[Ada] SPARK_Mode on synchronized units and entry declarations

This patch implements the following semantic rules:

   The SPARK_Mode aspect can be used in the following places in the code:

   * on a library-level subprogram spec or body (which now includes entry
     declarations)

   * on a library-level task spec or body

   * on a library-level protected spec or body

------------
-- Source --
------------

--  synchronized_spark_mode.ads

package Synchronized_SPARK_Mode is
   protected type Prot_Typ with SPARK_Mode is
      entry Prot_Ent with SPARK_Mode => Off;
   end Prot_Typ;

   task Task_Typ;
   pragma SPARK_Mode;
end Synchronized_SPARK_Mode;

--  synchronized_spark_mode.adb

package body Synchronized_SPARK_Mode is
   protected body Prot_Typ with SPARK_Mode => Off is
      entry Prot_Ent when True is
         pragma SPARK_Mode;                                          --  Error
      begin
         null;
      end Prot_Ent;
   end Prot_Typ;

   task body Task_Typ with SPARK_Mode => Off is
   begin
      null;
   end Task_Typ;
end Synchronized_SPARK_Mode;

-----------------
-- Compilation --
-----------------

$ gcc -c synchronized_spark_mode.adb
synchronized_spark_mode.adb:4:10: cannot change SPARK_Mode from Off to On
synchronized_spark_mode.adb:4:10: SPARK_Mode was set to Off at line 2

