A stack trace is a report of the active stack frames at a certain point in time during the execution of a program
Computer program
A computer program is a sequence of instructions written to perform a specified task with a computer. A computer requires programs to function, typically executing the program's instructions in a central processor. The program has an executable form that the computer can use directly to execute...
.
It is commonly used during interactive and post-mortem debugging
Debugging
Debugging is a methodical process of finding and reducing the number of bugs, or defects, in a computer program or a piece of electronic hardware, thus making it behave as expected. Debugging tends to be harder when various subsystems are tightly coupled, as changes in one may cause bugs to emerge...
. It can also be displayed to the user of a program as part of an error message
Error message
An error message is information displayed when an unexpected condition occurs, usually on a computer or other device. On modern operating systems with graphical user interfaces, error messages are often displayed using dialog boxes...
, which a user can report to a programmer.
A stack trace allows to track the sequence of nested function
Nested function
In computer programming, a nested function is a function which is lexically encapsulated within another function. It can only be called by the enclosing function or by functions directly or indirectly nested within the same enclosing function. In other words, the scope of the nested function is...
s called up to the point where the stack trace is generated. In a post-mortem scenario this is up to function where the failure occurred (but not necessarily is caused there). Sibling function calls are not visible in a stack trace.
Python is a general-purpose, high-level programming language whose design philosophy emphasizes code readability. Python claims to "[combine] remarkable power with very clear syntax", and its standard library is large and comprehensive...
program contains an error.
def a:
b
def b:
c
def c:
error
a
Running the program under the standard Python interpreter produces the following error message.
Traceback (most recent call last):
File "tb.py", line 10, in
a
File "tb.py", line 2, in a
b
File "tb.py", line 5, in b
c
File "tb.py", line 8, in c
error
NameError: global name 'error' is not defined
The stack trace shows where the error occurs, namely in the c function. It also shows that the c function was called by b, which was called by a, which was in turn called by the code on line 10 (the last line) of the program.
Java is a programming language originally developed by James Gosling at Sun Microsystems and released in 1995 as a core component of Sun Microsystems' Java platform. The language derives much of its syntax from C and C++ but has a simpler object model and fewer low-level facilities...
and C# have in-built support for retrieving the current stack trace via system calls. C++
C++
C++ is a statically typed, free-form, multi-paradigm, compiled, general-purpose programming language. It is regarded as an intermediate-level language, as it comprises a combination of both high-level and low-level language features. It was developed by Bjarne Stroustrup starting in 1979 at Bell...
has no in-built support for doing this, but the stack trace can be retrieved with, e.g., the stacktrace library.
The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.
