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Diffstat (limited to 'gcc/ada/s-intman-posix.adb')
| -rw-r--r-- | gcc/ada/s-intman-posix.adb | 285 |
1 files changed, 285 insertions, 0 deletions
diff --git a/gcc/ada/s-intman-posix.adb b/gcc/ada/s-intman-posix.adb new file mode 100644 index 00000000000..801adac39f2 --- /dev/null +++ b/gcc/ada/s-intman-posix.adb @@ -0,0 +1,285 @@ +------------------------------------------------------------------------------ +-- -- +-- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS -- +-- -- +-- S Y S T E M . I N T E R R U P T _ M A N A G E M E N T -- +-- -- +-- B o d y -- +-- -- +-- Copyright (C) 1992-2003, Free Software Foundation, Inc. -- +-- -- +-- GNARL is free software; you can redistribute it and/or modify it under -- +-- terms of the GNU General Public License as published by the Free Soft- -- +-- ware Foundation; either version 2, or (at your option) any later ver- -- +-- sion. GNARL is distributed in the hope that it will be useful, but WITH- -- +-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- +-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- +-- for more details. You should have received a copy of the GNU General -- +-- Public License distributed with GNARL; see file COPYING. If not, write -- +-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- +-- MA 02111-1307, USA. -- +-- -- +-- As a special exception, if other files instantiate generics from this -- +-- unit, or you link this unit with other files to produce an executable, -- +-- this unit does not by itself cause the resulting executable to be -- +-- covered by the GNU General Public License. This exception does not -- +-- however invalidate any other reasons why the executable file might be -- +-- covered by the GNU Public License. -- +-- -- +-- GNARL was developed by the GNARL team at Florida State University. -- +-- Extensive contributions were provided by Ada Core Technologies, Inc. -- +-- -- +------------------------------------------------------------------------------ + +-- This is the POSIX threads version of this package + +-- PLEASE DO NOT add any dependences on other packages. ??? why not ??? +-- This package is designed to work with or without tasking support. + +-- See the other warnings in the package specification before making +-- any modifications to this file. + +-- Make a careful study of all signals available under the OS, to see which +-- need to be reserved, kept always unmasked, or kept always unmasked. Be on +-- the lookout for special signals that may be used by the thread library. + +-- Since this is a multi target file, the signal <-> exception mapping +-- is simple minded. If you need a more precise and target specific +-- signal handling, create a new s-intman.adb that will fit your needs. + +-- This file assumes that: + +-- SIGFPE, SIGILL, SIGSEGV and SIGBUS exist. They are mapped as follows: +-- SIGPFE => Constraint_Error +-- SIGILL => Program_Error +-- SIGSEGV => Storage_Error +-- SIGBUS => Storage_Error + +-- SIGINT exists and will be kept unmasked unless the pragma +-- Unreserve_All_Interrupts is specified anywhere in the application. + +-- System.OS_Interface contains the following: +-- SIGADAABORT: the signal that will be used to abort tasks. +-- Unmasked: the OS specific set of signals that should be unmasked in +-- all the threads. SIGADAABORT is unmasked by +-- default +-- Reserved: the OS specific set of signals that are reserved. + +with Interfaces.C; +-- used for int and other types + +with System.OS_Interface; +-- used for various Constants, Signal and types + +package body System.Interrupt_Management is + + use Interfaces.C; + use System.OS_Interface; + + type Interrupt_List is array (Interrupt_ID range <>) of Interrupt_ID; + Exception_Interrupts : constant Interrupt_List := + (SIGFPE, SIGILL, SIGSEGV, SIGBUS); + + Unreserve_All_Interrupts : Interfaces.C.int; + pragma Import + (C, Unreserve_All_Interrupts, "__gl_unreserve_all_interrupts"); + + ----------------------- + -- Local Subprograms -- + ----------------------- + + procedure Notify_Exception (signo : Signal); + -- This function identifies the Ada exception to be raised using + -- the information when the system received a synchronous signal. + -- Since this function is machine and OS dependent, different code + -- has to be provided for different target. + + ---------------------- + -- Notify_Exception -- + ---------------------- + + Signal_Mask : aliased sigset_t; + -- The set of signals handled by Notify_Exception + + procedure Notify_Exception (signo : Signal) is + Result : Interfaces.C.int; + + begin + -- With the __builtin_longjmp, the signal mask is not restored, so we + -- need to restore it explicitely. + + Result := pthread_sigmask (SIG_UNBLOCK, Signal_Mask'Access, null); + pragma Assert (Result = 0); + + -- Check that treatment of exception propagation here + -- is consistent with treatment of the abort signal in + -- System.Task_Primitives.Operations. + + case signo is + when SIGFPE => + raise Constraint_Error; + when