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unused vars detector

Code

import std.stdio;
import std.regex;
import std.string : strip, format;
import std.file : readText;
import std.conv : to;
import std.algorithm;
import std.array;
static import std.ascii;

/**
 * Types
 */
enum : string {
	PrimitiveTypes = r"((?:void|bool|string|char|double|float)|u?(?:byte|short|int|long|cent)(?:\[.*?\])*)(?:\s*\*)?\s+(?:\s*\*\s*)?([a-zA-Z]+.*?)\;"
}

/**
 * Assign variants
 */
enum : string {
	DirectAssign = r"%s\s*(?:\+|-|\*|\/|~|&|\|)?=\s*.+?;",
	IncDecBinAssign = r"%s\s*(?:\+\+|--)",
	IncDecUnAssign  = r"(?:\+\+|--)\s*.*?%s",
	ByRefAssign  = "&%s",
	TenCondUse = r"\!?\s*%s.*?\?.+?"
}

/**
 * Stores Variable Information
 */
class Var {
public:
	const string Type;
	const string Name;
	const uint LineNr;
	const uint ScopeBegin;
	const uint ScopeEnd;

/**
	 * Is var used?
	 */
	bool Assigned;

this(string type, string name, uint line, uint begin, uint end) {
		Type = strip(type);
		Name = strip(name);

LineNr = line;

ScopeBegin = begin;
		ScopeEnd = end;
	}
}

/**
 * Stores Information about a single line
 */
class Line {
public:
	/**
	 * Line content
	 */
	const string Content;
	/**
	 * Line Number
	 */
	const uint Index;

this(string line, uint line_nr) {
		Content = strip(line);
		Index   = line_nr;
	}
}

void main(string[] args) {
	string buffer = readText(args[1]);
	/// read content and split into lines
	string[] lines = split(buffer, std.ascii.newline);

Line[][string] scopes;
	Line[][uint] temp_scopes;

/// Line numbers of beginning scopes
	uint[] open_brackets = [0];

/// scan file content
	foreach (uint line_nr, string line; lines) {
		if (match(line, r".*?\{.*?")) {
			debug writeln("Open -> ", line_nr);

open_brackets ~= line_nr;

debug writeln(open_brackets);

continue;
		}

if (match(line, r".*?\}.*?")) {
			debug writeln("Close -> ", line_nr);
			/// After found scope end, store temporay fields permanent

if (open_brackets.back !in temp_scopes) {
				continue;
			}

foreach (Line tline; temp_scopes[open_brackets.back]) {
				debug assert(tline !is null);

scopes[to!(string)(open_brackets.back) ~ "~" ~ to!(string)(line_nr)] ~= tline;
			}
			/// clear scope temporary field
			temp_scopes[open_brackets.back] = [];
			/// pop back last scope bracket
			open_brackets.popBack();

debug writeln(open_brackets);

continue;
		}

/// Stores first in temporay field
		temp_scopes[open_brackets.back] ~= new Line(line, line_nr);
	}

Var[] all_vars;

bool comment;

/// walk through scopes
	foreach (string scope_nr, Line[] scope_content; scopes.rehash) {
		foreach (uint index, Line line; scope_content) {
			/// multi line comment
			if (match(line.Content, r"\/\*+")) {
				comment = true;
			}

if (match(line.Content, r"\*+\/")) {
				comment = false;
			}

if (comment) {
				continue;
			}

/// single comment
			if (match(line.Content, r"^\s*\/\/")) {
				continue;
			}

/// search for all variables which are not directly assigned
			if (auto m = match(line.Content, PrimitiveTypes)) {
				auto c = m.captures;

string[] variables = split(c[2], ",");

string[2] scope_args = split(scope_nr, "~");
				const uint begin = to!(uint)(scope_args[0]);
				const uint end   = to!(uint)(scope_args[1]);

if (variables.length == 1) {
					string[] assign = split(c[2], "=");

if (assign.length == 1) {
						all_vars ~= new Var(c[1], c[2], line.Index, begin, end);
						debug writefln(" >> Found Var %s of type %s on line %d", c[2], c[1], line.Index);
					}
				} else {
					foreach (string var; variables) {
						debug writeln(" --> ", var);
						string[] assign = split(var, "=");

if (assign.length == 1) {
							all_vars ~= new Var(c[1], var, line.Index, begin, end);
							debug writefln(" >> Found Var %s of type %s on line %d", var, c[1], line.Index);
						}
					}
				}
			}
		}
	}

/// walk through the scopes
	foreach (string scope_nr, Line[] content; scopes.rehash) {
		string[2] scope_args = split(scope_nr, "~");

const uint s_begin = to!(uint)(scope_args[0]);
		const uint s_end = to!(uint)(scope_args[1]);

foreach (Var var; all_vars) {
			/// correct scope?
			if (var.ScopeEnd < s_begin || var.ScopeBegin > s_end) {
				//writeln(" ---------------> ", content);
				continue;
			}

foreach (Line line; content) {
				/// multi line comment
				if (match(line.Content, r"\/\*+")) {
					comment = true;
				}

if (match(line.Content, r"\*+\/")) {
					comment = false;
				}

if (comment) {
					continue;
				}

/// single comment
				if (match(line.Content, r"\/\/")) {
					continue;
				}

/// is variable assigned?
				if (match(line.Content, format(DirectAssign, var.Name))
				 || match(line.Content, format(IncDecBinAssign, var.Name))
				 || match(line.Content, format(IncDecUnAssign, var.Name))
				 || match(line.Content, format(TenCondUse, var.Name))
				 || match(line.Content, format(ByRefAssign, var.Name)))
				{
					debug writeln(" ==> ", var.Name, ", ", var.LineNr + 1, " is used!");
					var.Assigned = true;
				}
			}
		}
	}

writeln("----");

uint counter = 0;
	/// step through founded variables and check if they was assigned
	foreach (Var var; all_vars) {
		if (!var.Assigned) {
			counter++;

writefln("Variable %s of type %s on line %d is unused.", var.Name, var.Type, var.LineNr + 1);
		}
	}

writefln("----\nYou have %d unused variables.", counter);
}

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Author: Namespace

Views: 201

Private: no

Expires: Never

Uploaded: 30.07.12 18:40

Votes: 0

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Compiler: DMD 2.062

Pointer size: m64

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