Moving method layout to object layout chapter

Chapters/2-ObjectStructure/objectStructure.md

@@ -426,7 +426,62 @@ However, they use a different format so the runtime can differentiate them from
 
 ### Methods and Headers
 
-TODO!
+Pharo users write methods in Pharo syntax.
+However, Pharo source code is just text and is not executable.
+Before executing those methods, a bytecode compiler processes the source code and translates it to an executable form by performing a sequence of transformations until it generates a `CompiledMethod` instance.
+A parsing step translates the source code into a tree data structure called an _abstract syntax tree_, a name resolution step attaches semantics to identifiers, a lowering step creates a control flow graph representation, and finally a code generation step produces the `CompiledMethod` object containing the code and meta-data required for execution.
+A compiled method is structured around a method header, a literal frame, a bytecode sequence and a method trailer as shown in Figure *@methodshape@*.
+
+![Structure of a compiled method.%anchor=methodshape&width=60](figures/compile_method_shape.pdf)
+
+
+#### Literals and the Literal Frame
+
+Pharo code includes all sort of literal values that need to be known and accessed at runtime.
+For example, Listing *@exampleMethod@* shows a method using integers, arrays, and strings.
+
+```caption=Source code with several literals&anchor=exampleMethod
+MyClass >> exampleMethod
+    self someComputation > 1
+		ifTrue: [ ^ #() ]
+		ifFalse: [ self error: 'Unexpected!' ]
+```
+
+In Pharo, literal values are stored each in different reference slot in a method.
+The collection of reference slots in a method is called the _literal frame_.
+Remember from the object representation chapter, that `CompiledMethod` instances are variable objects that contain a variable reference part and a variable byte indexable part.
+
+- Commonly, the literal frame contains references to numbers, characters, strings, arrays and symbols used in a method.
+- In addition, when referencing globals (and thus classes), class variables and shared variables, the literal frame references their corresponding associations.
+- Finally, the literal frame references also runtime meta-data such as flags or message selectors required to perform message-sends.
+
+It is worth noticing that the literal frame poses no actual limitation to what type of object it references.
+Such capability is rarely exploited when a method's behavior cannot be expressed in Pharo syntax.
+This is for example the case of foreign function interface methods that are compiled by a separate compiler and store foreign function meta-data as literals.
+
+#### Method Header
+
+All methods contain at least one literal named the _method header_, referencing an immediate integer representing a mask of flags.
+
+- **Encoder:** a bit indicating if the method uses the default bytecode set or not.
+- **Primitive:** a bit indicating if the method has a primitive operation or not.
+- **Number of parameters:** 4 bits representing the number of parameters of the method.
+- **Number of temporaries:** 6 bits representing the number of temporary variables declared in the method.
+- **Number of literals:** 15 bits representing the number of literals contained in the method.
+- **Frame size:** 1 bit representing if the method will require small or large frame sizes.
+
+The encoder and primitive flags will be covered later in this chapter.
+The frame size will be explored in the context reification chapter.
+
+#### Method Trailer
+
+Following the method literals, a `CompiledMethod` instance contains a byte-indexable variable part, containing bytecode instructions.
+However, it is of common usage in Pharo to make this byte-indexable part slightly larger to contain trailing meta-data after a method's bytecode.
+Such meta-data is called the _method trailer_.
+
+The method trailer can be arbitrarily long, encoding binary data such as integers or encoded text.
+Pharo usually uses the trailer to encode the offset of the method source code in a file.
+It has, however, also been used to encode a method source code in utf8 encoding, or zipped.
 
 ### Classes
 

Chapters/3-MethodsAndBytecode/methodsbytecode.md

@@ -13,14 +13,7 @@ In this chapter, we explain in detail how methods are modeled using the sista by
 We explain how bytecode and primitive instructions are executed using a conceptual stack.
 The bytecode interpreter and the call stack are introduced in Chapter *@cha:Slang@*.
 
-### Compiled Methods
-
-Pharo users write methods in Pharo syntax.
-However, Pharo source code is just text and is not executable.
-Before executing those methods, a bytecode compiler processes the source code and translates it to an executable form by performing a sequence of transformations until it generates a `CompiledMethod` instance.
-A parsing step translates the source code into a tree data structure called an _abstract syntax tree_, a name resolution step attaches semantics to identifiers, a lowering step creates a control flow graph representation, and finally a code generation step produces the `CompiledMethod` object containing the code and meta-data required for execution.
-
-#### Intermezzo: Variables in Pharo
+### Intermezzo: Variables in Pharo
 
 To understand how Pharo code works, it is useful to do a quick reminder on how do variables work.
 In this chapter, we will deal with the low-level representation of variables (how read/writes are implemented).
@@ -63,59 +56,6 @@ Literal variables live as long as the program, or a developer decides to explici
 Literal variables do not have an index: they are represented as an association (a key-value object) and stored in dictionaries.
 Methods using literal variables store the corresponding associations in their literal frame, as we will see next.
 
