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Diffstat (limited to 'contrib/llvm/lib/CodeGen/SafeStackLayout.h')
-rw-r--r-- | contrib/llvm/lib/CodeGen/SafeStackLayout.h | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/contrib/llvm/lib/CodeGen/SafeStackLayout.h b/contrib/llvm/lib/CodeGen/SafeStackLayout.h new file mode 100644 index 0000000..313ed21 --- /dev/null +++ b/contrib/llvm/lib/CodeGen/SafeStackLayout.h @@ -0,0 +1,68 @@ +//===-- SafeStackLayout.h - SafeStack frame layout -------------*- C++ -*--===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_LIB_CODEGEN_SAFESTACKLAYOUT_H +#define LLVM_LIB_CODEGEN_SAFESTACKLAYOUT_H + +#include "SafeStackColoring.h" + +namespace llvm { +namespace safestack { + +/// Compute the layout of an unsafe stack frame. +class StackLayout { + unsigned MaxAlignment; + + struct StackRegion { + unsigned Start; + unsigned End; + StackColoring::LiveRange Range; + StackRegion(unsigned Start, unsigned End, + const StackColoring::LiveRange &Range) + : Start(Start), End(End), Range(Range) {} + }; + /// The list of current stack regions, sorted by StackRegion::Start. + SmallVector<StackRegion, 16> Regions; + + struct StackObject { + const Value *Handle; + unsigned Size, Alignment; + StackColoring::LiveRange Range; + }; + SmallVector<StackObject, 8> StackObjects; + + DenseMap<const Value *, unsigned> ObjectOffsets; + + void layoutObject(StackObject &Obj); + +public: + StackLayout(unsigned StackAlignment) : MaxAlignment(StackAlignment) {} + /// Add an object to the stack frame. Value pointer is opaque and used as a + /// handle to retrieve the object's offset in the frame later. + void addObject(const Value *V, unsigned Size, unsigned Alignment, + const StackColoring::LiveRange &Range); + + /// Run the layout computation for all previously added objects. + void computeLayout(); + + /// Returns the offset to the object start in the stack frame. + unsigned getObjectOffset(const Value *V) { return ObjectOffsets[V]; } + + /// Returns the size of the entire frame. + unsigned getFrameSize() { return Regions.empty() ? 0 : Regions.back().End; } + + /// Returns the alignment of the frame. + unsigned getFrameAlignment() { return MaxAlignment; } + void print(raw_ostream &OS); +}; + +} // namespace safestack +} // namespace llvm + +#endif // LLVM_LIB_CODEGEN_SAFESTACKLAYOUT_H |