Add abilities to generate bitcode buffers from munged bitcode.

unittests/Bitcode/NaClMungedIoTest.cpp

+//===- llvm/unittest/Bitcode/NaClMungedIoTest.cpp -------------------===//

[jvoung (off chromium), 2015/05/05 00:27:23]

could fill up the --- to line up

[Karl, 2015/05/05 22:38:04]

Done.

+//     Tests munging NaCl bitcode records.
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// For class NaClMungedBitcode, Tests reading initial sequence of records and

[jvoung (off chromium), 2015/05/05 00:27:23]

", Tests reading" -> ", tests reading"

[Karl, 2015/05/05 22:38:04]

Done.

+// writing out munged set of bitcode records.
+
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/Bitcode/NaCl/NaClBitcodeMungeUtils.h"
+#include "llvm/Bitcode/NaCl/NaClBitcodeMunge.h"
+
+#include "gtest/gtest.h"
+
+using namespace llvm;
+
+namespace {
+
+static const uint64_t Terminator = 0x5768798008978675LL;
+
+#define ARRAY_ARGS(name) name, array_lengthof(name), Terminator
+
+std::string stringify(NaClMungedBitcode &MungedBitcode) {
+  std::string Buffer;
+  raw_string_ostream StrBuf(Buffer);
+  MungedBitcode.print(StrBuf);
+  return StrBuf.str();
+}
+
+typedef SmallVector<char, 1024> TextBuffer;
+
+// Writes out a sequence of munged bitcode records, and writes them into
+// the text buffer. Returns a corresponding memory buffer containing
+// the munged bitcode records.
+std::unique_ptr<MemoryBuffer> writeMungedBitcode(
+    NaClMungedBitcode &Bitcode, TextBuffer &Buffer) {
+  Bitcode.write(Buffer, /* AddHeader = */ true,
+                /* RecoverOnBadAbbrevId = */ false);
+  StringRef Input(Buffer.data(), Buffer.size());
+
+  // Now read the bitcode back into a sequence of records.
+  return MemoryBuffer::getMemBuffer(Input, "Test", false);
+}
+
+// Test writing bitcode to a memory buffer.
+void testWriteMungedBitcode(NaClMungedBitcode &Bitcode) {

[jvoung (off chromium), 2015/05/05 00:27:23]

This seems a little weird that it's ignoring the result.

Could you just use parseWrittenMungedBitcode in the death test instead of having
this variant as well? EXPECT_DEATH doesn't really care if the statement returns
a value vs void does it or if there is a bunch of remaining work to do if it had
not crashed earlier?

[Karl, 2015/05/05 22:38:04]

The reason for this function was because I used it in two spots in an earlier
version. Each call was expected to be run in an EXPECT_DEATH test. However,
since I cleaned up the test cases, it only appears in one place (inside an
EXPECT_DEATH). Removing this function.

+  TextBuffer Buffer;
+  std::unique_ptr<MemoryBuffer> MemBuf(writeMungedBitcode(Bitcode, Buffer));
+}
+
+// Write out the bitcode, parse it back, and return the resulting
+// munged bitcode.
+std::string parseWrittenMungedBitcode(NaClMungedBitcode &OutBitcode) {
+  TextBuffer Buffer;
+  NaClMungedBitcode InBitcode(writeMungedBitcode(OutBitcode, Buffer));
+  return stringify(InBitcode);
+}
+
+/// Sample toy bitcode records.

[jvoung (off chromium), 2015/05/05 00:27:23]

nit: This isn't really an API or anything that needs to get doxygen'ized, so no
real need for the "///" in this file (here and line 87, and 124).

[Karl, 2015/05/05 22:38:04]

Done.

