In my compilers class we are writting Flex/Lex code. When I compiled the .l file and tried to compile the resultant lex.yy.c file with gcc, I got the following error:
Undefined symbols for architecture arm64:
"_yywrap", referenced from:
_yylex in lex-fb85c9.o
ld: symbol(s) not found for architecture arm64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Does is posible to compile it in a Apple Silicon (M1) Mac, at least in a Linux VM?
I created a test file and compiled:
% flex lex.l
% cc -o lex lex.yy.c -lc -ll
% grep 'yylex();' lex.yy.c
yylex();
The -ll on the cc command links against the libl library. Current M1 based macOS does not provide a libfl library you may see referenced.
Related
I am attempting to compile a C program on macOS Catalina. The program will make use of bzip2 decompression. My code includes the line
#include <bzlib.h>
and I am trying to call the function BZ2_bzBuffToBuffDecompress. However, when I run gcc myfile.c -o myfile.c.o, I get the following error:
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1
I am just using a plain text editor and gcc, no IDEs and no CMake files. I suspect I may need a CMake file for this but I am not really sure how to proceed. Any assistance with this is greatly appreciated!
You need to link in the bzip library. gcc myfile.c -o myfile -lbz2. That command assumes the lib is installed into the standard location. Also, you are compiling a final executable so (by strong convention) it should not have a .o suffix.
Just posted a simple c code and gotten this error message. can anyone explain where the problem could be?
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
mac#MACs-MacBook-Pro-2 C % cd "/Users/mac/C/" && g++ tes.c++ -o tes && "/Users/mac/C/"tes
Undefined symbols for architecture x86_64:
"_main", referenced from:
implicit entry/start for main executable
you have to compile with gcc and not g++, g++ is to compile .cpp or .cc files
gcc tes.c++ -o tes
I just started to learn gcc/g++ by reading "An introduction to GCC"
In chapter 3.1 the author showed an example of linking with external libraries and header files. The main source code uses 'gdbm.h' header (installed at /opt/gdbm-1.8.3/include/ in text book) file and the library ‘libgdbm.a’ (installed at /opt/gdbm-1.8.3/lib/ in text book). The process of linking with the library and header file is as follows:
Link to example screenshot
When I tried to repeat this, I got a contradictory result. When I used method 1 (in the example fails) which only includes header file path, the program can be compiled, however, when I used method 2 (in the example succeeds), I got an error, saying that
"ld: 1 duplicate symbol for architecture x86_64
clang: error: linker command failed with exit code 1"
(this is my full command line and error message:)
userMacBook-Pro:03 user$gcc -Wall -I/usr/local/include dbmain.c -L/usr/local/lib dbmain.c -lgdbm
duplicate symbol _main in:
/var/folders/6_/09vfzzms7dq1d73vl4mwlxmh0000gn/T/dbmain-9d15f9.o
/var/folders/6_/09vfzzms7dq1d73vl4mwlxmh0000gn/T/dbmain-907e96.o
this is my command that succeeds:
userMacBook-Pro:03 user$ gcc -Wall -I/usr/local/include dbmain.c -lgdbm
userMacBook-Pro:03 user$ ./a.out
Storing key-value pair... done.
ld: 1 duplicate symbol for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Can anyone explain why this happens?
I don't know which platform the author uses, I just use mac OS X.
gcc -Wall -I/usr/local/include dbmain.c -L/usr/local/lib dbmain.c -lgdbm
The file dbmain.c is present twice on your command line. For this reason the main function is present twice.
Can I use for example
gcc -o -S output.s abs.c
to generate an assembly file with name output.s? It seems like I can't. When I try to do that, I got following error message.
Undefined symbols for architecture x86_64: "_main", referenced from:
implicit entry/start for main executable ld: symbol(s) not found for architecture x86_64 clang: error: linker command failed with exit
code 1 (use -v to see invocation)
I do not intend to use the linker, just try to examine the assembly code.
-o must be followed by the name of the output file. So, this would work:
gcc -S abc.c -o output.s
I am getting the following persistent errors trying to debug a C program in Eclipse Juno on my mac:
Building target: TimeStamps
Invoking: MacOS X C Linker
gcc -v -o "TimeStamps" ./graphic/arrow.o ./graphic/axesdraw.o . . .
Apple LLVM version 6.0 (clang-600.0.57) (based on LLVM 3.5svn)
Target: x86_64-apple-darwin14.1.0
Thread model: posix
"/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ld" -demangle -dynamic -arch x86_64 -macosx_version_min 10.10.0 -o
Undefined symbols for architecture x86_64:
"_main", referenced from:
implicit entry/start for main executable
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [TimeStamps] Error 1
So, I am confused about how to fix this in Eclipse. The main routing is in timestamp_test.c
I have -g -v as compiler flags, and -v as a linker flag.
No .o files are made.
Based on the the error given, you need to add the main function to timestamp_test.c.
Or pass the file that have the main function implemented to the compiler.