Linker Error Undefined Reference To Function In C
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Undefined Reference Error In C
more about Stack Overflow the company Business Learn more about hiring developers or undefined reference to c++ error posting ads with us Stack Overflow Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community undefined reference to function c++ Stack Overflow is a community of 6.2 million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up What causes the error “undefined reference to (some function)”? [duplicate]
C++ Undefined Reference To Class
up vote 7 down vote favorite This question already has an answer here: What is an undefined reference/unresolved external symbol error and how do I fix it? 25 answers I get the error: main.o(.text+0x1ed): In function `main': : undefined reference to `avergecolumns' collect2: ld returned 1 exit status when I gcc *.o. I'm not quite sure what causes this error. Other posters have explained it as the function
C++ Undefined Reference To Constructor
is not found or the function is empty. If someone could clarify or refine, it would be greaty appreciated! Here is my function's code(I'm trying to calculate the average of the column in 2D arrays): #include "my.h" void averagecolumns (int x, int y, int** a) { int i; int j; float sum; float colAvg; sum = 0; colAvg = 0; printf("i. The column averages are: \n"); for(i = 0; i < x; i++) { for(j = 0; j < y; j++) { sum += a[i][j]; colAvg = sum / (float)x; } printf("Column: %3d, Average: %6.2f", j, colAvg); sum = 0; colAvg = 0; } The relavent parts of main are: #include "my.h" int main (int argc, char* argv[]) { int** a; float** colAvg; int ROWS; int COLS; int i; int j; int** table; FILE* fpmyfile; int closeResult; .... printme (ROWS, COLS, a); // call functions a - j oddvalues (ROWS, COLS, a); oddlocations (ROWS, COLS, a); countoddrows (ROWS, COLS, a); addrows (ROWS, COLS, a); findfirstsmall (ROWS, COLS, a); findlastlarge (ROWS,COLS, a); addcolumns (ROWS, COLS, a); avergecolumns (ROWS, COLS, a); .... } Also, is this a linker or a compile error (I wasn't sure which tag to add). c linker-error share|improve this qu
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C++ Undefined Reference To Function In Class
with us Stack Overflow Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow c++ undefined reference to static member is a community of 6.2 million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up Linking error: Undefined reference to functions that're defined in a separate file? http://stackoverflow.com/questions/8024440/what-causes-the-error-undefined-reference-to-some-function up vote 1 down vote favorite I'm probably forgetting something obvious that'll solve this. While there's other questions on SO with the same issue, none of the solutions have been applicable to my situation. I have a main file, sim.c, a header file net.h, a header file friends.h, and a file with the functions, net.c. I have a makefile, which I created with gmakemake > Makefile, and its contents http://stackoverflow.com/questions/26820736/linking-error-undefined-reference-to-functions-thatre-defined-in-a-separate-fi are very basic. Header.mak (makefile template): CFLAGS = -Wall -Wextra -pedantic -std=c99 -ggdb LFLAGS = -ggdb LDFLAGS = Makefile relevant contents: CPP_FILES = C_FILES = net.c sim.c PS_FILES = S_FILES = H_FILES = net.h friends.h SOURCEFILES = $(H_FILES) $(CPP_FILES) $(C_FILES) $(S_FILES) .PRECIOUS: $(SOURCEFILES) OBJFILES = # # Main targets # all: net sim net: net.o $(OBJFILES) $(CC) $(CFLAGS) -o net net.o $(OBJFILES) $(CLIBFLAGS) sim: sim.o $(OBJFILES) $(CC) $(CFLAGS) -o sim sim.o $(OBJFILES) $(CLIBFLAGS) # # Dependencies # net.o: net.h sim.o: net.h My sim.c file contains: #include "net.h" #include "friends.h" My header file contains the functions in net.c and defines them all as stubs. I copied and pasted them to create the function headers, so there shouldn't be any typos. My net.c file contains: #include "net.h" Yet any time a function in sim.c tries to call a function in net.c, it errors on that line with: "undefined reference to `function_name`". How can I make sim.c able to access the functions in net.c? c makefile share|improve this question edited Nov 8 '14 at 19:04 asked Nov 8 '14 at 18:44 Rohawk 11210 add a comment| 2 Answers 2 active oldest votes up vote 0 down vote accepted The message undefined reference to 'function_name' implies that of all
Practice Problems Quizzes Resources Source Code Source Code Snippets C and C++ Tips Finding a Job References Function Reference Syntax Reference Programming FAQ Getting Help Message Board Email About Us Dealing with Compiler Errors - http://www.cprogramming.com/tutorial/compiler_linker_errors.html Surviving the Compilation Process By Alex Allain It's your first C (or C++) program--it's not that long, and you're about to compile it. You hit compile (or enter the build command) and wait. Your compiler spits out fifty lines of text. You pick out words like "warning and "error". Does that mean it worked? you wonder. You look for the resulting executable. Nothing. Damn, you think, I guess I have undefined reference to figure out what this all means... The Types of Compilation Errors First, let's distinguish between the types of errors: most compilers will give three types of compile-time alerts: compiler warnings, compiler errors, and linker errors. Although you don't want to ignore them, compiler warnings aren't something severe enough to actually keep your program from compiling. Usually, compiler warnings are an indication that something might go wrong at runtime. undefined reference to How can the compiler know this at all? You might be making a typical mistake that the compiler knows about. A common example is using the assignment operator ('=') instead of the equality operator ('==') inside an if statement. Your compiler may also warn you about using variables that haven't been initialized and other similar mistakes. Generally, you can set the warning level of your compiler--I like to keep it at its highest level so that my compiler warnings don't turn in to bugs in the running program ('runtime bugs'). Nevertheless, compiler warnings aren't going to stop you from getting your program working (unless you tell your compiler to treat warnings as errors), so they're probably a bit less frustrating than errors. Errors are conditions that prevent the compiler from completing the compilation of your files. Compiler errors are restricted to single source code files and are the result of 'syntax errors'. What this really means is that you've done something that the compiler cannot understand. For instance, the statement "for(;)" isn't correct syntax because a for loop always needs to have three parts. Although the compiler would have expected a semicolon, it would also have expected a conditional expression, so the error message you get m