Introduce Regex::isLiteralERE function.
This will be used to implement an optimisation for literal entries
in special case lists.
Differential Revision: http://llvm-reviews.chandlerc.com/D1278
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187731 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/Support/Regex.h b/include/llvm/Support/Regex.h
index 82df2c6..3d071be 100644
--- a/include/llvm/Support/Regex.h
+++ b/include/llvm/Support/Regex.h
@@ -77,6 +77,10 @@
/// string.
std::string sub(StringRef Repl, StringRef String, std::string *Error = 0);
+ /// \brief If this function returns true, ^Str$ is an extended regular
+ /// expression that matches Str and only Str.
+ static bool isLiteralERE(StringRef Str);
+
private:
struct llvm_regex *preg;
int error;
diff --git a/lib/Support/Regex.cpp b/lib/Support/Regex.cpp
index efc8b90..dec967e 100644
--- a/lib/Support/Regex.cpp
+++ b/lib/Support/Regex.cpp
@@ -168,3 +168,10 @@
return Res;
}
+
+bool Regex::isLiteralERE(StringRef Str) {
+ // Check for regex metacharacters. This list was derived from our regex
+ // implementation in regcomp.c and double checked against the POSIX extended
+ // regular expression specification.
+ return Str.find_first_of("()^$|*+?.[]\\{}") == StringRef::npos;
+}
diff --git a/unittests/Support/RegexTest.cpp b/unittests/Support/RegexTest.cpp
index 3577d10..02869b3 100644
--- a/unittests/Support/RegexTest.cpp
+++ b/unittests/Support/RegexTest.cpp
@@ -112,4 +112,19 @@
EXPECT_EQ(Error, "invalid backreference string '100'");
}
+TEST_F(RegexTest, IsLiteralERE) {
+ EXPECT_TRUE(Regex::isLiteralERE("abc"));
+ EXPECT_FALSE(Regex::isLiteralERE("a(bc)"));
+ EXPECT_FALSE(Regex::isLiteralERE("^abc"));
+ EXPECT_FALSE(Regex::isLiteralERE("abc$"));
+ EXPECT_FALSE(Regex::isLiteralERE("a|bc"));
+ EXPECT_FALSE(Regex::isLiteralERE("abc*"));
+ EXPECT_FALSE(Regex::isLiteralERE("abc+"));
+ EXPECT_FALSE(Regex::isLiteralERE("abc?"));
+ EXPECT_FALSE(Regex::isLiteralERE("abc."));
+ EXPECT_FALSE(Regex::isLiteralERE("a[bc]"));
+ EXPECT_FALSE(Regex::isLiteralERE("abc\\1"));
+ EXPECT_FALSE(Regex::isLiteralERE("abc{1,2}"));
+}
+
}