X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=examples%2FKaleidoscope%2FChapter7%2Ftoy.cpp;h=a900c5f7b16f3039e6b74b0e6da8867f5f6bdcca;hb=44364a33be4f2729f0b00c6ab48685a39749ad6f;hp=3c988ac9aa2f78f0c649c1dab4cd3fbe5252a3af;hpb=09f1564d23c7f606a5419a89a5126b698624c3a7;p=oota-llvm.git

diff --git a/examples/Kaleidoscope/Chapter7/toy.cpp b/examples/Kaleidoscope/Chapter7/toy.cpp
index 3c988ac9aa2..a900c5f7b16 100644
--- a/examples/Kaleidoscope/Chapter7/toy.cpp
+++ b/examples/Kaleidoscope/Chapter7/toy.cpp
@@ -136,6 +136,7 @@ public:
 /// NumberExprAST - Expression class for numeric literals like "1.0".
 class NumberExprAST : public ExprAST {
   double Val;
+
 public:
   NumberExprAST(double Val) : Val(Val) {}
   Value *Codegen() override;
@@ -144,6 +145,7 @@ public:
 /// VariableExprAST - Expression class for referencing a variable, like "a".
 class VariableExprAST : public ExprAST {
   std::string Name;
+
 public:
   VariableExprAST(const std::string &Name) : Name(Name) {}
   const std::string &getName() const { return Name; }
@@ -154,6 +156,7 @@ public:
 class UnaryExprAST : public ExprAST {
   char Opcode;
   std::unique_ptr<ExprAST> Operand;
+
 public:
   UnaryExprAST(char Opcode, std::unique_ptr<ExprAST> Operand)
       : Opcode(Opcode), Operand(std::move(Operand)) {}
@@ -164,6 +167,7 @@ public:
 class BinaryExprAST : public ExprAST {
   char Op;
   std::unique_ptr<ExprAST> LHS, RHS;
+
 public:
   BinaryExprAST(char Op, std::unique_ptr<ExprAST> LHS,
                 std::unique_ptr<ExprAST> RHS)
@@ -175,6 +179,7 @@ public:
 class CallExprAST : public ExprAST {
   std::string Callee;
   std::vector<std::unique_ptr<ExprAST>> Args;
+
 public:
   CallExprAST(const std::string &Callee,
               std::vector<std::unique_ptr<ExprAST>> Args)
@@ -185,6 +190,7 @@ public:
 /// IfExprAST - Expression class for if/then/else.
 class IfExprAST : public ExprAST {
   std::unique_ptr<ExprAST> Cond, Then, Else;
+
 public:
   IfExprAST(std::unique_ptr<ExprAST> Cond, std::unique_ptr<ExprAST> Then,
             std::unique_ptr<ExprAST> Else)
@@ -196,6 +202,7 @@ public:
 class ForExprAST : public ExprAST {
   std::string VarName;
   std::unique_ptr<ExprAST> Start, End, Step, Body;
+
 public:
   ForExprAST(const std::string &VarName, std::unique_ptr<ExprAST> Start,
              std::unique_ptr<ExprAST> End, std::unique_ptr<ExprAST> Step,
@@ -209,25 +216,29 @@ public:
 class VarExprAST : public ExprAST {
   std::vector<std::pair<std::string, std::unique_ptr<ExprAST>>> VarNames;
   std::unique_ptr<ExprAST> Body;
+
 public:
-  VarExprAST(std::vector<std::pair<std::string, std::unique_ptr<ExprAST>>> VarNames,
-             std::unique_ptr<ExprAST> Body)
-    : VarNames(std::move(VarNames)), Body(std::move(Body)) {}
+  VarExprAST(
+      std::vector<std::pair<std::string, std::unique_ptr<ExprAST>>> VarNames,
+      std::unique_ptr<ExprAST> Body)
+      : VarNames(std::move(VarNames)), Body(std::move(Body)) {}
   Value *Codegen() override;
 };
 
