Compilation error

Compilation error refers to a state when a compiler fails to compile a piece of computer program source code, either due to errors from the compiler itself, or syntax errors in the code. A compilation error message often helps programmers debugging the source code for possible syntax errors.

Examples

Common C++ compilation errors

• Undeclared identifier, e.g.:

doy.cpp: In function `int main()': doy.cpp:25: `DayOfYear' undeclared (first use this function)^[1]

This means that the variable "DayOfYear" is trying to be used before being declared.

• Common function undeclared, e.g.:

xyz.cpp: In function `int main()': xyz.cpp:6: `cout' undeclared (first use this function)^[1]

This means that the programmer most likely forgot to include iostream.h.

• Parse error, e.g.:

somefile.cpp:24: parse error before `something'^[2]

This could mean that a semi-colon is missing at the end of the previous statement.

Internal Compiler Errors

These errors are not the same as normal compiler errors - they're caused by compiler itself and not the source code you're trying to compile. Which means, it's a bug in the compiler itself instead of the source code.

• internal compiler error:

somefile.c:1001: internal compiler error: Segmentation fault
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://bugs.gentoo.org/> for instructions.

References

1. ^ ^{a b} "Common C++ Compiler and Linker Errors". http://www.csee.umbc.edu/courses/undergraduate/341/misc/CommonErrors.shtml. 
2. ^ "Compiler, Linker and Run-Time Errors". http://www.cs.bu.edu/teaching/cpp/debugging/errors/.