-#### Literals and the Literal Frame
-
-Pharo code includes all sort of literal values that need to be known and accessed at runtime.
-For example, Listing *@exampleMethod@* shows a method using integers, arrays, and strings.
-
-```caption=Source code with several literals&anchor=exampleMethod
-MyClass >> exampleMethod
-    self someComputation > 1
-		ifTrue: [ ^ #() ]
-		ifFalse: [ self error: 'Unexpected!' ]
-```
-
-In Pharo, literal values are stored each in different reference slot in a method.
-The collection of reference slots in a method is called the _literal frame_.
-Remember from the object representation chapter, that `CompiledMethod` instances are variable objects that contain a variable reference part and a variable byte indexable part.
-
-- Commonly, the literal frame contains references to numbers, characters, strings, arrays and symbols used in a method.
-- In addition, when referencing globals (and thus classes), class variables and shared variables, the literal frame references their corresponding associations.
-- Finally, the literal frame references also runtime meta-data such as flags or message selectors required to perform message-sends.
-
-It is worth noticing that the literal frame poses no actual limitation to what type of object it references.
-Such capability is rarely exploited when a method's behavior cannot be expressed in Pharo syntax.
-This is for example the case of foreign function interface methods that are compiled by a separate compiler and store foreign function meta-data as literals.
-
-### Compiled Method
-
-A compiled method is structured around a method header, a literal frame, a bytecode sequence and a method trailer as shown in Figure *@methodshape@*.
-
-![Structure of a compiled method.%anchor=methodshape&width=60](figures/compile_method_shape.pdf)
-
-#### Method Header
-
-All methods contain at least one literal named the _method header_, referencing an immediate integer representing a mask of flags.
-
-- **Encoder:** a bit indicating if the method uses the default bytecode set or not.
-- **Primitive:** a bit indicating if the method has a primitive operation or not.
-- **Number of parameters:** 4 bits representing the number of parameters of the method.
-- **Number of temporaries:** 6 bits representing the number of temporary variables declared in the method.
-- **Number of literals:** 15 bits representing the number of literals contained in the method.
-- **Frame size:** 1 bit representing if the method will require small or large frame sizes.
-
-The encoder and primitive flags will be covered later in this chapter.
-The frame size will be explored in the context reification chapter.
-
-#### Method Trailer
-
-Following the method literals, a `CompiledMethod` instance contains a byte-indexable variable part, containing bytecode instructions.
-However, it is of common usage in Pharo to make this byte-indexable part slightly larger to contain trailing meta-data after a method's bytecode.
-Such meta-data is called the _method trailer_.
-
-The method trailer can be arbitrarily long, encoding binary data such as integers or encoded text.
-Pharo usually uses the trailer to encode the offset of the method source code in a file.
-It has, however, also been used to encode a method source code in utf8 encoding, or zipped.
 
 ### Stack Bytecode
 

Chapters/BasicsOnExecution/basicsOnExecution.md

@@ -61,7 +61,7 @@ The fact that the variable is named `origin` depends on the fact that this metho
 The commented form of the bytecodes for Rectangle width is shown below: 
 
 
-![.](figures/width_0.pdf)
+![.](figures/interpreter_activation.pdf)
 
 %Rectangle >> #width
 %- <01> pushRcvr: 1 - push the value of the receiver's second instance variable (corner) onto the stack

pillar.conf

@@ -1 +1 @@
-{	"series" : "Square Bracket tutorials",	"base_url" : "",	"\"tocFile\": \"index.pillar\" if you have a index.pillar file containing the table of contents of your book" : "comment",	"attribution" : "The Pharo team",	"latexWriter" : "miclatex:sbabook",	"keywords" : "Virtual machine, object encodings, garbage collection, Pharo, Smalltalk",	"htmlWriter" : "html",	"title" : "[DRAFT/WIP] The Pharo Virtual Machine Explained",	"site_name" : "Pharo Book",	"bibFile" : "vmbib.bib"}
+{	"series" : "Square Bracket tutorials",	"base_url" : "",	"\"tocFile\": \"index.md\" if you have a index.pillar file containing the table of contents of your book" : "comment",	"attribution" : "The Pharo team",	"latexWriter" : "miclatex:sbabook",	"keywords" : "Virtual machine, object encodings, garbage collection, Pharo, Smalltalk",	"htmlWriter" : "html",	"title" : "[DRAFT/WIP] The Pharo Virtual Machine Explained",	"site_name" : "Pharo Book",	"bibFile" : "vmbib.bib"}