diff options
author | Matt A. Tobin <mattatobin@localhost.localdomain> | 2018-02-02 04:16:08 -0500 |
---|---|---|
committer | Matt A. Tobin <mattatobin@localhost.localdomain> | 2018-02-02 04:16:08 -0500 |
commit | 5f8de423f190bbb79a62f804151bc24824fa32d8 (patch) | |
tree | 10027f336435511475e392454359edea8e25895d /mozglue/linker/Utils.h | |
parent | 49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff) | |
download | UXP-5f8de423f190bbb79a62f804151bc24824fa32d8.tar UXP-5f8de423f190bbb79a62f804151bc24824fa32d8.tar.gz UXP-5f8de423f190bbb79a62f804151bc24824fa32d8.tar.lz UXP-5f8de423f190bbb79a62f804151bc24824fa32d8.tar.xz UXP-5f8de423f190bbb79a62f804151bc24824fa32d8.zip |
Add m-esr52 at 52.6.0
Diffstat (limited to 'mozglue/linker/Utils.h')
-rw-r--r-- | mozglue/linker/Utils.h | 618 |
1 files changed, 618 insertions, 0 deletions
diff --git a/mozglue/linker/Utils.h b/mozglue/linker/Utils.h new file mode 100644 index 000000000..c5314ef60 --- /dev/null +++ b/mozglue/linker/Utils.h @@ -0,0 +1,618 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this file, + * You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef Utils_h +#define Utils_h + +#include <pthread.h> +#include <stdint.h> +#include <stddef.h> +#include <sys/mman.h> +#include <unistd.h> +#include "mozilla/Assertions.h" +#include "mozilla/Scoped.h" + +/** + * On architectures that are little endian and that support unaligned reads, + * we can use direct type, but on others, we want to have a special class + * to handle conversion and alignment issues. + */ +#if !defined(DEBUG) && (defined(__i386__) || defined(__x86_64__)) +typedef uint16_t le_uint16; +typedef uint32_t le_uint32; +#else + +/** + * Template that allows to find an unsigned int type from a (computed) bit size + */ +template <int s> struct UInt { }; +template <> struct UInt<16> { typedef uint16_t Type; }; +template <> struct UInt<32> { typedef uint32_t Type; }; + +/** + * Template to access 2 n-bit sized words as a 2*n-bit sized word, doing + * conversion from little endian and avoiding alignment issues. + */ +template <typename T> +class le_to_cpu +{ +public: + typedef typename UInt<16 * sizeof(T)>::Type Type; + + operator Type() const + { + return (b << (sizeof(T) * 8)) | a; + } + + const le_to_cpu& operator =(const Type &v) + { + a = v & ((1 << (sizeof(T) * 8)) - 1); + b = v >> (sizeof(T) * 8); + return *this; + } + + le_to_cpu() { } + le_to_cpu(const Type &v) + { + operator =(v); + } + + const le_to_cpu& operator +=(const Type &v) + { + return operator =(operator Type() + v); + } + + const le_to_cpu& operator ++(int) + { + return operator =(operator Type() + 1); + } + +private: + T a, b; +}; + +/** + * Type definitions + */ +typedef le_to_cpu<unsigned char> le_uint16; +typedef le_to_cpu<le_uint16> le_uint32; +#endif + + +/** + * AutoCloseFD is a RAII wrapper for POSIX file descriptors + */ +struct AutoCloseFDTraits +{ + typedef int type; + static int empty() { return -1; } + static void release(int fd) { if (fd != -1) close(fd); } +}; +typedef mozilla::Scoped<AutoCloseFDTraits> AutoCloseFD; + +/** + * AutoCloseFILE is a RAII wrapper for POSIX streams + */ +struct AutoCloseFILETraits +{ + typedef FILE *type; + static FILE *empty() { return nullptr; } + static void release(FILE *f) { if (f) fclose(f); } +}; +typedef mozilla::Scoped<AutoCloseFILETraits> AutoCloseFILE; + +/** + * Page alignment helpers + */ +static inline size_t PageSize() +{ + return 4096; +} + +static inline uintptr_t AlignedPtr(uintptr_t ptr, size_t alignment) +{ + return ptr & ~(alignment - 1); +} + +template <typename T> +static inline T *AlignedPtr(T *ptr, size_t alignment) +{ + return reinterpret_cast<T *>( + AlignedPtr(reinterpret_cast<uintptr_t>(ptr), alignment)); +} + +template <typename T> +static inline T PageAlignedPtr(T ptr) +{ + return AlignedPtr(ptr, PageSize()); +} + +static inline uintptr_t AlignedEndPtr(uintptr_t ptr, size_t alignment) +{ + return AlignedPtr(ptr + alignment - 1, alignment); +} + +template <typename T> +static inline T *AlignedEndPtr(T *ptr, size_t alignment) +{ + return reinterpret_cast<T *>( + AlignedEndPtr(reinterpret_cast<uintptr_t>(ptr), alignment)); +} + +template <typename T> +static inline T PageAlignedEndPtr(T ptr) +{ + return AlignedEndPtr(ptr, PageSize()); +} + +static inline size_t AlignedSize(size_t size, size_t alignment) +{ + return (size + alignment - 1) & ~(alignment - 1); +} + +static inline size_t PageAlignedSize(size_t size) +{ + return AlignedSize(size, PageSize()); +} + +static inline bool IsAlignedPtr(uintptr_t ptr, size_t alignment) +{ + return ptr % alignment == 0; +} + +template <typename T> +static inline bool IsAlignedPtr(T *ptr, size_t alignment) +{ + return IsAlignedPtr(reinterpret_cast<uintptr_t>(ptr), alignment); +} + +template <typename T> +static inline bool IsPageAlignedPtr(T ptr) +{ + return IsAlignedPtr(ptr, PageSize()); +} + +static inline bool IsAlignedSize(size_t size, size_t alignment) +{ + return size % alignment == 0; +} + +static inline bool IsPageAlignedSize(size_t size) +{ + return IsAlignedSize(size, PageSize()); +} + +static inline size_t PageNumber(size_t size) +{ + return (size + PageSize() - 1) / PageSize(); +} + +/** + * MemoryRange stores a pointer, size pair. + */ +class MemoryRange +{ +public: + MemoryRange(void *buf, size_t length): buf(buf), length(length) { } + + void Assign(void *b, size_t len) { + buf = b; + length = len; + } + + void Assign(const MemoryRange& other) { + buf = other.buf; + length = other.length; + } + + void *get() const + { + return buf; + } + + operator void *() const + { + return buf; + } + + operator unsigned char *() const + { + return reinterpret_cast<unsigned char *>(buf); + } + + bool operator ==(void *ptr) const { + return buf == ptr; + } + + bool operator ==(unsigned char *ptr) const { + return buf == ptr; + } + + void *operator +(off_t offset) const + { + return reinterpret_cast<char *>(buf) + offset; + } + + /** + * Returns whether the given address is within the mapped range + */ + bool Contains(void *ptr) const + { + return (ptr >= buf) && (ptr < reinterpret_cast<char *>(buf) + length); + } + + /** + * Returns the length of the mapped range + */ + size_t GetLength() const + { + return length; + } + + static MemoryRange mmap(void *addr, size_t length, int prot, int flags, + int fd, off_t offset) { + return MemoryRange(::mmap(addr, length, prot, flags, fd, offset), length); + } + +private: + void *buf; + size_t length; +}; + +/** + * MappedPtr is a RAII wrapper for mmap()ed memory. It can be used as + * a simple void * or unsigned char *. + * + * It is defined as a derivative of a template that allows to use a + * different unmapping strategy. + */ +template <typename T> +class GenericMappedPtr: public MemoryRange +{ +public: + GenericMappedPtr(void *buf, size_t length): MemoryRange(buf, length) { } + GenericMappedPtr(const MemoryRange& other): MemoryRange(other) { } + GenericMappedPtr(): MemoryRange(MAP_FAILED, 0) { } + + void Assign(void *b, size_t len) { + if (get() != MAP_FAILED) + static_cast<T *>(this)->munmap(get(), GetLength()); + MemoryRange::Assign(b, len); + } + + void Assign(const MemoryRange& other) { + Assign(other.get(), other.GetLength()); + } + + ~GenericMappedPtr() + { + if (get() != MAP_FAILED) + static_cast<T *>(this)->munmap(get(), GetLength()); + } + + void release() + { + MemoryRange::Assign(MAP_FAILED, 0); + } +}; + +struct MappedPtr: public GenericMappedPtr<MappedPtr> +{ + MappedPtr(void *buf, size_t length) + : GenericMappedPtr<MappedPtr>(buf, length) { } + MappedPtr(const MemoryRange& other) + : GenericMappedPtr<MappedPtr>(other) { } + MappedPtr(): GenericMappedPtr<MappedPtr>() { } + +private: + friend class GenericMappedPtr<MappedPtr>; + void munmap(void *buf, size_t length) + { + ::munmap(buf, length); + } +}; + +/** + * UnsizedArray is a way to access raw arrays of data in memory. + * + * struct S { ... }; + * UnsizedArray<S> a(buf); + * UnsizedArray<S> b; b.Init(buf); + * + * This is roughly equivalent to + * const S *a = reinterpret_cast<const S *>(buf); + * const S *b = nullptr; b = reinterpret_cast<const S *>(buf); + * + * An UnsizedArray has no known length, and it's up to the caller to make + * sure the accessed memory is mapped and makes sense. + */ +template <typename T> +class UnsizedArray +{ +public: + typedef size_t idx_t; + + /** + * Constructors and Initializers + */ + UnsizedArray(): contents(nullptr) { } + UnsizedArray(const void *buf): contents(reinterpret_cast<const T *>(buf)) { } + + void Init(const void *buf) + { + MOZ_ASSERT(contents == nullptr); + contents = reinterpret_cast<const T *>(buf); + } + + /** + * Returns the nth element of the array + */ + const T &operator[](const idx_t index) const + { + MOZ_ASSERT(contents); + return contents[index]; + } + + operator const T *() const + { + return contents; + } + /** + * Returns whether the array points somewhere + */ + operator bool() const + { + return contents != nullptr; + } +private: + const T *contents; +}; + +/** + * Array, like UnsizedArray, is a way to access raw arrays of data in memory. + * Unlike UnsizedArray, it has a known length, and is enumerable with an + * iterator. + * + * struct