[llvm] add support for mustache templating language

[PeterChou1]

Depends on: #105893

Adds a tool to validate the mustache support library the tool consumes the spec from https://github.com/mustache/spec and validates if any test fails

[github-actions]

⚠️ C/C++ code formatter, clang-format found issues in your code. ⚠️

You can test this locally with the following command:

git-clang-format --diff 62ae01201fc7185aca61d040c4f2df5303bae0ad 70e21e890c0d6ecc5eda7fbfc8c04bd60461ff1e --extensions h,cpp -- llvm/include/llvm/Support/Mustache.h llvm/lib/Support/Mustache.cpp llvm/tools/mustache/mustache.cpp llvm/unittests/Support/MustacheTest.cpp

View the diff from clang-format here.

diff --git a/llvm/include/llvm/Support/Mustache.h b/llvm/include/llvm/Support/Mustache.h
index 4d216ac59c..21e233eb12 100644
--- a/llvm/include/llvm/Support/Mustache.h
+++ b/llvm/include/llvm/Support/Mustache.h
@@ -63,8 +63,8 @@
 #include "Error.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/Support/Allocator.h"
-#include "llvm/Support/StringSaver.h"
 #include "llvm/Support/JSON.h"
+#include "llvm/Support/StringSaver.h"
 #include <vector>
 
 namespace llvm {
@@ -129,19 +129,19 @@ public:
     InvertSection,
   };
 
-  ASTNode() : T(Type::Root), LocalContext(nullptr){};
+  ASTNode() : T(Type::Root), LocalContext(nullptr) {};
 
   ASTNode(StringRef Body, ASTNode *Parent)
       : T(Type::Text), Body(Body), Parent(Parent), LocalContext(nullptr),
-        Indentation(0){};
+        Indentation(0) {};
 
   // Constructor for Section/InvertSection/Variable/UnescapeVariable
   ASTNode(Type T, Accessor Accessor, ASTNode *Parent)
       : T(T), Parent(Parent), Children({}), Accessor(Accessor),
-        LocalContext(nullptr), Indentation(0){};
+        LocalContext(nullptr), Indentation(0) {};
 
   void addChild(ASTNode *Child) { Children.emplace_back(Child); };
-  
+
   void setBody(StringRef NewBody) { Body = NewBody; };
 
   void setRawBody(StringRef NewBody) { RawBody = NewBody; };
@@ -149,30 +149,26 @@ public:
   void setIndentation(size_t NewIndentation) { Indentation = NewIndentation; };
 
   void render(llvm::json::Value Data, SmallString<0> &Output);
-  
+
   void setUpNode(llvm::BumpPtrAllocator &Allocator,
-                 StringMap<ASTNode *> &Partials,
-                 StringMap<Lambda> &Lambdas,
+                 StringMap<ASTNode *> &Partials, StringMap<Lambda> &Lambdas,
                  StringMap<SectionLambda> &SectionLambdas,
                  DenseMap<char, StringRef> &Escapes);
+
 private:
-  
-  void renderLambdas(llvm::json::Value& Contexts, 
-                     SmallString<0> &Output,
-                     Lambda& L);
-  
-  void renderSectionLambdas(llvm::json::Value& Contexts, 
-                          SmallString<0> &Output,
-                          SectionLambda& L);
-  
-  void renderPartial(llvm::json::Value& Contexts, 
-                     SmallString<0> &Output,
+  void renderLambdas(llvm::json::Value &Contexts, SmallString<0> &Output,
+                     Lambda &L);
+
+  void renderSectionLambdas(llvm::json::Value &Contexts, SmallString<0> &Output,
+                            SectionLambda &L);
+
+  void renderPartial(llvm::json::Value &Contexts, SmallString<0> &Output,
                      ASTNode *Partial);
 
-  void renderChild(llvm::json::Value& Context, SmallString<0> &Output);
-  
+  void renderChild(llvm::json::Value &Context, SmallString<0> &Output);
+
   llvm::json::Value findContext();
-  
+
   llvm::BumpPtrAllocator *Allocator;
   StringMap<ASTNode *> *Partials;
   StringMap<Lambda> *Lambdas;
diff --git a/llvm/lib/Support/Mustache.cpp b/llvm/lib/Support/Mustache.cpp
index daa2446f92..76532161fd 100644
--- a/llvm/lib/Support/Mustache.cpp
+++ b/llvm/lib/Support/Mustache.cpp
@@ -15,8 +15,8 @@ using namespace llvm::json;
 using namespace llvm::mustache;
 
