test: Add a unittest for the BitUnion types.

src/unittest/SConscript

@@ -32,6 +32,7 @@ Import('*')
 
 Source('unittest.cc')
 
+UnitTest('bituniontest', 'bituniontest.cc')
 UnitTest('bitvectest', 'bitvectest.cc')
 UnitTest('circletest', 'circletest.cc')
 UnitTest('cprintftest', 'cprintftest.cc')

src/unittest/bituniontest.cc

@@ -0,0 +1,182 @@
+/*
+ * Copyright 2014 Google, Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met: redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer;
+ * redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution;
+ * neither the name of the copyright holders nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Authors: Gabe Black
+ */
+
+#include <cassert>
+#include <iostream>
+
+#include "base/bitunion.hh"
+#include "base/cprintf.hh"
+#include "unittest/unittest.hh"
+
+using namespace std;
+using UnitTest::setCase;
+
+namespace {
+
+BitUnion64(SixtyFour)
+    Bitfield<39, 32> byte5;
+    Bitfield<2> bit2;
+    BitfieldRO<39, 32> byte5RO;
+    BitfieldWO<39, 32> byte5WO;
+    SubBitUnion(byte6, 47, 40)
+        Bitfield<43, 42> bits43To42;
+        Bitfield<41> bit41;
+        SignedBitfield<41> bit41Signed;
+    EndSubBitUnion(byte6)
+    SignedBitfield<47, 40> byte6Signed;
+    SignedBitfieldRO<47, 40> byte6SignedRO;
+    SignedBitfieldWO<47, 40> byte6SignedWO;
+EndBitUnion(SixtyFour)
+
+BitUnion64(EmptySixtyFour)
+EndBitUnion(EmptySixtyFour)
+
+BitUnion32(EmptyThirtyTwo)
+EndBitUnion(EmptyThirtyTwo)
+
+BitUnion16(EmptySixteen)
+EndBitUnion(EmptySixteen)
+
+BitUnion8(EmptyEight)
+EndBitUnion(EmptyEight)
+
+struct ContainingStruct
+{
+    BitUnion64(Contained)
+        Bitfield<63, 60> topNibble;
+    EndBitUnion(Contained)
+
+    Contained contained;
+};
+
+uint64_t
+containingFunc(uint64_t init_val, uint64_t fieldVal)
+{
+    BitUnion32(Contained)
+        Bitfield<16, 15> field;
+    EndBitUnion(Contained)
+
+    Contained contained = init_val;
+    contained.field = fieldVal;
+    return contained;
+}
+
+} // anonymous namespace
+
+// Declare these as global so g++ doesn't ignore them. Initialize them in
+// various ways.
+EmptySixtyFour emptySixtyFour = 0;
+EmptyThirtyTwo emptyThirtyTwo;
+EmptySixteen emptySixteen;
+EmptyEight emptyEight(0);
+
+int
+main()
+{
+    SixtyFour sixtyFour = 0;
+
+    setCase("normal bitfield");
+    EXPECT_EQ(sixtyFour.byte5, 0);
+    sixtyFour.byte5 = 0xff;
+    EXPECT_EQ(sixtyFour, 0xff00000000);
+    sixtyFour.byte5 = 0xfff;
+    EXPECT_EQ(sixtyFour, 0xff00000000);
+    EXPECT_EQ(sixtyFour.byte5, 0xff);
+    sixtyFour = 0;
+
+    setCase("single bitfield");
+    EXPECT_EQ(sixtyFour.bit2, 0);
+    sixtyFour.bit2 = 0x1;
+    EXPECT_EQ(sixtyFour, 0x4);
+    EXPECT_EQ(sixtyFour.bit2, 0x1);
+    sixtyFour = 0;
+
+    setCase("read only bitfield");
+    EXPECT_EQ(sixtyFour.byte5RO, 0);
+    sixtyFour.byte5 = 0xff;
+    EXPECT_EQ(sixtyFour.byte5RO, 0xff);
+    sixtyFour = 0;
+
+    setCase("write only bitfield");
+    sixtyFour.byte5WO = 0xff;
+    EXPECT_EQ(sixtyFour, 0xff00000000);
+    sixtyFour = 0;
+
+    setCase("sub bitunions and their bitfields");
+    EXPECT_EQ(sixtyFour.byte6.bit41, 0);
+    sixtyFour.byte6 = 0x2;
+    EXPECT_EQ(sixtyFour.byte6.bit41, 1);
+    sixtyFour.byte6.bits43To42 = 0x3;
+    EXPECT_EQ(sixtyFour.byte6, 0xe);
+    sixtyFour.byte6 = 0xff;
+    sixtyFour.byte6.bit41 = 0;
+    EXPECT_EQ(sixtyFour, 0xfd0000000000);
+    sixtyFour = 0;
+
+    setCase("normal, read only, and write only signed bitfields");
+    sixtyFour.byte6 = 0xff;
+    EXPECT_EQ(sixtyFour.byte6Signed, -1);
+    EXPECT_EQ(sixtyFour.byte6SignedRO, -1);
+    sixtyFour.byte6SignedWO = 0;
+    EXPECT_EQ(sixtyFour.byte6Signed, 0);
+    EXPECT_EQ(sixtyFour.byte6SignedRO, 0);
+    EXPECT_EQ(sixtyFour.byte6, 0);
+    sixtyFour = 0;
+
+    setCase("bitunion declared inside a struct");
+    ContainingStruct containing;
+    containing.contained = 0;
+    containing.contained.topNibble = 0xd;
+    EXPECT_EQ(containing.contained, 0xd000000000000000);
+
+    setCase("bitunion declared inside a function");
+    EXPECT_EQ(containingFunc(0xfffff, 0), 0xe7fff);
+
+    setCase("assigning bitfields to other bitfields");
+    SixtyFour otherSixtyFour = 0;
+    sixtyFour.bit2 = 1;
+    otherSixtyFour.byte6.bit41 = sixtyFour.bit2;
+    EXPECT_EQ(otherSixtyFour, 0x20000000000);
+    otherSixtyFour.bit2 = sixtyFour.bit2;
+    EXPECT_EQ(otherSixtyFour, 0x20000000004);
+
+    setCase("bitunion operators");
+    sixtyFour = 0;
+    otherSixtyFour = 0x4;
+    sixtyFour = otherSixtyFour;
+    EXPECT_EQ(sixtyFour, 0x4);
+    sixtyFour = 0;
+    EXPECT_TRUE(sixtyFour < otherSixtyFour);
+    EXPECT_TRUE(otherSixtyFour > sixtyFour);
+    EXPECT_TRUE(sixtyFour != otherSixtyFour);
+    sixtyFour = otherSixtyFour;
+    EXPECT_TRUE(sixtyFour == otherSixtyFour);
+
+    return UnitTest::printResults();
+}