9 // Origin id utils.
19 // Origin handling.
21 // Origin is a 32-bit identifier that is attached to any uninitialized value in
25 // There are 3 kinds of origin ids:
26 // 1xxx xxxx xxxx xxxx   heap origin id
27 // 0000 xxxx xxxx xxxx   stack origin id
28 // 0zzz xxxx xxxx xxxx   chained origin id
30 // Heap origin id describes a heap memory allocation and contains (in the xxx
33 // Stack origin id describes a stack memory allocation and contains (in the xxx
37 // Chained origin id describes an event of storing an uninitialized value to
42 //  * prev_id is another origin id that describes the earlier part of the
48 // points in value history marked with origin ids, and edges are events that are
51 // The "zzz" bits of chained origin id are used to store the length (or depth)
52 // of the origin chain.
54 class Origin {
84   // Returns the next origin in the chain and the current stack trace.
85   Origin getNextChainedOrigin(StackTrace *stack) const {  in getNextChainedOrigin()
90     return Origin(prev_id);  in getNextChainedOrigin()
97   static Origin CreateStackOrigin(u32 id) {  in CreateStackOrigin()
99     return Origin((1 << kHeapShift) | id);  in CreateStackOrigin()
102   static Origin CreateHeapOrigin(StackTrace *stack) {  in CreateHeapOrigin()
106     return Origin(stack_id);  in CreateHeapOrigin()
109   static Origin CreateChainedOrigin(Origin prev, StackTrace *stack) {  in CreateChainedOrigin()
137     return Origin((1 << kHeapShift) | (depth << kDepthShift) | chained_id);  in CreateChainedOrigin()
140   static Origin FromRawId(u32 id) {  in FromRawId()
141     return Origin(id);  in FromRawId()
155   explicit Origin(u32 raw_id) : raw_id_(raw_id) {}  in Origin()  function