/* Definitions for expressions designed to be executed on the agent
- Copyright 1998 Free Software Foundation, Inc.
+ Copyright (C) 1998-2020 Free Software Foundation, Inc.
This file is part of GDB.
This program 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 2 of the License, or
+ the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
-#ifndef AGENTEXPR_H
-#define AGENTEXPR_H
+#ifndef AX_H
+#define AX_H
/* It's sometimes useful to be able to debug programs that you can't
really stop for more than a fraction of a second. To this end, the
to the host GDB. */
\f
-/* Agent expression data structures. */
+/* Different kinds of flaws an agent expression might have, as
+ detected by ax_reqs. */
+enum agent_flaws
+ {
+ agent_flaw_none = 0, /* code is good */
-/* The type of an element of the agent expression stack.
- The bytecode operation indicates which element we should access;
- the value itself has no typing information. GDB generates all
- bytecode streams, so we don't have to worry about type errors. */
+ /* There is an invalid instruction in the stream. */
+ agent_flaw_bad_instruction,
-union agent_val
- {
- LONGEST l;
- DOUBLEST d;
+ /* There is an incomplete instruction at the end of the expression. */
+ agent_flaw_incomplete_instruction,
+
+ /* ax_reqs was unable to prove that every jump target is to a
+ valid offset. Valid offsets are within the bounds of the
+ expression, and to a valid instruction boundary. */
+ agent_flaw_bad_jump,
+
+ /* ax_reqs was unable to prove to its satisfaction that, for each
+ jump target location, the stack will have the same height whether
+ that location is reached via a jump or by straight execution. */
+ agent_flaw_height_mismatch,
+
+ /* ax_reqs was unable to prove that every instruction following
+ an unconditional jump was the target of some other jump. */
+ agent_flaw_hole
};
+/* Agent expression data structures. */
+
/* A buffer containing a agent expression. */
struct agent_expr
{
+ /* Construct an empty agent expression. */
+ explicit agent_expr (struct gdbarch *gdbarch, CORE_ADDR scope);
+
+ ~agent_expr ();
+
+ /* The bytes of the expression. */
unsigned char *buf;
- int len; /* number of characters used */
- int size; /* allocated size */
+
+ /* The number of bytecode in the expression. */
+ int len;
+
+ /* Allocated space available currently. */
+ int size;
+
+ /* The target architecture assumed to be in effect. */
+ struct gdbarch *gdbarch;
+
+ /* The address to which the expression applies. */
CORE_ADDR scope;
- };
+ /* If the following is not equal to agent_flaw_none, the rest of the
+ information in this structure is suspect. */
+ enum agent_flaws flaw;
+
+ /* Number of elements left on stack at end; may be negative if expr
+ only consumes elements. */
+ int final_height;
+
+ /* Maximum and minimum stack height, relative to initial height. */
+ int max_height, min_height;
+
+ /* Largest `ref' or `const' opcode used, in bits. Zero means the
+ expression has no such instructions. */
+ int max_data_size;
+ /* Bit vector of registers needed. Register R is needed iff
+ reg_mask[R / 8] & (1 << (R % 8))
+
+ is non-zero. Note! You may not assume that this bitmask is long
+ enough to hold bits for all the registers of the machine; the
+ agent expression code has no idea how many registers the machine
+ has. However, the bitmask is reg_mask_len bytes long, so the
+ valid register numbers run from 0 to reg_mask_len * 8 - 1.
+
+ Also note that this mask may contain registers that are needed
+ for the original collection expression to work, but that are
+ not referenced by any bytecode. This could, for example, occur
+ when collecting a local variable allocated to a register; the
+ compiler sets the mask bit and skips generating a bytecode whose
+ result is going to be discarded anyway.
+ */
+ int reg_mask_len;
+ unsigned char *reg_mask;
+
+ /* For the data tracing facility, we need to insert `trace' bytecodes
+ before each data fetch; this records all the memory that the
+ expression touches in the course of evaluation, so that memory will
+ be available when the user later tries to evaluate the expression
+ in GDB.
