/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- * vim: set ts=8 sts=4 et sw=4 tw=99: * 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 vm_Printer_h #define vm_Printer_h #include "mozilla/Attributes.h" #include <stdarg.h> #include <stddef.h> #include <stdio.h> #include <string.h> class JSString; namespace js { class ExclusiveContext; class LifoAlloc; // Generic printf interface, similar to an ostream in the standard library. // // This class is useful to make generic printers which can work either with a // file backend, with a buffer allocated with an ExclusiveContext or a link-list // of chunks allocated with a LifoAlloc. class GenericPrinter { protected: bool hadOOM_; // whether reportOutOfMemory() has been called. GenericPrinter(); public: // Puts |len| characters from |s| at the current position and return an offset to // the beginning of this new data. virtual int put(const char* s, size_t len) = 0; inline int put(const char* s) { return put(s, strlen(s)); } // Prints a formatted string into the buffer. virtual int printf(const char* fmt, ...) MOZ_FORMAT_PRINTF(2, 3); virtual int vprintf(const char* fmt, va_list ap); // Report that a string operation failed to get the memory it requested. The // first call to this function calls JS_ReportOutOfMemory, and sets this // Sprinter's outOfMemory flag; subsequent calls do nothing. virtual void reportOutOfMemory(); // Return true if this Sprinter ran out of memory. virtual bool hadOutOfMemory() const; }; // Sprintf, but with unlimited and automatically allocated buffering. class Sprinter final : public GenericPrinter { public: struct InvariantChecker { const Sprinter* parent; explicit InvariantChecker(const Sprinter* p) : parent(p) { parent->checkInvariants(); } ~InvariantChecker() { parent->checkInvariants(); } }; ExclusiveContext* context; // context executing the decompiler private: static const size_t DefaultSize; #ifdef DEBUG bool initialized; // true if this is initialized, use for debug builds #endif bool shouldReportOOM; // whether to report OOM to the context char* base; // malloc'd buffer address size_t size; // size of buffer allocated at base ptrdiff_t offset; // offset of next free char in buffer MOZ_MUST_USE bool realloc_(size_t newSize); public: explicit Sprinter(ExclusiveContext* cx, bool shouldReportOOM = true); ~Sprinter(); // Initialize this sprinter, returns false on error. MOZ_MUST_USE bool init(); void checkInvariants() const; const char* string() const; const char* stringEnd() const; // Returns the string at offset |off|. char* stringAt(ptrdiff_t off) const; // Returns the char at offset |off|. char& operator[](size_t off); // Attempt to reserve len + 1 space (for a trailing nullptr byte). If the // attempt succeeds, return a pointer to the start of that space and adjust the // internal content. The caller *must* completely fill this space on success. char* reserve(size_t len); // Puts |len| characters from |s| at the current position and return an offset to // the beginning of this new data. virtual int put(const char* s, size_t len) override; using GenericPrinter::put; // pick up |inline int put(const char* s);| // Format the given format/arguments as if by JS_vsmprintf, then put it. // Return true on success, else return false and report an error (typically // OOM). MOZ_MUST_USE bool jsprintf(const char* fmt, ...) MOZ_FORMAT_PRINTF(2, 3); // Prints a formatted string into the buffer. virtual int vprintf(const char* fmt, va_list ap) override; int putString(JSString* str); ptrdiff_t getOffset() const; // Report that a string operation failed to get the memory it requested. The // first call to this function calls JS_ReportOutOfMemory, and sets this // Sprinter's outOfMemory flag; subsequent calls do nothing. virtual void reportOutOfMemory() override; }; // Fprinter, print a string directly into a file. class Fprinter final : public GenericPrinter { private: FILE* file_; bool init_; public: explicit Fprinter(FILE* fp); Fprinter(); ~Fprinter(); // Initialize this printer, returns false on error. MOZ_MUST_USE bool init(const char* path); void init(FILE* fp); bool isInitialized() const { return file_ != nullptr; } void flush(); void finish(); // Puts |len| characters from |s| at the current position and return an // offset to the beginning of this new data. virtual int put(const char* s, size_t len) override; using GenericPrinter::put; // pick up |inline int put(const char* s);| // Prints a formatted string into the buffer. virtual int printf(const char* fmt, ...) override MOZ_FORMAT_PRINTF(2, 3); virtual int vprintf(const char* fmt, va_list ap) override; }; // LSprinter, is similar to Sprinter except that instead of using an // ExclusiveContext to allocate strings, it use a LifoAlloc as a backend for the // allocation of the chunk of the string. class LSprinter final : public GenericPrinter { private: struct Chunk { Chunk* next; size_t length; char* chars() { return reinterpret_cast<char*>(this + 1); } char* end() { return chars() + length; } }; private: LifoAlloc* alloc_; // LifoAlloc used as a backend of chunk allocations. Chunk* head_; Chunk* tail_; size_t unused_; public: explicit LSprinter(LifoAlloc* lifoAlloc); ~LSprinter(); // Copy the content of the chunks into another printer, such that we can // flush the content of this printer to a file. void exportInto(GenericPrinter& out) const; // Drop the current string, and let them be free with the LifoAlloc. void clear(); // Puts |len| characters from |s| at the current position and return an // offset to the beginning of this new data. virtual int put(const char* s, size_t len) override; using GenericPrinter::put; // pick up |inline int put(const char* s);| // Prints a formatted string into the buffer. virtual int printf(const char* fmt, ...) override MOZ_FORMAT_PRINTF(2, 3); virtual int vprintf(const char* fmt, va_list ap) override; // Report that a string operation failed to get the memory it requested. The // first call to this function calls JS_ReportOutOfMemory, and sets this // Sprinter's outOfMemory flag; subsequent calls do nothing. virtual void reportOutOfMemory() override; // Return true if this Sprinter ran out of memory. virtual bool hadOutOfMemory() const override; }; // Map escaped code to the letter/symbol escaped with a backslash. extern const char js_EscapeMap[]; // Return a GC'ed string containing the chars in str, with any non-printing // chars or quotes (' or " as specified by the quote argument) escaped, and // with the quote character at the beginning and end of the result string. extern JSString* QuoteString(ExclusiveContext* cx, JSString* str, char16_t quote); extern char* QuoteString(Sprinter* sp, JSString* str, char16_t quote); } // namespace js #endif // vm_Printer_h