 SmallString<0> escapeString(StringRef Input,
-                  DenseMap<char, StringRef> &Escape) {
-  
+                            DenseMap<char, StringRef> &Escape) {
+
   SmallString<0> Output;
   for (char C : Input) {
     if (Escape.find(C) != Escape.end())
@@ -42,8 +42,7 @@ Accessor split(StringRef Str, char Delimiter) {
   return Tokens;
 }
 
-void addIndentation(llvm::SmallString<0> &PartialStr,
-                    size_t IndentationSize) {
+void addIndentation(llvm::SmallString<0> &PartialStr, size_t IndentationSize) {
   std::string Indent(IndentationSize, ' ');
   llvm::SmallString<0> Result;
   for (size_t I = 0; I < PartialStr.size(); ++I) {
@@ -175,28 +174,28 @@ SmallVector<Token, 0> tokenize(StringRef Template) {
 
     if (!RequiresCleanUp)
       continue;
-    
-    // We adjust the token body if there's no text behind or ahead a token is 
+
+    // We adjust the token body if there's no text behind or ahead a token is
     // considered surrounded by no text if the right of the previous token
     // is a newline followed by spaces or 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 NoTextBehind = noTextBehind(Idx, Tokens);
     bool NoTextAhead = noTextAhead(Idx, Tokens);
-    
+
     // Adjust next token body if there is no text ahead
-    // eg. 
+    // eg.
     //  The template string
     //  "{{! Comment }} \nLine 2"
-    // would be considered as no text ahead and should be render as 
+    // would be considered as no text ahead and should be render as
     //  " Line 2"
     if ((NoTextBehind && NoTextAhead) || (NoTextAhead && Idx == 0)) {
       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")) 
+      if (NextTokenBody.starts_with("\r\n"))
         NextToken.setTokenBody(NextTokenBody.substr(2));
       else if (NextTokenBody.starts_with("\n"))
         NextToken.setTokenBody(NextTokenBody.substr(1));
@@ -205,9 +204,9 @@ SmallVector<Token, 0> tokenize(StringRef Template) {
     // eg.
     //  The template string
     //  " \t{{#section}}A{{/section}}"
-    // would be considered as no text ahead and should be render as 
+    // would be considered as no text ahead and should be render as
     //  "A"
-    // The exception for this is partial tag which requires us to 
+    // The exception for this is partial tag which requires us to
     // keep track of the indentation once it's rendered
     if (((NoTextBehind && NoTextAhead) || (NoTextBehind && Idx == LastIdx))) {
       Token &PrevToken = Tokens[Idx - 1];
@@ -230,7 +229,6 @@ public:
   ASTNode *parse();
 
 private:
-  
   void parseMustache(ASTNode *Parent);
 
   BumpPtrAllocator &Allocator;
@@ -352,7 +350,7 @@ Template::Template(StringRef TemplateStr) {
   registerEscape(HtmlEntities);
 }
 
-void toJsonString(Value &Data, SmallString<0>& Output) {
+void toJsonString(Value &Data, SmallString<0> &Output) {
   if (Data.getAsNull())
     return;
   if (auto *Arr = Data.getAsArray())
@@ -377,7 +375,6 @@ bool isFalsey(Value &V) {
          (V.getAsObject() && V.getAsObject()->empty());
 }
 
