Interview Preparation topic: Name Mangling - Revision history

Proj user18 at 06:46, 20 December 2016

2016-12-20T06:46:10Z

Proj user18 at 06:44, 20 December 2016

2016-12-20T06:44:44Z

Proj user18 at 06:26, 20 December 2016

2016-12-20T06:26:05Z

Proj user18 at 06:25, 20 December 2016

2016-12-20T06:25:07Z

Proj user18 at 06:24, 20 December 2016

2016-12-20T06:24:23Z

Proj user18 at 06:24, 20 December 2016

2016-12-20T06:24:07Z

Proj user18 at 06:23, 20 December 2016

2016-12-20T06:23:46Z

Proj user18 at 06:23, 20 December 2016

2016-12-20T06:23:26Z

Proj user18: Created page with "You might have seen some code covered with extern "C" keyword in your c++ code. Let’s discuss why we need this keyword in c++. As we all know c++ allows function overloadi..."

2016-12-20T06:17:36Z

Created page with "You might have seen some code covered with extern "C" keyword in your c++ code. Let’s discuss why we need this keyword in c++. As we all know c++ allows function overloadi..."

New page

You might have seen some code covered with extern "C" keyword in your c++ code.

Let’s discuss why we need this keyword in c++.

As we all know c++ allows function overloading, a code can have multiple functions with similar names but with different implementations.

Consider the following code snippet(main.cpp)

As you can see we have two methods with same name 'addition'. But two functions have different arguments.

At the time of compile, compiler uses 'name mangling' to distinguish between this two.

If we see the object file generated by the compiler. We can see that compiler has added some prefix as well as postfix to the name of the method. (Not going in to detail).

But in that process, it has changed the name of interruputHandler function as well.

Interrupt handlers are registered in the startup code with predefined names, for example ‘UART0_IRQHandler’ is registered for UART0 interrupt.

At run time system, cannot get the predefined handler name (because of name mangling) and it will report an error.

To remove this error, we need to surround the handler code with extern “C”. This will inform compiler and this function will not get name mangled.

Now interruptHandler function is not name mangled.

@@ Line 11: / Line 11: @@
-* As you can see we have two methods with same name 'addition'. But two functions have different arguments.
+As you can see we have two methods with same name 'addition'. But two functions have different arguments.
-:At the time of compile, compiler uses 'name mangling' to distinguish between this two.
+At the time of compile, compiler uses 'name mangling' to distinguish between this two.
-:If we see the object file generated by the compiler. We can see that compiler has added some prefix as well as postfix to the name of the method. (Not :going in to detail).
+If we see the object file generated by the compiler. We can see that compiler has added some prefix as well as postfix to the name of the method. (Not going in to detail).
 [[File:interview_name_mangling_image2.png|centre|caption|Code snippet]]

@@ Line 11: / Line 11: @@
-As you can see we have two methods with same name 'addition'. But two functions have different arguments.
+* As you can see we have two methods with same name 'addition'. But two functions have different arguments.
-At the time of compile, compiler uses 'name mangling' to distinguish between this two.
+:At the time of compile, compiler uses 'name mangling' to distinguish between this two.
-If we see the object file generated by the compiler. We can see that compiler has added some prefix as well as postfix to the name of the method. (Not going in to detail).
+:If we see the object file generated by the compiler. We can see that compiler has added some prefix as well as postfix to the name of the method. (Not :going in to detail).
 [[File:interview_name_mangling_image2.png|centre|caption|Code snippet]]

@@ Line 17: / Line 17: @@
 If we see the object file generated by the compiler. We can see that compiler has added some prefix as well as postfix to the name of the method. (Not going in to detail).
 But in that process, it has changed the name of interruputHandler function as well.
@@ Line 27: / Line 28: @@
+[[File:interview_name_mangling_image4.png|centre|caption|Code snippet]]

← Older revision		Revision as of 06:25, 20 December 2016
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−	~~</br>~~

	As you can see we have two methods with same name 'addition'. But two functions have different arguments.		As you can see we have two methods with same name 'addition'. But two functions have different arguments.

← Older revision		Revision as of 06:24, 20 December 2016
Line 7:		Line 7:
	Consider the following code snippet(main.cpp)		Consider the following code snippet(main.cpp)

−	[[File:interview_name_mangling_image1.png\|~~left~~\|caption\|Code snippet]]	+	[[File:interview_name_mangling_image1.png\|centre\|caption\|Code snippet]]

← Older revision		Revision as of 06:23, 20 December 2016
Line 7:		Line 7:
	Consider the following code snippet(main.cpp)		Consider the following code snippet(main.cpp)

−	[[File:interview_name_mangling_image1.png\|left\|~~frame~~\|Code snippet]]	+	[[File:interview_name_mangling_image1.png\|left\|caption\|Code snippet]]

← Older revision		Revision as of 06:23, 20 December 2016
Line 6:		Line 6:

	Consider the following code snippet(main.cpp)		Consider the following code snippet(main.cpp)
		+
		+	[[File:interview_name_mangling_image1.png\|left\|frame\|Code snippet]]