
         1, naclbitc::BLK_CODE_ENTER, naclbitc::FUNCTION_BLOCK_ID, 3, Terminator,
     RetVoidIndex, NaClMungedBitcode::AddBefore,
         // Bad abbreviation! Intentionally leave out "literal" operand: 1
         2, naclbitc::BLK_CODE_DEFINE_ABBREV, 1, // 1,
         naclbitc::FUNC_CODE_INST_RET, Terminator,
         };
 
-  // Show that the error is detected.
-  NaClWriteMunger Munger(ARRAY_TERM(BitcodeRecords));
-  EXPECT_FALSE(Munger.runTest(ARRAY(Edits)));
-  EXPECT_EQ(
-      "Error (Block 12): Error: Bad abbreviation operand encoding 10:"
-      " 2: [65533, 1, 10]\n"
-      "Error: Unable to generate bitcode file due to write errors\n",
-      Munger.getTestResults());
-
-  // Show that the writer can recover.
-  Munger.setTryToRecoverOnWrite(true);
-  EXPECT_TRUE(Munger.runTest(ARRAY(Edits)));
-  EXPECT_EQ(
-      "Error (Block 12): Error: Bad abbreviation operand encoding 10: "
-      "2: [65533, 1, 10]\n"
-      "       1: [65535, 8, 2]\n"
-      "         1: [65535, 17, 3]\n"
-      "           3: [1, 2]\n"
-      "           3: [2]\n"
-      "           3: [21, 0, 0]\n"
-      "         0: [65534]\n"
-      "         3: [8, 1, 0, 0, 0]\n"
-      "         1: [65535, 12, 3]\n"  // Note: not followed by abbreviation def.
-      "           3: [1, 1]\n"
-      "           3: [10]\n"
-      "         0: [65534]\n"
-      "       0: [65534]\n",
-      Munger.getTestResults());
+  CheckDumpEdits(
+      ARRAY(Edits),
+      "Error (Block 12): Bad abbreviation operand encoding 10:"
+      " 2: [65533, 1, 10]\n",
+      "",
+      "       0:0|<65532, 80, 69, 88, 69, 1, 0,|Magic Number: 'PEXE' (80, 69,"
+      " 88, 69)\n"
+      "          | 8, 0, 17, 0, 4, 0, 2, 0, 0, |PNaCl Version: 2\n"
+      "          | 0>                          |\n"
+      "      16:0|1: <65535, 8, 2>             |module {  // BlockID = 8\n"
+      "      24:0|  1: <65535, 17, 3>          |  types {  // BlockID = 17\n"
+      "      32:0|    3: <1, 2>                |    count 2;\n"
+      "      34:5|    3: <2>                   |    @t0 = void;\n"
+      "      36:4|    3: <21, 0, 0>            |    @t1 = void ();\n"
+      "      39:7|  0: <65534>                 |  }\n"
+      "      44:0|  3: <8, 1, 0, 0, 0>         |  define external void @f0();\n"
+      // Edit to change number of abbrev bits to 3.
+      "      48:6|  1: <65535, 12, 3>          |  function void @f0() {  \n"
+      "          |                             |                   // BlockID"
+      " = 12\n"
+      "      56:0|    3: <1, 1>                |    blocks 1;\n"
+      "          |                             |  %b0:\n"
+      "      58:5|    3: <10>                  |    ret void;\n"
+      "      60:4|  0: <65534>                 |  }\n"
+      "      64:0|0: <65534>                   |}\n");
 }
 
 // Show how we deal with additional abbreviations defined for a block,
 // once a bad abbreviation definition record is found. That is, we
 // remove all succeeding abbreviations definitions for that block. In
 // addition, any record refering to a remove abbreviation is changed
 // to use the default abbreviation.
 TEST(NaClMungedWriteErrorTests, TestRemovingAbbrevWithMultAbbrevs) {
   NaClWriteMunger Munger(ARRAY_TERM(BitcodeRecords));
   const uint64_t FunctionEnterIndex = 7;
   const uint64_t Edits[] {
     FunctionEnterIndex, NaClMungedBitcode::Replace,   // Set Abbrev bits = 3
         1, naclbitc::BLK_CODE_ENTER, naclbitc::FUNCTION_BLOCK_ID, 3, Terminator,
     RetVoidIndex, NaClMungedBitcode::AddBefore,  // bad abbreviation!
