1 //===------ Core/Pass.h - Base class for linker passes ----------*- C++ -*-===// 2 // 3 // The LLVM Linker 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 #ifndef LLD_CORE_PASS_H 11 #define LLD_CORE_PASS_H 12 13 #include "llvm/Support/Error.h" 14 15 namespace lld { 16 17 class SimpleFile; 18 19 /// Once the core linking is done (which resolves references, coalesces atoms 20 /// and produces a complete Atom graph), the linker runs a series of passes 21 /// on the Atom graph. The graph is modeled as a File, which means the pass 22 /// has access to all the atoms and to File level attributes. Each pass does 23 /// a particular transformation to the Atom graph or to the File attributes. 24 /// 25 /// This is the abstract base class for all passes. A Pass does its 26 /// actual work in it perform() method. It can iterator over Atoms in the 27 /// graph using the *begin()/*end() atom iterator of the File. It can add 28 /// new Atoms to the graph using the File's addAtom() method. 29 class Pass { 30 public: 31 virtual ~Pass() = default; 32 33 /// Do the actual work of the Pass. 34 virtual llvm::Error perform(SimpleFile &mergedFile) = 0; 35 36 protected: 37 // Only subclassess can be instantiated. 38 Pass() = default; 39 }; 40 41 } // end namespace lld 42 43 #endif // LLD_CORE_PASS_H 44
