diff options
Diffstat (limited to 'V8Binding/v8/src/jump-target.h')
| -rw-r--r-- | V8Binding/v8/src/jump-target.h | 277 |
1 files changed, 0 insertions, 277 deletions
diff --git a/V8Binding/v8/src/jump-target.h b/V8Binding/v8/src/jump-target.h deleted file mode 100644 index 0c42f1b..0000000 --- a/V8Binding/v8/src/jump-target.h +++ /dev/null @@ -1,277 +0,0 @@ -// Copyright 2008 the V8 project authors. All rights reserved. -// Redistribution and use in source and binary forms, with or without -// modification, are permitted provided that the following conditions are -// met: -// -// * Redistributions of source code must retain the above copyright -// notice, this list of conditions and the following disclaimer. -// * Redistributions in binary form must reproduce the above -// copyright notice, this list of conditions and the following -// disclaimer in the documentation and/or other materials provided -// with the distribution. -// * Neither the name of Google Inc. nor the names of its -// contributors may be used to endorse or promote products derived -// from this software without specific prior written permission. -// -// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS -// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT -// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR -// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT -// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, -// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT -// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, -// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY -// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT -// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE -// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. - -#ifndef V8_JUMP_TARGET_H_ -#define V8_JUMP_TARGET_H_ - -namespace v8 { -namespace internal { - -// Forward declarations. -class FrameElement; -class Result; -class VirtualFrame; - -// ------------------------------------------------------------------------- -// Jump targets -// -// A jump target is an abstraction of a basic-block entry in generated -// code. It collects all the virtual frames reaching the block by -// forward jumps and pairs them with labels for the merge code along -// all forward-reaching paths. When bound, an expected frame for the -// block is determined and code is generated to merge to the expected -// frame. For backward jumps, the merge code is generated at the edge -// leaving the predecessor block. -// -// A jump target must have been reached via control flow (either by -// jumping, branching, or falling through) at the time it is bound. -// In particular, this means that at least one of the control-flow -// graph edges reaching the target must be a forward edge. - -class JumpTarget : public ZoneObject { // Shadows are dynamically allocated. - public: - // Forward-only jump targets can only be reached by forward CFG edges. - enum Directionality { FORWARD_ONLY, BIDIRECTIONAL }; - - // Construct a jump target used to generate code and to provide - // access to a current frame. - explicit JumpTarget(Directionality direction) - : direction_(direction), - reaching_frames_(0), - merge_labels_(0), - entry_frame_(NULL) { - } - - // Construct a jump target. - JumpTarget() - : direction_(FORWARD_ONLY), - reaching_frames_(0), - merge_labels_(0), - entry_frame_(NULL) { - } - - virtual ~JumpTarget() {} - - // Set the direction of the jump target. - virtual void set_direction(Directionality direction) { - direction_ = direction; - } - - // Treat the jump target as a fresh one. The state is reset. - void Unuse(); - - inline CodeGenerator* cgen(); - - Label* entry_label() { return &entry_label_; } - - VirtualFrame* entry_frame() const { return entry_frame_; } - void set_entry_frame(VirtualFrame* frame) { - entry_frame_ = frame; - } - - // Predicates testing the state of the encapsulated label. - bool is_bound() const { return entry_label_.is_bound(); } - bool is_linked() const { - return !is_bound() && !reaching_frames_.is_empty(); - } - bool is_unused() const { - // This is !is_bound() && !is_linked(). - return !is_bound() && reaching_frames_.is_empty(); - } - - // Emit a jump to the target. There must be a current frame at the - // jump and there will be no current frame after the jump. - virtual void Jump(); - virtual void Jump(Result* arg); - - // Emit a conditional branch to the target. There must be a current - // frame at the branch. The current frame will fall through to the - // code after the branch. - virtual void Branch(Condition cc, Hint hint = no_hint); - virtual void Branch(Condition cc, Result* arg, Hint hint = no_hint); - - // Bind a jump target. If there is no current frame at the binding - // site, there must be at least one frame reaching via a forward - // jump. - virtual void Bind(); - virtual void Bind(Result* arg); - - // Emit a call to a jump target. There must be a current frame at - // the call. The frame at the target is the same as the current - // frame except for an extra return address on top of it. The frame - // after the call is the same as the frame before the