Tested on x86_64-pc-linux-gnu, committed on trunk

2015-10-26  Hristian Kirtchev  <kirtchev@adacore.com>

	* contracts.adb (Analyze_Subprogram_Body_Contract): Use
	Unique_Defining_Entity instead of Corresponding_Spec_Of.
	* einfo.adb SPARK_Pragma and SPARK_Aux_Pragma are now Node40 and
	Node41 respectively.
	(SPARK_Aux_Pragma): Update the assertion and node querry.
	(SPARK_Aux_Pragma_Inherited): Update the assertion and node query.
	(SPARK_Pragma): Update the assertion and node query.
	(SPARK_Pragma_Inherited): Update the assertion and node query.
	(Set_SPARK_Aux_Pragma): Update the assertion and node setting.
	(Set_SPARK_Aux_Pragma_Inherited): Update the assertion and node setting.
	(Set_SPARK_Pragma): Update the assertion and node setting.
	(Set_SPARK_Pragma_Inherited): Update the assertion and node setting.
	(Write_Field32_Name): Remove the output for SPARK_Pragma.
	(Write_Field33_Name): Remove the output for SPARK_Aux_Pragma.
	(Write_Field40_Name): Add output for SPARK_Pragma.
	(Write_Field41_Name): Add output for SPARK_Aux_Pragma.
	* einfo.ads Rewrite the documentation on attributes
	SPARK_Pragma, SPARK_Aux_Pragma, SPARK_Pragma_Inherited and
	SPARK_Aux_Pragma_Inherited. Update their uses in nodes.
	* exp_ch4.adb (Create_Anonymous_Master): Use
	Unique_Defining_Entity instead of Corresponding_Spec_Of.
	* exp_ch9.adb (Expand_Entry_Declaration): Mark the barrier
	function as such.
	(Expand_N_Task_Body): Mark the task body as such.
	(Expand_N_Task_Type_Declaration): Mark the task body as such.
	* exp_unst.adb (Visit_Node): Use Unique_Defining_Entity instead
	of Corresponding_Spec_Of.
	* sem_attr.adb (Analyze_Attribute_Old_Result): Use
	Unique_Defining_Entity instead of Corresponding_Spec_Of.
	* sem_ch6.adb (Analyze_Subprogram_Body_Helper): Entry barrier
	functions do not inherit the SPARK_Mode from the context.
	(Build_Subprogram_Declaration): The matching spec is now marked
	as a source construct to mimic the original stand alone body.
	* sem_ch7.adb (Analyze_Package_Body_Helper): Code cleanup.
	* sem_ch9.adb Add with and use clauses for Contracts.
	(Analyze_Entry_Body): An entry body freezes the contract of
	the nearest enclosing package body. The entry body now inherits
	the SPARK_Mode from the context.
	(Analyze_Entry_Declaration): A protected entry declaration now inherits
	the SPARK_Mode from the context.
	(Analyze_Protected_Body): A protected body freezes
	the contract of the nearest enclosing package body. Set the
	Etype of a protected body as this is neede for proper aspect
	analysis. Protected bodies can now carry meaningful aspects and
	those are now analyzed.
	(Analyze_Protected_Type_Declaration): A protected type now inherits the
	SPARK_Mode from the context.
	(Analyze_Task_Body): A task body freezes the contract of the
	nearest enclosing package body. Set the Etype of a task body
	as this is needed for proper aspect analysis. A task body
	now inherits the SPARK_Mode from the context.  Task bodies
	can now carry meaningful aspects and those are now analyzed.
	(Analyze_Task_Type_Declaration): A task type declaration now
	inherits the SPARK_Mode of from the context.
	* sem_ch10.adb (Analyze_Protected_Body_Stub): Protected body
	stubs can now carry meaningful aspects.
	(Analyze_Task_Body_Stub): Task body stubs can now carry meaningful
	aspects.
	* sem_ch13.adb (Analyze_Aspect_Specifications): Aspects SPARK_Mode
	Warnings now use routine Insert_Pragma as means of insertion into
	the tree.
	(Insert_After_SPARK_Mode): Clean up documentation.
	(Insert_Pragma): Clean up documentation. The routine is now
	capable of operating on synchronized units.
	* sem_prag.adb (Add_Entity_To_Name_Buffer): New routine.
	(Analyze_Contract_Cases_In_Decl_Part): Use
	Unique_Defining_Entity instead of Corresponding_Spec_Of.
	(Analyze_Depends_Global): Use Unique_Defining_Entity instead
	of Corresponding_Spec_Of.
	(Analyze_Depends_In_Decl_Part): Use Unique_Defining_Entity instead of
	Corresponding_Spec_Of.
	(Analyze_Global_In_Decl_Part): Use Unique_Defining_Entity instead of
	Corresponding_Spec_Of.
	(Analyze_Pragma): Use Unique_Defining_Entity instead of
	Corresponding_Spec_Of.
	Update the detection of an illegal pragma Ghost when it applies
	to a task or protected unit. Reimplement the handling of
	pragma SPARK_Mode.
	(Analyze_Pre_Post_Condition_In_Decl_Part): Use Unique_Defining_Entity
	instead of Corresponding_Spec_Of.
	(Analyze_Test_Case_In_Decl_Part): Use Unique_Defining_Entity instead of
	Corresponding_Spec_Of.
	(Check_Library_Level_Entity): Update the comment on usage.
	Reimplemented to offer a more specialized errror context.
	(Check_Pragma_Conformance): Update profile and comment on usage.
	Handle error message output on single protected or task units.
	(Collect_Subprogram_Inputs_Outputs): Use Unique_Defining_Entity
	instead of Corresponding_Spec_Of.
	(Process_Body): New routine.
	(Process_Overloadable): New routine.
	(Process_Private_Part): New routine.
	(Process_Statement_Part): New routine.
	(Process_Visible_Part): New routine.
	(Set_SPARK_Context): New routine.
	(Set_SPARK_Flags): Removed.
	* sem_util.adb (Corresponding_Spec_Of): Removed.
	(Unique_Entity): Reimplemented to handle many more cases.
	* sem_util.ads (Corresponding_Spec_Of): Removed.
	(Unique_Defining_Entity): Update the comment on usage.
	* sinfo.ads (Is_Entry_Barrier_Function): Update the assertion.
	(Is_Task_Body_Procedure): New routine.
	(Set_Is_Entry_Barrier_Function): Update the assertion.
	(Set_Is_Task_Body_Procedure): New routine.
	* sinfo.adb Update the documentation of attribute
	Is_Entry_Barrier_Function along with use in nodes. Add new
	attribute Is_Task_Body_Procedure along with use in nodes.
	(Is_Task_Body_Procedure): New routine along with pragma Inline.
	(Set_Is_Task_Body_Procedure): New routine along with pragma Inline.

[Ada] SPARK_Mode on synchronized units and entry declarations

Commit Message

Patch