7: ERRORS AT DIFFERENT STAGES OF C++

Types of Errors

1. Preprocessing Stage Errors

2. Compilation Stage Errors

3. Assembly Stage Errors

4. Linking Stage Errors

5. Runtime Errors

6. Logical Errors

Preprocessing Stage Errors

• Happens before actual compilation, while handling #include, #define, and macros

Common Preprocessing Stage Errors

1. Missing Header Files

2. Incorrect Macro Usage

Missing Header Files

Incorrect Macro Usage

Common Preprocessing Stage Errors

Missing Header Files

Incorrect Macro Usage

Compilation Stage Errors

• ___ checks grammar (syntax) and mean (semantics)

• Also called “Syntax and Sematic Errors”

Syntax and Sematic Errors

Compilation Stage Errors

Common Compilation Stage Errors

1. Syntax Errors

2. Undeclared Variables

3. Type Mismatch

Syntax Errors

Undeclared Variables

Type Mismatch

Common Compilation Stage Errors

Syntax Errors

Undeclared Variables

Type Mismatch

Assembly Stage Errors

• Rare, since this stage just translates complier output into machine code

• Possible Issue: If the complier generates something the assembler cannot understand (unlikely modern compliers)

Linking Stage Errors

Happens when combining object files and libraries

Common Linking Stage Errors

1. Undefined References

2. Multiple Definitions

3. Missing Library

Undefined References

Multiple Definitions

Missing Library

Common Linking Stage Errors

Undefined References

Multiple Definitions

Missing Library

• If you use math functions but forget to link the math library (in old compliers)

Runtime Errors

• Program compiles and links successfully, but crashes or misbehaves while running

Common Runtime Errors

1. Divide by 0

2. Null Point Dereference

3. Memory Leak

Divide by 0

Null Point Dereference

Memory Leak

Common Runtime Errors

Divide by 0

Null Point Dereference

Memory Leak

• Not freeing memory with delete/free

Logical Errors

The program runs, but produces the wrong output (hardest to detect)

Logical Error