         2, naclbitc::BLK_CODE_DEFINE_ABBREV, 1, // 1,
         naclbitc::FUNC_CODE_INST_RET - 1, Terminator,
     RetVoidIndex, NaClMungedBitcode::AddBefore,  // good abbreviation to ignore.
         2, naclbitc::BLK_CODE_DEFINE_ABBREV, 1, 1,
         naclbitc::FUNC_CODE_INST_RET, Terminator,
     RetVoidIndex, NaClMungedBitcode::Replace,  // reference to good abreviation.
         5, naclbitc::FUNC_CODE_INST_RET, Terminator
         };
 
-  Munger.setTryToRecoverOnWrite(true);
-  EXPECT_TRUE(Munger.runTest(ARRAY(Edits)));
-  EXPECT_EQ(
-      "Error (Block 12): Error: Bad abbreviation operand encoding 9:"
-      " 2: [65533, 1, 9]\n"
+  CheckDumpEdits(
+      ARRAY(Edits),
+      "Error (Block 12): Bad abbreviation operand encoding 9:"
+      " 2: [65533, 1, 9]\n",
       "Error (Block 12): Ignoring abbreviation: 2: [65533, 1, 1, 10]\n"
-      "Error (Block 12): Uses illegal abbreviation index: 5: [10]\n"
-      "       1: [65535, 8, 2]\n"
-      "         1: [65535, 17, 3]\n"
-      "           3: [1, 2]\n"
-      "           3: [2]\n"
-      "           3: [21, 0, 0]\n"
-      "         0: [65534]\n"
-      "         3: [8, 1, 0, 0, 0]\n"
-      "         1: [65535, 12, 3]\n"
-      "           3: [1, 1]\n"
-      "           3: [10]\n"     // Abbreviation index 5 replaced with default.
-      "         0: [65534]\n"
-      "       0: [65534]\n",
-      Munger.getTestResults());
-}
-
-// Show that error recovery works when writing an illegal abbreviation
-// index. Show success by parsing fixed bitcode.
-TEST(NaClMungeWriteErrorTests, RecoverWhenParsingBadAbbrevIndex) {
-  NaClParseBitcodeMunger Munger(ARRAY_TERM(BitcodeRecords));
-  Munger.setTryToRecoverOnWrite(true);
-  EXPECT_TRUE(
-      Munger.runTest(ARRAY(AbbrevIndex4VoidTypeEdit), true));
-  EXPECT_EQ(
-      "Error (Block 17): Uses illegal abbreviation index: 4: [2]\n"
-      "Successful parse!\n",
-      Munger.getTestResults());
-}
-
-// Show that error recovery works when writing an illegal abbreviation
-// index.  Show success by Dumping fixed bitcode.
-TEST(NaClMungeWriteErrorTests, RecoverWhenParsingBadAbbreviationIndex) {
-  NaClObjDumpMunger Munger(ARRAY_TERM(BitcodeRecords));
-  Munger.setTryToRecoverOnWrite(true);
-  EXPECT_TRUE(Munger.runTest(ARRAY(AbbrevIndex4VoidTypeEdit)));
-  std::string Results(
-      "Error (Block 17): Uses illegal abbreviation index: 4: [2]\n");
-  Results.append(ExpectedDump);
-  EXPECT_EQ(Results, Munger.getTestResults());
-}
-
-// Show that error recovery works when writing too many locally
-// defined abbreviations for the corresponding number of bits defined
-// in the corresponding enter block. Show success by dumping the fixed
-// bitcode.
