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Diffstat (limited to 'gcc/ada/sigtramp-arm-qnx.c')
| -rw-r--r-- | gcc/ada/sigtramp-arm-qnx.c | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/gcc/ada/sigtramp-arm-qnx.c b/gcc/ada/sigtramp-arm-qnx.c new file mode 100644 index 0000000..4d359d7 --- /dev/null +++ b/gcc/ada/sigtramp-arm-qnx.c @@ -0,0 +1,155 @@ +/**************************************************************************** + * * + * GNAT COMPILER COMPONENTS * + * * + * S I G T R A M P * + * * + * Asm Implementation File * + * * + * Copyright (C) 2015-2022, Free Software Foundation, Inc. * + * * + * GNAT 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 3, or (at your option) any later ver- * + * sion. GNAT 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. * + * * + * As a special exception 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. * + * * + * In particular, you can freely distribute your programs built with the * + * GNAT Pro compiler, including any required library run-time units, using * + * any licensing terms of your choosing. See the AdaCore Software License * + * for full details. * + * * + * GNAT was originally developed by the GNAT team at New York University. * + * Extensive contributions were provided by Ada Core Technologies Inc. * + * * + ****************************************************************************/ + +/************************************************** + * ARM-QNX version of the __gnat_sigtramp service * + **************************************************/ + +#include <ucontext.h> + +#include "sigtramp.h" +/* See sigtramp.h for a general explanation of functionality. */ + +/* ---------------------- + -- General comments -- + ---------------------- + + Stubs are generated from toplevel asms, + The general idea is to establish CFA as the sigcontext + and state where to find the registers as offsets from there. + + Note that the registers we "restore" here are those to which we have + direct access through the system sigcontext structure, which includes + only a partial set of the non-volatiles ABI-wise. */ + +/* ----------------------------------------- + -- Protypes for our internal asm stubs -- + ----------------------------------------- + + The registers are expected to be at SIGCONTEXT + 12 (reference the + sicontext structure in asm/sigcontext.h which describes the first + 3 * 4byte fields.) Even though our symbols will remain local, the + prototype claims "extern" and not "static" to prevent compiler complaints + about a symbol used but never defined. */ + +/* sigtramp stub providing unwind info for common registers. */ + +extern void __gnat_sigtramp_common + (int signo, void *siginfo, void *sigcontext, + __sigtramphandler_t * handler); + +void __gnat_sigtramp (int signo, void *si, void *sc, + __sigtramphandler_t * handler) + __attribute__((optimize(2))); + +void __gnat_sigtramp (int signo, void *si, void *ucontext, + __sigtramphandler_t * handler) +{ + struct sigcontext *mcontext = &((ucontext_t *) ucontext)->uc_mcontext; + + __gnat_sigtramp_common (signo, si, mcontext, handler); +} + +/* asm string construction helpers. */ + +#define STR(TEXT) #TEXT +/* stringify expanded TEXT, surrounding it with double quotes. */ + +#define S(E) STR(E) +/* stringify E, which will resolve as text but may contain macros + still to be expanded. */ + +/* asm (TEXT) outputs <tab>TEXT. These facilitate the output of + multiline contents: */ +#define TAB(S) "\t" S +#define CR(S) S "\n" + +#undef TCR +#define TCR(S) TAB(CR(S)) + +/* Trampoline body block + --------------------- */ + +#define SIGTRAMP_BODY \ +CR("") \ +TCR("# Allocate frame and also save r2 which is the argument register") \ +TCR("# containing the sigcontext, so that we can restore it during") \ +TCR("# unwinding and thereby load the rest of the desired context.") \ +TCR("stmfd sp!, {r2, r3, lr}") \ +TCR("# The unwinder undo's these operations in reverse order so starting") \ +TCR("# from bottom, restore r2 from the current vsp location, move r2 into") \ +TCR("# the vsp, add 12 bytes to get the start of the register save area") \ +TCR("# then restore the 15 general purpose registers of the frame which") \ +TCR("# raised the signal.") \ +TCR(".save {r0-r15}") \ +TCR(".pad #12") \ +TCR(".movsp r2") \ +TCR(".save {r2}") \ +TCR("# Call the real handler. The signo, siginfo and sigcontext") \ +TCR("# arguments are the same as those we received in r0, r1 and r2.") \ +TCR("blx r3") \ +TCR("# Restore our callee-saved items, release our frame and return") \ +TCR("# (should never get here!).") \ +TCR("ldmfd sp, {r2, r3, pc}") + +/* Symbol definition block + ----------------------- */ + +#define SIGTRAMP_START(SYM) \ +CR("# " S(SYM) " unwind trampoline") \ +TCR(".type " S(SYM) ", %function") \ +CR("") \ +CR(S(SYM) ":") \ +TCR(".fnstart") + +/* Symbol termination block + ------------------------ */ + +#define SIGTRAMP_END(SYM) \ +CR(".fnend") \ +TCR(".size " S(SYM) ", .-" S(SYM)) + +/*---------------------------- + -- And now, the real code -- + ---------------------------- */ + +/* Text section start. The compiler isn't aware of that switch. */ + +asm (".text\n" + TCR(".align 2")); + +/* sigtramp stub for common registers. */ + +#define TRAMP_COMMON __gnat_sigtramp_common + +asm (SIGTRAMP_START(TRAMP_COMMON)); +asm (SIGTRAMP_BODY); +asm (SIGTRAMP_END(TRAMP_COMMON)); |