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(* M2RTS.mod Implements the run time system facilities of Modula-2.
Copyright (C) 2001-2023 Free Software Foundation, Inc.
Contributed by Gaius Mulley <gaius.mulley@southwales.ac.uk>.
This file is part of GNU Modula-2.
GNU Modula-2 is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
GNU Modula-2 is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. *)
IMPLEMENTATION MODULE M2RTS ;
FROM libc IMPORT abort, exit, write, getenv, printf, strlen ;
(* FROM Builtins IMPORT strncmp, strcmp ; not available during bootstrap. *)
FROM NumberIO IMPORT CardToStr ;
FROM StrLib IMPORT StrCopy, StrLen, StrEqual ;
FROM SYSTEM IMPORT ADDRESS, ADR ;
FROM ASCII IMPORT nl, nul ;
FROM Storage IMPORT ALLOCATE ;
IMPORT RTExceptions ;
IMPORT M2EXCEPTION ;
IMPORT M2Dependent ;
CONST
stderrFd = 2 ;
TYPE
PtrToChar = POINTER TO CHAR ;
ProcedureList = RECORD
head, tail: ProcedureChain
END ;
ProcedureChain = POINTER TO RECORD
p : PROC ;
prev,
next: ProcedureChain ;
END ;
VAR
InitialProc,
TerminateProc: ProcedureList ;
ExitValue : INTEGER ;
isHalting,
CallExit : BOOLEAN ;
Initialized : BOOLEAN ;
(*
ConstructModules - resolve dependencies and then call each
module constructor in turn.
*)
PROCEDURE ConstructModules (applicationmodule, libname: ADDRESS;
argc: INTEGER; argv, envp: ADDRESS) ;
BEGIN
M2Dependent.ConstructModules (applicationmodule, libname,
argc, argv, envp)
END ConstructModules ;
(*
DeconstructModules - resolve dependencies and then call each
module constructor in turn.
*)
PROCEDURE DeconstructModules (applicationmodule, libname: ADDRESS;
argc: INTEGER; argv, envp: ADDRESS) ;
BEGIN
M2Dependent.DeconstructModules (applicationmodule, libname,
argc, argv, envp)
END DeconstructModules ;
(*
RegisterModule - adds module name to the list of outstanding
modules which need to have their dependencies
explored to determine initialization order.
*)
PROCEDURE RegisterModule (name, libname: ADDRESS;
init, fini: ArgCVEnvP;
dependencies: PROC) ;
BEGIN
M2Dependent.RegisterModule (name, libname, init, fini, dependencies)
END RegisterModule ;
(*
RequestDependant - used to specify that modulename is dependant upon
module dependantmodule.
*)
PROCEDURE RequestDependant (modulename, libname,
dependantmodule, dependantlibname: ADDRESS) ;
BEGIN
M2Dependent.RequestDependant (modulename, libname,
dependantmodule, dependantlibname)
END RequestDependant ;
(*
ExecuteReverse - execute the procedure associated with procptr
and then proceed to try and execute all previous
procedures in the chain.
*)
PROCEDURE ExecuteReverse (procptr: ProcedureChain) ;
BEGIN
WHILE procptr # NIL DO
procptr^.p ; (* Invoke the procedure. *)
procptr := procptr^.prev
END
END ExecuteReverse ;
(*
ExecuteTerminationProcedures - calls each installed termination procedure
in reverse order.
*)
PROCEDURE ExecuteTerminationProcedures ;
BEGIN
ExecuteReverse (TerminateProc.tail)
END ExecuteTerminationProcedures ;
(*
ExecuteInitialProcedures - executes the initial procedures installed by
InstallInitialProcedure.
*)
PROCEDURE ExecuteInitialProcedures ;
BEGIN
ExecuteReverse (InitialProc.tail)
END ExecuteInitialProcedures ;
(*
AppendProc - append proc to the end of the procedure list
defined by proclist.
*)
PROCEDURE AppendProc (VAR proclist: ProcedureList; proc: PROC) : BOOLEAN ;
VAR
pdes: ProcedureChain ;
BEGIN
NEW (pdes) ;
WITH pdes^ DO
p := proc ;
prev := proclist.tail ;
next := NIL
END ;
IF proclist.head = NIL
THEN
proclist.head := pdes
END ;
proclist.tail := pdes ;
RETURN TRUE
END AppendProc ;
(*
InstallTerminationProcedure - installs a procedure, p, which will
be called when the procedure
ExecuteTerminationProcedures
is invoked. It returns TRUE if the
procedure is installed.
