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-rw-r--r--base/include/base/file.h43
-rw-r--r--base/include/base/logging.h297
-rw-r--r--base/include/base/macros.h188
-rw-r--r--base/include/base/memory.h47
-rw-r--r--base/include/base/stringprintf.h40
-rw-r--r--base/include/base/strings.h52
6 files changed, 667 insertions, 0 deletions
diff --git a/base/include/base/file.h b/base/include/base/file.h
new file mode 100644
index 0000000..acd29b3
--- /dev/null
+++ b/base/include/base/file.h
@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef BASE_FILE_H
+#define BASE_FILE_H
+
+#include <sys/stat.h>
+#include <string>
+
+namespace android {
+namespace base {
+
+bool ReadFdToString(int fd, std::string* content);
+bool ReadFileToString(const std::string& path, std::string* content);
+
+bool WriteStringToFile(const std::string& content, const std::string& path);
+bool WriteStringToFd(const std::string& content, int fd);
+
+#if !defined(_WIN32)
+bool WriteStringToFile(const std::string& content, const std::string& path,
+ mode_t mode, uid_t owner, gid_t group);
+#endif
+
+bool ReadFully(int fd, void* data, size_t byte_count);
+bool WriteFully(int fd, const void* data, size_t byte_count);
+
+} // namespace base
+} // namespace android
+
+#endif // BASE_FILE_H
diff --git a/base/include/base/logging.h b/base/include/base/logging.h
new file mode 100644
index 0000000..230adb8
--- /dev/null
+++ b/base/include/base/logging.h
@@ -0,0 +1,297 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef BASE_LOGGING_H
+#define BASE_LOGGING_H
+
+#include <functional>
+#include <memory>
+#include <ostream>
+
+#include "base/macros.h"
+
+namespace android {
+namespace base {
+
+enum LogSeverity {
+ VERBOSE,
+ DEBUG,
+ INFO,
+ WARNING,
+ ERROR,
+ FATAL,
+};
+
+enum LogId {
+ DEFAULT,
+ MAIN,
+ SYSTEM,
+};
+
+typedef std::function<void(LogId, LogSeverity, const char*, const char*,
+ unsigned int, const char*)> LogFunction;
+
+extern void StderrLogger(LogId, LogSeverity, const char*, const char*,
+ unsigned int, const char*);
+
+#ifdef __ANDROID__
+// We expose this even though it is the default because a user that wants to
+// override the default log buffer will have to construct this themselves.
+class LogdLogger {
+ public:
+ explicit LogdLogger(LogId default_log_id = android::base::MAIN);
+
+ void operator()(LogId, LogSeverity, const char* tag, const char* file,
+ unsigned int line, const char* message);
+
+ private:
+ LogId default_log_id_;
+};
+#endif
+
+// Configure logging based on ANDROID_LOG_TAGS environment variable.
+// We need to parse a string that looks like
+//
+// *:v jdwp:d dalvikvm:d dalvikvm-gc:i dalvikvmi:i
+//
+// The tag (or '*' for the global level) comes first, followed by a colon and a
+// letter indicating the minimum priority level we're expected to log. This can
+// be used to reveal or conceal logs with specific tags.
+extern void InitLogging(char* argv[], LogFunction&& logger);
+
+// Configures logging using the default logger (logd for the device, stderr for
+// the host).
+extern void InitLogging(char* argv[]);
+
+// Replace the current logger.
+extern void SetLogger(LogFunction&& logger);
+
+// Logs a message to logcat on Android otherwise to stderr. If the severity is
+// FATAL it also causes an abort. For example:
+//
+// LOG(FATAL) << "We didn't expect to reach here";
+#define LOG(severity) \
+ ::android::base::LogMessage(__FILE__, __LINE__, ::android::base::DEFAULT, \
+ ::android::base::severity, -1).stream()
+
+// Logs a message to logcat with the specified log ID on Android otherwise to
+// stderr. If the severity is FATAL it also causes an abort.
