[Support] Add StringRef::consumeInteger.

StringRef::getInteger() exists and treats the entire string as
an integer of the specified radix, failing if any invalid characters
are encountered or the number overflows.

Sometimes you might have something like "123456foo" and you want
to get the number 123456 and leave the string "foo" remaining.
This is similar to what would be possible by using the standard
runtime library functions strtoul et al and specifying an end
pointer.

This patch adds consumeInteger(), which does exactly that.  It
consumes as much as possible until an invalid character is found,
and modifies the StringRef in place so that upon return only
the portion of the StringRef after the number remains.

Differential Revision: https://reviews.llvm.org/D24778

llvm-svn: 282164

1 files changed, 177 insertions, 0 deletions

diff --git a/llvm/unittests/ADT/StringRefTest.cpp b/llvm/unittests/ADT/StringRefTest.cpp
index 97ddaf6adcc..4249f231481 100644
--- a/llvm/unittests/ADT/StringRefTest.cpp
+++ b/llvm/unittests/ADT/StringRefTest.cpp
@@ -590,6 +590,183 @@ TEST(StringRefTest, getAsUnsignedIntegerBadStrings) {
   }
 }
 
+struct ConsumeUnsignedPair {
+  const char *Str;
+  uint64_t Expected;
+  const char *Leftover;
+} ConsumeUnsigned[] = {
+    {"0", 0, ""},
+    {"255", 255, ""},
+    {"256", 256, ""},
+    {"65535", 65535, ""},
+    {"65536", 65536, ""},
+    {"4294967295", 4294967295ULL, ""},
+    {"4294967296", 4294967296ULL, ""},
+    {"255A376", 255, "A376"},
+    {"18446744073709551615", 18446744073709551615ULL, ""},
+    {"18446744073709551615ABC", 18446744073709551615ULL, "ABC"},
+    {"042", 34, ""},
+    {"0x42", 66, ""},
+    {"0x42-0x34", 66, "-0x34"},
+    {"0b101010", 42, ""},
+    {"0429F", 042, "9F"},            // Auto-sensed octal radix, invalid digit
+    {"0x42G12", 0x42, "G12"},        // Auto-sensed hex radix, invalid digit
+    {"0b10101020101", 42, "20101"}}; // Auto-sensed binary radix, invalid digit.
+
+struct ConsumeSignedPair {
+  const char *Str;
+  int64_t Expected;
+  const char *Leftover;
+} ConsumeSigned[] = {
+    {"0", 0, ""},
+    {"-0", 0, ""},
+    {"0-1", 0, "-1"},
+    {"-0-1", 0, "-1"},
+    {"127", 127, ""},
+    {"128", 128, ""},
+    {"127-1", 127, "-1"},
+    {"128-1", 128, "-1"},
+    {"-128", -128, ""},
+    {"-129", -129, ""},
+    {"-128-1", -128, "-1"},
+    {"-129-1", -129, "-1"},
+    {"32767", 32767, ""},
+    {"32768", 32768, ""},
+    {"32767-1", 32767, "-1"},
+    {"32768-1", 32768, "-1"},
+    {"-32768", -32768, ""},
+    {"-32769", -32769, ""},
+    {"-32768-1", -32768, "-1"},
+    {"-32769-1", -32769, "-1"},
+    {"2147483647", 2147483647LL, ""},
+    {"2147483648", 2147483648LL, ""},
+    {"2147483647-1", 2147483647LL, "-1"},
+    {"2147483648-1", 2147483648LL, "-1"},
+    {"-2147483648", -2147483648LL, ""},
+    {"-2147483649", -2147483649LL, ""},
+    {"-2147483648-1", -2147483648LL, "-1"},
+    {"-2147483649-1", -2147483649LL, "-1"},
+    {"-9223372036854775808", -(9223372036854775807LL) - 1, ""},
+    {"-9223372036854775808-1", -(9223372036854775807LL) - 1, "-1"},
+    {"042", 34, ""},
+    {"042-1", 34, "-1"},
+    {"0x42", 66, ""},
+    {"0x42-1", 66, "-1"},
+    {"0b101010", 42, ""},
+    {"0b101010-1", 42, "-1"},
+    {"-042", -34, ""},
+    {"-042-1", -34, "-1"},
+    {"-0x42", -66, ""},
+    {"-0x42-1", -66, "-1"},
+    {"-0b101010", -42, ""},
+    {"-0b101010-1", -42, "-1"}};
+
+TEST(StringRefTest, consumeIntegerUnsigned) {