*)
PROCEDURE InstallTerminationProcedure (p: PROC) : BOOLEAN ;
BEGIN
RETURN AppendProc (TerminateProc, p)
END InstallTerminationProcedure ;
(*
InstallInitialProcedure - installs a procedure to be executed just
before the BEGIN code section of the
main program module.
*)
PROCEDURE InstallInitialProcedure (p: PROC) : BOOLEAN ;
BEGIN
RETURN AppendProc (InitialProc, p)
END InstallInitialProcedure ;
(*
HALT - terminate the current program. The procedure
ExecuteTerminationProcedures
is called before the program is stopped. The parameter
exitcode is optional. If the parameter is not supplied
HALT will call libc 'abort', otherwise it will exit with
the code supplied. Supplying a parameter to HALT has the
same effect as calling ExitOnHalt with the same code and
then calling HALT with no parameter.
*)
PROCEDURE HALT ([exitcode: INTEGER = -1]) <* noreturn *> ;
BEGIN
IF exitcode#-1
THEN
CallExit := TRUE ;
ExitValue := exitcode
END ;
IF isHalting
THEN
(* double HALT found *)
exit(-1)
ELSE
isHalting := TRUE ;
ExecuteTerminationProcedures ;
END ;
IF CallExit
THEN
exit(ExitValue)
ELSE
abort
END
END HALT ;
(*
Terminate - provides compatibility for pim. It calls exit with
the exitcode provided in a prior call to ExitOnHalt
(or zero if ExitOnHalt was never called). It does
not call ExecuteTerminationProcedures.
*)
PROCEDURE Terminate <* noreturn *> ;
BEGIN
exit (ExitValue)
END Terminate ;
(*
ErrorString - writes a string to stderr.
*)
PROCEDURE ErrorString (a: ARRAY OF CHAR) ;
VAR
n: INTEGER ;
BEGIN
n := write (stderrFd, ADR (a), StrLen (a))
END ErrorString ;
(*
ErrorStringC - writes a string to stderr.
*)
PROCEDURE ErrorStringC (str: ADDRESS) ;
VAR
len: INTEGER ;
BEGIN
len := write (stderrFd, str, strlen (str))
END ErrorStringC ;
(*
ErrorMessage - emits an error message to stderr and then calls exit (1).
*)
PROCEDURE ErrorMessage (message: ARRAY OF CHAR;
filename: ARRAY OF CHAR;
line: CARDINAL;
function: ARRAY OF CHAR) <* noreturn *> ;
VAR
buffer: ARRAY [0..10] OF CHAR ;
BEGIN
ErrorString (filename) ; ErrorString(':') ;
CardToStr (line, 0, buffer) ;
ErrorString (buffer) ; ErrorString(':') ;
IF NOT StrEqual (function, '')
THEN
ErrorString ('in ') ;
ErrorString (function) ;
ErrorString (' has caused ') ;
END ;
ErrorString (message) ;
buffer[0] := nl ; buffer[1] := nul ;
ErrorString (buffer) ;
exit (1)
END ErrorMessage ;
(*
ErrorMessageC - emits an error message to stderr and then calls exit (1).
*)
PROCEDURE ErrorMessageC (message, filename: ADDRESS;
line: CARDINAL;
function: ADDRESS) <* noreturn *> ;
VAR
buffer: ARRAY [0..10] OF CHAR ;
BEGIN
ErrorStringC (filename) ; ErrorString (':') ;
CardToStr (line, 0, buffer) ;
ErrorString (buffer) ; ErrorString(':') ;
IF strlen (function) > 0
THEN
ErrorString ('in ') ;
ErrorStringC (function) ;
ErrorString (' has caused ') ;
END ;
ErrorStringC (message) ;
buffer[0] := nl ; buffer[1] := nul ;
ErrorString (buffer) ;
exit (1)
END ErrorMessageC ;
(*
HaltC - provides a more user friendly version of HALT, which takes
four parameters to aid debugging. It writes an error message
to stderr and calls exit (1).
*)
PROCEDURE HaltC (description, filename, function: ADDRESS; line: CARDINAL) ;
BEGIN
ErrorMessageC (description, filename, line, function)
END HaltC ;
(*
Halt - provides a more user friendly version of HALT, which takes
four parameters to aid debugging. It writes an error message
to stderr and calls exit (1).