+#define LOG_TO(dest, severity) \
+ ::android::base::LogMessage(__FILE__, __LINE__, ::android::base::dest, \
+ ::android::base::severity, -1).stream()
+
+// A variant of LOG that also logs the current errno value. To be used when
+// library calls fail.
+#define PLOG(severity) \
+ ::android::base::LogMessage(__FILE__, __LINE__, ::android::base::DEFAULT, \
+ ::android::base::severity, errno).stream()
+
+// Behaves like PLOG, but logs to the specified log ID.
+#define PLOG_TO(dest, severity) \
+ ::android::base::LogMessage(__FILE__, __LINE__, ::android::base::dest, \
+ ::android::base::severity, errno).stream()
+
+// Marker that code is yet to be implemented.
+#define UNIMPLEMENTED(level) \
+ LOG(level) << __PRETTY_FUNCTION__ << " unimplemented "
+
+// Check whether condition x holds and LOG(FATAL) if not. The value of the
+// expression x is only evaluated once. Extra logging can be appended using <<
+// after. For example:
+//
+// CHECK(false == true) results in a log message of
+// "Check failed: false == true".
+#define CHECK(x) \
+ if (UNLIKELY(!(x))) \
+ ::android::base::LogMessage(__FILE__, __LINE__, ::android::base::DEFAULT, \
+ ::android::base::FATAL, -1).stream() \
+ << "Check failed: " #x << " "
+
+// Helper for CHECK_xx(x,y) macros.
+#define CHECK_OP(LHS, RHS, OP) \
+ for (auto _values = ::android::base::MakeEagerEvaluator(LHS, RHS); \
+ UNLIKELY(!(_values.lhs OP _values.rhs)); \
+ /* empty */) \
+ ::android::base::LogMessage(__FILE__, __LINE__, ::android::base::DEFAULT, \
+ ::android::base::FATAL, -1).stream() \
+ << "Check failed: " << #LHS << " " << #OP << " " << #RHS \
+ << " (" #LHS "=" << _values.lhs << ", " #RHS "=" << _values.rhs << ") "
+
+// Check whether a condition holds between x and y, LOG(FATAL) if not. The value
+// of the expressions x and y is evaluated once. Extra logging can be appended
+// using << after. For example:
+//
+// CHECK_NE(0 == 1, false) results in
+// "Check failed: false != false (0==1=false, false=false) ".
+#define CHECK_EQ(x, y) CHECK_OP(x, y, == )
+#define CHECK_NE(x, y) CHECK_OP(x, y, != )
+#define CHECK_LE(x, y) CHECK_OP(x, y, <= )
+#define CHECK_LT(x, y) CHECK_OP(x, y, < )
+#define CHECK_GE(x, y) CHECK_OP(x, y, >= )
+#define CHECK_GT(x, y) CHECK_OP(x, y, > )
+
+// Helper for CHECK_STRxx(s1,s2) macros.
+#define CHECK_STROP(s1, s2, sense) \
+ if (UNLIKELY((strcmp(s1, s2) == 0) != sense)) \
+ LOG(FATAL) << "Check failed: " \
+ << "\"" << s1 << "\"" \
+ << (sense ? " == " : " != ") << "\"" << s2 << "\""
+
+// Check for string (const char*) equality between s1 and s2, LOG(FATAL) if not.
+#define CHECK_STREQ(s1, s2) CHECK_STROP(s1, s2, true)
+#define CHECK_STRNE(s1, s2) CHECK_STROP(s1, s2, false)
+
+// Perform the pthread function call(args), LOG(FATAL) on error.
+#define CHECK_PTHREAD_CALL(call, args, what) \
+ do { \
+ int rc = call args; \
+ if (rc != 0) { \
+ errno = rc; \
+ PLOG(FATAL) << #call << " failed for " << what; \
+ } \
+ } while (false)
+
+// CHECK that can be used in a constexpr function. For example:
+//
+// constexpr int half(int n) {
+// return
+// DCHECK_CONSTEXPR(n >= 0, , 0)
+// CHECK_CONSTEXPR((n & 1) == 0),
+// << "Extra debugging output: n = " << n, 0)
+// n / 2;
+// }
+#define CHECK_CONSTEXPR(x, out, dummy) \
+ (UNLIKELY(!(x))) \
+ ? (LOG(FATAL) << "Check failed: " << #x out, dummy) \
+ :
+
+// DCHECKs are debug variants of CHECKs only enabled in debug builds. Generally
+// CHECK should be used unless profiling identifies a CHECK as being in
+// performance critical code.
