| //===-- CodeGenFunction.h - Target features for builtin ---------*- C++ -*-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This is the internal required target features for builtin. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_CLANG_LIB_BASIC_BUILTINTARGETFEATURES_H |
| #define LLVM_CLANG_LIB_BASIC_BUILTINTARGETFEATURES_H |
| #include "llvm/ADT/StringMap.h" |
| #include "llvm/ADT/StringRef.h" |
| |
| using llvm::StringRef; |
| |
| namespace clang { |
| namespace Builtin { |
| /// TargetFeatures - This class is used to check whether the builtin function |
| /// has the required tagert specific features. It is able to support the |
| /// combination of ','(and), '|'(or), and '()'. By default, the priority of |
| /// ',' is higher than that of '|' . |
| /// E.g: |
| /// A,B|C means the builtin function requires both A and B, or C. |
| /// If we want the builtin function requires both A and B, or both A and C, |
| /// there are two ways: A,B|A,C or A,(B|C). |
| /// The FeaturesList should not contain spaces, and brackets must appear in |
| /// pairs. |
| class TargetFeatures { |
| struct FeatureListStatus { |
| bool HasFeatures; |
| StringRef CurFeaturesList; |
| }; |
| |
| const llvm::StringMap<bool> &CallerFeatureMap; |
| |
| FeatureListStatus getAndFeatures(StringRef FeatureList) { |
| int InParentheses = 0; |
| bool HasFeatures = true; |
| size_t SubexpressionStart = 0; |
| for (size_t i = 0, e = FeatureList.size(); i < e; ++i) { |
| char CurrentToken = FeatureList[i]; |
| switch (CurrentToken) { |
| default: |
| break; |
| case '(': |
| if (InParentheses == 0) |
| SubexpressionStart = i + 1; |
| ++InParentheses; |
| break; |
| case ')': |
| --InParentheses; |
| assert(InParentheses >= 0 && "Parentheses are not in pair"); |
| LLVM_FALLTHROUGH; |
| case '|': |
| case ',': |
| if (InParentheses == 0) { |
| if (HasFeatures && i != SubexpressionStart) { |
| StringRef F = FeatureList.slice(SubexpressionStart, i); |
| HasFeatures = CurrentToken == ')' ? hasRequiredFeatures(F) |
| : CallerFeatureMap.lookup(F); |
| } |
| SubexpressionStart = i + 1; |
| if (CurrentToken == '|') { |
| return {HasFeatures, FeatureList.substr(SubexpressionStart)}; |
| } |
| } |
| break; |
| } |
| } |
| assert(InParentheses == 0 && "Parentheses are not in pair"); |
| if (HasFeatures && SubexpressionStart != FeatureList.size()) |
| HasFeatures = |
| CallerFeatureMap.lookup(FeatureList.substr(SubexpressionStart)); |
| return {HasFeatures, StringRef()}; |
| } |
| |
| public: |
| bool hasRequiredFeatures(StringRef FeatureList) { |
| FeatureListStatus FS = {false, FeatureList}; |
| while (!FS.HasFeatures && !FS.CurFeaturesList.empty()) |
| FS = getAndFeatures(FS.CurFeaturesList); |
| return FS.HasFeatures; |
| } |
| |
| TargetFeatures(const llvm::StringMap<bool> &CallerFeatureMap) |
| : CallerFeatureMap(CallerFeatureMap) {} |
| }; |
| |
| } // namespace Builtin |
| } // namespace clang |
| #endif /* CLANG_LIB_BASIC_BUILTINTARGETFEATURES_H */ |