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Module `dmd.ob`

Flow analysis for Ownership/Borrowing

Documentation

https://dlang.org/phobos/dmd_escape.html

Coverage

https://codecov.io/gh/dlang/dmd/src/master/src/dmd/ob.d Bug reports: use 'live' keyword:

https

//issues.dlang.org/buglist.cgi?bug_status=NEW&bug_status=REOPENED&keywords=live

References

https://github.com/dlang/DIPs/blob/master/DIPs/accepted/DIP1021.md Argument Ownership and Function Calls

Functions

Name	Description
`allocDeps(pvss)`	Allocate BitArrays in PtrVarState. Can be allocated much more efficiently by subdividing a single large array of bits
`allocStates(obstate)`	Allocate state variables foreach node.
`checkObErrors(obstate)`	Check for Ownership/Borrowing errors.
`collectVars(funcdecl, vars)`	Find the pointer variable declarations in this function, and fill `vars` with them.
`computePreds(obnodes)`	Compute predecessors.
`doDataFlowAnalysis(obstate)`	Do the data flow analysis (i.e. compute the input[] and output[] vectors for each ObNode).
`escapeLive(e, onVar)`	Check for escaping variables using DIP1000's `escapeByValue`, with `live` set to `true`
`genKill(obstate, ob)`	Compute the gen vector for ob.
`hasMutableFields(t)`	Does type `t` have any mutable fields?
`hasPointersToMutableFields(t)`	Does type `t` contain any pointers to mutable?
`insertFinallyBlockCalls(obnodes)`	Insert finally block calls when doing a goto from inside a try block to outside. Done after blocks are generated because then we know all the edges of the graph, but before the pred's are computed.
`insertFinallyBlockGotos(obnodes)`	Remove try-finally scaffolding.
`isBorrowedPtr(v)`	Does v meet the definiton of a `Borrowed` pointer?
`isMutableRef(t)`	Is type `t` a reference to a const or a reference to a mutable?
`isReadonlyPtr(v)`	Does v meet the definiton of a `Readonly` pointer?
`isTrackableVar(v)`	Are we interested in tracking variable `v`?
`isTrackableVarExp(e)`	Are we interested in tracking this expression?
`makeChildrenUndefined(vi, gen)`	Recursively make Undefined all who list vi as a dependency
`makeUndefined(vi, gen)`	Recursively make Undefined vi undefined and all who list vi as a dependency
`numberNodes(obnodes)`	Set the `index` field of each ObNode to its index in the `obnodes[]` array.
`oblive(funcdecl)`	Perform ownership/borrowing checks for funcdecl. Does not modify the AST, just checks for errors.
`PtrStateToChars(state)`
`readVar(ob, vi, mutable, gen)`	Read from variable vi. The beginning of the 'scope' of a variable is when it is first read. Hence, when a read is done, instead of when assignment to the variable is done, the O/B rules are enforced. (Also called "non-lexical scoping".)
`removeUnreachable(obnodes)`	Remove unreachable nodes and compress them out of obnodes[].
`setLabelStatementExtraFields(labtab)`	Set the `.extra` field for LabelStatements in labtab[].
`toObNodes(obnodes, s)`	Convert statement into ObNodes.
`toPtrState(v)`	Determine the state of a variable based on its type and storage class.

Structs

Name	Description
`ObNode`	A node in the function's expression graph, and its edges to predecessors and successors.
`ObState`	Collect the state information.
`PtrVarState`	Carries the state of a pointer variable.

Enums

Name	Description
`PtrState`	Pointer variable states:

Authors

Walter Bright

License

Boost License 1.0