+#if defined(NDEBUG)
+static constexpr bool kEnableDChecks = false;
+#else
+static constexpr bool kEnableDChecks = true;
+#endif
+
+#define DCHECK(x) \
+ if (::android::base::kEnableDChecks) CHECK(x)
+#define DCHECK_EQ(x, y) \
+ if (::android::base::kEnableDChecks) CHECK_EQ(x, y)
+#define DCHECK_NE(x, y) \
+ if (::android::base::kEnableDChecks) CHECK_NE(x, y)
+#define DCHECK_LE(x, y) \
+ if (::android::base::kEnableDChecks) CHECK_LE(x, y)
+#define DCHECK_LT(x, y) \
+ if (::android::base::kEnableDChecks) CHECK_LT(x, y)
+#define DCHECK_GE(x, y) \
+ if (::android::base::kEnableDChecks) CHECK_GE(x, y)
+#define DCHECK_GT(x, y) \
+ if (::android::base::kEnableDChecks) CHECK_GT(x, y)
+#define DCHECK_STREQ(s1, s2) \
+ if (::android::base::kEnableDChecks) CHECK_STREQ(s1, s2)
+#define DCHECK_STRNE(s1, s2) \
+ if (::android::base::kEnableDChecks) CHECK_STRNE(s1, s2)
+#if defined(NDEBUG)
+#define DCHECK_CONSTEXPR(x, out, dummy)
+#else
+#define DCHECK_CONSTEXPR(x, out, dummy) CHECK_CONSTEXPR(x, out, dummy)
+#endif
+
+// Temporary class created to evaluate the LHS and RHS, used with
+// MakeEagerEvaluator to infer the types of LHS and RHS.
+template <typename LHS, typename RHS>
+struct EagerEvaluator {
+ EagerEvaluator(LHS l, RHS r) : lhs(l), rhs(r) {
+ }
+ LHS lhs;
+ RHS rhs;
+};
+
+// Helper function for CHECK_xx.
+template <typename LHS, typename RHS>
+static inline EagerEvaluator<LHS, RHS> MakeEagerEvaluator(LHS lhs, RHS rhs) {
+ return EagerEvaluator<LHS, RHS>(lhs, rhs);
+}
+
+// Explicitly instantiate EagerEvalue for pointers so that char*s aren't treated
+// as strings. To compare strings use CHECK_STREQ and CHECK_STRNE. We rely on
+// signed/unsigned warnings to protect you against combinations not explicitly
+// listed below.
+#define EAGER_PTR_EVALUATOR(T1, T2) \
+ template <> \
+ struct EagerEvaluator<T1, T2> { \
+ EagerEvaluator(T1 l, T2 r) \
+ : lhs(reinterpret_cast<const void*>(l)), \
+ rhs(reinterpret_cast<const void*>(r)) { \
+ } \
+ const void* lhs; \
+ const void* rhs; \
+ }
+EAGER_PTR_EVALUATOR(const char*, const char*);
+EAGER_PTR_EVALUATOR(const char*, char*);
+EAGER_PTR_EVALUATOR(char*, const char*);
+EAGER_PTR_EVALUATOR(char*, char*);
+EAGER_PTR_EVALUATOR(const unsigned char*, const unsigned char*);
+EAGER_PTR_EVALUATOR(const unsigned char*, unsigned char*);
+EAGER_PTR_EVALUATOR(unsigned char*, const unsigned char*);
+EAGER_PTR_EVALUATOR(unsigned char*, unsigned char*);
+EAGER_PTR_EVALUATOR(const signed char*, const signed char*);
+EAGER_PTR_EVALUATOR(const signed char*, signed char*);
+EAGER_PTR_EVALUATOR(signed char*, const signed char*);
+EAGER_PTR_EVALUATOR(signed char*, signed char*);
+
+// Data for the log message, not stored in LogMessage to avoid increasing the
+// stack size.
