FFI: FFI-Kernel-mt.92.mcz

Marcel Taeumel uploaded a new version of FFI-Kernel to project FFI:
http://source.squeak.org/FFI/FFI-Kernel-mt.92.mcz

==================== Summary ====================

Name: FFI-Kernel-mt.92
Author: mt
Time: 4 June 2020, 7:09:12.449722 pm
UUID: d0fd6e1d-8ad7-d14d-b592-f129e45e93cb
Ancestors: FFI-Kernel-mt.91

Offer a more obvious way to define type aliases.

=============== Diff against FFI-Kernel-mt.91 ===============

Item was changed:
  ----- Method: ExternalStructure class>>compileFields:withAccessors: (in category 'field definition') -----
  compileFields: specArray withAccessors: aSymbol
  "Compile a type specification for the FFI machinery.
  Return the newly compiled spec.
  Eventually generate the field accessors according to following rules:
  - aSymbol = #always always generate the accessors
  - aSymbol = #never never generate the accessors
  - aSymbol = #generated only generate the auto-generated accessors
  - aSymbol = #absent only generate the absent accessors"
  | newByteAlignment byteOffset typeSpec newCompiledSpec |
+ (self isTypeAlias: specArray) ifTrue:
- (specArray size > 0 and: [specArray first class ~~ Array]) ifTrue:
  [^ self compileAlias: specArray withAccessors: aSymbol].
  byteOffset := 0.
  newByteAlignment := self minStructureAlignment.
  typeSpec := WriteStream on: (WordArray new: 10).
  typeSpec nextPut: FFIFlagStructure.
  specArray do: [:spec |
  | fieldName fieldTypeName isPointerField externalType typeSize fieldAlignment |
  fieldName := spec first.
  fieldTypeName := spec second.
  isPointerField := fieldTypeName last = $*.
  fieldTypeName := (fieldTypeName findTokens: '*') first withBlanksTrimmed.
  externalType := (ExternalType typeNamed: fieldTypeName)
  ifNil: [self errorTypeNotFound: spec second].
  isPointerField ifTrue: [externalType := externalType asPointerType].
  typeSize := externalType byteSize.
  fieldAlignment := (externalType byteAlignment
  max: self minFieldAlignment)
  min: self maxFieldAlignment.
  byteOffset := byteOffset alignedTo: fieldAlignment.
  newByteAlignment := newByteAlignment max: fieldAlignment.
  spec size > 2 ifTrue: ["extra size"
  spec third < typeSize
  ifTrue: [^ self error: 'Explicit type size is less than expected'].
  typeSize := spec third.
  ].
  (fieldName notNil and: [self shouldGenerate: fieldName policy: aSymbol]) ifTrue: [
  self defineFieldAccessorsFor: fieldName startingAt: byteOffset + 1 type: externalType.
  ].
  typeSpec nextPutAll: (externalType embeddedSpecWithSize: typeSize).
  byteOffset := byteOffset + typeSize.
  ].
 
  newByteAlignment := newByteAlignment min: self maxStructureAlignment.
  byteOffset := byteOffset alignedTo: newByteAlignment.
  newCompiledSpec := typeSpec contents.
  newCompiledSpec at: 1 put: (byteOffset bitOr: FFIFlagStructure).
  byteAlignment := newByteAlignment.
  ^ newCompiledSpec!

Item was changed:
  ----- Method: ExternalStructure class>>isTypeAlias (in category 'testing') -----
  isTypeAlias
- "Answer whether this structure is an alias for another C type, enum, etc."
- "Example: #( nil 'long' )"
 
+ ^ self isTypeAlias: self fields!
- | fields |
- ^ (fields := self fields) size = 2
- and: [fields first isNil]!

Item was added:
+ ----- Method: ExternalStructure class>>isTypeAlias: (in category 'testing') -----
+ isTypeAlias: specArray
+ "Answer whether this structure is an alias for another C type, enum, etc."
+ "Example: #( nil 'long' )"
+
+ ^ (specArray size > 0 and: [specArray first class ~~ Array])!

Item was added:
+ ExternalStructure subclass: #ExternalTypeAlias
+ instanceVariableNames: ''
+ classVariableNames: ''
+ poolDictionaries: ''
+ category: 'FFI-Kernel'!
+
+ !ExternalTypeAlias commentStamp: 'mt 6/4/2020 19:02' prior: 0!
+ You can subclass from here to make type aliasing more clear.!

Item was added:
+ ----- Method: ExternalTypeAlias class>>fields (in category 'field definition') -----
+ fields
+
+ ^ { nil. self originalTypeName }!

Item was added:
+ ----- Method: ExternalTypeAlias class>>isTypeAlias (in category 'testing') -----
+ isTypeAlias
+
+ ^ true!

Item was added:
+ ----- Method: ExternalTypeAlias class>>originalTypeName (in category 'field definition') -----
+ originalTypeName
+ "Anser the typeName this alias should be for, e.g., 'long', 'ulonglong*', ..."
+
+ self subclassResponsibility.!

Item was changed:
  ----- Method: ExternalUnion class>>compileFields:withAccessors: (in category 'field definition') -----
  compileFields: specArray withAccessors: aSymbol
  "Compile a type specification for the FFI machinery.
  Return the newly compiled spec.
  Eventually generate the field accessors according to the policy defined in aSymbol."
  | byteOffset maxByteSize typeSpec newCompiledSpec newByteAlignment |
+ (self isTypeAlias: specArray) ifTrue:
+ [^ self error: 'Use ExternalStructure or ExternalTypeAlias to define a type alias, not ExternalUnion'].
- (specArray size > 0 and: [specArray first class ~~ Array]) ifTrue:
- [^ self error: 'Use ExternalStructure to define a type alias, not ExternalUnion'].
  byteOffset := 1.
  newByteAlignment := 1.
  maxByteSize := 0.
  typeSpec := WriteStream on: (WordArray new: specArray size + 1).
  typeSpec nextPut: FFIFlagStructure.
  specArray do: [:spec |
  | fieldName fieldTypeName isPointerField externalType typeSize typeAlignment |
  fieldName := spec first.
  fieldTypeName := spec second.
  isPointerField := fieldTypeName last = $*.
  fieldTypeName := (fieldTypeName findTokens: '*') first withBlanksTrimmed.
  externalType := (ExternalType typeNamed: fieldTypeName)
  ifNil: [self errorTypeNotFound: spec second].
  isPointerField ifTrue: [externalType := externalType asPointerType].
  typeSize := externalType byteSize.
  typeAlignment := externalType byteAlignment.
  spec size > 2 ifTrue: ["extra size"
  spec third < typeSize
  ifTrue: [^ self error: 'Explicit type size is less than expected'].
  typeSize := spec third.
  ].
  (fieldName notNil and: [self shouldGenerate: fieldName policy: aSymbol]) ifTrue: [
  self defineFieldAccessorsFor: fieldName startingAt: byteOffset type: externalType.
  ].
  typeSpec nextPutAll: (externalType embeddedSpecWithSize: typeSize).
  maxByteSize := maxByteSize max: typeSize.
  newByteAlignment := newByteAlignment max: typeAlignment
  ].
  maxByteSize := maxByteSize alignedTo: newByteAlignment.
  newCompiledSpec := typeSpec contents.
  newCompiledSpec at: 1 put: (maxByteSize bitOr: FFIFlagStructure).
  byteAlignment := newByteAlignment.
  ^ newCompiledSpec!