I've been working on my uncrustify config for a few hours now and I'm very close to having it the way I need it. However, I can't find an option to control newlines between function bodies. Uncrustify always removes blank lines between functions, but I'd like to enforce one blank line. Currently I get this:
Input:
void foo() {
std::cout << "foo!" << std::endl;
}
void bar() {
std::cout << "bar!" << std::endl;
}
Output:
void foo() {
std::cout << "foo!" << std::endl;
}
void bar() {
std::cout << "bar!" << std::endl;
}
In my case, I'd like to preserve (force!) the blank line in the input. Is there an option to control this?
Epiphany - I was miscounting 'newlines'. The configuration option for this is:
# The number of newlines after '}' of a multi-line function body
nl_after_func_body = 2 # number
I originally set this to 1. However, Uncrustify includes the newline on the line containing the brace (}). Setting this to 2 gives the desired result.
Related
I am trying to convert a Boost UDP server from using raw pointers to using std::vector which I believe is possible from https://www.boost.org/doc/libs/1_66_0/doc/html/boost_asio/reference/buffer.html
However my vector is always filled with 0 values.
void start_receive()
{
std::vector<unsigned char> recv_buffer_(64);
socket_.async_receive_from(
boost::asio::buffer(recv_buffer_), remote_endpoint_,
boost::bind(&udp_server::handle_receive, this,
boost::asio::placeholders::error,
boost::asio::placeholders::bytes_transferred));
std::cout << "Receive length is :" << recv_buffer_.size() << std::endl;
std::cout << "recv_buffer_ = \n";
for (unsigned char n : recv_buffer_)
std::cout << n << ' ';
std::cout << '\n';
}
Any ideas what I may be doing wrong ? socket_ is a udp::socket socket_; and the above code works with a unsigned char *
I'm wondering if any of you guys have experience in reading/logging the input arguments of an instrumented method?
Technically it's so simple and straightforward when the method has some primitive data type as input parameters. For example, integer or double. However, when it's a more complex data type, like string, I faced some weird behavior from pin framework. In nutshell, I cannot recover the original data input.
Below you see my instrumentation function. It simply tries to print the input arguments passed to the instrumented method.
VOID start_of_execution(uint64_t hash_name, int type,
ADDRINT input_arg1,
ADDRINT input_arg2
){
cout << "int arg:" << input_arg1 << endl; // prints the integer input
cout << "string*:" << hex << input_arg2 << endl; // prints the pointer value
cout << "string arg:" << *(reinterpret_cast<string*>(input_arg2)) << endl; // prints nothing!
}
Here is the instrumented method which it's the only functionality is to print the input arguments.
int sample_method(int i, string* str){
cout << "-----" << endl;
cout << "i: " << i << ", str:" << *str <<", ptr:" << str << endl;
return 0;
}
Below is the output:
$ sudo ../../../pin -t obj-intel64/code/mypin.so -- ./code/a.out
int arg:5
string*:0x1704434923
string arg:
-----
i: 5, str:sample text, ptr:0x1704434923
As you see, the integer argument (number 5) has been retrived properly. However, even though the string pointer is valid, PIN wasn't able to recover the string input argument.
Does anybody have an idea about my problem?
Using c++14. I have read many posts regarding the problem.
If I run this code below, it jumps over the getline lines.
#include <iostream>
#include "main_menu.h"
void MainMenu::AddTest()
{
std::string courseName = "";
std::string testName = "";
std::string date = "";
std::cout << "Enter course name: " << std::endl;
std::getline(std::cin, courseName);
std::cout << "Enter test name: " << std::endl;
std::getline(std::cin, testName);
std::cout << "Enter test date: " << std::endl;
std::getline(std::cin, date);
Test test(courseName, testName, date);
tests.Add(test);
std::cout << "Test registered : " << std::endl;
tests.Print(test.id);
}
If I add cin ignore after each getline lines (example below how I implement it), it deletes some characters from the input strings and uses wrong variables to store them. Note that I have strings with whitespaces.
std::getline(std::cin, courseName);
std::cin.ignore();
This is what I get:
Enter course name:
History 2
Enter test name:
History 2 exam
Enter test date:
2017.01.02
Test registered :
test id = 2, course name = , test name = istory 2, date = istory 2 exam
I also tried to flush cout, didn't help.
My Print function works like a charm, if I add courses manually from main, I get the expected output, so the problem is definitely the cin / getline.
Test registered :
test id = 1, course name = History 2, test name = History 2 exam , date = 01.02.2017
I use getline as explained here: http://www.cplusplus.com/reference/string/string/getline/?kw=getline
Any help would be much appreciated, thank you.
By using cin.ignore you are messing with the input itself. If you want to get rid of \n character you don't have to! getline will just do that automatically. So just don't use ignore function and the code will be fine.
This works:
#include<iostream>
using namespace std;
int main()
{
string courseName = "";
string testName = "";
string date = "";
cout << "Enter course name: " << std::endl;
getline(std::cin, courseName);
cout << "Enter test name: " << std::endl;
getline(std::cin, testName);
cout << "Enter test date: " << std::endl;
getline(std::cin, date);
cout << courseName << endl;
cout << testName << endl;
cout << date << endl;
return 0;
}
I'm answering an ancient question, but try clearing the input stream before you use all the getline()'s. It is possible that you have some extra returns in the buffer before you ask for input.
cin.clear();
cin.ignore(INT_MAX);
So at my college we haven't covered do while loops yet so I wanted to try one out before we do but I am running into an issue with it, I want the program to carry out different functions based on the users input, A carries out an addition, B a subtraction and C exits the program.
