Merge: phase: Introduction of new hook method

This pr introduces a new hook method in the execution of the `process_nmodule_after_phases` phases. This method makes it possible to analyze each module again after the execution of all phases in order to benefit from the information of the whole program.

This method is useful in the context of contracts. Example:

```nit
module b

redef class A
	redef fun foo
	is
		ensure(result > 2)
	do
		return 2
	end
end

var a = new A
a.bar
```
```nit
module a

class A
	fun foo: Int do
		return 1
	end

	fun bar do
		self.foo
	end
end
```

Actually, when you call the foo property in the bar method, no contract is called, while a postcondition was added by refinement in the `b` module. In fact it was not possible to call the contract face because it was not yet introduced during the analysis of module `a`. It is now possible to re-analyze all the modules to make the redirection once all the information are known.

Pull-Request: #2828

Author: privat

src/compiler/abstract_compiler.nit

@@ -26,6 +26,7 @@ import mixin
 import counter
 import pkgconfig
 private import explain_assert_api
+import contracts
 
 # Add compiling options
 redef class ToolContext

src/compiler/global_compiler.nit

@@ -30,7 +30,7 @@ redef class ToolContext
 	# option --global
 	var opt_global = new OptionBool("Use global compilation", "--global")
 
-	var global_compiler_phase = new GlobalCompilerPhase(self, null)
+	var global_compiler_phase = new GlobalCompilerPhase(self, [contracts_phase])
 
 	redef init do
 		super

src/compiler/separate_compiler.nit

@@ -97,7 +97,7 @@ redef class ToolContext
 		end
 	end
 
-	var separate_compiler_phase = new SeparateCompilerPhase(self, null)
+	var separate_compiler_phase = new SeparateCompilerPhase(self, [contracts_phase])
 end
 
 class SeparateCompilerPhase

src/compiler/separate_erasure_compiler.nit

@@ -46,7 +46,7 @@ redef class ToolContext
 		end
 	end
 
-	var erasure_compiler_phase = new ErasureCompilerPhase(self, null)
+	var erasure_compiler_phase = new ErasureCompilerPhase(self, [contracts_phase])
 end
 
 class ErasureCompilerPhase

src/contracts.nit

@@ -35,33 +35,35 @@ end
 private class ContractsPhase
 	super Phase
 
-	# The entry point of the contract phase
-	# In reality, the contract phase is executed on each module
-	# FIXME: Actually all method is checked to add method if any contract is inherited
 	redef fun process_nmodule(nmodule)do
 		# Check if the contracts are disabled
 		if toolcontext.opt_no_contract.value then return
 		nmodule.do_contracts(self.toolcontext)
 	end
+
+	redef fun process_mainmodule(mainmodule: MModule, given_mmodules: SequenceRead[MModule]) do
+		# Visit all loaded modules `toolcontext.nmodules` to do contract weaving
+		for nmodule in toolcontext.modelbuilder.nmodules do
+			nmodule.do_weaving_contracts(self.toolcontext)
+		end
+	end
 end
 
 redef class AModule
-	# Compile all contracts
-	#
-	# The implementation of the contracts is done in two visits.
-	#
-	# - First step, the visitor analyzes and constructs the contracts
-	#   for each class (invariant) and method (expect, ensure).
-	#
-	# - Second step the visitor analyzes each `ASendExpr` to see
-	#   if the callsite calls a method with a contract. If this is
-	#	the case the callsite is replaced by another callsite to the contract method.
+
+	# Entry point to generate the entire contract infrastructure.
+	# Once this method is called we must call the `do_weaving_contracts` method (see it for more information).
 	fun do_contracts(toolcontext: ToolContext) do
 		var ast_builder = new ASTBuilder(mmodule.as(not null))
 		#
 		var contract_visitor = new ContractsVisitor(toolcontext, toolcontext.modelbuilder.identified_modules.first, self, ast_builder)
 		contract_visitor.enter_visit(self)
-		#
+	end
+
+	# Entry point to execute the weaving in order to redirect the calls to the contract sides if it's needed.
+	fun do_weaving_contracts(toolcontext: ToolContext)
+	do
+		var ast_builder = new ASTBuilder(mmodule.as(not null))
 		var callsite_visitor = new CallSiteVisitor(toolcontext, ast_builder)
 		callsite_visitor.enter_visit(self)
 	end

src/nit.nit

@@ -75,6 +75,7 @@ else
 end
 
 modelbuilder.run_phases
+toolcontext.run_global_phases(modelbuilder.parsed_modules)
 
 if toolcontext.opt_only_metamodel.value then toolcontext.quit
 

tests/sav/nit_args9.res

@@ -16,6 +16,7 @@
 test_keep_going.nit:44,18--21: Error: method `fail` does not exists in `Sys`.
 		var a = new Sys.fail
 		                ^
+Errors: 6. Warnings: 0.
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