-TEST(NaClMungeWriteErrorTests, RecoverTooManyLocalAbbreviations) {
-  NaClObjDumpMunger Munger(ARRAY_TERM(BitcodeRecords));
-  Munger.setTryToRecoverOnWrite(true);
-  Munger.munge(ARRAY(UseLocalRetVoidAbbrevEdits));
-  EXPECT_TRUE(Munger.runTest());
-  EXPECT_EQ(
-      "Error (Block 12): Uses illegal abbreviation index: 4: [10]\n"
-      "       0:0|<65532, 80, 69, 88, 69, 1, 0,|Magic Number: 'PEXE'"
-      " (80, 69, 88, 69)\n"
+      "Error (Block 12): Uses illegal abbreviation index: 5: [10]\n",
+      "       0:0|<65532, 80, 69, 88, 69, 1, 0,|Magic Number: 'PEXE' (80, 69,"
+      " 88, 69)\n"
       "          | 8, 0, 17, 0, 4, 0, 2, 0, 0, |PNaCl Version: 2\n"
       "          | 0>                          |\n"
       "      16:0|1: <65535, 8, 2>             |module {  // BlockID = 8\n"
       "      24:0|  1: <65535, 17, 3>          |  types {  // BlockID = 17\n"
       "      32:0|    3: <1, 2>                |    count 2;\n"
       "      34:5|    3: <2>                   |    @t0 = void;\n"
       "      36:4|    3: <21, 0, 0>            |    @t1 = void ();\n"
       "      39:7|  0: <65534>                 |  }\n"
       "      44:0|  3: <8, 1, 0, 0, 0>         |  define external void @f0();\n"
-      // Block only specifies 2 bits for abbreviations (i.e. limit = 3).
-      "      48:6|  1: <65535, 12, 2>          |  function void @f0() {  \n"
+      // Edit to change number of abbrev bits to 3.
+      "      48:6|  1: <65535, 12, 3>          |  function void @f0() {  \n"
       "          |                             |                   // BlockID"
       " = 12\n"
       "      56:0|    3: <1, 1>                |    blocks 1;\n"
-      // Added abbreviation. Defines abbreviation index 4.
-      "      58:4|    2: <65533, 1, 1, 10>     |    %a0 = abbrev <10>;\n"
       "          |                             |  %b0:\n"
-      // Repaired abbreviation index of 4 (now 3).
-      "      60:4|    3: <10>                  |    ret void;\n"
-      "      62:2|  0: <65534>                 |  }\n"
-      "      64:0|0: <65534>                   |}\n",
-      Munger.getTestResults());
+      "      58:5|    3: <10>                  |    ret void;\n"
+      "      60:4|  0: <65534>                 |  }\n"
+      "      64:0|0: <65534>                   |}\n");
 }
 
-// Show that error recovery works when writing and there are more
-// enter blocks than exit blocks. Show success by dumping fixed
-// bitcode.
-TEST(NaClMungeWriteErrorTests, RecoverTooManyEnterBlocks) {
-  NaClObjDumpMunger Munger(ARRAY_TERM(BitcodeRecords));
-  // Remove all but first two records (i.e. two enter blocks).
-  NaClMungedBitcode &MungedBitcode = Munger.getMungedBitcode();
-  for (size_t i = 2; i < MungedBitcode.getBaseRecords().size(); ++i) {
-    MungedBitcode.remove(i);
-  }
-
-  Munger.setTryToRecoverOnWrite(true);
-  EXPECT_TRUE(Munger.runTest());
-  EXPECT_EQ(
-      "Error (Block 17): Missing close block.\n"
-      "Error (Block 8): Missing close block.\n"
-      "       0:0|<65532, 80, 69, 88, 69, 1, 0,|Magic Number: 'PEXE' (80, 69,"
-      " 88, 69)\n"
-      "          | 8, 0, 17, 0, 4, 0, 2, 0, 0, |PNaCl Version: 2\n"
-      "          | 0>                          |\n"
-      "      16:0|1: <65535, 8, 2>             |module {  // BlockID = 8\n"
-      "      24:0|  1: <65535, 17, 3>          |  types {  // BlockID = 17\n"
-      "      32:0|  0: <65534>                 |  }\n"
-      "      36:0|0: <65534>                   |}\n",
-      Munger.getTestResults());
+// Show that inserting an abbreviation with a bad fixed width is dealt with.
+TEST(NaClMungeWriteErrorTests, InvalidFixedAbbreviationSize) {
+  // Insert bad abbreviation Fixed(36) into type block.
