================ @@ -0,0 +1,724 @@ +//===-- Mustache.cpp ------------------------------------------------------===// +// +// 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 +// +//===----------------------------------------------------------------------===// + +#include "llvm/Support/Mustache.h" +#include "llvm/Support/Error.h" +#include "llvm/Support/raw_ostream.h" +#include <sstream> + +using namespace llvm; +using namespace llvm::json; + +namespace llvm { +namespace mustache { + +class Token { +public: + enum class Type { + Text, + Variable, + Partial, + SectionOpen, + SectionClose, + InvertSectionOpen, + UnescapeVariable, + Comment, + }; + + Token(StringRef Str); + + Token(StringRef RawBody, StringRef Str, char Identifier); + + StringRef getTokenBody() const { return TokenBody; }; + + StringRef getRawBody() const { return RawBody; }; + + void setTokenBody(StringRef NewBody) { TokenBody = NewBody.str(); }; + + Accessor getAccessor() const { return Accessor; }; + + Type getType() const { return TokenType; }; + + void setIndentation(size_t NewIndentation) { Indentation = NewIndentation; }; + + size_t getIndentation() const { return Indentation; }; + + static Type getTokenType(char Identifier); + +private: + size_t Indentation; + Type TokenType; + // RawBody is the original string that was tokenized + std::string RawBody; + Accessor Accessor; + // TokenBody is the original string with the identifier removed + std::string TokenBody; +}; + +class ASTNode { +public: + enum Type { + Root, + Text, + Partial, + Variable, + UnescapeVariable, + Section, + InvertSection, + }; + + ASTNode() : T(Type::Root), ParentContext(nullptr) {}; + + ASTNode(StringRef Body, ASTNode *Parent) + : T(Type::Text), Body(Body), Parent(Parent), ParentContext(nullptr) {}; + + // Constructor for Section/InvertSection/Variable/UnescapeVariable + ASTNode(Type T, Accessor Accessor, ASTNode *Parent) + : T(T), Parent(Parent), Children({}), Accessor(Accessor), + ParentContext(nullptr) {}; + + void addChild(ASTNode *Child) { Children.emplace_back(Child); }; + + void setBody(StringRef NewBody) { Body = NewBody; }; + + void setRawBody(StringRef NewBody) { RawBody = NewBody; }; + + void setIndentation(size_t NewIndentation) { Indentation = NewIndentation; }; + + void render(const llvm::json::Value &Data, llvm::raw_ostream &OS); + + void setUpNode(llvm::BumpPtrAllocator &Alloc, StringMap<ASTNode *> &Partials, + StringMap<Lambda> &Lambdas, + StringMap<SectionLambda> &SectionLambdas, + DenseMap<char, StringRef> &Escapes); + +private: + void renderLambdas(const llvm::json::Value &Contexts, llvm::raw_ostream &OS, + Lambda &L); + + void renderSectionLambdas(const llvm::json::Value &Contexts, + llvm::raw_ostream &OS, SectionLambda &L); + + void renderPartial(const llvm::json::Value &Contexts, llvm::raw_ostream &OS, + ASTNode *Partial); + + void renderChild(const llvm::json::Value &Context, llvm::raw_ostream &OS); + + const llvm::json::Value *findContext(); + + llvm::BumpPtrAllocator *Allocator; + StringMap<ASTNode *> *Partials; + StringMap<Lambda> *Lambdas; + StringMap<SectionLambda> *SectionLambdas; + DenseMap<char, StringRef> *Escapes; + Type T; + size_t Indentation = 0; + std::string RawBody; + std::string Body; + ASTNode *Parent; + // TODO: switch implementation to SmallVector<T> + std::vector<ASTNode *> Children; + const Accessor Accessor; + const llvm::json::Value *ParentContext; +}; + +// Custom stream to escape strings +class EscapeStringStream : public raw_ostream { +public: + explicit EscapeStringStream(llvm::raw_ostream &WrappedStream, + DenseMap<char, StringRef> &Escape) + : Escape(Escape), WrappedStream(WrappedStream) { + SetUnbuffered(); + } + +protected: + void write_impl(const char *Ptr, size_t Size) override { + llvm::StringRef Data(Ptr, Size); + for (char C : Data) { + auto It = Escape.find(C); + if (It != Escape.end()) + WrappedStream << It->getSecond(); + else + WrappedStream << C; + } + } + + uint64_t current_pos() const override { return WrappedStream.tell(); } + +private: + DenseMap<char, StringRef> &Escape; + llvm::raw_ostream &WrappedStream; +}; + +// Custom stream to add indentation used to for rendering partials +class AddIndentationStringStream : public raw_ostream { +public: + explicit AddIndentationStringStream(llvm::raw_ostream &WrappedStream, + size_t Indentation) + : Indentation(Indentation), WrappedStream(WrappedStream) { + SetUnbuffered(); + } + +protected: + void write_impl(const char *Ptr, size_t Size) override { + llvm::StringRef Data(Ptr, Size); + std::string Indent(Indentation, ' '); + for (char C : Data) { + WrappedStream << C; + if (C == '\n') + WrappedStream << Indent; + } + } + + uint64_t current_pos() const override { return WrappedStream.tell(); } + +private: + size_t Indentation; + llvm::raw_ostream &WrappedStream; +}; + +Accessor split(StringRef Str, char Delimiter) { + Accessor Tokens; + if (Str == ".") { + Tokens.emplace_back(Str); + return Tokens; + } + StringRef Ref(Str); + while (!Ref.empty()) { + StringRef Part; + std::tie(Part, Ref) = Ref.split(Delimiter); + Tokens.emplace_back(Part.trim()); + } + return Tokens; +} + +Token::Token(StringRef RawBody, StringRef InnerBody, char Identifier) + : RawBody(RawBody), TokenBody(InnerBody), Indentation(0) { + TokenType = getTokenType(Identifier); + if (TokenType == Type::Comment) + return; + + StringRef AccessorStr = + TokenType == Type::Variable ? InnerBody : InnerBody.substr(1); + + Accessor = split(AccessorStr.trim(), '.'); +} + +Token::Token(StringRef Str) + : TokenType(Type::Text), RawBody(Str), Accessor({}), TokenBody(Str), + Indentation(0) {} + +Token::Type Token::getTokenType(char Identifier) { + switch (Identifier) { + case '#': + return Type::SectionOpen; + case '/': + return Type::SectionClose; + case '^': + return Type::InvertSectionOpen; + case '!': + return Type::Comment; + case '>': + return Type::Partial; + case '&': + return Type::UnescapeVariable; + default: + return Type::Variable; + } +} + +// Function to check if there is meaningful text behind. +// We determine if a token has meaningful text behind +// if the right of previous token contains anything that is +// not a newline +// For example: "Stuff {{#Section}}" +// We make an exception for when previous token is empty +// and the current token is the second token +// For example: "{{#Section}}" +bool hasTextBehind(size_t Idx, const ArrayRef<Token> &Tokens) { + if (Idx == 0) + return true; + + int PrevIdx = Idx - 1; + if (Tokens[PrevIdx].getType() != Token::Type::Text) + return true; + + const Token &PrevToken = Tokens[Idx - 1]; + StringRef TokenBody = PrevToken.getRawBody().rtrim(" \t\v"); + return !TokenBody.ends_with("\n") && !(TokenBody.empty() && Idx == 1); +} + +// Function to check if there's no meaningful text ahead +// We determine if a token has no meaningful text behind +// if the left of previous token is empty spaces or tabs followed +// by a newline +// For example: "{{#Section}} \n" +bool hasTextAhead(size_t Idx, const ArrayRef<Token> &Tokens) { + if (Idx >= Tokens.size() - 1) + return true; + + int NextIdx = Idx + 1; + if (Tokens[NextIdx].getType() != Token::Type::Text) + return true; + + const Token &NextToken = Tokens[Idx + 1]; + StringRef TokenBody = NextToken.getRawBody().ltrim(" "); + return !TokenBody.starts_with("\r\n") && !TokenBody.starts_with("\n"); +} + +bool requiresCleanUp(Token::Type T) { + // We must clean up all the tokens that could contain child nodes + return T == Token::Type::SectionOpen || T == Token::Type::InvertSectionOpen || + T == Token::Type::SectionClose || T == Token::Type::Comment || + T == Token::Type::Partial; +} + +// Adjust next token body if there is no text ahead +// For example: +// The template string +// "{{! Comment }} \nLine 2" +// would be considered as no text ahead and should be render as +// " Line 2" +void stripTokenAhead(SmallVector<Token> &Tokens, size_t Idx) { + Token &NextToken = Tokens[Idx + 1]; + StringRef NextTokenBody = NextToken.getTokenBody(); + // cut off the leading newline