gdb/ravenscar-thread.h

   1 /* Ada Ravenscar thread support.
   2
   3    Copyright (C) 2004-2022 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef RAVENSCAR_THREAD_H
  21 #define RAVENSCAR_THREAD_H
  22
  23 /* Architecture-specific hooks.  */
  24
  25 struct ravenscar_arch_ops
  26 {
  27   ravenscar_arch_ops (gdb::array_view<const int> offsets_,
  28                       int first_stack = -1,
  29                       int last_stack = -1,
  30                       int v_init = -1,
  31                       int fpu_offset = -1,
  32                       int first_fp = -1,
  33                       int last_fp = -1)
  34     : offsets (offsets_),
  35       first_stack_register (first_stack),
  36       last_stack_register (last_stack),
  37       v_init_offset (v_init),
  38       fpu_context_offset (fpu_offset),
  39       first_fp_register (first_fp),
  40       last_fp_register (last_fp)
  41   {
  42     /* These must either both be -1 or both be valid.  */
  43     gdb_assert ((first_stack_register == -1) == (last_stack_register == -1));
  44     /* They must also be ordered.  */
  45     gdb_assert (last_stack_register >= first_stack_register);
  46     /* These must either all be -1 or all be valid.  */
  47     gdb_assert ((v_init_offset == -1) == (fpu_context_offset == -1)
  48                 && (fpu_context_offset == -1) == (first_fp_register == -1)
  49                 && (first_fp_register == -1) == (last_fp_register == -1));
  50   }
  51
  52   /* Return true if this architecture implements on-demand floating
  53      point.  */
  54   bool on_demand_fp () const
  55   { return v_init_offset != -1; }
  56
  57   /* Return true if REGNUM is a floating-point register for this
  58      target.  If this target does not use the on-demand FP scheme,
  59      this will always return false.  */
  60   bool is_fp_register (int regnum) const
  61   {
  62     return regnum >= first_fp_register && regnum <= last_fp_register;
  63   }
  64
  65   /* Return the offset, in the current task context, of the byte
  66      indicating whether the FPU has been initialized for the task.
  67      This can only be called when the architecture implements
  68      on-demand floating-point.  */
  69   int get_v_init_offset () const
  70   {
  71     gdb_assert (on_demand_fp ());
  72     return v_init_offset;
  73   }
  74
  75   /* Return the offset, in the current task context, of the FPU
  76      context.  This can only be called when the architecture
  77      implements on-demand floating-point.  */
  78   int get_fpu_context_offset () const
  79   {
  80     gdb_assert (on_demand_fp ());
  81     return fpu_context_offset;
  82   }
  83
  84   void fetch_register (struct regcache *recache, int regnum) const;
  85   void store_register (struct regcache *recache, int regnum) const;
  86
  87 private:
  88
  89   /* An array where the indices are register numbers and the contents
  90      are offsets.  The offsets are either in the thread descriptor or
  91      the stack, depending on the other fields.  An offset of -1 means
  92      that the corresponding register is not stored.  */
  93   const gdb::array_view<const int> offsets;
  94
  95   /* If these are -1, then all registers for this architecture are
  96      stored in the thread descriptor.  Otherwise, these mark a range
  97      of registers that are stored on the stack.  */
  98   const int first_stack_register;
  99   const int last_stack_register;
 100
 101   /* If these are -1, there is no special treatment for floating-point
 102      registers -- they are handled, or not, just like all other
 103      registers.
 104
 105      Otherwise, they must all not be -1, and the target is one that
 106      uses on-demand FP initialization.  V_INIT_OFFSET is the offset of
 107      a boolean field in the context that indicates whether the FP
 108      registers have been initialized for this task.
 109      FPU_CONTEXT_OFFSET is the offset of the FPU context from the task
 110      context.  (This is needed to check whether the FPU registers have
 111      been saved.)  FIRST_FP_REGISTER and LAST_FP_REGISTER are the
 112      register numbers of the first and last (inclusive) floating point
 113      registers.  */
 114   const int v_init_offset;
 115   const int fpu_context_offset;
 116   const int first_fp_register;
 117   const int last_fp_register;
 118
 119   /* Helper function to supply one register.  */
 120   void supply_one_register (struct regcache *regcache, int regnum,
 121                             CORE_ADDR descriptor,
 122                             CORE_ADDR stack_base) const;
 123   /* Helper function to store one register.  */
 124   void store_one_register (struct regcache *regcache, int regnum,
 125                            CORE_ADDR descriptor,
 126                            CORE_ADDR stack_base) const;
 127   /* Helper function to find stack address where registers are stored.
 128      This must be called with the stack pointer already supplied in
 129      the register cache.  */
 130   CORE_ADDR get_stack_base (struct regcache *) const;
 131 };
 132
 133 #endif /* !defined (RAVENSCAR_THREAD_H) */