1 //===- AST.cpp - Helper for printing out the Toy AST ----------------------===//
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 // This file implements the AST dump for the Toy language.
10 //
11 //===----------------------------------------------------------------------===//
12
13 #include "toy/AST.h"
14
15 #include "llvm/ADT/Twine.h"
16 #include "llvm/ADT/TypeSwitch.h"
17 #include "llvm/Support/raw_ostream.h"
18
19 using namespace toy;
20
21 namespace {
22
23 // RAII helper to manage increasing/decreasing the indentation as we traverse
24 // the AST
25 struct Indent {
Indent__anon7bf5b0dc0111::Indent26 Indent(int &level) : level(level) { ++level; }
~Indent__anon7bf5b0dc0111::Indent27 ~Indent() { --level; }
28 int &level;
29 };
30
31 /// Helper class that implement the AST tree traversal and print the nodes along
32 /// the way. The only data member is the current indentation level.
33 class ASTDumper {
34 public:
35 void dump(ModuleAST *node);
36
37 private:
38 void dump(const VarType &type);
39 void dump(VarDeclExprAST *varDecl);
40 void dump(ExprAST *expr);
41 void dump(ExprASTList *exprList);
42 void dump(NumberExprAST *num);
43 void dump(LiteralExprAST *node);
44 void dump(VariableExprAST *node);
45 void dump(ReturnExprAST *node);
46 void dump(BinaryExprAST *node);
47 void dump(CallExprAST *node);
48 void dump(PrintExprAST *node);
49 void dump(PrototypeAST *node);
50 void dump(FunctionAST *node);
51
52 // Actually print spaces matching the current indentation level
indent()53 void indent() {
54 for (int i = 0; i < curIndent; i++)
55 llvm::errs() << " ";
56 }
57 int curIndent = 0;
58 };
59
60 } // namespace
61
62 /// Return a formatted string for the location of any node
loc(T * node)63 template <typename T> static std::string loc(T *node) {
64 const auto &loc = node->loc();
65 return (llvm::Twine("@") + *loc.file + ":" + llvm::Twine(loc.line) + ":" +
66 llvm::Twine(loc.col))
67 .str();
68 }
69
70 // Helper Macro to bump the indentation level and print the leading spaces for
71 // the current indentations
72 #define INDENT() \
73 Indent level_(curIndent); \
74 indent();
75
76 /// Dispatch to a generic expressions to the appropriate subclass using RTTI
dump(ExprAST * expr)77 void ASTDumper::dump(ExprAST *expr) {
78 llvm::TypeSwitch<ExprAST *>(expr)
79 .Case<BinaryExprAST, CallExprAST, LiteralExprAST, NumberExprAST,
80 PrintExprAST, ReturnExprAST, VarDeclExprAST, VariableExprAST>(
81 [&](auto *node) { this->dump(node); })
82 .Default([&](ExprAST *) {
83 // No match, fallback to a generic message
84 INDENT();
85 llvm::errs() << "<unknown Expr, kind " << expr->getKind() << ">\n";
86 });
87 }
88
89 /// A variable declaration is printing the variable name, the type, and then
90 /// recurse in the initializer value.
dump(VarDeclExprAST * varDecl)91 void ASTDumper::dump(VarDeclExprAST *varDecl) {
92 INDENT();
93 llvm::errs() << "VarDecl " << varDecl->getName();
94 dump(varDecl->getType());
95 llvm::errs() << " " << loc(varDecl) << "\n";
96 dump(varDecl->getInitVal());
97 }
98
99 /// A "block", or a list of expression
dump(ExprASTList * exprList)100 void ASTDumper::dump(ExprASTList *exprList) {
101 INDENT();
102 llvm::errs() << "Block {\n";
103 for (auto &expr : *exprList)
104 dump(expr.get());
105 indent();
106 llvm::errs() << "} // Block\n";
107 }
108
109 /// A literal number, just print the value.