The program I have wrote with a do while in it carries out these functions one after the other regardless of what the user has input and I am unsure how to get this working properly.
Any advice is much appreciated.
Couple things to note. You have user entering a character for a choice, so make userChoice a character. Notice how the do-while is used for input-validation in this case. I changed the extra while loops with semi-colons at end to condition statements. You can substitute the if and else ifs with switch, "menu driven program". Here is a working program that you want. If you want the do-while around the whole condition statement and not use it as input validation then have it around all the condition statements and check while it is not C.
#include <iostream>
#include <string>
using namespace std;
int main()
{
char userChoice;
int vaulue1;
int vaulue2;
int addtionValue;
int subtractionValue;
cout << "Choice A: will preform an addition" << endl;
cout << "Choice B: will preform a subtraction" << endl;
cout << "Choice C: will quit\n" << endl;
do
{
cout << "Enter your choice\n" << endl;
cin >> userChoice;
} while(userChoice != 'A' && userChoice != 'B' && userChoice != 'C');
if(userChoice == 'A')
{
cout << "Addition\n" << endl;
cout << "Please enter the first value you want to add\n" << endl;
cin >> vaulue1;
cout << "Please enter the second value you want to add\n" << endl;
cin >> vaulue2;
addtionValue = vaulue1 + vaulue2;
cout << "The addtion answer is " << addtionValue << endl;
}
else if(userChoice == 'B')
{
cout << "Subtraction\n" << endl;
cout << "Please enter the first value you want to subtract\n" << endl;
cin >> vaulue1;
cout << "Please enter the second value you want to subtract\n" << endl;
cin >> vaulue2;
subtractionValue = vaulue1 - vaulue2;
cout << "The subtract answer is " << subtractionValue << endl;
}
else if(userChoice == 'C')
{
cout << "Exit ";
return -1;
}
return 0;
}
you should use only one "while" - just first while is correct
other "whiles" are empty loop; clean them
it's better to use "switch - case"
while you enter A as input your method wants to give A another one
I have recently tried using GNU Bison and Flex to write a interpreter. The text I want the interpreter to recognize is print "Hello" and I have tried the following:
flex file:
%{
#include <iostream>
using namespace std;
#define YY_DECL extern "C" int yylex()
#include "gbison.tab.h"
%}
%%
[ \t\n] ;
'\"' return QUOTE;
[a-zA-Z0-9]+ { yylval.sval = strdup(yytext); return STRING; }
%%
bison file:
%{
#include <cstdio>
#include <cstring>
#include <iostream>
using namespace std;
extern "C" int yylex();
extern "C" int yyparse();
extern "C" FILE* yyin;
void yyerror (const char* s);
%}
%union {
char* sval;
}
%token <sval> STRING
%token QUOTE
%%
str:
STRING QUOTE STRING QUOTE
{
if (strcmp($1, "print") == 0)
{
cout << $3 << flush;
}
if (strcmp($1, "println") == 0)
{
cout << $3 << endl;
}
}
;
%%
main(int argc, char* argv[])
{
FILE* input = fopen(argv[1], "r");
if (!input)
{
cout << "Bad input. Nonexistant file" << endl;
return -1;
}
yyin = input;
do
{
yyparse();
} while (!feof(yyin));
}
void yyerror(const char* s)
{
cout << "Error. " << s << endl;
exit(-1);
}
But when I pass print "hello" to the compiled program I get:
"Error. syntax error
I think that the issue is the STRING QUOTE STRING QUOTE but I am not sure. What is exactly is going wrong? How would I get the interpreter to print hello?
The answers are below, but I hope the following is more generally useful, as fishing instruction.
There are a variety of debugging tools which would help you. In particular, flex provides the -d flag:
-d, --debug
makes the generated scanner run in "debug" mode. Whenever a pattern is recognized and the global variable yy_flex_debug is non-zero (which is the default), the scanner will write to stderr a line… (flex manual)
bison also provides a debug facility. (bison manual)
There are several means to enable compilation of trace facilities:
the macro YYDEBUG…
the option -t (POSIX Yacc compliant)…
the option --debug (Bison extension)…
the directive %debug…
We suggest that you always enable the debug option so that debugging
is always possible.
…
Once you have compiled the program with trace facilities, the way to
request a trace is to store a nonzero value in the variable yydebug.
You can do this by making the C code do it (in main, perhaps), or you
can alter the value with a C debugger.
Also, remember that flex inserts an automatic rule which causes any otherwise unrecognized character to be echoed to the output. ("By default, any text not matched by a flex scanner is copied to the output" -- Some simple examples) That's why you have the extra " in the error message being printed by your program:
"Error. syntax error
^
That's a bit subtle, though. Tracing flex would have shown you that more directly.
So, finally, the problem(s):
The flex pattern '\"' does not match a ". It matches '"', because single quotes are not special to flex. That's definitely why your parse fails.
Fixing that will let your program parse a single command, but it will generate a syntax error if you try to give it two print commands in the same input. That's because bison always parses until it receives an END token from the lexer, and the lexer (by default) only provides an END token when it reaches the end of the input. You can change
the lexer behaviour (by sending END in other circumstances, for example a new-line) (not recommended)
the parser behaviour (by using ACCEPT) (possible, but rarely necessary)
the grammar, so that it recognizes any number of statements. (recommended)