+class LogMessageData;
+
+// A LogMessage is a temporarily scoped object used by LOG and the unlikely part
+// of a CHECK. The destructor will abort if the severity is FATAL.
+class LogMessage {
+ public:
+ LogMessage(const char* file, unsigned int line, LogId id,
+ LogSeverity severity, int error);
+
+ ~LogMessage();
+
+ // Returns the stream associated with the message, the LogMessage performs
+ // output when it goes out of scope.
+ std::ostream& stream();
+
+ // The routine that performs the actual logging.
+ static void LogLine(const char* file, unsigned int line, LogId id,
+ LogSeverity severity, const char* msg);
+
+ private:
+ const std::unique_ptr<LogMessageData> data_;
+
+ DISALLOW_COPY_AND_ASSIGN(LogMessage);
+};
+
+// Allows to temporarily change the minimum severity level for logging.
+class ScopedLogSeverity {
+ public:
+ explicit ScopedLogSeverity(LogSeverity level);
+ ~ScopedLogSeverity();
+
+ private:
+ LogSeverity old_;
+};
+
+} // namespace base
+} // namespace android
+
+#endif // BASE_LOGGING_H
diff --git a/base/include/base/macros.h b/base/include/base/macros.h
new file mode 100644
index 0000000..b1ce7c6
--- /dev/null
+++ b/base/include/base/macros.h
@@ -0,0 +1,188 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef UTILS_MACROS_H
+#define UTILS_MACROS_H
+
+#include <stddef.h> // for size_t
+#include <unistd.h> // for TEMP_FAILURE_RETRY
+
+// bionic and glibc both have TEMP_FAILURE_RETRY, but eg Mac OS' libc doesn't.
+#ifndef TEMP_FAILURE_RETRY
+#define TEMP_FAILURE_RETRY(exp) \
+ ({ \
+ decltype(exp) _rc; \
+ do { \
+ _rc = (exp); \
+ } while (_rc == -1 && errno == EINTR); \
+ _rc; \
+ })
+#endif
+
+// A macro to disallow the copy constructor and operator= functions
+// This must be placed in the private: declarations for a class.
+//
+// For disallowing only assign or copy, delete the relevant operator or
+// constructor, for example:
+// void operator=(const TypeName&) = delete;
+// Note, that most uses of DISALLOW_ASSIGN and DISALLOW_COPY are broken
+// semantically, one should either use disallow both or neither. Try to
+// avoid these in new code.
+//
+// When building with C++11 toolchains, just use the language support
+// for explicitly deleted methods.
+#if __cplusplus >= 201103L
+#define DISALLOW_COPY_AND_ASSIGN(TypeName) \
+ TypeName(const TypeName&) = delete; \
+ void operator=(const TypeName&) = delete
+#else
+#define DISALLOW_COPY_AND_ASSIGN(TypeName) \
+ TypeName(const TypeName&); \
+ void operator=(const TypeName&)
+#endif
+
+// A macro to disallow all the implicit constructors, namely the
+// default constructor, copy constructor and operator= functions.
+//
+// This should be used in the private: declarations for a class
+// that wants to prevent anyone from instantiating it. This is
+// especially useful for classes containing only static methods.
+#define DISALLOW_IMPLICIT_CONSTRUCTORS(TypeName) \
+ TypeName(); \
+ DISALLOW_COPY_AND_ASSIGN(TypeName)
+
+// The arraysize(arr) macro returns the # of elements in an array arr.
+// The expression is a compile-time constant, and therefore can be
+// used in defining new arrays, for example. If you use arraysize on
+// a pointer by mistake, you will get a compile-time error.
+//
+// One caveat is that arraysize() doesn't accept any array of an
+// anonymous type or a type defined inside a function. In these rare
+// cases, you have to use the unsafe ARRAYSIZE_UNSAFE() macro below. This is
+// due to a limitation in C++'s template system. The limitation might
+// eventually be removed, but it hasn't happened yet.
