Common Coding Bugs

Latest revision as of 01:44, 14 July 2009

Note: these diagnoses will tend towards being too narrow, and may have solutions that are more general

C++

/usr/libexec/gcc/PATH/4.0.1/ld: Undefined symbols:
Something
collect2: ld returned 1 exit status
make: *** [program] Error 1

• if it is for a whole class, it could mean that in an abstract class, I didn't set a function declaration to 0
• if it is for a specific static field, it could mean that I forgot "ClassName::" on initializing it
• if a function is declared from another file but that file isn't included
• or forgot to comile the cpp file in make

/usr/libexec/gcc/path/ld: multiple definitions of symbol

• If there are too many copies of a file name in the makefile.
• Or some other Makefile problem

020walker.cpp:311: error: a function-definition is not allowed here before '{' token
020walker.cpp:332: error: expected `}' at end of input

• Missing closing curly bracket on an if-statement

error: expected unqualified-id before 'using'

• forgot closing bracket on class definition

error: expected unqualified-id at end of input  

• forgot semi colon at the end of class definition

error: expected constructor, destructor, or type conversion before '&' token

• forgot to include header file on .cpp file

error: invalid use of member (did you forget the '&' ?)

• forgot parens on a function

error: 'string' does not name a type

• forgot "using namespace std;"

unknown:FATAL:can't create output file

• maybe permissions are off or a directory doesn't exist or something like that.

Lots more: [[1]]