S { ... }; + * Array<S> a(buf, len); + * UnsizedArray<S> b; b.Init(buf, len); + * + * In the above examples, len is the number of elements in the array. It is + * also possible to initialize an Array with the buffer size: + * + * Array<S> c; c.InitSize(buf, size); + * + * It is also possible to initialize an Array in two steps, only providing + * one data at a time: + * + * Array<S> d; + * d.Init(buf); + * d.Init(len); // or d.InitSize(size); + * + */ +template <typename T> +class Array: public UnsizedArray<T> +{ +public: + typedef typename UnsizedArray<T>::idx_t idx_t; + + /** + * Constructors and Initializers + */ + Array(): UnsizedArray<T>(), length(0) { } + Array(const void *buf, const idx_t length) + : UnsizedArray<T>(buf), length(length) { } + + void Init(const void *buf) + { + UnsizedArray<T>::Init(buf); + } + + void Init(const idx_t len) + { + MOZ_ASSERT(length == 0); + length = len; + } + + void InitSize(const idx_t size) + { + Init(size / sizeof(T)); + } + + void Init(const void *buf, const idx_t len) + { + UnsizedArray<T>::Init(buf); + Init(len); + } + + void InitSize(const void *buf, const idx_t size) + { + UnsizedArray<T>::Init(buf); + InitSize(size); + } + + /** + * Returns the nth element of the array + */ + const T &operator[](const idx_t index) const + { + MOZ_ASSERT(index < length); + MOZ_ASSERT(operator bool()); + return UnsizedArray<T>::operator[](index); + } + + /** + * Returns the number of elements in the array + */ + idx_t numElements() const + { + return length; + } + + /** + * Returns whether the array points somewhere and has at least one element. + */ + operator bool() const + { + return (length > 0) && UnsizedArray<T>::operator bool(); + } + + /** + * Iterator for an Array. Use is similar to that of STL const_iterators: + * + * struct S { ... }; + * Array<S> a(buf, len); + * for (Array<S>::iterator it = a.begin(); it < a.end(); ++it) { + * // Do something with *it. + * } + */ + class iterator + { + public: + iterator(): item(nullptr) { } + + const T &operator *() const + { + return *item; + } + + const T *operator ->() const + { + return item; + } + + iterator &operator ++() + { + ++item; + return *this; + } + + bool operator<(const iterator &other) const + { + return item < other.item; + } + protected: + friend class Array<T>; + iterator(const T &item): item(&item) { } + + private: + const T *item; + }; + + /** + * Returns an iterator pointing at the beginning of the Array + */ + iterator begin() const { + if (length) + return iterator(UnsizedArray<T>::operator[](0)); + return iterator(); + } + + /** + * Returns an iterator pointing past the end of the Array + */ + iterator end() const { + if (length) + return iterator(UnsizedArray<T>::operator[](length)); + return iterator(); + } + + /** + * Reverse iterator for an Array. Use is similar to that of STL + * const_reverse_iterators: + * + * struct S { ... }; + * Array<S> a(buf, len); + * for (Array<S>::reverse_iterator it = a.rbegin(); it < a.rend(); ++it) { + * // Do something with *it. + * } + */ + class reverse_iterator + { + public: + reverse_iterator(): item(nullptr) { } + + const T &operator *() const + { + const T *tmp = item; + return *--tmp; + } + + const T *operator ->() const + { + return &operator*(); + } + + reverse_iterator &operator ++() + { + --item; + return *this; + } + + bool operator<(const reverse_iterator &other) const + { + return item > other.item; + } + protected: + friend class Array<T>; + reverse_iterator(const T &item): item(&item) { } + + private: + const T *item; + }; + + /** + * Returns a reverse iterator pointing at the end of the Array + */ + reverse_iterator rbegin() const { + if (length) + return reverse_iterator(UnsizedArray<T>::operator[](length)); + return reverse_iterator(); + } + + /** + * Returns a reverse iterator pointing past the beginning of the Array + */ + reverse_iterator rend() const { + if (length) + return reverse_iterator(UnsizedArray<T>::operator[](0)); + return reverse_iterator(); + } +private: + idx_t length; +}; + +/** + * Transforms a pointer-to-function to a pointer-to-object pointing at the + * same address. + */ +template <typename T> +void *FunctionPtr(T func) +{ + union { + void *ptr; + T func; + } f; + f.func = func; + return f.ptr; +} + +class AutoLock { +public: + AutoLock(pthread_mutex_t *mutex): mutex(mutex) + { + if (pthread_mutex_lock(mutex)) + MOZ_CRASH("pthread_mutex_lock failed"); + } + ~AutoLock() + { + if (pthread_mutex_unlock(mutex)) + MOZ_CRASH("pthread_mutex_unlock failed"); + } +private: + pthread_mutex_t *mutex; +}; + +#endif /* Utils_h */ + |