10 // Origin id utils.
20 // Origin handling.
22 // Origin is a 32-bit identifier that is attached to any uninitialized value in
26 // There are 3 kinds of origin ids:
27 // 1xxx xxxx xxxx xxxx   heap origin id
28 // 0000 xxxx xxxx xxxx   stack origin id
29 // 0zzz xxxx xxxx xxxx   chained origin id
31 // Heap origin id describes a heap memory allocation and contains (in the xxx
34 // Stack origin id describes a stack memory allocation and contains (in the xxx
38 // Chained origin id describes an event of storing an uninitialized value to
43 //  * prev_id is another origin id that describes the earlier part of the
49 // points in value history marked with origin ids, and edges are events that are
52 // The "zzz" bits of chained origin id are used to store the length (or depth)
53 // of the origin chain.
55 class Origin {
85   // Returns the next origin in the chain and the current stack trace.
86   Origin getNextChainedOrigin(StackTrace *stack) const {  in getNextChainedOrigin()
91     return Origin(prev_id);  in getNextChainedOrigin()
98   static Origin CreateStackOrigin(u32 id) {  in CreateStackOrigin()
100     return Origin((1 << kHeapShift) | id);  in CreateStackOrigin()
103   static Origin CreateHeapOrigin(StackTrace *stack) {  in CreateHeapOrigin()
107     return Origin(stack_id);  in CreateHeapOrigin()
110   static Origin CreateChainedOrigin(Origin prev, StackTrace *stack) {  in CreateChainedOrigin()
138     return Origin((1 << kHeapShift) | (depth << kDepthShift) | chained_id);  in CreateChainedOrigin()
141   static Origin FromRawId(u32 id) {  in FromRawId()
142     return Origin(id);  in FromRawId()
156   explicit Origin(u32 raw_id) : raw_id_(raw_id) {}  in Origin()  function