skia2/resources/sksl/errors/UnassignedOutParameter.rts

// Expect 2 errors in "testOut"

void testIn(in float2 a, in float2 b, in float2 c)             { a = float2(1); }
void testOut(out float2 a, out float2 b, out float2 c)         { a = float2(1); }
void testInout(inout float2 a, inout float2 b, inout float2 c) { a = float2(1); }

void func(float2 p) {
    testIn(p, p, p);
    testOut(p, p, p);
    testInout(p, p, p);
}

/*%%*
function 'testOut' never assigns a value to out parameter 'b'
function 'testOut' never assigns a value to out parameter 'c'
*%%*/
Report an error if an out param is never written to. GLSL ES2 behavior is explicitly undefined if an out-param is never written to: "If a function does not write to an out parameter, the value of the actual parameter is undefined when the function returns." We do see divergence here in practice: SkVM's behavior (the parameter is left alone) differs from my GPU's behavior (the parameter is zeroed out). SkSL will now report an error if an out parameter is never assigned-to. There is no control flow analysis performed, so we will not report cases where the out parameter is assigned-to on some paths but not others. (Technically the return-on-all-paths logic could be adapted for this, but it would be a fair amount of work.) Structs are currently exempt from the rule because custom mesh specifications require an `out` parameter for a Varyings struct, even if your mesh program doesn't need Varyings. Bug: skia:12867 Change-Id: Ie828d3ce91c2c67e008ae304fdb163ffa88d744c Reviewed-on: https://skia-review.googlesource.com/c/skia/+/500440 Auto-Submit: John Stiles <johnstiles@google.com> Reviewed-by: Brian Osman <brianosman@google.com> Commit-Queue: Brian Osman <brianosman@google.com> 2022-01-26 19:11:26 +00:00			`// Expect 2 errors in "testOut"`

			`void testIn(in float2 a, in float2 b, in float2 c) { a = float2(1); }`
			`void testOut(out float2 a, out float2 b, out float2 c) { a = float2(1); }`
			`void testInout(inout float2 a, inout float2 b, inout float2 c) { a = float2(1); }`

Rename ES2 error tests 'T' through 'Z' to .rts. Change-Id: I528d2b7a53748077f2dd7e7e04927d2a6b78ac8f Bug: skia:13042 Reviewed-on: https://skia-review.googlesource.com/c/skia/+/523429 Commit-Queue: John Stiles <johnstiles@google.com> Auto-Submit: John Stiles <johnstiles@google.com> Reviewed-by: Arman Uguray <armansito@google.com> Commit-Queue: Arman Uguray <armansito@google.com> 2022-03-22 19:09:15 +00:00			`void func(float2 p) {`
Report an error if an out param is never written to. GLSL ES2 behavior is explicitly undefined if an out-param is never written to: "If a function does not write to an out parameter, the value of the actual parameter is undefined when the function returns." We do see divergence here in practice: SkVM's behavior (the parameter is left alone) differs from my GPU's behavior (the parameter is zeroed out). SkSL will now report an error if an out parameter is never assigned-to. There is no control flow analysis performed, so we will not report cases where the out parameter is assigned-to on some paths but not others. (Technically the return-on-all-paths logic could be adapted for this, but it would be a fair amount of work.) Structs are currently exempt from the rule because custom mesh specifications require an `out` parameter for a Varyings struct, even if your mesh program doesn't need Varyings. Bug: skia:12867 Change-Id: Ie828d3ce91c2c67e008ae304fdb163ffa88d744c Reviewed-on: https://skia-review.googlesource.com/c/skia/+/500440 Auto-Submit: John Stiles <johnstiles@google.com> Reviewed-by: Brian Osman <brianosman@google.com> Commit-Queue: Brian Osman <brianosman@google.com> 2022-01-26 19:11:26 +00:00			`testIn(p, p, p);`
			`testOut(p, p, p);`
			`testInout(p, p, p);`
			`}`
Add expected errors to every test file. This was (crudely) automated with shell scripts: http://go/paste/5484300603490304 Change-Id: Ic9e1c93112772d303d1158eb26d995f27b439eba Bug: skia:12665 Reviewed-on: https://skia-review.googlesource.com/c/skia/+/505637 Reviewed-by: Brian Osman <brianosman@google.com> Commit-Queue: John Stiles <johnstiles@google.com> Auto-Submit: John Stiles <johnstiles@google.com> 2022-02-08 17:19:26 +00:00
			`/%%`
			`function 'testOut' never assigns a value to out parameter 'b'`
			`function 'testOut' never assigns a value to out parameter 'c'`
			`%%/`