+
+// This template function declaration is used in defining arraysize.
+// Note that the function doesn't need an implementation, as we only
+// use its type.
+template <typename T, size_t N>
+char(&ArraySizeHelper(T(&array)[N]))[N]; // NOLINT(readability/casting)
+
+#define arraysize(array) (sizeof(ArraySizeHelper(array)))
+
+// ARRAYSIZE_UNSAFE performs essentially the same calculation as arraysize,
+// but can be used on anonymous types or types defined inside
+// functions. It's less safe than arraysize as it accepts some
+// (although not all) pointers. Therefore, you should use arraysize
+// whenever possible.
+//
+// The expression ARRAYSIZE_UNSAFE(a) is a compile-time constant of type
+// size_t.
+//
+// ARRAYSIZE_UNSAFE catches a few type errors. If you see a compiler error
+//
+// "warning: division by zero in ..."
+//
+// when using ARRAYSIZE_UNSAFE, you are (wrongfully) giving it a pointer.
+// You should only use ARRAYSIZE_UNSAFE on statically allocated arrays.
+//
+// The following comments are on the implementation details, and can
+// be ignored by the users.
+//
+// ARRAYSIZE_UNSAFE(arr) works by inspecting sizeof(arr) (the # of bytes in
+// the array) and sizeof(*(arr)) (the # of bytes in one array
+// element). If the former is divisible by the latter, perhaps arr is
+// indeed an array, in which case the division result is the # of
+// elements in the array. Otherwise, arr cannot possibly be an array,
+// and we generate a compiler error to prevent the code from
+// compiling.
+//
+// Since the size of bool is implementation-defined, we need to cast
+// !(sizeof(a) & sizeof(*(a))) to size_t in order to ensure the final
+// result has type size_t.
+//
+// This macro is not perfect as it wrongfully accepts certain
+// pointers, namely where the pointer size is divisible by the pointee
+// size. Since all our code has to go through a 32-bit compiler,
+// where a pointer is 4 bytes, this means all pointers to a type whose
+// size is 3 or greater than 4 will be (righteously) rejected.
+#define ARRAYSIZE_UNSAFE(a) \
+ ((sizeof(a) / sizeof(*(a))) / \
+ static_cast<size_t>(!(sizeof(a) % sizeof(*(a)))))
+
+#define LIKELY(x) __builtin_expect((x), true)
+#define UNLIKELY(x) __builtin_expect((x), false)
+
+#define WARN_UNUSED __attribute__((warn_unused_result))
+
+// A deprecated function to call to create a false use of the parameter, for
+// example:
+// int foo(int x) { UNUSED(x); return 10; }
+// to avoid compiler warnings. Going forward we prefer ATTRIBUTE_UNUSED.
+template <typename... T>
+void UNUSED(const T&...) {
+}
+
+// An attribute to place on a parameter to a function, for example:
+// int foo(int x ATTRIBUTE_UNUSED) { return 10; }
+// to avoid compiler warnings.
+#define ATTRIBUTE_UNUSED __attribute__((__unused__))
+
+// The FALLTHROUGH_INTENDED macro can be used to annotate implicit fall-through
+// between switch labels:
+// switch (x) {
+// case 40:
+// case 41:
+// if (truth_is_out_there) {
+// ++x;
+// FALLTHROUGH_INTENDED; // Use instead of/along with annotations in
+// // comments.
+// } else {
+// return x;
+// }
+// case 42:
+// ...
+//
+// As shown in the example above, the FALLTHROUGH_INTENDED macro should be
+// followed by a semicolon. It is designed to mimic control-flow statements
+// like 'break;', so it can be placed in most places where 'break;' can, but
+// only if there are no statements on the execution path between it and the
+// next switch label.
+//
+// When compiled with clang in C++11 mode, the FALLTHROUGH_INTENDED macro is
+// expanded to [[clang::fallthrough]] attribute, which is analysed when
+// performing switch labels fall-through diagnostic ('-Wimplicit-fallthrough').
