gcc/ada/sigtramp-qnx.c - gcc - Git at Google

 /****************************************************************************
  *                                                                          *
  *                         GNAT COMPILER COMPONENTS                         *
  *                                                                          *
  *                             S I G T R A M P                              *
  *                                                                          *
  *                         Asm Implementation File                          *
  *                                                                          *
  *           Copyright (C) 2017-2021, 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.      *
  *                                                                          *
  ****************************************************************************/

 /**********************************************
  * QNX version of the __gnat_sigtramp service *
  **********************************************/

 #include <ucontext.h>

 #include "sigtramp.h"
 /* See sigtramp.h for a general explanation of functionality.  */

 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 COMMON_CFI(REG) \
   ".cfi_offset " S(REGNO_##REG) "," S(REG_OFFSET_##REG)

 #ifdef __x86_64__
 /*****************************************
  *               x86-64                  *
  *****************************************/

 // CFI register numbers
 #define REGNO_RAX 0
 #define REGNO_RDX 1
 #define REGNO_RCX 2
 #define REGNO_RBX 3
 #define REGNO_RSI 4
 #define REGNO_RDI 5
 #define REGNO_RBP 6
 #define REGNO_RSP 7
 #define REGNO_R8 8
 #define REGNO_R9 9
 #define REGNO_R10 10
 #define REGNO_R11 11
 #define REGNO_R12 12
 #define REGNO_R13 13
 #define REGNO_R14 14
 #define REGNO_R15 15 /* Used as CFA */
 #define REGNO_RPC 16 /* aka %rip */

 //  Registers offset from the regset structure
 #define REG_OFFSET_RDI 0x00
 #define REG_OFFSET_RSI 0x08
 #define REG_OFFSET_RDX 0x10
 #define REG_OFFSET_R10 0x18
 #define REG_OFFSET_R8  0x20
 #define REG_OFFSET_R9  0x28
 #define REG_OFFSET_RAX 0x30
 #define REG_OFFSET_RBX 0x38
 #define REG_OFFSET_RBP 0x40
 #define REG_OFFSET_RCX 0x48
 #define REG_OFFSET_R11 0x50
 #define REG_OFFSET_R12 0x58
 #define REG_OFFSET_R13 0x60
 #define REG_OFFSET_R14 0x68
 #define REG_OFFSET_R15 0x70
 #define REG_OFFSET_RPC 0x78 /* RIP */
 #define REG_OFFSET_RSP 0x90

 #define CFI_COMMON_REGS \
 CR("# CFI for common registers\n") \
 TCR(COMMON_CFI(RSP)) \
 TCR(COMMON_CFI(R15)) \
 TCR(COMMON_CFI(R14)) \
 TCR(COMMON_CFI(R13)) \
 TCR(COMMON_CFI(R12)) \
 TCR(COMMON_CFI(R11)) \
 TCR(COMMON_CFI(RCX)) \
 TCR(COMMON_CFI(RBP)) \
 TCR(COMMON_CFI(RBX)) \
 TCR(COMMON_CFI(RAX)) \
 TCR(COMMON_CFI(R9)) \
 TCR(COMMON_CFI(R8)) \
 TCR(COMMON_CFI(R10)) \
 TCR(COMMON_CFI(RSI)) \
 TCR(COMMON_CFI(RDI)) \
 TCR(COMMON_CFI(RDX)) \
 TCR(COMMON_CFI(RPC)) \
 TCR(".cfi_return_column " S(REGNO_RPC))

 #define SIGTRAMP_BODY     \
 TCR(".cfi_def_cfa 15, 0") \
 CFI_COMMON_REGS \
 CR("") \
 TCR("# Allocate frame and save the non-volatile") \
 TCR("# registers we're going to modify") \
 TCR("subq	$8, %rsp") \
 TCR("# Setup CFA_REG = context, which we'll retrieve as our CFA value") \
 TCR("movq	%rdx, %r15") \
 TCR("# Call the real handler. The signo, siginfo and sigcontext") \
 TCR("# arguments are the same as those we received") \
 TCR("call	*%rcx") \
 TCR("# This part should never be executed") \
 TCR("addq	$8, %rsp") \
 TCR("ret")
 #endif

 #ifdef __aarch64__
 /*****************************************
  *               Aarch64                 *
  *****************************************/

 /* CFA reg: any callee saved register will do */
 #define CFA_REG  19

 /* General purpose registers */
 #define REG_OFFSET_GR(n)     (n * 8)
 #define REGNO_GR(n)   n

 /* ELR value offset withing the mcontext registers list */
 #define REG_OFFSET_ELR           (32 * 8)
 /* The register used to hold the PC value to restore. We need a scratch
    register.  */
 #define REGNO_PC      9

 #define CFI_DEF_CFA \
   TCR(".cfi_def_cfa " S(CFA_REG) ", 0")

