1 //===- AST.cpp - Helper for printing out the Toy AST ----------------------===//
2 //
3 // Part of the MLIR 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 "mlir/ADT/TypeSwitch.h"
16 #include "mlir/Support/STLExtras.h"
17 #include "llvm/ADT/Twine.h"
18 #include "llvm/Support/raw_ostream.h"
19
20 using namespace toy;
21
22 namespace {
23
24 // RAII helper to manage increasing/decreasing the indentation as we traverse
25 // the AST
26 struct Indent {
Indent__anon2e7c1d150111::Indent27 Indent(int &level) : level(level) { ++level; }
~Indent__anon2e7c1d150111::Indent28 ~Indent() { --level; }
29 int &level;
30 };
31
32 /// Helper class that implement the AST tree traversal and print the nodes along
33 /// the way. The only data member is the current indentation level.
34 class ASTDumper {
35 public:
36 void dump(ModuleAST *node);
37
38 private:
39 void dump(const VarType &type);
40 void dump(VarDeclExprAST *varDecl);
41 void dump(ExprAST *expr);
42 void dump(ExprASTList *exprList);
43 void dump(NumberExprAST *num);
44 void dump(LiteralExprAST *node);
45 void dump(VariableExprAST *node);
46 void dump(ReturnExprAST *node);
47 void dump(BinaryExprAST *node);
48 void dump(CallExprAST *node);
49 void dump(PrintExprAST *node);
50 void dump(PrototypeAST *node);
51 void dump(FunctionAST *node);
52
53 // Actually print spaces matching the current indentation level
indent()54 void indent() {
55 for (int i = 0; i < curIndent; i++)
56 llvm::errs() << " ";
57 }
58 int curIndent = 0;
59 };
60
61 } // namespace
62
63 /// Return a formatted string for the location of any node
loc(T * node)64 template <typename T> static std::string loc(T *node) {
65 const auto &loc = node->loc();
66 return (llvm::Twine("@") + *loc.file + ":" + llvm::Twine(loc.line) + ":" +
67 llvm::Twine(loc.col))
68 .str();
69 }
70
71 // Helper Macro to bump the indentation level and print the leading spaces for
72 // the current indentations
73 #define INDENT() \
74 Indent level_(curIndent); \
75 indent();
76
77 /// Dispatch to a generic expressions to the appropriate subclass using RTTI
dump(ExprAST * expr)78 void ASTDumper::dump(ExprAST *expr) {
79 mlir::TypeSwitch<ExprAST *>(expr)
80 .Case<BinaryExprAST, CallExprAST, LiteralExprAST, NumberExprAST,
81 PrintExprAST, ReturnExprAST, VarDeclExprAST, VariableExprAST>(
82 [&](auto *node) { this->dump(node); })
83 .Default([&](ExprAST *) {
84 // No match, fallback to a generic message
85 INDENT();
86 llvm::errs() << "<unknown Expr, kind " << expr->getKind() << ">\n";
87 });
88 }
89
90 /// A variable declaration is printing the variable name, the type, and then
91 /// recurse in the initializer value.
dump(VarDeclExprAST * varDecl)92 void ASTDumper::dump(VarDeclExprAST *varDecl) {
93 INDENT();
94 llvm::errs() << "VarDecl " << varDecl->getName();
95 dump(varDecl->getType());
96 llvm::errs() << " " << loc(varDecl) << "\n";
97 dump(varDecl->getInitVal());
98 }
99
100 /// A "block", or a list of expression
dump(ExprASTList * exprList)101 void ASTDumper::dump(ExprASTList *exprList) {
102 INDENT();
103 llvm::errs() << "Block {\n";
104 for (auto &expr : *exprList)
105 dump(expr.get());
106 indent();
107 llvm::errs() << "} // Block\n";
108 }
109
110 /// A literal number, just print the value.