call. - void Call(); - - static void set_compiling_deferred_code(bool flag) { - compiling_deferred_code_ = flag; - } - - protected: - // Directionality flag set at initialization time. - Directionality direction_; - - // A list of frames reaching this block via forward jumps. - ZoneList<VirtualFrame*> reaching_frames_; - - // A parallel list of labels for merge code. - ZoneList<Label> merge_labels_; - - // The frame used on entry to the block and expected at backward - // jumps to the block. Set when the jump target is bound, but may - // or may not be set for forward-only blocks. - VirtualFrame* entry_frame_; - - // The actual entry label of the block. - Label entry_label_; - - // Implementations of Jump, Branch, and Bind with all arguments and - // return values using the virtual frame. - void DoJump(); - void DoBranch(Condition cc, Hint hint); - void DoBind(); - - private: - static bool compiling_deferred_code_; - - // Add a virtual frame reaching this labeled block via a forward jump, - // and a corresponding merge code label. - void AddReachingFrame(VirtualFrame* frame); - - // Perform initialization required during entry frame computation - // after setting the virtual frame element at index in frame to be - // target. - inline void InitializeEntryElement(int index, FrameElement* target); - - // Compute a frame to use for entry to this block. - void ComputeEntryFrame(); - - DISALLOW_COPY_AND_ASSIGN(JumpTarget); -}; - - -// ------------------------------------------------------------------------- -// Break targets -// -// A break target is a jump target that can be used to break out of a -// statement that keeps extra state on the stack (eg, for/in or -// try/finally). They know the expected stack height at the target -// and will drop state from nested statements as part of merging. -// -// Break targets are used for return, break, and continue targets. - -class BreakTarget : public JumpTarget { - public: - // Construct a break target. - BreakTarget() {} - - virtual ~BreakTarget() {} - - // Set the direction of the break target. - virtual void set_direction(Directionality direction); - - // Copy the state of this break target to the destination. The - // lists of forward-reaching frames and merge-point labels are - // copied. All virtual frame pointers are copied, not the - // pointed-to frames. The previous state of the destination is - // overwritten, without deallocating pointed-to virtual frames. - void CopyTo(BreakTarget* destination); - - // Emit a jump to the target. There must be a current frame at the - // jump and there will be no current frame after the jump. - virtual void Jump(); - virtual void Jump(Result* arg); - - // Emit a conditional branch to the target. There must be a current - // frame at the branch. The current frame will fall through to the - // code after the branch. - virtual void Branch(Condition cc, Hint hint = no_hint); - virtual void Branch(Condition cc, Result* arg, Hint hint = no_hint); - - // Bind a break target. If there is no current frame at the binding - // site, there must be at least one frame reaching via a forward - // jump. - virtual void Bind(); - virtual void Bind(Result* arg); - - // Setter for expected height. - void set_expected_height(int expected) { expected_height_ = expected; } - - private: - // The expected height of the expression stack where the target will - // be bound, statically known at initialization time. - int expected_height_; - - DISALLOW_COPY_AND_ASSIGN(BreakTarget); -}; - - -// ------------------------------------------------------------------------- -// Shadow break targets -// -// A shadow break target represents a break target that is temporarily -// shadowed by another one (represented by the original during -// shadowing). They are used to catch jumps to labels in certain -// contexts, e.g. try blocks. After shadowing ends, the formerly -// shadowed target is again represented by the original and the -// ShadowTarget can be used as a jump target in its own right, -// representing the formerly shadowing target. - -class ShadowTarget : public BreakTarget { - public: - // Construct a shadow jump target. After construction the shadow - // target object holds the state of the original target, and the - // original target is actually a fresh one that intercepts control - // flow intended for the shadowed one. - explicit ShadowTarget(BreakTarget* shadowed); - - virtual ~ShadowTarget() {} - - // End shadowing. After shadowing ends, the original jump target - // again gives access to the formerly shadowed target and the shadow - // target object gives access to the formerly shadowing target. - void StopShadowing(); - - // During shadowing, the currently shadowing target. After - // shadowing, the target that was shadowed. - BreakTarget* other_target() const { return other_target_; } - - private: - // During shadowing, the currently shadowing target. After - // shadowing, the target that was shadowed. - BreakTarget* other_target_; - -#ifdef DEBUG - bool is_shadowing_; -#endif - - DISALLOW_COPY_AND_ASSIGN(ShadowTarget); -}; - - -} } // namespace v8::internal - -#endif // V8_JUMP_TARGET_H_ |