+// See clang documentation on language extensions for details:
+// http://clang.llvm.org/docs/LanguageExtensions.html#clang__fallthrough
+//
+// When used with unsupported compilers, the FALLTHROUGH_INTENDED macro has no
+// effect on diagnostics.
+//
+// In either case this macro has no effect on runtime behavior and performance
+// of code.
+#if defined(__clang__) && __cplusplus >= 201103L && defined(__has_warning)
+#if __has_feature(cxx_attributes) && __has_warning("-Wimplicit-fallthrough")
+#define FALLTHROUGH_INTENDED [[clang::fallthrough]] // NOLINT
+#endif
+#endif
+
+#ifndef FALLTHROUGH_INTENDED
+#define FALLTHROUGH_INTENDED \
+ do { \
+ } while (0)
+#endif
+
+#endif // UTILS_MACROS_H
diff --git a/base/include/base/memory.h b/base/include/base/memory.h
new file mode 100644
index 0000000..882582f
--- /dev/null
+++ b/base/include/base/memory.h
@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef BASE_MEMORY_H
+#define BASE_MEMORY_H
+
+namespace android {
+namespace base {
+
+// Use packed structures for access to unaligned data on targets with alignment
+// restrictions. The compiler will generate appropriate code to access these
+// structures without generating alignment exceptions.
+template <typename T>
+static inline T get_unaligned(const T* address) {
+ struct unaligned {
+ T v;
+ } __attribute__((packed));
+ const unaligned* p = reinterpret_cast<const unaligned*>(address);
+ return p->v;
+}
+
+template <typename T>
+static inline void put_unaligned(T* address, T v) {
+ struct unaligned {
+ T v;
+ } __attribute__((packed));
+ unaligned* p = reinterpret_cast<unaligned*>(address);
+ p->v = v;
+}
+
+} // namespace base
+} // namespace android
+
+#endif // BASE_MEMORY_H
diff --git a/base/include/base/stringprintf.h b/base/include/base/stringprintf.h
new file mode 100644
index 0000000..195c1de
--- /dev/null
+++ b/base/include/base/stringprintf.h
@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2011 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef BASE_STRINGPRINTF_H
+#define BASE_STRINGPRINTF_H
+
+#include <stdarg.h>
+#include <string>
+
+namespace android {
+namespace base {
+
+// Returns a string corresponding to printf-like formatting of the arguments.
+std::string StringPrintf(const char* fmt, ...)
+ __attribute__((__format__(__printf__, 1, 2)));
+
+// Appends a printf-like formatting of the arguments to 'dst'.
+void StringAppendF(std::string* dst, const char* fmt, ...)
+ __attribute__((__format__(__printf__, 2, 3)));
+
+// Appends a printf-like formatting of the arguments to 'dst'.
+void StringAppendV(std::string* dst, const char* format, va_list ap);
+
+} // namespace base
+} // namespace android
+
+#endif // BASE_STRINGPRINTF_H
diff --git a/base/include/base/strings.h b/base/include/base/strings.h
new file mode 100644
index 0000000..3559342
--- /dev/null
+++ b/base/include/base/strings.h
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef BASE_STRINGS_H
+#define BASE_STRINGS_H
+
+#include <string>
+#include <vector>
+
+namespace android {
+namespace base {
+
+// Splits a string into a vector of strings.
+//
+// The string is split at each occurrence of a character in delimiters.
+//
+// Empty splits will be omitted. I.e. Split("a,,b", ",") -> {"a", "b"}
+//
+// The empty string is not a valid delimiter list.
+std::vector<std::string> Split(const std::string& s,
+ const std::string& delimiters);
+
+// Trims whitespace off both ends of the given string.
+std::string Trim(const std::string& s);
+
+// Joins a vector of strings into a single string, using the given separator.
+template <typename StringT>
+std::string Join(const std::vector<StringT>& strings, char separator);
+
+// Tests whether 's' starts with 'prefix'.
+bool StartsWith(const std::string& s, const char* prefix);
+
+// Tests whether 's' ends with 'suffix'.
+bool EndsWith(const std::string& s, const char* suffix);
+
+} // namespace base
+} // namespace android
+
+#endif // BASE_STRINGS_H