*)
PROCEDURE Halt (description, filename, function: ARRAY OF CHAR; line: CARDINAL) ;
BEGIN
ErrorMessage (description, filename, line, function)
END Halt ;
(*
The following are the runtime exception handler routines.
*)
PROCEDURE AssignmentException (filename: ADDRESS; line, column: CARDINAL; scope, message: ADDRESS) ;
BEGIN
RTExceptions.Raise (ORD (M2EXCEPTION.rangeException),
filename, line, column, scope, message)
END AssignmentException ;
PROCEDURE ReturnException (filename: ADDRESS; line, column: CARDINAL; scope, message: ADDRESS) ;
BEGIN
RTExceptions.Raise (ORD (M2EXCEPTION.rangeException),
filename, line, column, scope, message)
END ReturnException ;
PROCEDURE IncException (filename: ADDRESS; line, column: CARDINAL; scope, message: ADDRESS) ;
BEGIN
RTExceptions.Raise (ORD (M2EXCEPTION.rangeException),
filename, line, column, scope, message)
END IncException ;
PROCEDURE DecException (filename: ADDRESS; line, column: CARDINAL; scope, message: ADDRESS) ;
BEGIN
RTExceptions.Raise (ORD (M2EXCEPTION.rangeException),
filename, line, column, scope, message)
END DecException ;
PROCEDURE InclException (filename: ADDRESS; line, column: CARDINAL; scope, message: ADDRESS) ;
BEGIN
RTExceptions.Raise (ORD (M2EXCEPTION.rangeException),
filename, line, column, scope, message)
END InclException ;
PROCEDURE ExclException (filename: ADDRESS; line, column: CARDINAL; scope, message: ADDRESS) ;
BEGIN
RTExceptions.Raise (ORD (M2EXCEPTION.rangeException),
filename, line, column, scope, message)
END ExclException ;
PROCEDURE ShiftException (filename: ADDRESS; line, column: CARDINAL; scope, message: ADDRESS) ;
BEGIN
RTExceptions.Raise (ORD (M2EXCEPTION.rangeException),
filename, line, column, scope, message)
END ShiftException ;
PROCEDURE RotateException (filename: ADDRESS; line, column: CARDINAL; scope, message: ADDRESS) ;
BEGIN
RTExceptions.Raise (ORD (M2EXCEPTION.rangeException),
filename, line, column, scope, message)
END RotateException ;
PROCEDURE StaticArraySubscriptException (filename: ADDRESS; line, column: CARDINAL; scope, message: ADDRESS) ;
BEGIN
RTExceptions.Raise (ORD (M2EXCEPTION.indexException),
filename, line, column, scope, message)
END StaticArraySubscriptException ;
PROCEDURE DynamicArraySubscriptException (filename: ADDRESS; line, column: CARDINAL; scope, message: ADDRESS) ;
BEGIN
RTExceptions.Raise (ORD (M2EXCEPTION.indexException),
filename, line, column, scope, message)
END DynamicArraySubscriptException ;
PROCEDURE ForLoopBeginException (filename: ADDRESS; line, column: CARDINAL; scope, message: ADDRESS) ;
BEGIN
RTExceptions.Raise (ORD (M2EXCEPTION.rangeException),
filename, line, column, scope, message)
END ForLoopBeginException ;
PROCEDURE ForLoopToException (filename: ADDRESS; line, column: CARDINAL; scope, message: ADDRESS) ;
BEGIN
RTExceptions.Raise (ORD (M2EXCEPTION.rangeException),
filename, line, column, scope, message)
END ForLoopToException ;
PROCEDURE ForLoopEndException (filename: ADDRESS; line, column: CARDINAL; scope, message: ADDRESS) ;
BEGIN
RTExceptions.Raise (ORD (M2EXCEPTION.rangeException),
filename, line, column, scope, message)
END ForLoopEndException ;
PROCEDURE PointerNilException (filename: ADDRESS; line, column: CARDINAL; scope, message: ADDRESS) ;
BEGIN
RTExceptions.Raise (ORD (M2EXCEPTION.invalidLocation),
filename, line, column, scope, message)
END PointerNilException ;
PROCEDURE NoReturnException (filename: ADDRESS; line, column: CARDINAL; scope, message: ADDRESS) ;
