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V520. Comma operator ',' in array index expression.
The analyzer found a potential error that may be caused by a misprint. An expression containing the ',' operator is used as an index for an array.
Here is a sample of suspicious code:
float **array_2D;
array_2D[getx() , gety()] = 0;Most probably, it was meant to be:
array_2D[ getx() ][ gety() ] = 0;Such errors might appear if the programmer worked earlier with a programming language where array indexes are separated by commas.
Let's look at a sample of an error found by the analyzer in one project:
float **m;
TextOutput &t = ...
...
t.printf("%10.5f, %10.5f, %10.5f,\n%10.5f, %10.5f, %10.5f,\n%10.5f,
%10.5f, %10.5f)",
m[0, 0], m[0, 1], m[0, 2],
m[1, 0], m[1, 1], m[1, 2],
m[2, 0], m[2, 1], m[2, 2]);Since the printf function of the TextOutput class works with a variable number of arguments, it cannot check whether pointers will be passed to it instead of values of the float type. As a result, we will get rubbish displayed instead of matrix items' values. This is the correct code:
t.printf("%10.5f, %10.5f, %10.5f,\n%10.5f, %10.5f, %10.5f,\n%10.5f,
%10.5f, %10.5f)",
m[0][0], m[0][1], m[0][2],
m[1][0], m[1][1], m[1][2],
m[2][0], m[2][1], m[2][2]);This diagnostic is classified as:
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You can look at examples of errors detected by the V520 diagnostic. |
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