utils/TableGen/GlobalISel/CodeExpander.h

   1 //===- CodeExpander.h - Expand variables in a string ----------------------===//
   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 //
   9 /// \file Expand the variables in a string.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #ifndef LLVM_UTILS_TABLEGEN_CODEEXPANDER_H
  14 #define LLVM_UTILS_TABLEGEN_CODEEXPANDER_H
  15
  16 #include "llvm/ADT/ArrayRef.h"
  17 #include "llvm/ADT/StringRef.h"
  18 #include "llvm/Support/SMLoc.h"
  19
  20 namespace llvm {
  21 class CodeExpansions;
  22 class raw_ostream;
  23
  24 /// Emit the given code with all '${foo}' placeholders expanded to their
  25 /// replacements.
  26 ///
  27 /// It's an error to use an undefined expansion and expansion-like output that
  28 /// needs to be emitted verbatim can be escaped as '\${foo}'
  29 ///
  30 /// The emitted code can be given a custom indent to enable both indentation by
  31 /// an arbitrary amount of whitespace and emission of the code as a comment.
  32 class CodeExpander {
  33   StringRef Code;
  34   const CodeExpansions &Expansions;
  35   const ArrayRef<SMLoc> &Loc;
  36   bool ShowExpansions;
  37   StringRef Indent;
  38
  39 public:
  40   CodeExpander(StringRef Code, const CodeExpansions &Expansions,
  41                const ArrayRef<SMLoc> &Loc, bool ShowExpansions,
  42                StringRef Indent = "    ")
  43       : Code(Code), Expansions(Expansions), Loc(Loc),
  44         ShowExpansions(ShowExpansions), Indent(Indent) {}
  45
  46   void emit(raw_ostream &OS) const;
  47 };
  48
  49 inline raw_ostream &operator<<(raw_ostream &OS, const CodeExpander &Expander) {
  50   Expander.emit(OS);
  51   return OS;
  52 }
  53 } // end namespace llvm
  54
  55 #endif // ifndef LLVM_UTILS_TABLEGEN_CODEEXPANDER_H