 /// PrototypeAST - This class represents the "prototype" for a function,
-/// which captures its argument names as well as if it is an operator.
+/// which captures its name, and its argument names (thus implicitly the number
+/// of arguments the function takes), as well as if it is an operator.
 class PrototypeAST {
   std::string Name;
   std::vector<std::string> Args;
   bool IsOperator;
   unsigned Precedence; // Precedence if a binary op.
+
 public:
   PrototypeAST(const std::string &Name, std::vector<std::string> Args,
                bool IsOperator = false, unsigned Prec = 0)
-    : Name(Name), Args(std::move(Args)), IsOperator(IsOperator),
-      Precedence(Prec) {}
+      : Name(Name), Args(std::move(Args)), IsOperator(IsOperator),
+        Precedence(Prec) {}
 
   bool isUnaryOp() const { return IsOperator && Args.size() == 1; }
   bool isBinaryOp() const { return IsOperator && Args.size() == 2; }
@@ -248,8 +259,10 @@ public:
 class FunctionAST {
   std::unique_ptr<PrototypeAST> Proto;
   std::unique_ptr<ExprAST> Body;
+
 public:
-  FunctionAST(std::unique_ptr<PrototypeAST> Proto, std::unique_ptr<ExprAST> Body)
+  FunctionAST(std::unique_ptr<PrototypeAST> Proto,
+              std::unique_ptr<ExprAST> Body)
       : Proto(std::move(Proto)), Body(std::move(Body)) {}
   Function *Codegen();
 };
@@ -297,6 +310,26 @@ std::unique_ptr<FunctionAST> ErrorF(const char *Str) {
 
 static std::unique_ptr<ExprAST> ParseExpression();
 
+/// numberexpr ::= number
+static std::unique_ptr<ExprAST> ParseNumberExpr() {
+  auto Result = llvm::make_unique<NumberExprAST>(NumVal);
+  getNextToken(); // consume the number
+  return std::move(Result);
+}
+
+/// parenexpr ::= '(' expression ')'
+static std::unique_ptr<ExprAST> ParseParenExpr() {
+  getNextToken(); // eat (.
+  auto V = ParseExpression();
+  if (!V)
+    return nullptr;
+
+  if (CurTok != ')')
+    return Error("expected ')'");
+  getNextToken(); // eat ).
+  return V;
+}
+
 /// identifierexpr
 ///   ::= identifier
 ///   ::= identifier '(' expression* ')'
@@ -333,26 +366,6 @@ static std::unique_ptr<ExprAST> ParseIdentifierExpr() {
   return llvm::make_unique<CallExprAST>(IdName, std::move(Args));
 }
 
-/// numberexpr ::= number
-static std::unique_ptr<ExprAST> ParseNumberExpr() {
-  auto Result = llvm::make_unique<NumberExprAST>(NumVal);
-  getNextToken(); // consume the number
-  return std::move(Result);
-}
-
-/// parenexpr ::= '(' expression ')'
-static std::unique_ptr<ExprAST> ParseParenExpr() {
-  getNextToken(); // eat (.
-  auto V = ParseExpression();
-  if (!V)
-    return nullptr;
-
-  if (CurTok != ')')
-    return Error("expected ')'");
-  getNextToken(); // eat ).
-  return V;
-}
-
 /// ifexpr ::= 'if' expression 'then' expression 'else' expression
 static std::unique_ptr<ExprAST> ParseIfExpr() {
   getNextToken(); // eat the if.
@@ -521,7 +534,8 @@ static std::unique_ptr<ExprAST> ParseUnary() {
 
 /// binoprhs
 ///   ::= ('+' unary)*
-  static std::unique_ptr<ExprAST> ParseBinOpRHS(int ExprPrec, std::unique_ptr<ExprAST> LHS) {
+static std::unique_ptr<ExprAST> ParseBinOpRHS(int ExprPrec,
+                                              std::unique_ptr<ExprAST> LHS) {
   // If this is a binop, find its precedence.
   while (1) {
     int TokPrec = GetTokPrecedence();
@@ -550,7 +564,8 @@ static std::unique_ptr<ExprAST> ParseUnary() {
     }
 
