| 1 | //===- TemplatingUtils.h - Templater for text templates -----------------===// |
|---|---|
| 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 | #ifndef MLIR_LIB_TARGET_IRDLTOCPP_TEMPLATINGUTILS_H |
| 10 | #define MLIR_LIB_TARGET_IRDLTOCPP_TEMPLATINGUTILS_H |
| 11 | |
| 12 | #include "llvm/ADT/SmallString.h" |
| 13 | #include "llvm/ADT/StringMap.h" |
| 14 | #include "llvm/ADT/StringRef.h" |
| 15 | #include "llvm/Support/ErrorHandling.h" |
| 16 | #include "llvm/Support/raw_ostream.h" |
| 17 | #include <variant> |
| 18 | |
| 19 | namespace mlir::irdl::detail { |
| 20 | |
| 21 | /// A dictionary stores a mapping of template variable names to their assigned |
| 22 | /// string values. |
| 23 | using dictionary = llvm::StringMap<llvm::SmallString<8>>; |
| 24 | |
| 25 | /// Template Code as used by IRDL-to-Cpp. |
| 26 | /// |
| 27 | /// For efficiency, produces a bytecode representation of an input template. |
| 28 | /// - LiteralToken: A contiguous stream of characters to be printed |
| 29 | /// - ReplacementToken: A template variable that will be replaced |
| 30 | class Template { |
| 31 | public: |
| 32 | Template(llvm::StringRef str) { |
| 33 | bool processingReplacementToken = false; |
| 34 | while (!str.empty()) { |
| 35 | auto [token, remainder] = str.split(Separator: "__"); |
| 36 | |
| 37 | if (processingReplacementToken) { |
| 38 | assert(!token.empty() && "replacement name cannot be empty"); |
| 39 | bytecode.emplace_back(args: ReplacementToken{.keyName: token}); |
| 40 | } else { |
| 41 | if (!token.empty()) |
| 42 | bytecode.emplace_back(args: LiteralToken{.text: token}); |
| 43 | } |
| 44 | |
| 45 | processingReplacementToken = !processingReplacementToken; |
| 46 | str = remainder; |
| 47 | } |
| 48 | } |
| 49 | |
| 50 | /// Render will apply a dictionary to the Template and send the rendered |
| 51 | /// result to the specified output stream. |
| 52 | void render(llvm::raw_ostream &out, const dictionary &replacements) const { |
| 53 | for (auto instruction : bytecode) { |
| 54 | if (auto *inst = std::get_if<LiteralToken>(ptr: &instruction)) { |
| 55 | out << inst->text; |
| 56 | continue; |
| 57 | } |
| 58 | |
| 59 | if (auto *inst = std::get_if<ReplacementToken>(ptr: &instruction)) { |
| 60 | auto replacement = replacements.find(Key: inst->keyName); |
| 61 | #ifndef NDEBUG |
| 62 | if (replacement == replacements.end()) { |
| 63 | llvm::errs() << "Missing template key: "<< inst->keyName << "\n"; |
| 64 | llvm_unreachable("Missing template key"); |
| 65 | } |
| 66 | #endif |
| 67 | out << replacement->second; |
| 68 | continue; |
| 69 | } |
| 70 | |
| 71 | llvm_unreachable("non-exhaustive bytecode visit"); |
| 72 | } |
| 73 | } |
| 74 | |
| 75 | private: |
| 76 | struct LiteralToken { |
| 77 | llvm::StringRef text; |
| 78 | }; |
| 79 | |
| 80 | struct ReplacementToken { |
| 81 | llvm::StringRef keyName; |
| 82 | }; |
| 83 | |
| 84 | std::vector<std::variant<LiteralToken, ReplacementToken>> bytecode; |
| 85 | }; |
| 86 | |
| 87 | } // namespace mlir::irdl::detail |
| 88 | |
| 89 | #endif // MLIR_LIB_TARGET_IRDLTOCPP_TEMPLATINGUTILS_H |
| 90 |