+  uint8_t U8;
+  uint16_t U16;
+  uint32_t U32;
+  uint64_t U64;
+
+  for (size_t i = 0; i < array_lengthof(ConsumeUnsigned); ++i) {
+    StringRef Str = ConsumeUnsigned[i].Str;
+    bool U8Success = Str.consumeInteger(0, U8);
+    if (static_cast<uint8_t>(ConsumeUnsigned[i].Expected) ==
+        ConsumeUnsigned[i].Expected) {
+      ASSERT_FALSE(U8Success);
+      EXPECT_EQ(U8, ConsumeUnsigned[i].Expected);
+      EXPECT_EQ(Str, ConsumeUnsigned[i].Leftover);
+    } else {
+      ASSERT_TRUE(U8Success);
+    }
+
+    Str = ConsumeUnsigned[i].Str;
+    bool U16Success = Str.consumeInteger(0, U16);
+    if (static_cast<uint16_t>(ConsumeUnsigned[i].Expected) ==
+        ConsumeUnsigned[i].Expected) {
+      ASSERT_FALSE(U16Success);
+      EXPECT_EQ(U16, ConsumeUnsigned[i].Expected);
+      EXPECT_EQ(Str, ConsumeUnsigned[i].Leftover);
+    } else {
+      ASSERT_TRUE(U16Success);
+    }
+
+    Str = ConsumeUnsigned[i].Str;
+    bool U32Success = Str.consumeInteger(0, U32);
+    if (static_cast<uint32_t>(ConsumeUnsigned[i].Expected) ==
+        ConsumeUnsigned[i].Expected) {
+      ASSERT_FALSE(U32Success);
+      EXPECT_EQ(U32, ConsumeUnsigned[i].Expected);
+      EXPECT_EQ(Str, ConsumeUnsigned[i].Leftover);
+    } else {
+      ASSERT_TRUE(U32Success);
+    }
+
+    Str = ConsumeUnsigned[i].Str;
+    bool U64Success = Str.consumeInteger(0, U64);
+    if (static_cast<uint64_t>(ConsumeUnsigned[i].Expected) ==
+        ConsumeUnsigned[i].Expected) {
+      ASSERT_FALSE(U64Success);
+      EXPECT_EQ(U64, ConsumeUnsigned[i].Expected);
+      EXPECT_EQ(Str, ConsumeUnsigned[i].Leftover);
+    } else {
+      ASSERT_TRUE(U64Success);
+    }
+  }
+}
+
+TEST(StringRefTest, consumeIntegerSigned) {
+  int8_t S8;
+  int16_t S16;
+  int32_t S32;
+  int64_t S64;
+
+  for (size_t i = 0; i < array_lengthof(ConsumeSigned); ++i) {
+    StringRef Str = ConsumeSigned[i].Str;
+    bool S8Success = Str.consumeInteger(0, S8);
+    if (static_cast<int8_t>(ConsumeSigned[i].Expected) ==
+        ConsumeSigned[i].Expected) {
+      ASSERT_FALSE(S8Success);
+      EXPECT_EQ(S8, ConsumeSigned[i].Expected);
+      EXPECT_EQ(Str, ConsumeSigned[i].Leftover);
+    } else {
+      ASSERT_TRUE(S8Success);
+    }
+
+    Str = ConsumeSigned[i].Str;
+    bool S16Success = Str.consumeInteger(0, S16);
+    if (static_cast<int16_t>(ConsumeSigned[i].Expected) ==
+        ConsumeSigned[i].Expected) {
+      ASSERT_FALSE(S16Success);
+      EXPECT_EQ(S16, ConsumeSigned[i].Expected);
+      EXPECT_EQ(Str, ConsumeSigned[i].Leftover);
+    } else {
+      ASSERT_TRUE(S16Success);
+    }
+
+    Str = ConsumeSigned[i].Str;
+    bool S32Success = Str.consumeInteger(0, S32);
+    if (static_cast<int32_t>(ConsumeSigned[i].Expected) ==
+        ConsumeSigned[i].Expected) {
+      ASSERT_FALSE(S32Success);
+      EXPECT_EQ(S32, ConsumeSigned[i].Expected);
+      EXPECT_EQ(Str, ConsumeSigned[i].Leftover);
+    } else {
+      ASSERT_TRUE(S32Success);
+    }
+
+    Str = ConsumeSigned[i].Str;
+    bool S64Success = Str.consumeInteger(0, S64);
+    if (static_cast<int64_t>(ConsumeSigned[i].Expected) ==
+        ConsumeSigned[i].Expected) {
+      ASSERT_FALSE(S64Success);
+      EXPECT_EQ(S64, ConsumeSigned[i].Expected);
+      EXPECT_EQ(Str, ConsumeSigned[i].Leftover);
+    } else {
+      ASSERT_TRUE(S64Success);
+    }
+  }
+}
+
 static const char *join_input[] = { "a", "b", "c" };
 static const char join_result1[] = "a";
 static const char join_result2[] = "a:b:c";