forked from vikunja/vikunja
47 lines
1.0 KiB
Go
47 lines
1.0 KiB
Go
package functions
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import (
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"honnef.co/go/tools/ssa"
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)
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func filterDebug(instr []ssa.Instruction) []ssa.Instruction {
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var out []ssa.Instruction
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for _, ins := range instr {
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if _, ok := ins.(*ssa.DebugRef); !ok {
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out = append(out, ins)
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}
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}
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return out
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}
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// IsStub reports whether a function is a stub. A function is
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// considered a stub if it has no instructions or exactly one
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// instruction, which must be either returning only constant values or
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// a panic.
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func IsStub(fn *ssa.Function) bool {
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if len(fn.Blocks) == 0 {
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return true
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}
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if len(fn.Blocks) > 1 {
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return false
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}
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instrs := filterDebug(fn.Blocks[0].Instrs)
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if len(instrs) != 1 {
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return false
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}
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switch instrs[0].(type) {
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case *ssa.Return:
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// Since this is the only instruction, the return value must
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// be a constant. We consider all constants as stubs, not just
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// the zero value. This does not, unfortunately, cover zero
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// initialised structs, as these cause additional
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// instructions.
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return true
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case *ssa.Panic:
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return true
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default:
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return false
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}
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}
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