 /* This restores the callee-saved registers, the FP, the LR, and the SP.
    A scratch register is used as return column to indicate the new value
    for PC */
 #define CFI_COMMON_REGS \
   CR("# CFI for common registers\n") \
   TCR(COMMON_CFI(GR(18))) \
   TCR(COMMON_CFI(GR(19))) \
   TCR(COMMON_CFI(GR(20))) \
   TCR(COMMON_CFI(GR(21))) \
   TCR(COMMON_CFI(GR(22))) \
   TCR(COMMON_CFI(GR(23))) \
   TCR(COMMON_CFI(GR(24))) \
   TCR(COMMON_CFI(GR(25))) \
   TCR(COMMON_CFI(GR(26))) \
   TCR(COMMON_CFI(GR(27))) \
   TCR(COMMON_CFI(GR(28))) \
   TCR(COMMON_CFI(GR(29))) \
   TCR(COMMON_CFI(GR(30))) \
   TCR(COMMON_CFI(GR(31))) \
   TCR(".cfi_offset " S(REGNO_PC) "," S(REG_OFFSET_ELR)) \
   TCR(".cfi_return_column " S(REGNO_PC))

 #define SIGTRAMP_BODY \
   CFI_DEF_CFA \
   CFI_COMMON_REGS \
   TCR("# Allocate the frame (16bytes aligned) and push FP and LR") \
   TCR("stp x29, x30, [sp, #-32]!") \
   TCR("add x29, sp, 0") \
   TCR("# Push register used to hold the CFA on stack") \
   TCR("str x" S(CFA_REG) ", [sp, 16]")  \
   TCR("# Set the CFA: x2 value") \
   TCR("mov x" S(CFA_REG) ", x2") \
   TCR("# Call the handler") \
   TCR("blr x3") \
   TCR("# Release our frame and return (should never get here!).") \
   TCR("ldr x" S(CFA_REG) ", [sp, 16]") \
   TCR("ldp x29, x30, [sp], 32") \
   TCR("ret")

 #endif /* AARCH64 */

 /* Symbol definition block
    -----------------------  */

 #if defined (__x86_64__) || defined (__aarch64__)
 #define FUNC_ALIGN TCR(".p2align 4,,15")
 #else
 #define FUNC_ALIGN
 #endif

 #define SIGTRAMP_START(SYM)       \
 CR("# " S(SYM) " cfi trampoline") \
 TCR(".type " S(SYM) ", @function") \
 CR("") \
 FUNC_ALIGN \
 CR(S(SYM) ":") \
 TCR(".cfi_startproc") \
 TCR(".cfi_signal_frame")

 /* Symbol termination block
    ------------------------  */

 #define SIGTRAMP_END(SYM) \
 CR(".cfi_endproc") \
 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));
	/****************************************************************************
	* *
	* GNAT COMPILER COMPONENTS *
	* *
	* S I G T R A M P *
	* *
	* Asm Implementation File *
	* *
	* Copyright (C) 2017-2021, 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. *
	* *
	****************************************************************************/

	/**********************************************
	* QNX version of the __gnat_sigtramp service *
	**********************************************/

	#include <ucontext.h>

	#include "sigtramp.h"
	/* See sigtramp.h for a general explanation of functionality. */

	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 COMMON_CFI(REG) \
	".cfi_offset " S(REGNO_##REG) "," S(REG_OFFSET_##REG)

	#ifdef __x86_64__
	/*****************************************
	* x86-64 *
	*****************************************/

	// CFI register numbers
	#define REGNO_RAX 0
	#define REGNO_RDX 1
	#define REGNO_RCX 2
	#define REGNO_RBX 3
	#define REGNO_RSI 4
	#define REGNO_RDI 5
	#define REGNO_RBP 6
	#define REGNO_RSP 7
	#define REGNO_R8 8
	#define REGNO_R9 9
	#define REGNO_R10 10
	#define REGNO_R11 11
	#define REGNO_R12 12
	#define REGNO_R13 13
	#define REGNO_R14 14
	#define REGNO_R15 15 /* Used as CFA */
	#define REGNO_RPC 16 /* aka %rip */

	// Registers offset from the regset structure
	#define REG_OFFSET_RDI 0x00
	#define REG_OFFSET_RSI 0x08
	#define REG_OFFSET_RDX 0x10
	#define REG_OFFSET_R10 0x18
	#define REG_OFFSET_R8 0x20
	#define REG_OFFSET_R9 0x28
	#define REG_OFFSET_RAX 0x30
	#define REG_OFFSET_RBX 0x38
	#define REG_OFFSET_RBP 0x40
	#define REG_OFFSET_RCX 0x48
	#define REG_OFFSET_R11 0x50
	#define REG_OFFSET_R12 0x58
	#define REG_OFFSET_R13 0x60
	#define REG_OFFSET_R14 0x68
	#define REG_OFFSET_R15 0x70
	#define REG_OFFSET_RPC 0x78 /* RIP */
	#define REG_OFFSET_RSP 0x90

