2017-12-05  Olivier Hainque  <hainque@adacore.com>

	* s-dwalin.adb (Read_And_Execute_Isn): Adjust test checking for the end
	of section. Add comments explaining the rationale of the computation.

2017-12-05  Bob Duff  <duff@adacore.com>

	* exp_ch11.adb: Minor refactoring.

2017-12-05  Hristian Kirtchev  <kirtchev@adacore.com>

	* debug.adb: Add debug switches d_a, d_e, and d_p, along with
	documentation.
	(Set_Underscored_Debug_Flag): New routine.
	* debug.ads: Add the flags for all underscore switches.
	(Set_Underscored_Debug_Flag): New routine.
	* einfo.adb: Flag303 is now Suppress_Elaboration_Warnings.
	(Suppress_Elaboration_Warnings): New routine.
	(Set_Suppress_Elaboration_Warnings): New routine.
	(Write_Entity_Flags): Add output for Suppress_Elaboration_Warnings.
	* einfo.ads: Add new flag Suppress_Elaboration_Warnings.
	(Suppress_Elaboration_Warnings): New routine along with pragma Inline.
	(Set_Suppress_Elaboration_Warnings): New routine along with pragma
	Inline.
	* exp_ch3.adb (Build_Init_Procedure): Restore the behavior of the
	legacy elaboration model.
	(Default_Initialize_Object): Restore the behavior of the legacy
	elaboration model.
	* exp_ch9.adb: Add with and use clause for Sem_Elab.
	(Build_Task_Activation_Call): Restore the behavior of the legacy
	elaboration model.
	* frontend.adb (Frontend): Restore the behavior of the legacy
	elaboration model.
	* opt.ads: Add new flags Legacy_Elaboration_Checks and
	Relaxed_Elaboration_Checks, along with documentation.
	* sem_attr.adb (Analyze_Access_Attribute): Restore the behavior of the
	legacy elaboration model.
	* sem_ch5.adb (Analyze_Assignment): Restore the behavior of the legacy
	elaboration model.
	* sem_ch7.adb (Analyze_Package_Declaration): Restore the behavior of
	the legacy elaboration model.
	* sem_ch8.adb (Attribute_Renaming): Restore the behavior of the legacy
	elaboration model.
	* sem_ch12.adb (Analyze_Instance_And_Renamings): Restore the behavior
	of the legacy elaboration model.
	(Analyze_Package_Instantiation): Restore the behavior of the legacy
	elaboration model.
	(Analyze_Subprogram_Instantiation): Restore the behavior of the legacy
	elaboration model.
	* sem_elab.adb: Update the documentation of the Processing phase.
	Update the documentation on elaboration-related compilation
	switches.  Update the documentation on adding a new target.  Add
	Processing_Attributes which represent the state of the Processing
	phase.  Resurrect the previous elaboration model as "legacy elaboration
	model".
	(Build_Call_Marker): This routine does not function when the legacy
	elaboration model is in effect. Do not consider entry calls and requeue
	statements when debug flag d_e is in effect. Do not consider calls to
	subprograms which verify the runtime semantics of certain assertion
	pragmas when debug flag d_p is in effect.
	(Build_Variable_Reference_Marker): This routine does not function when
	the legacy elaboration model is in effect.
	(Check_Elaboration_Scenarios): This routine does not function when the
	legacy elaboration model is in effect.
	(Ensure_Prior_Elaboration): The various flags have now been replaced
	with a state. Do not generate implicit Elaborate[_All] pragmas when
	their creation has been suppressed.
	(Ensure_Prior_Elaboration_Static): The with clause is marked based on
	the requested pragma, not on the nature of the scenario.
	(In_External_Context): Removed.
	(Is_Assertion_Pragma_Target): New routine.
	(Is_Potential_Scenario): Stop the traversal of a task body when
	reaching an accept or select statement, and debug switch d_a is in
	effect.
	(Kill_Elaboration_Scenario): This routine does not function when the
	legacy elaboration model is in effect.
	(Process_Activation_Generic): The various flags have now been replaced
	with a state.
