yiqin / Compiler-Abstract-Syntax-Tree

Compiler: Abstract Syntax Tree

It's in x86 Assembly/GAS Syntax. The assembly code is directly executable.

1. Type make

2. Type ./calc <testCase.txt >testCase.s to run the test case.

3. Type gcc -m32 testCase.s -o testCase to build the executable file.

4. Type ./testCase to run the executable file.

Type make clean to clean files.

Note:

1. We build the Abstract Syntax Tree first. In the clac.y, we have Node* root to track the root of the AST. Then we traverse the nodes. During the travering, we generate the assembly code.

2. Node class is in the node.hpp file. function generate_code is to find the subnode recursely. Node

3. We also make some modifications to the Symbol class. The function get_assembly_code() is to get the addresss of the node. The node can be a constant integer, an intermediate value or a local variable. For the intermediate value and the local variable, we need to know the address or the register, which has been defined in the calc.y.

	const std::string get_assembly_code() {
		if (type == Type::CONST_INT) {
			return "$"+std::to_string(int_value);
		}
		if (!address.empty()) {
			return address;
		}
		return "";
	};

4. A sepcial case is the depth of AST is 0. For example:

a;
1;

We have considered this case in the node.hpp.