Manage linking of SSA version even if the variable got shadowed in the middle

Author: jecisc

src/FAST-Python-Tools-Tests/FASTPythonSSATest.class.st

@@ -1023,6 +1023,44 @@ print(x)'.
 			assignedVar5 ssaVersion }
 ]
 
+{ #category : 'tests' }
+FASTPythonSSATest >> testSSAVersionFollowPreviouslyShadowedName [
+
+	| assignedVar1 assignedVar2 usedVar1 usedFunction usedVar2 |
+	self parseAndResolve: 'x = 3
+
+print(x)
+
+def x(): pass
+
+print(x)
+
+x = 4
+
+print(x)'.
+
+	assignedVar1 := model module statements first left.
+	self assert: assignedVar1 ssaVersion version equals: 1.
+	self assert: assignedVar1 ssaName equals: 'x_1'.
+	self assert: assignedVar1 ssaVersion localDeclaration equals: assignedVar1 localDeclaration.
+	self assert: assignedVar1 ssaVersion localUses size equals: 2.
+
+	usedVar1 := model module statements second arguments first.
+	self assert: usedVar1 ssaVersion identicalTo: assignedVar1 ssaVersion.
+
+	usedFunction := model module statements fourth arguments first.
+	self assert: usedFunction ssaVersion isNil.
+
+	assignedVar2 := model module statements fifth left.
+	self assert: assignedVar2 ssaVersion version equals: 2.
+	self assert: assignedVar2 ssaName equals: 'x_2'.
+	self assert: assignedVar2 ssaVersion localDeclaration equals: assignedVar2 localDeclaration.
+	self assert: assignedVar2 ssaVersion localUses size equals: 2.
+
+	usedVar2 := model module statements sixth arguments first.
+	self assert: usedVar2 ssaVersion identicalTo: assignedVar2 ssaVersion
+]
+
 { #category : 'tests - assignments' }
 FASTPythonSSATest >> testSingleAssignement [
 

src/FAST-Python-Tools/FASTPyEntity.extension.st

@@ -12,6 +12,29 @@ FASTPyEntity >> fullCfg [
 	^ FASTPythonCFGVisitor new buildFullCFGOf: self
 ]
 
+{ #category : '*FAST-Python-Tools' }
+FASTPyEntity >> lastSSAVersion [
+	"Return the last active SSA version if there is one. In Python lots of things can shadow each other, so we check if there was not a variable shadowed previously.
+	
+	For example:
+	
+	x = 3 
+	
+	def x(): pass
+	
+	x = 4
+	
+	Here the second assignment follow the first one but was interrupted by the function. But we still need to link them in the SSA."
+
+	| entity |
+	entity := self localDeclaration.
+	[
+		entity := entity shadowing.
+		entity isNotNil ] whileTrue: [ entity activeVersion ifNotNil: [ :version | ^ version ] ].
+
+	^ nil
+]
+
 { #category : '*FAST-Python-Tools' }
 FASTPyEntity >> localResolverKind [
 	"In the local resolver, if we redefine an entity with an entity of the same kind, we keep the same declaration. Else we create a new one. 

src/FAST-Python-Tools/FASTPythonSSAVisitor.class.st

@@ -35,7 +35,7 @@ FASTPythonSSAVisitor >> createVariableVersionFor: aFASTEntity [
 
 	| newSSA |
 	newSSA := FASTVariableVersionSSA for: aFASTEntity.
-	aFASTEntity localDeclaration activeVersion ifNotNil: [ :lastSSA | newSSA version: lastSSA version ].
+	aFASTEntity lastSSAVersion ifNotNil: [ :lastSSA | newSSA version: lastSSA version ].
 
 	aFASTEntity localDeclaration activeVersion: newSSA.