NSVGgradient stops array always has only one item in it?

[aaronfranke]

It seems like a bug to have an array with exactly one item, what's the point?

typedef struct NSVGgradient {
    float xform[6];
    char spread;
    float fx, fy;
    int nstops;
    NSVGgradientStop stops[1]; // here
} NSVGgradient;

[tesch1]

Have you looked at the code to see why it might be done like that?

[aaronfranke]

It was introduced 6 years ago here, cc @memononen

[tesch1]

Do you even C, bro?

Here's a hint:

grad = (NSVGgradient*)malloc(sizeof(NSVGgradient) + sizeof(NSVGgradientStop)*(nstops-1));

Btw, this project isn't actively maintained.

[memononen]

It's "oldskool" trick to create variable length array without extra pointer and alloc.

On Sat, Nov 16, 2019 at 4:41 AM Aaron Franke [email protected] wrote:

It seems like a bug to have an array with exactly one item, what's the point?

typedef struct NSVGgradient { float xform[6]; char spread; float fx, fy; int nstops; NSVGgradientStop stops[1]; // here } NSVGgradient;

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[derekdai]

after change from stops[1] to stops[0] and nstops-1 to nstops (gcc), it explicit tell address sanitizer it is a variable size array, no warning message generated.

typedef struct NSVGgradient {
    float xform[6];
    char spread;
    float fx, fy;
    int nstops;
    NSVGgradientStop stops[0]; // here
} NSVGgradient;

grad = (NSVGgradient*)malloc(sizeof(NSVGgradient) + sizeof(NSVGgradientStop)*(nstops));