BEGIN
RTExceptions.Raise (ORD (M2EXCEPTION.functionException),
filename, line, column, scope, message)
END NoReturnException ;
PROCEDURE CaseException (filename: ADDRESS; line, column: CARDINAL; scope, message: ADDRESS) ;
BEGIN
RTExceptions.Raise (ORD (M2EXCEPTION.caseSelectException),
filename, line, column, scope, message)
END CaseException ;
PROCEDURE WholeNonPosDivException (filename: ADDRESS; line, column: CARDINAL; scope, message: ADDRESS) ;
BEGIN
RTExceptions.Raise (ORD (M2EXCEPTION.wholeDivException),
filename, line, column, scope, message)
END WholeNonPosDivException ;
PROCEDURE WholeNonPosModException (filename: ADDRESS; line, column: CARDINAL; scope, message: ADDRESS) ;
BEGIN
RTExceptions.Raise (ORD (M2EXCEPTION.wholeDivException),
filename, line, column, scope, message)
END WholeNonPosModException ;
PROCEDURE WholeZeroDivException (filename: ADDRESS; line, column: CARDINAL; scope, message: ADDRESS) ;
BEGIN
RTExceptions.Raise(ORD (M2EXCEPTION.wholeDivException),
filename, line, column, scope, message)
END WholeZeroDivException ;
PROCEDURE WholeZeroRemException (filename: ADDRESS; line, column: CARDINAL; scope, message: ADDRESS) ;
BEGIN
RTExceptions.Raise (ORD (M2EXCEPTION.wholeDivException),
filename, line, column, scope, message)
END WholeZeroRemException ;
PROCEDURE WholeValueException (filename: ADDRESS; line, column: CARDINAL; scope, message: ADDRESS) ;
BEGIN
RTExceptions.Raise (ORD (M2EXCEPTION.wholeValueException),
filename, line, column, scope, message)
END WholeValueException ;
PROCEDURE RealValueException (filename: ADDRESS; line, column: CARDINAL; scope, message: ADDRESS) ;
BEGIN
RTExceptions.Raise (ORD (M2EXCEPTION.realValueException),
filename, line, column, scope, message)
END RealValueException ;
PROCEDURE ParameterException (filename: ADDRESS; line, column: CARDINAL; scope, message: ADDRESS) ;
BEGIN
RTExceptions.Raise (ORD (M2EXCEPTION.rangeException),
filename, line, column, scope, message)
END ParameterException ;
PROCEDURE NoException (filename: ADDRESS; line, column: CARDINAL; scope, message: ADDRESS) ;
BEGIN
RTExceptions.Raise (ORD (M2EXCEPTION.exException),
filename, line, column, scope, message)
END NoException ;
(*
ExitOnHalt - if HALT is executed then call exit with the exit code, e.
*)
PROCEDURE ExitOnHalt (e: INTEGER) ;
BEGIN
ExitValue := e ;
CallExit := TRUE
END ExitOnHalt ;
(*
Length - returns the length of a string, a. This is called whenever
the user calls LENGTH and the parameter cannot be calculated
at compile time.
*)
PROCEDURE Length (a: ARRAY OF CHAR) : CARDINAL ;
VAR
l, h: CARDINAL ;
BEGIN
l := 0 ;
h := HIGH(a) ;
WHILE (l<=h) AND (a[l]#nul) DO
INC(l)
END ;
RETURN( l )
END Length ;
(*
InitProcList - initialize the head and tail pointers to NIL.
*)
PROCEDURE InitProcList (VAR p: ProcedureList) ;
BEGIN
p.head := NIL ;
p.tail := NIL
END InitProcList ;
(*
Init - initialize the initial, terminate procedure lists and booleans.
*)
PROCEDURE Init ;
BEGIN
InitProcList (InitialProc) ;
InitProcList (TerminateProc) ;
ExitValue := 0 ;
isHalting := FALSE ;
CallExit := FALSE (* default by calling abort *)
END Init ;
(*
CheckInitialized - checks to see if this module has been initialized
and if it has not it calls Init. We need this
approach as this module is called by module ctors
before we reach main.
*)
PROCEDURE CheckInitialized ;
BEGIN
IF NOT Initialized
THEN
Initialized := TRUE ;
Init
END
END CheckInitialized ;
BEGIN
CheckInitialized
END M2RTS.
|