unittests/ADT/TwineTest.cpp

   1 //===- TwineTest.cpp - Twine unit tests -----------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "llvm/ADT/Twine.h"
  10 #include "llvm/ADT/SmallString.h"
  11 #include "llvm/Support/FormatAdapters.h"
  12 #include "llvm/Support/FormatVariadic.h"
  13 #include "llvm/Support/raw_ostream.h"
  14 #include "gtest/gtest.h"
  15 using namespace llvm;
  16
  17 namespace {
  18
  19 std::string repr(const Twine &Value) {
  20   std::string res;
  21   llvm::raw_string_ostream OS(res);
  22   Value.printRepr(OS);
  23   return OS.str();
  24 }
  25
  26 TEST(TwineTest, Construction) {
  27   EXPECT_EQ("", Twine().str());
  28   EXPECT_EQ("hi", Twine("hi").str());
  29   EXPECT_EQ("hi", Twine(std::string("hi")).str());
  30   EXPECT_EQ("hi", Twine(StringRef("hi")).str());
  31   EXPECT_EQ("hi", Twine(StringRef(std::string("hi"))).str());
  32   EXPECT_EQ("hi", Twine(StringRef("hithere", 2)).str());
  33   EXPECT_EQ("hi", Twine(SmallString<4>("hi")).str());
  34   EXPECT_EQ("hi", Twine(formatv("{0}", "hi")).str());
  35 }
  36
  37 TEST(TwineTest, Numbers) {
  38   EXPECT_EQ("123", Twine(123U).str());
  39   EXPECT_EQ("123", Twine(123).str());
  40   EXPECT_EQ("-123", Twine(-123).str());
  41   EXPECT_EQ("123", Twine(123).str());
  42   EXPECT_EQ("-123", Twine(-123).str());
  43
  44   EXPECT_EQ("7b", Twine::utohexstr(123).str());
  45 }
  46
  47 TEST(TwineTest, Characters) {
  48   EXPECT_EQ("x", Twine('x').str());
  49   EXPECT_EQ("x", Twine(static_cast<unsigned char>('x')).str());
  50   EXPECT_EQ("x", Twine(static_cast<signed char>('x')).str());
  51 }
  52
  53 TEST(TwineTest, Concat) {
  54   // Check verse repr, since we care about the actual representation not just
  55   // the result.
  56
  57   // Concat with null.
  58   EXPECT_EQ("(Twine null empty)",
  59             repr(Twine("hi").concat(Twine::createNull())));
  60   EXPECT_EQ("(Twine null empty)",
  61             repr(Twine::createNull().concat(Twine("hi"))));
  62
  63   // Concat with empty.
  64   EXPECT_EQ("(Twine cstring:\"hi\" empty)",
  65             repr(Twine("hi").concat(Twine())));
  66   EXPECT_EQ("(Twine cstring:\"hi\" empty)",
  67             repr(Twine().concat(Twine("hi"))));
  68   EXPECT_EQ("(Twine smallstring:\"hi\" empty)",
  69             repr(Twine().concat(Twine(SmallString<5>("hi")))));
  70   EXPECT_EQ("(Twine formatv:\"howdy\" empty)",
  71             repr(Twine(formatv("howdy")).concat(Twine())));
  72   EXPECT_EQ("(Twine formatv:\"howdy\" empty)",
  73             repr(Twine().concat(Twine(formatv("howdy")))));
  74   EXPECT_EQ("(Twine smallstring:\"hey\" cstring:\"there\")",
  75             repr(Twine(SmallString<7>("hey")).concat(Twine("there"))));
  76
  77   // Concatenation of unary ropes.
  78   EXPECT_EQ("(Twine cstring:\"a\" cstring:\"b\")",
  79             repr(Twine("a").concat(Twine("b"))));
  80
  81   // Concatenation of other ropes.
  82   EXPECT_EQ("(Twine rope:(Twine cstring:\"a\" cstring:\"b\") cstring:\"c\")",
  83             repr(Twine("a").concat(Twine("b")).concat(Twine("c"))));
  84   EXPECT_EQ("(Twine cstring:\"a\" rope:(Twine cstring:\"b\" cstring:\"c\"))",
  85             repr(Twine("a").concat(Twine("b").concat(Twine("c")))));
  86   EXPECT_EQ("(Twine cstring:\"a\" rope:(Twine smallstring:\"b\" cstring:\"c\"))",
  87             repr(Twine("a").concat(Twine(SmallString<3>("b")).concat(Twine("c")))));
  88 }
  89
  90 TEST(TwineTest, toNullTerminatedStringRef) {
  91   SmallString<8> storage;
  92   EXPECT_EQ(0, *Twine("hello").toNullTerminatedStringRef(storage).end());
  93   EXPECT_EQ(0,
  94            *Twine(StringRef("hello")).toNullTerminatedStringRef(storage).end());
  95   EXPECT_EQ(0, *Twine(SmallString<11>("hello"))
  96                     .toNullTerminatedStringRef(storage)
  97                     .end());
  98   EXPECT_EQ(0, *Twine(formatv("{0}{1}", "how", "dy"))
  99                     .toNullTerminatedStringRef(storage)
 100                     .end());
 101 }
 102
 103 TEST(TwineTest, LazyEvaluation) {
 104   struct formatter : FormatAdapter<int> {
 105     explicit formatter(int &Count) : FormatAdapter(0), Count(Count) {}
 106     int &Count;
 107
 108     void format(raw_ostream &OS, StringRef Style) { ++Count; }
 109   };
 110
 111   int Count = 0;
 112   formatter Formatter(Count);
 113   (void)Twine(formatv("{0}", Formatter));
 114   EXPECT_EQ(0, Count);
 115   (void)Twine(formatv("{0}", Formatter)).str();
 116   EXPECT_EQ(1, Count);
 117 }
 118
 119   // I suppose linking in the entire code generator to add a unit test to check
 120   // the code size of the concat operation is overkill... :)
 121
 122 } // end anonymous namespace