prepare comment support

smalltalksrc/Slang/TParseNode.class.st

@@ -201,6 +201,13 @@ TParseNode >> hasExplicitReturn [
 	^false
 ]
 
+{ #category : 'testing' }
+TParseNode >> hasNothingButComments [
+	"an alternative to isEmpty related to inlining"
+
+	^ self children allSatisfy: [ :child | child isComment ]
+]
+
 { #category : 'testing' }
 TParseNode >> hasSideEffect [
 	"Answer if the parse tree rooted at this node has a side-effect or not.  By default assume it has.  Nodes that don't override."
@@ -452,7 +459,7 @@ TParseNode >> removeUnusedNodesInBranch: aChild [
 	"this method should be only called when cleaning an AST tree after an unused expression was found"
 
 	self children remove: aChild.
-	self children isEmpty ifTrue: [
+	(self children isEmpty or: [ self hasNothingButComments ]) ifTrue: [
 		self parent removeUnusedNodesInBranch: self ]
 ]
 

smalltalksrc/Slang/TSendNode.class.st

@@ -76,6 +76,13 @@ TSendNode >> argumentsForInliningCodeGenerator: aCodeGen [
 		ifFalse: [arguments]
 ]
 
+{ #category : 'testing' }
+TSendNode >> argumentsHasNothingButComments [
+	"related to dead code elimination and inlining, see if the cases has nothing but comment meaning they are empty"
+
+	^ arguments allSatisfy: [ :arg | arg isComment ]
+]
+
 { #category : 'tranforming' }
 TSendNode >> asCASTAsFieldReferenceIn: aCodeGen [
 
@@ -567,7 +574,7 @@ TSendNode >> removeUnusedNodesInBranch: aChild [
 	| branchIndex |
 	branchIndex := arguments indexOf: aChild.
 	arguments := arguments select: [ :e | e ~= aChild ].
-	arguments isEmpty
+	(arguments isEmpty or: [ self argumentsHasNothingButComments ])
 		ifTrue: [
 			self transformReceiverAfterEmptyArguments.
 			self parent removeUnusedNodesInBranch: self ]

smalltalksrc/Slang/TStatementListNode.class.st

@@ -372,6 +372,12 @@ TStatementListNode >> initialize [
 	arguments := #()
 ]
 
+{ #category : 'testing' }
+TStatementListNode >> isComment [
+
+	^ self hasNothingButComments
+]
+
 { #category : 'testing' }
 TStatementListNode >> isEmptyStmtListNode [
 	"return true if the statement node is empty or has just a nil in it"
@@ -513,7 +519,7 @@ TStatementListNode >> removeUnusedNodesInBranch: aChild [
 	"this method should be only called when cleaning an AST tree after an unused expression was found, remove aChild from the list of statements"
 
 	statements := statements select: [ :stmt | stmt ~~ aChild ].
-	statements isEmpty ifTrue: [
+	(statements isEmpty or: [ self hasNothingButComments ]) ifTrue: [
 		self parent removeUnusedNodesInBranch: self ]
 ]
 

smalltalksrc/Slang/TSwitchStmtNode.class.st

@@ -244,6 +244,13 @@ TSwitchStmtNode >> cases: anObject [
 	cases := anObject
 ]
 
+{ #category : 'testing' }
+TSwitchStmtNode >> casesHasNothingButComments [
+	"related to dead code elimination and inlining, see if the cases has nothing but comment meaning they are empty"
+
+	^ cases allSatisfy: [ :case | case second isComment ]
+]
+
 { #category : 'accessing' }
 TSwitchStmtNode >> children [
 
@@ -455,7 +462,8 @@ TSwitchStmtNode >> removeUnusedNodesInBranch: aChild [
 	"when removing a node from a switch, we have to be careful of if it comes from a caseOf: or a caseOf:otherwise:. if it comes from a caseOf:, otherwise is nil and must be kept it will be translated as a no case found error. To indicate that otherwise does nothing Slang use an empty TStatementListNode, hence the following code"
 
 	cases := cases select: [ :each | each second ~~ aChild ].
-	self cases isEmpty ifFalse: [ ^ self ].
+	(cases isEmpty or: [ self casesHasNothingButComments ])
+	ifFalse: [ ^ self ].
 	"we're from a caseOf: so we keep the node"
 	otherwiseOrNil ifNil: [ ^ self ].
 	"otherwiseOrNil may have been empty from the start or during the cleaning process, either way the node is now completely empty so we can supress it"