+  assert(36 > naclbitc::MaxAbbrevWidth);
+  const uint64_t Edit[] = {
+    VoidTypeIndex, NaClMungedBitcode::AddBefore,
+    naclbitc::DEFINE_ABBREV, naclbitc::BLK_CODE_DEFINE_ABBREV, 1,
+    0, NaClBitCodeAbbrevOp::Fixed, 36, Terminator
+  };
+  CheckDumpEdits(
+      ARRAY(Edit),
+      "Error (Block 17): Invalid abbreviation Fixed(36) in: 2: [65533, 1, 0,"
+      " 1, 36]\n",
+      NoErrorRecoveryMessages,
+      ExpectedDumpedBitcode);
 }
 
-// Show that error recovery works when writing and there are fewer
-// enter blocks than exit blocks. Show success by dumping the fixed
-// bitcode.
-TEST(NaClMungeWriteErrorTests, RecoverTooManyExitBlocks) {
-  NaClObjDumpMunger Munger(ARRAY_TERM(BitcodeRecords));
-  // Add two exit blocks.
-  NaClMungedBitcode &MungedBitcode = Munger.getMungedBitcode();
-  NaClRecordVector Values;
-  NaClBitcodeAbbrevRecord Record(0, naclbitc::BLK_CODE_EXIT, Values);
-  for (size_t i = 0; i < 2; ++i)
-    MungedBitcode.addAfter(MungedBitcode.getBaseRecords().size() - 1, Record);
-
-  Munger.setTryToRecoverOnWrite(true);
-  EXPECT_TRUE(Munger.runTest());
-  std::string Results(
-      "Error (Block unknown): Extraneous exit block: 0: [65534]\n"
-      "Error (Block unknown): Extraneous exit block: 0: [65534]\n");
-  Results.append(ExpectedDump);
-  EXPECT_EQ(
-      Results,
-      Munger.getTestResults());
+// Show that inserting an abbreviation with a bad vbr width is dealt with.
+TEST(NaClMungeWriteErrorTests, InvalidVbrAbbreviationSize) {
+  // Insert bad abbreviation Vbr(36) into type block.
+  assert(36 > naclbitc::MaxAbbrevWidth);
+  const uint64_t Edit[] = {
+    VoidTypeIndex, NaClMungedBitcode::AddBefore,
+    naclbitc::DEFINE_ABBREV, naclbitc::BLK_CODE_DEFINE_ABBREV, 1,
+    0, NaClBitCodeAbbrevOp::VBR, 36, Terminator
+  };
+  CheckDumpEdits(
+      ARRAY(Edit),
+      "Error (Block 17): Invalid abbreviation VBR(36) in: 2: [65533, 1, 0,"
+      " 2, 36]\n",
+      NoErrorRecoveryMessages,
+      ExpectedDumpedBitcode);
 }
 
-// Show that error recovery works when writing a bitcode record that
-// isn't in any block. Show success by showing fixed bitcode records.
-TEST(NaClMungeWriteErrorTests, RecoverWriteRecordOutsideBlock) {
-  NaClWriteMunger Munger(ARRAY_TERM(BitcodeRecords));
-  NaClMungedBitcode &MungedBitcode = Munger.getMungedBitcode();
-  NaClRecordVector Values;
-  Values.push_back(4);
-  NaClBitcodeAbbrevRecord Record(naclbitc::UNABBREV_RECORD,
-                                 naclbitc::MODULE_CODE_VERSION,
-                                 Values);
-  MungedBitcode.addAfter(MungedBitcode.getBaseRecords().size() - 1, Record);
+// Show that the array operator can't appear last.
+TEST(NaClMungeWriteErrorTests, InvalidArrayAbbreviationLast) {
+  const uint64_t Edit[] = {
+    VoidTypeIndex, NaClMungedBitcode::AddBefore,
+    naclbitc::DEFINE_ABBREV, naclbitc::BLK_CODE_DEFINE_ABBREV, 1,
+    0, NaClBitCodeAbbrevOp::Array, Terminator
+  };
+  CheckDumpEdits(
+      ARRAY(Edit),
+      "Error (Block 17): Array abbreviation must be second to last: 2: [65533,"
+      " 1, 0, 3]\n",
+      NoErrorRecoveryMessages,
+      ExpectedDumpedBitcode);
+}
 
-  Munger.setTryToRecoverOnWrite(true);
-  EXPECT_TRUE(Munger.runTest());
-  EXPECT_EQ(
-      "Error (Block unknown): Record outside block: 3: [1, 4]\n"
-      "Error (Block unknown): Missing close block.\n"
-      "       1: [65535, 8, 2]\n"
-      "         1: [65535, 17, 3]\n"
-      "           3: [1, 2]\n"
-      "           3: [2]\n"
-      "           3: [21, 0, 0]\n"
-      "         0: [65534]\n"
-      "         3: [8, 1, 0, 0, 0]\n"
-      "         1: [65535, 12, 2]\n"
-      "           3: [1, 1]\n"
-      "           3: [10]\n"
-      "         0: [65534]\n"
-      "       0: [65534]\n"
-      "       1: [65535, 4294967295, 3]\n"
-      "         3: [1, 4]\n"
-      "       0: [65534]\n",
-      Munger.getTestResults());
+// Show that the array operator can't appear before the second to last
+// operand.
