1 files changed, 233 insertions, 0 deletions
diff --git a/js/src/vm/Printer.h b/js/src/vm/Printer.h
new file mode 100644
index 000000000..3ee76da44
--- /dev/null
+++ b/js/src/vm/Printer.h
@@ -0,0 +1,233 @@
+/* -*- 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