	(Process_Conditional_ABE): The various flags have now been replaced
	with a state.
	(Process_Conditional_ABE_Access): The various flags have now been
	replaced with a state.
	(Process_Conditional_ABE_Activation_Impl): The various flags have now
	been replaced with a state. Do not process an activation call which
	activates a task whose type is defined in an external instance, and
	debug switch dL is in effect. Suppress the generation of implicit
	Elaborate[_All] pragmas once a conditional ABE check has been
	installed.
	(Process_Conditional_ABE_Call): The various flags have now been
	replaced with a state. Do not process a call which invokes a subprogram
	defined in an external instance, and debug switch dL is in effect.
	(Process_Conditional_ABE_Call_Ada): The various flags have now been
	replaced with a state. Suppress the generation of implicit
	Elaborate[_All] pragmas once a conditional ABE check has been
	installed.
	(Process_Conditional_ABE_Call_SPARK): The various flags have now been
	replaced with a state.
	(Process_Conditional_ABE_Instantiation): The various flags have now
	been replaced with a state.
	(Process_Conditional_ABE_Instantiation_Ada): The various flags have now
	been replaced with a state. Suppress the generation of implicit
	Elaborate[_All] pragmas once a conditional ABE check has been
	installed.
	(Process_Conditional_ABE_Instantiation_SPARK): The various flags have
	now been replaced with a state.
	(Process_Guaranteed_ABE_Activation_Impl): The various flags have now
	been replaced with a state.
	(Process_Single_Activation): The various flags have now been replaced
	with a state.
	(Record_Elaboration_Scenario): This routine does not function when the
	legacy elaboration model is in effect.
	(Traverse_Body): The various flags have now been replaced with a state.
	* sem_elab.ads: Resurrect the pre-18.x elaboration model as "legacy
	elaboration model".
	* sem_prag.adb (Analyze_Pragma): Restore the behavior of the legacy
	elaboration model.
	* sem_res.adb (Resolve_Call): Restore the behavior of the legacy
	elaboration model.
	(Resolve_Entity_Name): Restore the behavior of the legacy elaboration
	model.
	* sem_util.adb (Mark_Elaboration_Attributes): This routine does not
	function when the legacy elaboration model is in effect.
	* sinfo.adb (Is_Known_Guaranteed_ABE): Update the assertion check.
	(No_Elaboration_Check): New routine.
	(Set_Is_Known_Guaranteed_ABE): Update the assertion check.
	(Set_No_Elaboration_Check): New routine.
	* sinfo.ads: Update the documentation of flag Is_Known_Guaranteed_ABE
	along with occurrences in nodes.  Add new flag No_Elaboration_Check
	along with occurrences in nodes.
	* switch-c.adb (Scan_Front_End_Switches): Add processing for debug
	switches with underscores.  Add processing for switches -gnatH and
	-gnatJ.
	* usage.adb (Usage): Add output for switches -gnatH and -gnatJ.
	* doc/gnat_ugn/elaboration_order_handling_in_gnat.rst: Update the
	documentation to include the legacy and relaxed elaboration models.
	* gnat_ugn.texi: Regenerate.

2017-12-05  Arnaud Charlet  <charlet@adacore.com>

	* doc/gnat_ugn/platform_specific_information.rst: Minor edit.
	Improve doc on required packages for linux 32bits.

2017-12-05  Doug Rupp  <rupp@adacore.com>

	* tracebak.c (ppc64-vx7): USE_GCC_UNWINDER for 64bit.

2017-12-05  Javier Miranda  <miranda@adacore.com>

	* checks.adb (Generate_Range_Check): Force evaluation of the node in
	more cases.  This patch was written to improve the code generated by
	the CCG compiler but it is enabled for all targets since double
	evaluation is always a potential source of inefficiency.

2017-12-05  Gary Dismukes  <dismukes@adacore.com>

	* doc/gnat_ugn/gnat_utility_programs.rst: Remove reference to obsolete
	-fdump-xref switch.

From-SVN: r255412