[CMake] Function variable name question

[Matthew Woehlke]

James Bigler wrote:
> I have the following code in a script:
> 
> function(set_var var)
>   message("var = ${var}")
>   message("${var} = ${${var}}")
>   set(${var} "new_val")
>   message("${var} = ${${var}}\n")
> endfunction()
> 
> set(myvar 10)
> set_var(myvar)
> 
> # Empty variable
> set_var(myvar2)
> 
> set_var(var)
> 
> # Set variable
> set(var 11)
> set_var(var)
> 
> When I run it I get the following output:
> 
> var = myvar
> myvar = 10
> myvar = new_val
> 
> var = myvar2
> myvar2 =
> myvar2 = new_val
> 
> var = var
> var = var
> new_val =
> 
> var = var
> var = var
> new_val =
> 
> I get expected output when the name of the variable I pass in isn't the same
> as the one used in the function parameter list.
> 
> Is this the desired behavior of the language?  I would argue that it isn't,
> because you get different behavior based on the name of the variable passed
> in.

Um... and how would you claim it is supposed to work? You've got a 
classic case of variable shadowing here. If you think about it, CMake is 
doing exactly what you told it to do.

IOW, don't do that ;-).

-- 
Matthew
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