SIGILL => + raise Program_Error; + when SIGSEGV => + raise Storage_Error; + when SIGBUS => + raise Storage_Error; + when others => + null; + end case; + end Notify_Exception; + + --------------------------- + -- Initialize_Interrupts -- + --------------------------- + + -- Nothing needs to be done on this platform. + + procedure Initialize_Interrupts is + begin + null; + end Initialize_Interrupts; + +------------------------- +-- Package Elaboration -- +------------------------- + +begin + declare + act : aliased struct_sigaction; + old_act : aliased struct_sigaction; + Result : System.OS_Interface.int; + + function State (Int : Interrupt_ID) return Character; + pragma Import (C, State, "__gnat_get_interrupt_state"); + -- Get interrupt state. Defined in a-init.c + -- The input argument is the interrupt number, + -- and the result is one of the following: + + User : constant Character := 'u'; + Runtime : constant Character := 'r'; + Default : constant Character := 's'; + -- 'n' this interrupt not set by any Interrupt_State pragma + -- 'u' Interrupt_State pragma set state to User + -- 'r' Interrupt_State pragma set state to Runtime + -- 's' Interrupt_State pragma set state to System (use "default" + -- system handler) + + begin + -- Need to call pthread_init very early because it is doing signal + -- initializations. + + pthread_init; + + Abort_Task_Interrupt := SIGADAABORT; + + act.sa_handler := Notify_Exception'Address; + + act.sa_flags := SA_SIGINFO; + + -- Setting SA_SIGINFO asks the kernel to pass more than just the signal + -- number argument to the handler when it is called. The set of extra + -- parameters typically includes a pointer to a structure describing + -- the interrupted context. Although the Notify_Exception handler does + -- not use this information, it is actually required for the GCC/ZCX + -- exception propagation scheme because on some targets (at least + -- alpha-tru64), the structure contents are not even filled when this + -- flag is not set. + + -- On some targets, we set sa_flags to SA_NODEFER so that during the + -- handler execution we do not change the Signal_Mask to be masked for + -- the Signal. + + -- This is a temporary fix to the problem that the Signal_Mask is + -- not restored after the exception (longjmp) from the handler. + -- The right fix should be made in sigsetjmp so that we save + -- the Signal_Set and restore it after a longjmp. + + -- Since SA_NODEFER is obsolete, instead we reset explicitely + -- the mask in the exception handler. + + Result := sigemptyset (Signal_Mask'Access); + pragma Assert (Result = 0); + + -- Add signals that map to Ada exceptions to the mask. + for J in Exception_Interrupts'Range loop + if State (Exception_Interrupts (J)) /= Default then + Result := + sigaddset (Signal_Mask'Access, Signal (Exception_Interrupts (J))); + pragma Assert (Result = 0); + end if; + end loop; + + act.sa_mask := Signal_Mask; + + pragma Assert (Keep_Unmasked = (Interrupt_ID'Range => False)); + pragma Assert (Reserve = (Interrupt_ID'Range => False)); + + -- Process state of exception signals + for J in Exception_Interrupts'Range loop + if State (Exception_Interrupts (J)) /= User then + Keep_Unmasked (Exception_Interrupts (J)) := True; + Reserve (Exception_Interrupts (J)) := True; + + if State (Exception_Interrupts (J)) /= Default then + Result := + sigaction + (Signal (Exception_Interrupts (J)), act'Unchecked_Access, + old_act'Unchecked_Access); + pragma Assert (Result = 0); + end if; + end if; + end loop; + + if State (Abort_Task_Interrupt) /= User then + Keep_Unmasked (Abort_Task_Interrupt) := True; + Reserve (Abort_Task_Interrupt) := True; + end if; + + -- Set SIGINT to unmasked state as long as it is not in "User" + -- state. Check for Unreserve_All_Interrupts last + + if State (SIGINT) /= User then + Keep_Unmasked (SIGINT) := True; + Reserve (SIGINT) := True; + end if; + + -- Check all signals for state that requires keeping them + -- unmasked and reserved + + for J in Interrupt_ID'Range loop + if State (J) = Default or else State (J) = Runtime then + Keep_Unmasked (J) := True; + Reserve (J) := True; + end if; + end loop; + + -- Add the set of signals that must always be unmasked for this target + + for J in Unmasked'Range loop + Keep_Unmasked (Interrupt_ID (Unmasked (J))) := True; + Reserve (Interrupt_ID (Unmasked (J))) := True; + end loop; + + -- Add target-specific reserved signals + + for J in Reserved'Range loop + Reserve (Interrupt_ID (Reserved (J))) := True; + end loop; + + -- Process pragma Unreserve_All_Interrupts. This overrides any + -- settings due to pragma Interrupt_State: + + if Unreserve_All_Interrupts /= 0 then + Keep_Unmasked (SIGINT) := False; + Reserve (SIGINT) := False; + end if; + + -- We do not have Signal 0 in reality. We just use this value + -- to identify non-existent signals (see s-intnam.ads). Therefore, + -- Signal 0 should not be used in all signal related operations hence + -- mark it as reserved. + + Reserve (0) := True; + end; +end System.Interrupt_Management; |