	#define CFI_COMMON_REGS \
	CR("# CFI for common registers\n") \
	TCR(COMMON_CFI(RSP)) \
	TCR(COMMON_CFI(R15)) \
	TCR(COMMON_CFI(R14)) \
	TCR(COMMON_CFI(R13)) \
	TCR(COMMON_CFI(R12)) \
	TCR(COMMON_CFI(R11)) \
	TCR(COMMON_CFI(RCX)) \
	TCR(COMMON_CFI(RBP)) \
	TCR(COMMON_CFI(RBX)) \
	TCR(COMMON_CFI(RAX)) \
	TCR(COMMON_CFI(R9)) \
	TCR(COMMON_CFI(R8)) \
	TCR(COMMON_CFI(R10)) \
	TCR(COMMON_CFI(RSI)) \
	TCR(COMMON_CFI(RDI)) \
	TCR(COMMON_CFI(RDX)) \
	TCR(COMMON_CFI(RPC)) \
	TCR(".cfi_return_column " S(REGNO_RPC))

	#define SIGTRAMP_BODY \
	TCR(".cfi_def_cfa 15, 0") \
	CFI_COMMON_REGS \
	CR("") \
	TCR("# Allocate frame and save the non-volatile") \
	TCR("# registers we're going to modify") \
	TCR("subq $8, %rsp") \
	TCR("# Setup CFA_REG = context, which we'll retrieve as our CFA value") \
	TCR("movq %rdx, %r15") \
	TCR("# Call the real handler. The signo, siginfo and sigcontext") \
	TCR("# arguments are the same as those we received") \
	TCR("call *%rcx") \
	TCR("# This part should never be executed") \
	TCR("addq $8, %rsp") \
	TCR("ret")
	#endif

	#ifdef __aarch64__
	/*****************************************
	* Aarch64 *
	*****************************************/

	/* CFA reg: any callee saved register will do */
	#define CFA_REG 19

	/* General purpose registers */
	#define REG_OFFSET_GR(n) (n * 8)
	#define REGNO_GR(n) n

	/* ELR value offset withing the mcontext registers list */
	#define REG_OFFSET_ELR (32 * 8)
	/* The register used to hold the PC value to restore. We need a scratch
	register. */
	#define REGNO_PC 9

	#define CFI_DEF_CFA \
	TCR(".cfi_def_cfa " S(CFA_REG) ", 0")

	/* This restores the callee-saved registers, the FP, the LR, and the SP.
	A scratch register is used as return column to indicate the new value
	for PC */
	#define CFI_COMMON_REGS \
	CR("# CFI for common registers\n") \
	TCR(COMMON_CFI(GR(18))) \
	TCR(COMMON_CFI(GR(19))) \
	TCR(COMMON_CFI(GR(20))) \
	TCR(COMMON_CFI(GR(21))) \
	TCR(COMMON_CFI(GR(22))) \
	TCR(COMMON_CFI(GR(23))) \
	TCR(COMMON_CFI(GR(24))) \
	TCR(COMMON_CFI(GR(25))) \
	TCR(COMMON_CFI(GR(26))) \
	TCR(COMMON_CFI(GR(27))) \
	TCR(COMMON_CFI(GR(28))) \
	TCR(COMMON_CFI(GR(29))) \
	TCR(COMMON_CFI(GR(30))) \
	TCR(COMMON_CFI(GR(31))) \
	TCR(".cfi_offset " S(REGNO_PC) "," S(REG_OFFSET_ELR)) \
	TCR(".cfi_return_column " S(REGNO_PC))

	#define SIGTRAMP_BODY \
	CFI_DEF_CFA \
	CFI_COMMON_REGS \
	TCR("# Allocate the frame (16bytes aligned) and push FP and LR") \
	TCR("stp x29, x30, [sp, #-32]!") \
	TCR("add x29, sp, 0") \
	TCR("# Push register used to hold the CFA on stack") \
	TCR("str x" S(CFA_REG) ", [sp, 16]") \
	TCR("# Set the CFA: x2 value") \
	TCR("mov x" S(CFA_REG) ", x2") \
	TCR("# Call the handler") \
	TCR("blr x3") \
	TCR("# Release our frame and return (should never get here!).") \
	TCR("ldr x" S(CFA_REG) ", [sp, 16]") \
	TCR("ldp x29, x30, [sp], 32") \
	TCR("ret")

	#endif /* AARCH64 */

	/* Symbol definition block
	----------------------- */

	#if defined (__x86_64__) \|\| defined (__aarch64__)
	#define FUNC_ALIGN TCR(".p2align 4,,15")
	#else
	#define FUNC_ALIGN
	#endif

	#define SIGTRAMP_START(SYM) \
	CR("# " S(SYM) " cfi trampoline") \
	TCR(".type " S(SYM) ", @function") \
	CR("") \
	FUNC_ALIGN \
	CR(S(SYM) ":") \
	TCR(".cfi_startproc") \
	TCR(".cfi_signal_frame")

	/* Symbol termination block
	------------------------ */

	#define SIGTRAMP_END(SYM) \
	CR(".cfi_endproc") \
	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));