-
 void ASTNode::render(Value Data, SmallString<0> &Output) {
   LocalContext = Data;
   Value Context = T == Root ? Data : findContext();
@@ -418,12 +415,12 @@ void ASTNode::render(Value Data, SmallString<0> &Output) {
     bool IsLambda = SectionLambda != SectionLambdas->end();
     if (isFalsey(Context) && !IsLambda)
       return;
-    
+
     if (IsLambda) {
-        renderSectionLambdas(Data, Output, SectionLambda->getValue());
-        return;
+      renderSectionLambdas(Data, Output, SectionLambda->getValue());
+      return;
     }
-    
+
     if (Context.getAsArray()) {
       SmallString<0> Result;
       json::Array *Arr = Context.getAsArray();
@@ -432,16 +429,15 @@ void ASTNode::render(Value Data, SmallString<0> &Output) {
       Output = Result;
       return;
     }
-    
+
     renderChild(Context, Output);
   }
   case InvertSection: {
-    bool IsLambda = SectionLambdas->find(Accessor[0]) != 
-                    SectionLambdas->end();
-    
+    bool IsLambda = SectionLambdas->find(Accessor[0]) != SectionLambdas->end();
+
     if (!isFalsey(Context) || IsLambda)
       return;
-    
+
     renderChild(Context, Output);
   }
   }
@@ -451,8 +447,8 @@ void ASTNode::render(Value Data, SmallString<0> &Output) {
 Value ASTNode::findContext() {
   // The mustache spec allows for dot notation to access nested values
   // a single dot refers to the current context.
-  // We attempt to find the JSON context in the current node, if it is not 
-  // found, then we traverse the parent nodes to find the context until we 
+  // We attempt to find the JSON context in the current node, if it is not
+  // found, then we traverse the parent nodes to find the context until we
   // reach the root node or the context is found
   if (Accessor.empty())
     return nullptr;
@@ -493,25 +489,19 @@ void ASTNode::renderChild(Value &Context, SmallString<0> &Output) {
   }
 }
 
-void ASTNode::renderPartial(Value &Context, 
-                            SmallString<0> &Output,
+void ASTNode::renderPartial(Value &Context, SmallString<0> &Output,
                             ASTNode *Partial) {
   Partial->render(Context, Output);
   addIndentation(Output, Indentation);
 }
 
-void ASTNode::renderLambdas(Value &Context, 
-                            SmallString<0> &Output,
-                            Lambda& L) {
+void ASTNode::renderLambdas(Value &Context, SmallString<0> &Output, Lambda &L) {
   Value LambdaResult = L();
   SmallString<0> LambdaStr;
   toJsonString(LambdaResult, LambdaStr);
   Parser P = Parser(LambdaStr, *Allocator);
   ASTNode *LambdaNode = P.parse();
-  LambdaNode->setUpNode(*Allocator, 
-                        *Partials, 
-                        *Lambdas, 
-                        *SectionLambdas,
+  LambdaNode->setUpNode(*Allocator, *Partials, *Lambdas, *SectionLambdas,
                         *Escapes);
   LambdaNode->render(Context, Output);
   if (T == Variable)
@@ -519,9 +509,7 @@ void ASTNode::renderLambdas(Value &Context,
   return;
 }
 
-
-void ASTNode::renderSectionLambdas(Value &Contexts, 
-                                   SmallString<0> &Output,
+void ASTNode::renderSectionLambdas(Value &Contexts, SmallString<0> &Output,
                                    SectionLambda &L) {
   Value Return = L(RawBody);
   if (isFalsey(Return))
@@ -530,21 +518,16 @@ void ASTNode::renderSectionLambdas(Value &Contexts,
   toJsonString(Return, LambdaStr);
   Parser P = Parser(LambdaStr, *Allocator);
   ASTNode *LambdaNode = P.parse();
-  LambdaNode->setUpNode(*Allocator, 
-                        *Partials, 
-                        *Lambdas, 
-                        *SectionLambdas,
+  LambdaNode->setUpNode(*Allocator, *Partials, *Lambdas, *SectionLambdas,
                         *Escapes);
   LambdaNode->render(Contexts, Output);
   return;
 }
 
-void ASTNode::setUpNode(BumpPtrAllocator &Alloc,
-                        StringMap<ASTNode *> &Par,
-                        StringMap<Lambda> &L,
-                        StringMap<SectionLambda> &SC,
+void ASTNode::setUpNode(BumpPtrAllocator &Alloc, StringMap<ASTNode *> &Par,
+                        StringMap<Lambda> &L, StringMap<SectionLambda> &SC,
                         DenseMap<char, StringRef> &E) {
-  
+
   // Passed down datastructures needed for rendering to
   // the children nodes
   Allocator = &Alloc;
@@ -554,5 +537,4 @@ void ASTNode::setUpNode(BumpPtrAllocator &Alloc,
   Escapes = &E;
   for (ASTNode *Child : Children)
     Child->setUpNode(Alloc, Par, L, SC, E);
-  
 }