which could be \n or \r\n + if (NextTokenBody.starts_with("\r\n")) + NextToken.setTokenBody(NextTokenBody.substr(2)); + else if (NextTokenBody.starts_with("\n")) + NextToken.setTokenBody(NextTokenBody.substr(1)); +} + +// Adjust previous token body if there no text behind +// For example: +// The template string +// " \t{{#section}}A{{/section}}" +// would be considered as having no text ahead and would be render as +// "A" +// The exception for this is partial tag which requires us to +// keep track of the indentation once it's rendered. +void stripTokenBefore(SmallVector<Token> &Tokens, size_t Idx, + Token &CurrentToken, Token::Type CurrentType) { + Token &PrevToken = Tokens[Idx - 1]; + StringRef PrevTokenBody = PrevToken.getTokenBody(); + StringRef Unindented = PrevTokenBody.rtrim(" \t\v"); + size_t Indentation = PrevTokenBody.size() - Unindented.size(); + if (CurrentType != Token::Type::Partial) + PrevToken.setTokenBody(Unindented); + CurrentToken.setIndentation(Indentation); +} + +// Simple tokenizer that splits the template into tokens. +// The mustache spec allows {{{ }}} to unescape variables +// but we don't support that here. An unescape variable +// is represented only by {{& variable}}. +SmallVector<Token> tokenize(StringRef Template) { + SmallVector<Token> Tokens; + std::string Open("{{"); + std::string Close("}}"); + size_t Start = 0; + size_t DelimiterStart = Template.find(Open); + if (DelimiterStart == StringRef::npos) { + Tokens.emplace_back(Template); + return Tokens; + } + while (DelimiterStart != StringRef::npos) { + if (DelimiterStart != Start) { + Tokens.emplace_back(Template.substr(Start, DelimiterStart - Start)); + } + + size_t DelimiterEnd = Template.find(Close, DelimiterStart); + if (DelimiterEnd == StringRef::npos) { + break; + } + + // Extract the Interpolated variable without delimiters {{ and }} + size_t InterpolatedStart = DelimiterStart + Open.size(); + size_t InterpolatedEnd = DelimiterEnd - DelimiterStart - Close.size(); + std::string Interpolated = + Template.substr(InterpolatedStart, InterpolatedEnd).str(); + std::string RawBody = Open + Interpolated + Close; + Tokens.emplace_back(RawBody, Interpolated, Interpolated[0]); + Start = DelimiterEnd + Close.size(); + DelimiterStart = Template.find(Open, Start); + } + + if (Start < Template.size()) + Tokens.emplace_back(Template.substr(Start)); + + // Fix up white spaces for: + // - open sections + // - inverted sections + // - close sections + // - comments + // + // This loop attempts to find standalone tokens and tries to trim out + // the surrounding whitespace. + // For example: + // if you have the template string + // {{#section}} \n Example \n{{/section}} + // The output should would be + // For example + // \n Example \n + size_t LastIdx = Tokens.size() - 1; + for (size_t Idx = 0, End = Tokens.size(); Idx < End; ++Idx) { + Token &CurrentToken = Tokens[Idx]; + Token::Type CurrentType = CurrentToken.getType(); + // Check if token type requires cleanup + bool RequiresCleanUp = requiresCleanUp(CurrentType); + + if (!RequiresCleanUp) + continue; + + // We adjust the token body if there's no text behind or ahead. + // A token is considered to have no text ahead if the right of the previous + // token is a newline followed by spaces. + // A token is considered to have no text behind if the left of the next + // token is spaces followed by a newline. + // eg. + // "Line 1\n {{#section}} \n Line 2 \n {{/section}} \n Line 3" + bool HasTextBehind = hasTextBehind(Idx, Tokens); + bool HasTextAhead = hasTextAhead(Idx, Tokens); + + if ((!HasTextAhead && !HasTextBehind) || (!HasTextAhead && Idx == 0)) + stripTokenAhead(Tokens, Idx); + + if ((!HasTextBehind && !HasTextAhead) || (!HasTextBehind && Idx == LastIdx)) + stripTokenBefore(Tokens, Idx, CurrentToken, CurrentType); + } + return Tokens; +} + +class Parser { +public: + Parser(StringRef TemplateStr, BumpPtrAllocator &Allocator) + : Allocator(Allocator), TemplateStr(TemplateStr) {} + + ASTNode *parse(); + +private: + void parseMustache(ASTNode *Parent); + + BumpPtrAllocator &Allocator; + SmallVector<Token> Tokens; + size_t CurrentPtr; + StringRef TemplateStr; +}; + +ASTNode *Parser::parse() { + Tokens = tokenize(TemplateStr); + CurrentPtr = 0; + void *Root = Allocator.Allocate(sizeof(ASTNode), alignof(ASTNode)); + ASTNode *RootNode = new (Root) ASTNode(); + parseMustache(RootNode); + return RootNode; +} + +void Parser::parseMustache(ASTNode *Parent) { + + while (CurrentPtr < Tokens.size()) { + Token CurrentToken = Tokens[CurrentPtr]; + CurrentPtr++; + Accessor A = CurrentToken.getAccessor(); + ASTNode *CurrentNode; + void *Node = Allocator.Allocate(sizeof(ASTNode), alignof(ASTNode)); + + switch (CurrentToken.getType()) { + case Token::Type::Text: { + CurrentNode = new (Node) ASTNode(CurrentToken.getTokenBody(), Parent); + Parent->addChild(CurrentNode); + break; + } + case Token::Type::Variable: { + CurrentNode = new (Node) ASTNode(ASTNode::Variable, A, Parent); + Parent->addChild(CurrentNode); + break; + } + case Token::Type::UnescapeVariable: { + CurrentNode = new (Node) ASTNode(ASTNode::UnescapeVariable, A, Parent); + Parent->addChild(CurrentNode); + break; + } + case Token::Type::Partial: { + CurrentNode = new (Node) ASTNode(ASTNode::Partial, A, Parent); + CurrentNode->setIndentation(CurrentToken.getIndentation()); + Parent->addChild(CurrentNode); + break; + } + case Token::Type::SectionOpen: { + CurrentNode = new (Node) ASTNode(ASTNode::Section, A, Parent); + size_t Start = CurrentPtr; + parseMustache(CurrentNode); + size_t End = CurrentPtr; + std::string RawBody; + for (std::size_t I = Start; I < End - 1; I++) + RawBody += Tokens[I].getRawBody(); + CurrentNode->setRawBody(RawBody); + Parent->addChild(CurrentNode); + break; + } + case Token::Type::InvertSectionOpen: { + CurrentNode = new (Node) ASTNode(ASTNode::InvertSection, A, Parent); + size_t Start = CurrentPtr; + parseMustache(CurrentNode); + size_t End = CurrentPtr; + std::string RawBody; + for (size_t Idx = Start; Idx < End - 1; Idx++) + RawBody += Tokens[Idx].getRawBody(); + CurrentNode->setRawBody(RawBody); + Parent->addChild(CurrentNode); + break; + } + case Token::Type::Comment: + break; + case Token::Type::SectionClose: + return; + } + } +} + +void Template::render(Value &Data, llvm::raw_ostream &OS) { + Tree->render(Data, OS); + LocalAllocator.Reset(); +} + +void Template::registerPartial(StringRef Name, StringRef Partial) { + Parser P = Parser(Partial, Allocator); + ASTNode *PartialTree = P.parse(); + PartialTree->setUpNode(LocalAllocator, Partials, Lambdas, SectionLambdas, + Escapes); + Partials.insert(std::make_pair(Name, PartialTree)); +} + +void Template::registerLambda(StringRef Name, Lambda L) { Lambdas[Name] = L; } + +void Template::registerLambda(StringRef Name, SectionLambda L) { + SectionLambdas[Name] = L; +} + +void Template::registerEscape(DenseMap<char, StringRef> E) { Escapes = E; } + +Template::Template(StringRef TemplateStr) { + Parser P = Parser(TemplateStr, Allocator); + Tree = P.parse(); + // the default behaviour is to escape html entities + DenseMap<char, StringRef> HtmlEntities = {{'&', "&"}, + {'<', "<"}, + {'>', ">"}, + {'"', """}, + {'\'', "'"}}; + registerEscape(HtmlEntities); + Tree->setUpNode(LocalAllocator, Partials, Lambdas, SectionLambdas, Escapes); +} + +void toJsonString(const Value &Data, raw_ostream &OS) { + switch (Data.kind()) { + case Value::Null: + return; + case Value::Number: { + auto Num = *Data.getAsNumber(); + std::ostringstream Oss; + Oss << Num; + OS << Oss.str(); + return; + } + case Value::String: { + auto Str = *Data.getAsString(); + OS << Str.str(); + return; + } + case Value::Array: { + auto Arr = *Data.getAsArray(); + if (Arr.empty()) + return; + } + case Value::Object: + case Value::Boolean: { + llvm::json::OStream JOS(OS, 2); + JOS.value(Data); + break; + } + } ---------------- ilovepi wrote:
The formatting here looks a bit odd. https://github.com/llvm/llvm-project/pull/105893 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
