Print name of the function that the variables belong to in C++ - c++

Question

I am having so much trouble trying to solve this one out. I have to read a .c file that has three functions (add, sub and main) and I want to print to the console the name of their variables with the name of the function in brackets. I tried implementing a string function_name in my struct to store the value of the functions, but I don't know how to print it next to my variables until I hit another function. Any help or advice will be much appreciated.
For example:
From this .c text
int add ( int a , int b )
{
return a + b ;
}
I want to get this:
add, line 1, function, int, referenced 2
a (add), line 1, variable, int, referenced 1
b (add), line 1, variable, int, referenced 1
But I get this:
add(add), line 1, function, int, referenced 16
a, line 1, variable, int, referenced 15
b, line 1, variable, int, referenced 15
My code so far looks like this.
#include <iostream>
#include <string>
#include <fstream>
#include <sstream>
#include <vector>
using namespace std;
struct identifier
{
string id_name;
string function_name;
int id_count;
string id_function;
string id_type;
int id_ref;
};
int main(int argc, char** argv)
{
if (argc < 2)
{
cout << "ERROR: There is no file selected." << endl;
}
ifstream file(argv[1]);
string line;
string token;
vector<identifier> id_list;
int line_counter = 0;
int num_functions = 0;
int num_variables = 0;
int num_if = 0;
int num_for = 0;
int num_while = 0;
while (getline(file, line))
{
stringstream stream(line);
line_counter++;
while (stream >> token)
{
bool found = false;
for (auto& v : id_list)
{
if (v.id_name == token)
{
//We have seen the word so add one to its count
v.id_ref++;
found = true;
break;
}
}
if (token == "int" || token == "int*")
{
string star = token;
identifier intI;
stream >> token;
string name = token;
intI.id_name = name;
intI.id_count = line_counter;
intI.id_type = "int";
stream >> token; //Get the next token
if (token == "(")
{
//We have a function
intI.id_function = "function";
if (intI.id_name != "main")
{
intI.function_name = "(" + name + ")";
}
num_functions++;
}
else
{
//We have a variable
intI.id_function = "variable";
if (star == "int*")
{
intI.id_type = "int*";
}
num_variables++;
}
id_list.push_back(intI);
}
}
file.close();
//Print the words and their counts
for (auto& v : id_list)
{
cout << v.id_name << v.function_name << ", line " << v.id_count << ", " << v.id_function << ", " << v.id_type << ", referenced " << v.id_ref << endl;
}
return 0;

Answer 1

I can see you're incrementing id_ref now, but it's still not initialized, so you have undefined behaviour. Easiest way is to do = 0; where its defined in the struct.
As for your function, assuming there's no nested functions here, then you can just use a variable to keep track of that.
#include <iostream>
#include <string>
#include <fstream>
#include <sstream>
#include <vector>
struct identifier {
std::string id_name;
std::string function_name;
int id_count;
std::string id_function;
std::string id_type;
int id_ref = 0; // if not initialized, then you will get seemingly random numbers
};
int main( int argc, char **argv ) {
if ( argc < 2 ) {
std::cout << "ERROR: There is no file selected." << std::endl;
return 1; // quit early
}
std::ifstream file( argv[1] );
std::string line;
std::string token;
std::vector<identifier> id_list;
int line_counter = 0;
int num_functions = 0;
int num_variables = 0;
int num_if = 0;
int num_for = 0;
int num_while = 0;
std::string current_function; // keep track of the function
while ( std::getline( file, line ) ) {
std::stringstream stream( line );
line_counter++;
while ( stream >> token ) {
bool found = false;
for ( auto &v : id_list ) {
if ( v.id_name == token ) {
//We have seen the word so add one to its count
v.id_ref++;
found = true;
break;
}
}
if ( token == "int" || token == "int*" ) {
std::string star = token;
identifier intI;
stream >> token;
std::string name = token;
intI.id_name = name;
intI.id_count = line_counter;
intI.id_type = "int";
stream >> token; //Get the next token
if ( token == "(" ) {
//We have a function
intI.id_function = "function";
if ( intI.id_name != "main" ) {
current_function = name; // update the current function name
}
num_functions++;
} else {
intI.function_name = "(" + current_function + ")"; // add the function name to the variable name
//We have a variable
intI.id_function = "variable";
if ( star == "int*" ) {
intI.id_type = "int*";
}
num_variables++;
}
id_list.push_back( intI );
}
}
}
//file.close();
//Print the words and their counts
for ( const auto &v : id_list ) {
std::cout << v.id_name << v.function_name << ", line " << v.id_count << ", " << v.id_function << ", " << v.id_type << ", referenced " << v.id_ref << std::endl;
}
return 0;
}
Also, some recommended reading on using namespace std
Working example modified to work with a string, instead of parameter: https://godbolt.org/z/jKqqrhce6