dump(NumberExprAST * num)111 void ASTDumper::dump(NumberExprAST *num) {
112 INDENT();
113 llvm::errs() << num->getValue() << " " << loc(num) << "\n";
114 }
115
116 /// Helper to print recursively a literal. This handles nested array like:
117 /// [ [ 1, 2 ], [ 3, 4 ] ]
118 /// We print out such array with the dimensions spelled out at every level:
119 /// <2,2>[<2>[ 1, 2 ], <2>[ 3, 4 ] ]
printLitHelper(ExprAST * litOrNum)120 void printLitHelper(ExprAST *litOrNum) {
121 // Inside a literal expression we can have either a number or another literal
122 if (auto num = llvm::dyn_cast<NumberExprAST>(litOrNum)) {
123 llvm::errs() << num->getValue();
124 return;
125 }
126 auto *literal = llvm::cast<LiteralExprAST>(litOrNum);
127
128 // Print the dimension for this literal first
129 llvm::errs() << "<";
130 mlir::interleaveComma(literal->getDims(), llvm::errs());
131 llvm::errs() << ">";
132
133 // Now print the content, recursing on every element of the list
134 llvm::errs() << "[ ";
135 mlir::interleaveComma(literal->getValues(), llvm::errs(),
136 [&](auto &elt) { printLitHelper(elt.get()); });
137 llvm::errs() << "]";
138 }
139
140 /// Print a literal, see the recursive helper above for the implementation.
dump(LiteralExprAST * node)141 void ASTDumper::dump(LiteralExprAST *node) {
142 INDENT();
143 llvm::errs() << "Literal: ";
144 printLitHelper(node);
145 llvm::errs() << " " << loc(node) << "\n";
146 }
147
148 /// Print a variable reference (just a name).
dump(VariableExprAST * node)149 void ASTDumper::dump(VariableExprAST *node) {
150 INDENT();
151 llvm::errs() << "var: " << node->getName() << " " << loc(node) << "\n";
152 }
153
154 /// Return statement print the return and its (optional) argument.
dump(ReturnExprAST * node)155 void ASTDumper::dump(ReturnExprAST *node) {
156 INDENT();
157 llvm::errs() << "Return\n";
158 if (node->getExpr().hasValue())
159 return dump(*node->getExpr());
160 {
161 INDENT();
162 llvm::errs() << "(void)\n";
163 }
164 }
165
166 /// Print a binary operation, first the operator, then recurse into LHS and RHS.
dump(BinaryExprAST * node)167 void ASTDumper::dump(BinaryExprAST *node) {
168 INDENT();
169 llvm::errs() << "BinOp: " << node->getOp() << " " << loc(node) << "\n";
170 dump(node->getLHS());
171 dump(node->getRHS());
172 }
173
174 /// Print a call expression, first the callee name and the list of args by
175 /// recursing into each individual argument.
dump(CallExprAST * node)176 void ASTDumper::dump(CallExprAST *node) {
177 INDENT();
178 llvm::errs() << "Call '" << node->getCallee() << "' [ " << loc(node) << "\n";
179 for (auto &arg : node->getArgs())
180 dump(arg.get());
181 indent();
182 llvm::errs() << "]\n";
183 }
184
185 /// Print a builtin print call, first the builtin name and then the argument.
dump(PrintExprAST * node)186 void ASTDumper::dump(PrintExprAST *node) {
187 INDENT();
188 llvm::errs() << "Print [ " << loc(node) << "\n";
189 dump(node->getArg());
190 indent();
191 llvm::errs() << "]\n";
192 }
193
194 /// Print type: only the shape is printed in between '<' and '>'
dump(const VarType & type)195 void ASTDumper::dump(const VarType &type) {
196 llvm::errs() << "<";
197 mlir::interleaveComma(type.shape, llvm::errs());
198 llvm::errs() << ">";
199 }
200
201 /// Print a function prototype, first the function name, and then the list of
202 /// parameters names.
dump(PrototypeAST * node)203 void ASTDumper::dump(PrototypeAST *node) {
204 INDENT();
205 llvm::errs() << "Proto '" << node->getName() << "' " << loc(node) << "'\n";
206 indent();
207 llvm::errs() << "Params: [";
208 mlir::interleaveComma(node->getArgs(), llvm::errs(),
209 [](auto &arg) { llvm::errs() << arg->getName(); });
210 llvm::errs() << "]\n";
211 }
212
213 /// Print a function, first the prototype and then the body.
dump(FunctionAST * node)214 void ASTDumper::dump(FunctionAST *node) {
215 INDENT();
216 llvm::errs() << "Function \n";
217 dump(node->getProto());
218 dump(node->getBody());
219 }
220
221 /// Print a module, actually loop over the functions and print them in sequence.
dump(ModuleAST * node)222 void ASTDumper::dump(ModuleAST *node) {
223 INDENT();
224 llvm::errs() << "Module:\n";
225 for (auto &f : *node)
226 dump(&f);
227 }
228
229 namespace toy {
230
231 // Public API
dump(ModuleAST & module)232 void dump(ModuleAST &module) { ASTDumper().dump(&module); }
233
234 } // namespace toy
235