1 //===-------------------------- CodeRegion.h -------------------*- C++ -* -===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 /// \file
9 ///
10 /// This file implements class CodeRegion and CodeRegions.
11 ///
12 /// A CodeRegion describes a region of assembly code guarded by special LLVM-MCA
13 /// comment directives.
14 ///
15 ///   # LLVM-MCA-BEGIN foo
16 ///     ...  ## asm
17 ///   # LLVM-MCA-END
18 ///
19 /// A comment starting with substring LLVM-MCA-BEGIN marks the beginning of a
20 /// new region of code.
21 /// A comment starting with substring LLVM-MCA-END marks the end of the
22 /// last-seen region of code.
23 ///
24 /// Code regions are not allowed to overlap. Each region can have a optional
25 /// description; internally, regions are described by a range of source
26 /// locations (SMLoc objects).
27 ///
28 /// An instruction (a MCInst) is added to a region R only if its location is in
29 /// range [R.RangeStart, R.RangeEnd].
30 //
31 //===----------------------------------------------------------------------===//
32 
33 #ifndef LLVM_TOOLS_LLVM_MCA_CODEREGION_H
34 #define LLVM_TOOLS_LLVM_MCA_CODEREGION_H
35 
36 #include "llvm/ADT/ArrayRef.h"
37 #include "llvm/ADT/SmallVector.h"
38 #include "llvm/ADT/StringMap.h"
39 #include "llvm/ADT/StringRef.h"
40 #include "llvm/MC/MCInst.h"
41 #include "llvm/Support/Error.h"
42 #include "llvm/Support/SMLoc.h"
43 #include "llvm/Support/SourceMgr.h"
44 #include <vector>
45 
46 namespace llvm {
47 namespace mca {
48 
49 /// A region of assembly code.
50 ///
51 /// It identifies a sequence of machine instructions.
52 class CodeRegion {
53   // An optional descriptor for this region.
54   llvm::StringRef Description;
55   // Instructions that form this region.
56   llvm::SmallVector<llvm::MCInst, 16> Instructions;
57   // Source location range.
58   llvm::SMLoc RangeStart;
59   llvm::SMLoc RangeEnd;
60 
61   CodeRegion(const CodeRegion &) = delete;
62   CodeRegion &operator=(const CodeRegion &) = delete;
63 
64 public:
65   CodeRegion(llvm::StringRef Desc, llvm::SMLoc Start)
66       : Description(Desc), RangeStart(Start) {}
67 
68   void addInstruction(const llvm::MCInst &Instruction) {
69     Instructions.emplace_back(Instruction);
70   }
71 
72   llvm::SMLoc startLoc() const { return RangeStart; }
73   llvm::SMLoc endLoc() const { return RangeEnd; }
74 
75   void setEndLocation(llvm::SMLoc End) { RangeEnd = End; }
76   bool empty() const { return Instructions.empty(); }
77   bool isLocInRange(llvm::SMLoc Loc) const;
78 
79   llvm::ArrayRef<llvm::MCInst> getInstructions() const { return Instructions; }
80 
81   llvm::StringRef getDescription() const { return Description; }
82 };
83 
84 class CodeRegionParseError final : public Error {};
85 
86 class CodeRegions {
87   // A source manager. Used by the tool to generate meaningful warnings.
88   llvm::SourceMgr &SM;
89 
90   using UniqueCodeRegion = std::unique_ptr<CodeRegion>;
91   std::vector<UniqueCodeRegion> Regions;
92   llvm::StringMap<unsigned> ActiveRegions;
93   bool FoundErrors;
94 
95   CodeRegions(const CodeRegions &) = delete;
96   CodeRegions &operator=(const CodeRegions &) = delete;
97 
98 public:
99   CodeRegions(llvm::SourceMgr &S);
100 
101   typedef std::vector<UniqueCodeRegion>::iterator iterator;
102   typedef std::vector<UniqueCodeRegion>::const_iterator const_iterator;
103 
104   iterator begin() { return Regions.begin(); }
105   iterator end() { return Regions.end(); }
106   const_iterator begin() const { return Regions.cbegin(); }
107   const_iterator end() const { return Regions.cend(); }
108 
109   void beginRegion(llvm::StringRef Description, llvm::SMLoc Loc);
110   void endRegion(llvm::StringRef Description, llvm::SMLoc Loc);
111   void addInstruction(const llvm::MCInst &Instruction);
112   llvm::SourceMgr &getSourceMgr() const { return SM; }
113 
114   llvm::ArrayRef<llvm::MCInst> getInstructionSequence(unsigned Idx) const {
115     return Regions[Idx]->getInstructions();
116   }
117 
118   bool empty() const {
119     return llvm::all_of(Regions, [](const UniqueCodeRegion &Region) {
120       return Region->empty();
121     });
122   }
123 
124   bool isValid() const { return !FoundErrors; }
125 };
126 
127 } // namespace mca
128 } // namespace llvm
129 
130 #endif
131