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 
19 namespace llvm {
20 class CodeExpansions;
21 class SMLoc;
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
56