[libc] Add strcpsn and strpbrk implementation.

Reviewed By: sivachandra

Differential Revision: https://reviews.llvm.org/D85386

3 files changed, 131 insertions, 0 deletions

diff --git a/libc/test/src/string/CMakeLists.txt b/libc/test/src/string/CMakeLists.txt
index e1db8d67becd..f7c580dd1876 100644
--- a/libc/test/src/string/CMakeLists.txt
+++ b/libc/test/src/string/CMakeLists.txt
@@ -103,6 +103,16 @@ add_libc_unittest(
 )
 
 add_libc_unittest(
+  strcspn_test
+  SUITE
+    libc_string_unittests
+  SRCS
+    strcspn_test.cpp
+  DEPENDS
+    libc.src.string.strcspn
+)
+
+add_libc_unittest(
   strspn_test
   SUITE
     libc_string_unittests
@@ -112,6 +122,15 @@ add_libc_unittest(
     libc.src.string.strspn
 )
 
+add_libc_unittest(
+  strpbrk_test
+  SUITE
+    libc_string_unittests
+  SRCS
+    strpbrk_test.cpp
+  DEPENDS
+    libc.src.string.strpbrk
+)
 
 # Tests all implementations that can run on the host.
 function(add_libc_multi_impl_test name)
diff --git a/libc/test/src/string/strcspn_test.cpp b/libc/test/src/string/strcspn_test.cpp
new file mode 100644
index 000000000000..80de495f9623
--- /dev/null
+++ b/libc/test/src/string/strcspn_test.cpp
@@ -0,0 +1,50 @@
+//===-- Unittests for strcspn ---------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/string/strcspn.h"
+
+#include "utils/UnitTest/Test.h"
+
+TEST(StrCSpnTest, ComplementarySpanShouldNotGoPastNullTerminator) {
+  const char src[5] = {'a', 'b', '\0', 'c', 'd'};
+  EXPECT_EQ(__llvm_libc::strcspn(src, "b"), size_t{1});
+  EXPECT_EQ(__llvm_libc::strcspn(src, "d"), size_t{2});
+
+  // Same goes for the segment to be searched for.
+  const char segment[5] = {'1', '2', '\0', '3', '4'};
+  EXPECT_EQ(__llvm_libc::strcspn("123", segment), size_t{0});
+}
+
+TEST(StrCSpnTest, ComplementarySpanForEachIndividualCharacter) {
+  const char *src = "12345";
+  // The complementary span size should increment accordingly.
+  EXPECT_EQ(__llvm_libc::strcspn(src, "1"), size_t{0});
+  EXPECT_EQ(__llvm_libc::strcspn(src, "2"), size_t{1});
+  EXPECT_EQ(__llvm_libc::strcspn(src, "3"), size_t{2});
+  EXPECT_EQ(__llvm_libc::strcspn(src, "4"), size_t{3});
+  EXPECT_EQ(__llvm_libc::strcspn(src, "5"), size_t{4});
+}
+
+TEST(StrCSpnTest, ComplementarySpanIsStringLengthIfNoCharacterFound) {
+  // Null terminator.
+  EXPECT_EQ(__llvm_libc::strcspn("", ""), size_t{0});
+  EXPECT_EQ(__llvm_libc::strcspn("", "_"), size_t{0});
+  // Single character.
+  EXPECT_EQ(__llvm_libc::strcspn("a", "b"), size_t{1});
+  // Multiple characters.
+  EXPECT_EQ(__llvm_libc::strcspn("abc", "1"), size_t{3});
+}
+
+TEST(StrCSpnTest, DuplicatedCharactersNotPartOfComplementarySpan) {
+  // Complementary span should be zero in all these cases.
+  EXPECT_EQ(__llvm_libc::strcspn("a", "aa"), size_t{0});
+  EXPECT_EQ(__llvm_libc::strcspn("aa", "a"), size_t{0});
+  EXPECT_EQ(__llvm_libc::strcspn("aaa", "aa"), size_t{0});
+  EXPECT_EQ(__llvm_libc::strcspn("aaaa", "aa"), size_t{0});
+  EXPECT_EQ(__llvm_libc::strcspn("aaaa", "baa"), size_t{0});
+}
diff --git a/libc/test/src/string/strpbrk_test.cpp b/libc/test/src/string/strpbrk_test.cpp
new file mode 100644
index 000000000000..498e8473a890
--- /dev/null
+++ b/libc/test/src/string/strpbrk_test.cpp
@@ -0,0 +1,62 @@
+//===-- Unittests for strpbrk ---------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/string/strpbrk.h"
+
+#include "utils/UnitTest/Test.h"
+
+TEST(StrPBrkTest, EmptyStringShouldReturnNullptr) {
+  // The search should not include the null terminator.
+  EXPECT_STREQ(__llvm_libc::strpbrk("", ""), nullptr);
+  EXPECT_STREQ(__llvm_libc::strpbrk("_", ""), nullptr);
+  EXPECT_STREQ(__llvm_libc::strpbrk("", "_"), nullptr);
+}
+
+TEST(StrPBrkTest, ShouldNotFindAnythingAfterNullTerminator) {
+  const char src[4] = {'a', 'b', '\0', 'c'};
+  EXPECT_STREQ(__llvm_libc::strpbrk(src, "c"), nullptr);
+}
+
+TEST(StrPBrkTest, ShouldReturnNullptrIfNoCharactersFound) {
+  EXPECT_STREQ(__llvm_libc::strpbrk("12345", "abcdef"), nullptr);
+}
+
+TEST(StrPBrkTest, FindsFirstCharacter) {
+  const char *src = "12345";
+  EXPECT_STREQ(__llvm_libc::strpbrk(src, "1"), "12345");
+  EXPECT_STREQ(__llvm_libc::strpbrk(src, "-1"), "12345");
+  EXPECT_STREQ(__llvm_libc::strpbrk(src, "1_"), "12345");
+  EXPECT_STREQ(__llvm_libc::strpbrk(src, "f1_"), "12345");
+  ASSERT_STREQ(src, "12345");
+}
+
+TEST(StrPBrkTest, FindsMiddleCharacter) {
+  const char *src = "12345";
+  EXPECT_STREQ(__llvm_libc::strpbrk(src, "3"), "345");
+  EXPECT_STREQ(__llvm_libc::strpbrk(src, "?3"), "345");
+  EXPECT_STREQ(__llvm_libc::strpbrk(src, "3F"), "345");
+  EXPECT_STREQ(__llvm_libc::strpbrk(src, "z3_"), "345");
+  ASSERT_STREQ(src, "12345");
+}
+
+TEST(StrPBrkTest, FindsLastCharacter) {
+  const char *src = "12345";
+  EXPECT_STREQ(__llvm_libc::strpbrk(src, "5"), "5");
+  EXPECT_STREQ(__llvm_libc::strpbrk(src, "r5"), "5");
+  EXPECT_STREQ(__llvm_libc::strpbrk(src, "59"), "5");
+  EXPECT_STREQ(__llvm_libc::strpbrk(src, "n5_"), "5");
+  ASSERT_STREQ(src, "12345");
+}
+
+TEST(StrPBrkTest, FindsFirstOfRepeated) {
+  EXPECT_STREQ(__llvm_libc::strpbrk("A,B,C,D", ","), ",B,C,D");
+}
+
+TEST(StrPBrkTest, FindsFirstInBreakset) {
+  EXPECT_STREQ(__llvm_libc::strpbrk("12345", "34"), "345");
+}