Msg/FunctionNestCount - Revision history

Henry at 04:06, 17 March 2019

2019-03-17T04:06:03Z

@@ Line 24: / Line 24: @@
 NotAFunction:
      br _start
 </syntaxhighlight>

Henry at 08:49, 11 March 2019

2019-03-11T08:49:01Z

← Older revision		Revision as of 08:49, 11 March 2019
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	A function is called from a caller, runs some code, and then returns to its caller. Although a function may call other functions (possibly recursively), it is unusual for the function call depth to be very large. This warning tells you that you have exceeded 32 nested function calls.		A function is called from a caller, runs some code, and then returns to its caller. Although a function may call other functions (possibly recursively), it is unusual for the function call depth to be very large. This warning tells you that you have exceeded 32 nested function calls.

	~~This~~ isn't technically an error, ~~but if~~ this ~~behaviour is~~ not ~~expected~~, it is likely indicative of a bug.		Deep function call nesting isn't technically an error. If your program really uses more than 32 nested functions, disable this warning. If not, this is likely indicative of a bug.

	=== Examples ===		=== Examples ===

Henry at 08:47, 11 March 2019

2019-03-11T08:47:22Z

← Older revision		Revision as of 08:47, 11 March 2019
Line 2:		Line 2:

	This isn't technically an error, but if this behaviour is not expected, it is likely indicative of a bug.		This isn't technically an error, but if this behaviour is not expected, it is likely indicative of a bug.

			=== Examples ===
			==== ARMv7 ====
			<syntaxhighlight line lang="Asm" highlight="4">
			.global _start
			_start:
			nop
			bl NotAFunction // This is a function call, but the target doesn't behave like a function (no return).
			nop
			NotAFunction:
			b _start
			</syntaxhighlight>

			==== Nios II ====
			<syntaxhighlight line lang="Asm" highlight="4">
			.global _start
			_start:
			nop
			call NotAFunction # This is a function call, but the target doesn't behave like a function (no return).
			nop
			NotAFunction:
			br _start
			</syntaxhighlight>

			The call at line 4 repeatedly calls a function that never returns. The function call depth increases by one every time the call is executed. The Call stack will show a stack of calls originating from line 4.

	=== Debugging ===		=== Debugging ===

Henry at 08:32, 11 March 2019

2019-03-11T08:32:41Z

← Older revision		Revision as of 08:32, 11 March 2019
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	* Make sure functions are returning, not stuck in an unending recursion.		* Make sure functions are returning, not stuck in an unending recursion.
	* Make sure you do not use a call (or branch-and-link) instruction when the intention is to use a regular branch instruction.		* Make sure you do not use a call (or branch-and-link) instruction when the intention is to use a regular branch instruction.
	* Use the [https://cpulator.01xz.net/doc/#callstack '''Call stack window'''] (located in the same panel as the registers window) to see where the function calls are occurring. The top entry is the current PC. Each entry below that is the location of the call in the ~~caller~~ one nesting level up.		* Use the [https://cpulator.01xz.net/doc/#callstack '''Call stack window'''] (located in the same panel as the registers window) to see where the function calls are occurring. The top entry is the current PC. Each entry below that is the location of the call instruction in the function one nesting level up.
	* The [https://cpulator.01xz.net/doc/#callstack '''Trace window'''] may also be useful to see the last 200 instructions executed.		* The [https://cpulator.01xz.net/doc/#callstack '''Trace window'''] may also be useful to see the last 200 instructions executed.

Henry: Created page with "A function is called from a caller, runs some code, and then returns to its caller. Although a function may call other functions (possibly recursively), it is unusual for the..."

2019-03-11T08:29:38Z

Created page with "A function is called from a caller, runs some code, and then returns to its caller. Although a function may call other functions (possibly recursively), it is unusual for the..."

New page

A function is called from a caller, runs some code, and then returns to its caller. Although a function may call other functions (possibly recursively), it is unusual for the function call depth to be very large. This warning tells you that you have exceeded 32 nested function calls.

This isn't technically an error, but if this behaviour is not expected, it is likely indicative of a bug.

=== Debugging ===
* Make sure functions are returning, not stuck in an unending recursion.
* Make sure you do not use a call (or branch-and-link) instruction when the intention is to use a regular branch instruction.
* Use the [https://cpulator.01xz.net/doc/#callstack '''Call stack window'''] (located in the same panel as the registers window) to see where the function calls are occurring. The top entry is the current PC. Each entry below that is the location of the call in the caller one nesting level up.
* The [https://cpulator.01xz.net/doc/#callstack '''Trace window'''] may also be useful to see the last 200 instructions executed.

=== Implementation ===
The simulator tracks idiomatic call and return instructions and counts the function call nesting depth. This message is generated at a call instruction when the new call depth exceeds 32.

{{DisableMsg|Function nesting too deep}}