+TEST(NaClMungeWriteErrorTests, InvalidArrayAbbreviationTooEarly) {
+  const uint64_t Edit[] = {
+    VoidTypeIndex, NaClMungedBitcode::AddBefore,
+    naclbitc::DEFINE_ABBREV, naclbitc::BLK_CODE_DEFINE_ABBREV, 3,
+    0, NaClBitCodeAbbrevOp::Array,  // array
+    1, 15,                          // lit(15)
+    1, 10,                          // lit(10)
+    Terminator
+  };
+  CheckDumpEdits(
+      ARRAY(Edit),
+      "Error (Block 17): Array abbreviation must be second to last: 2: [65533,"
+      " 3, 0, 3, 1, 15, 1, 10]\n",
+      NoErrorRecoveryMessages,
+      ExpectedDumpedBitcode);
+}
+
+// Show that the array operator can't appear as last two operators.
+TEST(NaClMungeWriteErrorTests, InvalidArrayAbbreviationLastTwo) {
+  const uint64_t Edit[] = {
+    VoidTypeIndex, NaClMungedBitcode::AddBefore,
+    naclbitc::DEFINE_ABBREV, naclbitc::BLK_CODE_DEFINE_ABBREV, 2,
+    0, NaClBitCodeAbbrevOp::Array,  // array
+    0, NaClBitCodeAbbrevOp::Array,  // array
+    Terminator
+  };
+  CheckDumpEdits(
+      ARRAY(Edit),
+      "Error (Block 17): Array abbreviation must be second to last: 2: [65533,"
+      " 2, 0, 3, 0, 3]\n",
+      NoErrorRecoveryMessages,
+      ExpectedDumpedBitcode);
+}
+
+// Show what happens when an abbreviation is specified to only contain
+// one operator, but is then followed with more than one operator.
+TEST(NaClMungeWriteErrorTests, SpecifiesTooFewOperands) {
+  const uint64_t Edit[] = {
+    VoidTypeIndex, NaClMungedBitcode::AddBefore,
+    // Note: 1 at end of next line specified that the abbreviation
+    // should only have one operator.
+    naclbitc::DEFINE_ABBREV, naclbitc::BLK_CODE_DEFINE_ABBREV, 1,
+    1, 10,                          // lit(10)
+    1, 15,                          // lit(15)
+    Terminator
+  };
+  CheckDumpEdits(
+      ARRAY(Edit),
+      "Error (Block 17): Error: Too many values for number of operands (1):"
+      " 2: [65533, 1, 1, 10, 1, 15]\n",
+      NoErrorRecoveryMessages,
+      ExpectedDumpedBitcode);
+}
+
+// Show that the code checks if specifies too many operands for an
+// abbreviation, based on the record size.
+TEST(NaClMungeWriteErrorTests, SpecifiesTooManyOperands) {
+  // Insert bad abbreviation Vbr(36) into type block.
+  const uint64_t Edit[] = {
+    VoidTypeIndex, NaClMungedBitcode::AddBefore,
+    naclbitc::DEFINE_ABBREV, naclbitc::BLK_CODE_DEFINE_ABBREV, 3,
+    1, 10,                          // lit(10)
+    1, 15,                          // lit(15)
+    Terminator
+  };
+  CheckDumpEdits(
+      ARRAY(Edit),
+      "Error (Block 17): Malformed abbreviation found: 2: [65533, 3, 1, 10,"
+      " 1, 15]\n",
+      NoErrorRecoveryMessages,
+      ExpectedDumpedBitcode);
 }
 
 } // end of namespace naclmungetest