+const uint64_t Records[] = {
+  1, naclbitc::BLK_CODE_ENTER, 8, 2, Terminator,
+  3, naclbitc::MODULE_CODE_VERSION, 1, Terminator,
+  1, naclbitc::BLK_CODE_ENTER, 0, 2, Terminator,
+  3, naclbitc::BLOCKINFO_CODE_SETBID, 12, Terminator,
+  2, naclbitc::BLK_CODE_DEFINE_ABBREV, 1, 1, 10, Terminator,
+  0, naclbitc::BLK_CODE_EXIT, Terminator,
+  1, naclbitc::BLK_CODE_ENTER, 17, 3, Terminator,
+  2, naclbitc::BLK_CODE_DEFINE_ABBREV, 4, 1, 21, 0, 1, 1, 0, 3,
+    0, 1, 2, Terminator,
+  3, naclbitc::TYPE_CODE_NUMENTRY, 2, Terminator,
+  3, naclbitc::TYPE_CODE_VOID, Terminator,
+  4, naclbitc::TYPE_CODE_FUNCTION, 0, 0, Terminator,
+  0, naclbitc::BLK_CODE_EXIT, Terminator,
+  3, naclbitc::MODULE_CODE_FUNCTION, 1, 0, 0, 3, Terminator,
+  1, naclbitc::BLK_CODE_ENTER, 12, 3, Terminator,
+  3, naclbitc::FUNC_CODE_DECLAREBLOCKS, 1, Terminator,
+  4, naclbitc::FUNC_CODE_INST_RET, Terminator,
+  0, naclbitc::BLK_CODE_EXIT, Terminator,
+  0, naclbitc::BLK_CODE_EXIT, Terminator,
+};
+
+/// Show a more readable form of what the program is.
+TEST(NaClMungedIoTest, TestDumpingBitcode) {
+  NaClObjDumpMunger DumpMunger(ARRAY_ARGS(Records));
+  EXPECT_TRUE(DumpMunger.runTest("Display assembly"));
+  EXPECT_EQ(
+      "       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|  3: <1, 1>                  |  version 1;\n"
+      "      26:4|  1: <65535, 0, 2>           |  abbreviations {  // BlockID "
+      "= 0\n"
+      "      36:0|    3: <1, 12>               |    function:\n"
+      "      38:4|    2: <65533, 1, 1, 10>     |      @a0 = abbrev <10>;\n"
+      "      40:4|  0: <65534>                 |  }\n"
+      "      44:0|  1: <65535, 17, 3>          |  types {  // BlockID = 17\n"
+      "      52:0|    2: <65533, 4, 1, 21, 0,  |    %a0 = abbrev <21, fixed(1),"
+      " \n"
+      "          |        1, 1, 0, 3, 0, 1, 2> |                  array(fixed("
+      "2))>;\n"
+      "      56:7|    3: <1, 2>                |    count 2;\n"
+      "      59:4|    3: <2>                   |    @t0 = void;\n"
+      "      61:3|    4: <21, 0, 0>            |    @t1 = void (); <%a0>\n"
+      "      62:7|  0: <65534>                 |  }\n"
+      "      64:0|  3: <8, 1, 0, 0, 3>         |  define internal void @f0();\n"
+      "      68:6|  1: <65535, 12, 3>          |  function void @f0() {  \n"
+      "          |                             |                   // BlockID "
+      "= 12\n"
+      "      76:0|    3: <1, 1>                |    blocks 1;\n"
+      "          |                             |  %b0:\n"
+      "      78:5|    4: <10>                  |    ret void; <@a0>\n"
+      "      79:0|  0: <65534>                 |  }\n"
+      "      80:0|0: <65534>                   |}\n",
+      DumpMunger.getTestResults());
+}
+
+/// Test that we can write out bitcode, and then read it back in.
+TEST(NaClMungedIoTest, TestWriteThenRead) {
+  // Create munged bitcode for the given records.
+  NaClMungedBitcode Bitcode(ARRAY_ARGS(Records));
+
+  // The expected output when stringifying this input.
+  const std::string ExpectedRecords(
+      "       1: [65535, 8, 2]\n"
+      "         3: [1, 1]\n"
+      "         1: [65535, 0, 2]\n"
+      "           3: [1, 12]\n"
+      "           2: [65533, 1, 1, 10]\n"
+      "         0: [65534]\n"
+      "         1: [65535, 17, 3]\n"
+      "           2: [65533, 4, 1, 21, 0, 1, 1, 0, 3, 0, 1, 2]\n"
+      "           3: [1, 2]\n"
+      "           3: [2]\n"
+      "           4: [21, 0, 0]\n"
+      "         0: [65534]\n"
+      "         3: [8, 1, 0, 0, 3]\n"
+      "         1: [65535, 12, 3]\n"
+      "           3: [1, 1]\n"
+      "           4: [10]\n"
+      "         0: [65534]\n"
+      "       0: [65534]\n");
+  EXPECT_EQ(ExpectedRecords, stringify(Bitcode));
+
+  // Write and read the bitcode back into a sequence of records.
+  EXPECT_EQ(ExpectedRecords, parseWrittenMungedBitcode(Bitcode));
+}
+
+
+// Test that writing truncated bitcode is difficult, due to word
+// alignment requirements for bitcode files. Note: Bitcode files must
+// be divisible by 4.
+TEST(NaClMungedIoTest, TestTruncatedNonalignedBitcode) {
+  // Created an example of a truncated bitcode file.
+  NaClMungedBitcode Bitcode(ARRAY_ARGS(Records));
+  for (size_t i = 2, e = Bitcode.getBaseRecords().size(); i < e; ++i)
+    Bitcode.remove(i);
+
+  // The expected output when stringifying this input.
+  EXPECT_EQ(
+      "       1: [65535, 8, 2]\n"
+      "         3: [1, 1]\n",
+      stringify(Bitcode));
+
+  // Show that we can write the bitcode.
+  EXPECT_DEATH(testWriteMungedBitcode(Bitcode),
+               ".*Unflushed data remaining.*");
+}
+
+} // end of anonymous namespace