dump(NumberExprAST * num)110 void ASTDumper::dump(NumberExprAST *num) {
111 INDENT();
112 llvm::errs() << num->getValue() << " " << loc(num) << "\n";
113 }
114
115 /// Helper to print recursively a literal. This handles nested array like:
116 /// [ [ 1, 2 ], [ 3, 4 ] ]
117 /// We print out such array with the dimensions spelled out at every level:
118 /// <2,2>[<2>[ 1, 2 ], <2>[ 3, 4 ] ]
printLitHelper(ExprAST * litOrNum)119 void printLitHelper(ExprAST *litOrNum) {
120 // Inside a literal expression we can have either a number or another literal
121 if (auto num = llvm::dyn_cast<NumberExprAST>(litOrNum)) {
122 llvm::errs() << num->getValue();
123 return;
124 }
125 auto *literal = llvm::cast<LiteralExprAST>(litOrNum);
126
127 // Print the dimension for this literal first
128 llvm::errs() << "<";
129 llvm::interleaveComma(literal->getDims(), llvm::errs());
130 llvm::errs() << ">";
131
132 // Now print the content, recursing on every element of the list
133 llvm::errs() << "[ ";
134 llvm::interleaveComma(literal->getValues(), llvm::errs(),
135 [&](auto &elt) { printLitHelper(elt.get()); });
136 llvm::errs() << "]";
137 }
138
139 /// Print a literal, see the recursive helper above for the implementation.
dump(LiteralExprAST * node)140 void ASTDumper::dump(LiteralExprAST *node) {
141 INDENT();
142 llvm::errs() << "Literal: ";
143 printLitHelper(node);
144 llvm::errs() << " " << loc(node) << "\n";
145 }
146
147 /// Print a variable reference (just a name).
dump(VariableExprAST * node)148 void ASTDumper::dump(VariableExprAST *node) {
149 INDENT();
150 llvm::errs() << "var: " << node->getName() << " " << loc(node) << "\n";
151 }
152
153 /// Return statement print the return and its (optional) argument.
dump(ReturnExprAST * node)154 void ASTDumper::dump(ReturnExprAST *node) {
155 INDENT();
156 llvm::errs() << "Return\n";
157 if (node->getExpr().hasValue())
158 return dump(*node->getExpr());
159 {
160 INDENT();
161 llvm::errs() << "(void)\n";
162 }
163 }
164
165 /// Print a binary operation, first the operator, then recurse into LHS and RHS.
dump(BinaryExprAST * node)166 void ASTDumper::dump(BinaryExprAST *node) {
167 INDENT();
168 llvm::errs() << "BinOp: " << node->getOp() << " " << loc(node) << "\n";
169 dump(node->getLHS());
170 dump(node->getRHS());
171 }
172
173 /// Print a call expression, first the callee name and the list of args by
174 /// recursing into each individual argument.
dump(CallExprAST * node)175 void ASTDumper::dump(CallExprAST *node) {
176 INDENT();
177 llvm::errs() << "Call '" << node->getCallee() << "' [ " << loc(node) << "\n";
178 for (auto &arg : node->getArgs())
179 dump(arg.get());
180 indent();
181 llvm::errs() << "]\n";
182 }
183
184 /// Print a builtin print call, first the builtin name and then the argument.
dump(PrintExprAST * node)185 void ASTDumper::dump(PrintExprAST *node) {
186 INDENT();
187 llvm::errs() << "Print [ " << loc(node) << "\n";
188 dump(node->getArg());
189 indent();
190 llvm::errs() << "]\n";
191 }
192
193 /// Print type: only the shape is printed in between '<' and '>'
dump(const VarType & type)194 void ASTDumper::dump(const VarType &type) {
195 llvm::errs() << "<";
196 llvm::interleaveComma(type.shape, llvm::errs());
197 llvm::errs() << ">";
198 }
199
200 /// Print a function prototype, first the function name, and then the list of
201 /// parameters names.
dump(PrototypeAST * node)202 void ASTDumper::dump(PrototypeAST *node) {
203 INDENT();
204 llvm::errs() << "Proto '" << node->getName() << "' " << loc(node) << "\n";
205 indent();
206 llvm::errs() << "Params: [";
207 llvm::interleaveComma(node->getArgs(), llvm::errs(),
208 [](auto &arg) { llvm::errs() << arg->getName(); });
209 llvm::errs() << "]\n";
210 }
211
212 /// Print a function, first the prototype and then the body.
dump(FunctionAST * node)213 void ASTDumper::dump(FunctionAST *node) {
214 INDENT();
215 llvm::errs() << "Function \n";
216 dump(node->getProto());
217 dump(node->getBody());
218 }
219
220 /// Print a module, actually loop over the functions and print them in sequence.
dump(ModuleAST * node)221 void ASTDumper::dump(ModuleAST *node) {
222 INDENT();
223 llvm::errs() << "Module:\n";
224 for (auto &f : *node)
225 dump(&f);
226 }
227
228 namespace toy {
229
230 // Public API
dump(ModuleAST & module)231 void dump(ModuleAST &module) { ASTDumper().dump(&module); }
232
233 } // namespace toy
234