C/C++ :: GCC Compiler Does Not Detect Multiple Definition Error
Oct 31, 2012
I am trying to compile the files file1.c and file2.c using Mingw (gcc)
/////////////////////
header.h
////////////////////
#ifndef header
#define header
int variable;
#endif
[Code] ....
I would have expected a multiple defnition error when linking the two .c files. as in both the files, with the 'int variable' command, the variable 'variable' is defined (memory allocated) and during linking the linker doesnot know which variable to link to.
I get an error though when i use "int variable =123;" in the header file instead of the "int variable;" statement. i dont understand as in both the cases the variable is defined (memory is allocated) and the linker should give a multiple definition error.
I'm using multiple C++ files in one project for the first time. Both have need to include a protected (#ifndef) header file. However, when I do that, I get a multiple definition error.
From what I found from research, adding the word inline before the function fixes the error. Is this the right way to do this, and why does it work? Should I make a habbit of just declaring any function that might be used in two .cpp files as inline?
how to get this bug to go away and I am stressing about it. The project im working on simulates packet sending and receiving along with ROT13 encryption of the packets. The error lies within the .cpp file anywhere that I used IPHost.
header file
#ifndef IPHOST_H #define IPHOST_H #include <string> #include <iostream> class IPHost { public: //Default constructor defaults to 0.0.0.0
[code]...
error message:
In function 'ZStorSt13_Ios_OpenmodeS_': line 11: multiple definition of 'IPHost::IPHost()' line 11: first defined here
**this error repeats for every line in the .cpp in which IPHost is used.
Well, I thought I had this program working but now I'm getting the above referenced compiler error. The program is just a basic user interface. It is for a classwork assignment.
The program is to accept user information as a string, convert it (if needed) to either the int or double variable, and then display the result. I'm using stringstream convert to make the change between types, but I'm not sure if I'm using it right (that might be what's causing the error, I'm not sure). Line 36-37 generates the error.
Code: #include <iostream> #include <iomanip> #include <sstream> using namespace std;
I found way around this, but I would like to know why it shows multiple declarations.
My solution is to declare this class in function body(void LoadLevel()), just before the throw statement. But why can't I define it inside my namespace, but outside function?
I am trying to have a program that I am writing detect a controller and then say whether there is or is not one connected. But I am getting a lot of errors(25 actually) . Here is my code:
I have an issue converting VC++6 code to VC++ 2010. The following template function definition is not allowed by the new compiler:
template <> void AFXAPI DelElems <CBrush*> ( CPen** objects, int count ) { for ( int i = 0; i < count; i++, objects++ ) if (*objects) delete *objects; }
All errors refer to the header of the template function:
- syntax error : '<' - syntax error : missing ';' before '<' - 'DelElems' : illegal use of type 'void' - unrecognizable template declaration/definition
Working on a basic class program and I'm generating two compiler errors that I'm not sure how to fix. Header file, implementation cpp and main cpp are shown below. The specific errors are shown after the code.
The file generates the second error, C2228, at lines 37-41 and 43. Basically where I tried using the second created object. Error message is "left of '.setFirstName' must have class/struct/union"
Working on a solution involving inheritance. The whole solution is pretty massive at this point so I'll just focus on the problem areas. I'm getting a lot of "redefinition" and "undefined class type" compiler errors, including C2370, 2011, 2504, and 2027, in Benefit.h, Employee.h (the constant members are a big occurance) I'm also getting 2027 and 2079 in EmployeeMain.cpp. with my Benefit and Employee object calls.
Clearly I missed something in about how to code this correctly. Sadly the course textbook focuses on general OOP theory instead on the accompanying C++ syntax.
My compiler (GCC) keeps expecting an expression where it shouldn't in 1 specific piece of my code:
int zxcNewWindow( HWND parent, TCHAR *text, zxWINDOW *kid, UINT style, int x, int y, int w, int h, int type ) // right here { *kid = zxDefWINDOW;
The project contains only 2 files right now and the settings are just the default for an empty Code::Blocks 12.11 project. Both files are in UTF-8 format (tried in ASCII too), I just cannot see why this is not compiling correctly. I'll post the files in the next two posts.