     // Merge LHS/RHS.
-    LHS = llvm::make_unique<BinaryExprAST>(BinOp, std::move(LHS), std::move(RHS));
+    LHS =
+        llvm::make_unique<BinaryExprAST>(BinOp, std::move(LHS), std::move(RHS));
   }
 }
 
@@ -647,7 +662,8 @@ static std::unique_ptr<FunctionAST> ParseDefinition() {
 static std::unique_ptr<FunctionAST> ParseTopLevelExpr() {
   if (auto E = ParseExpression()) {
     // Make an anonymous proto.
-    auto Proto = llvm::make_unique<PrototypeAST>("", std::vector<std::string>());
+    auto Proto =
+        llvm::make_unique<PrototypeAST>("", std::vector<std::string>());
     return llvm::make_unique<FunctionAST>(std::move(Proto), std::move(E));
   }
   return nullptr;
@@ -716,7 +732,7 @@ Value *BinaryExprAST::Codegen() {
     // This assume we're building without RTTI because LLVM builds that way by
     // default.  If you build LLVM with RTTI this can be changed to a
     // dynamic_cast for automatic error checking.
-    VariableExprAST *LHSE = static_cast<VariableExprAST*>(LHS.get());
+    VariableExprAST *LHSE = static_cast<VariableExprAST *>(LHS.get());
     if (!LHSE)
       return ErrorV("destination of '=' must be a variable");
     // Codegen the RHS.
@@ -759,7 +775,7 @@ Value *BinaryExprAST::Codegen() {
   Function *F = TheModule->getFunction(std::string("binary") + Op);
   assert(F && "binary operator not found!");
 
-  Value *Ops[] = { L, R };
+  Value *Ops[] = {L, R};
   return Builder.CreateCall(F, Ops, "binop");
 }
 
@@ -837,27 +853,26 @@ Value *IfExprAST::Codegen() {
   return PN;
 }
 
+// Output for-loop as:
+//   var = alloca double
+//   ...
+//   start = startexpr
+//   store start -> var
+//   goto loop
+// loop:
+//   ...
+//   bodyexpr
+//   ...
+// loopend:
+//   step = stepexpr
+//   endcond = endexpr
+//
+//   curvar = load var
+//   nextvar = curvar + step
+//   store nextvar -> var
+//   br endcond, loop, endloop
+// outloop:
 Value *ForExprAST::Codegen() {
-  // Output this as:
-  //   var = alloca double
-  //   ...
-  //   start = startexpr
-  //   store start -> var
-  //   goto loop
-  // loop:
-  //   ...
-  //   bodyexpr
-  //   ...
-  // loopend:
-  //   step = stepexpr
-  //   endcond = endexpr
-  //
-  //   curvar = load var
-  //   nextvar = curvar + step
-  //   store nextvar -> var
-  //   br endcond, loop, endloop
-  // outloop:
-
   Function *TheFunction = Builder.GetInsertBlock()->getParent();
 
   // Create an alloca for the variable in the entry block.
@@ -894,7 +909,7 @@ Value *ForExprAST::Codegen() {
     return nullptr;
 
   // Emit the step value.
-  Value *StepVal;
+  Value *StepVal = nullptr;
   if (Step) {
     StepVal = Step->Codegen();
     if (!StepVal)
@@ -907,7 +922,7 @@ Value *ForExprAST::Codegen() {
   // Compute the end condition.
   Value *EndCond = End->Codegen();
   if (!EndCond)
-    return EndCond;
+    return nullptr;
 
   // Reload, increment, and restore the alloca.  This handles the case where
   // the body of the loop mutates the variable.
@@ -1137,9 +1152,9 @@ static void MainLoop() {
     switch (CurTok) {
     case tok_eof:
       return;
-    case ';':
+    case ';': // ignore top-level semicolons.
       getNextToken();
-      break; // ignore top-level semicolons.
+      break;
     case tok_def:
       HandleDefinition();
       break;