Edit: For those of you who didn't get what the error was from the above here's the full log:
mingw32-gcc.exe -Wall -g -DzxDEBUG -c C:MePrjscppzxGUImain.c -o objmain.o C:MePrjscppzxGUImain.c: In function 'zxcNewWindow': C:MePrjscppzxGUImain.c:39:10: error: expected expression before '{' token Process terminated with status 1 (0 minutes, 0 seconds) 1 errors, 0 warnings (0 minutes, 0 seconds)
I am trying to run this source code but i am getting the compiler error Expression Must Have a Constant Value. I tried making both the variables x and y constants and assigned them to a significantly big number but then i am getting the error expression must be a modifiable lvalue.I have made comments in the code in front where Visual Studio is giving me the syntax error (red squiggly line).
#include<iostream> #include <string> #include<cmath> using namespace std; int main(){ int x; int y;
I am having problems compiling this program. line 29 causes the error "left operand must be l-value".
// chap5proj.cpp : Defines the entry point for the console application. // # include <stdafx.h> # include <iostream> using namespace std; int main() { double mph, time, disPerHour, milesTrav;
Full disclosure: this is an exercise from "Sams Teach Yourself C++ in 24 Hours" by Jesse Liberty and Rogers Candenhead. This refers to Chapter 9 (Hour 9 Activity 1)
I created a class called Point, in Point.h
I created a class called Rectangle in Rectangle.h and Rectangle.cpp
If I create an int main() function in Rectangle.cpp (that includes Rectangle.h), I can compile Rectangle.cpp and run the resulting program. Fine.
Question:
I create a separate file called main.cpp. I include Rectangle.h. But now the compiler complains.
Code: $ g++ main.cpp -o main /tmp/cc38JIph.o: In function `main': main.cpp:(.text+0x26): undefined reference to `Rectangle::Rectangle(int, int, int, int)' main.cpp:(.text+0x32): undefined reference to `Rectangle::getArea() const' collect2: ld returned 1 exit status If I can create a class in Point.h and use it in Rectangle.h, why can I not just use Rectangle in main.cpp?
And the files, of course:
file: main.cpp Code: #include <iostream> #include "Rectangle.h" using std::cout; using std::endl;
Having issues with program to create a shape area calculator with circle square and rectangle. the uml goes as follows:
Where the UML has shape as the abstract class with public area():double, getName():string,and getDimensions:string, rectangle derived from shape with protected height, and width, and a public rectangle(h:double, w:double), followed by a derived square from rectangle with just a public square(h:double), and finally a circle derived from shape with a private radius, and a public circle(r:double).
[URL]
Have linked my program and it is giving me the following compiler errors:
error: 'qdebug' was not declared in this scope line 15 of main
error: cannot declare variable 'shp' to be of abstract type 'shape' line 22 of main
error: expected primary-expression before ')' token lines 29 -31 of main
(note previously had qstring as a header file yet changed to string since I was getting error qstring was not declared in this scope.)
I have been implementing a Hash Table class made, and ran into a bit of a problem in my Delete function. I have the hash table made up as
vector<list<HashNode<T,X>>> m_Table
My problem is when I iterate through the vector, and then the list in that current element to try and find the Node I want to delete, the STL list class gives me the error:
Error1error C2678: binary '==' : no operator found which takes a left-hand operand of type 'HashNode<T,X>' (or there is no acceptable conversion)
i was trying to write a program in c language which can detect mouse movement, but the program which i have written can only detect the mouse click or scroll the program which i have written given below..
Code:
#include<stdio.h> #include<string.h> #include <ncurses.h> int main() { }
[code]....
run the programme with linked-lncurses. improve my program which also detect when the mouse moves.