+
+ Setting the flag 'tracing' to non-zero enables the code that
+ emits the trace bytecodes at the appropriate points. */
+
+ unsigned int tracing : 1;
+
+ /* This indicates that pointers to chars should get an added
+ tracenz bytecode to record nonzero bytes, up to a length that
+ is the value of trace_string. */
+
+ int trace_string;
+ };
-/* The actual values of the various bytecode operations.
+/* An agent_expr owning pointer. */
+typedef std::unique_ptr<agent_expr> agent_expr_up;
- Other independent implementations of the agent bytecode engine will
- rely on the exact values of these enums, and may not be recompiled
- when we change this table. The numeric values should remain fixed
- whenever possible. Thus, we assign them values explicitly here (to
- allow gaps to form safely), and the disassembly table in
- agentexpr.h behaves like an opcode map. If you want to see them
- grouped logically, see doc/agentexpr.texi. */
+/* The actual values of the various bytecode operations. */
enum agent_op
{
- aop_float = 0x01,
- aop_add = 0x02,
- aop_sub = 0x03,
- aop_mul = 0x04,
- aop_div_signed = 0x05,
- aop_div_unsigned = 0x06,
- aop_rem_signed = 0x07,
- aop_rem_unsigned = 0x08,
- aop_lsh = 0x09,
- aop_rsh_signed = 0x0a,
- aop_rsh_unsigned = 0x0b,
- aop_trace = 0x0c,
- aop_trace_quick = 0x0d,
- aop_log_not = 0x0e,
- aop_bit_and = 0x0f,
- aop_bit_or = 0x10,
- aop_bit_xor = 0x11,
- aop_bit_not = 0x12,
- aop_equal = 0x13,
- aop_less_signed = 0x14,
- aop_less_unsigned = 0x15,
- aop_ext = 0x16,
- aop_ref8 = 0x17,
- aop_ref16 = 0x18,
- aop_ref32 = 0x19,
- aop_ref64 = 0x1a,
- aop_ref_float = 0x1b,
- aop_ref_double = 0x1c,
- aop_ref_long_double = 0x1d,
- aop_l_to_d = 0x1e,
- aop_d_to_l = 0x1f,
- aop_if_goto = 0x20,
- aop_goto = 0x21,
- aop_const8 = 0x22,
- aop_const16 = 0x23,
- aop_const32 = 0x24,
- aop_const64 = 0x25,
- aop_reg = 0x26,
- aop_end = 0x27,
- aop_dup = 0x28,
- aop_pop = 0x29,
- aop_zero_ext = 0x2a,
- aop_swap = 0x2b,
- aop_trace16 = 0x30,
+#define DEFOP(NAME, SIZE, DATA_SIZE, CONSUMED, PRODUCED, VALUE) \
+ aop_ ## NAME = VALUE,
+#include "gdbsupport/ax.def"
+#undef DEFOP
aop_last
};
\f
/* Functions for building expressions. */
-/* Allocate a new, empty agent expression. */
-extern struct agent_expr *new_agent_expr PARAMS ((CORE_ADDR));
-
-/* Free a agent expression. */
-extern void free_agent_expr PARAMS ((struct agent_expr *));
+/* Append a raw byte to EXPR. */
+extern void ax_raw_byte (struct agent_expr *expr, gdb_byte byte);
/* Append a simple operator OP to EXPR. */
-extern void ax_simple PARAMS ((struct agent_expr * EXPR, enum agent_op OP));
+extern void ax_simple (struct agent_expr *EXPR, enum agent_op OP);
+
+/* Append a pick operator to EXPR. DEPTH is the stack item to pick,
+ with 0 being top of stack. */
+extern void ax_pick (struct agent_expr *EXPR, int DEPTH);
/* Append the floating-point prefix, for the next bytecode. */
#define ax_float(EXPR) (ax_simple ((EXPR), aop_float))
/* Append a sign-extension instruction to EXPR, to extend an N-bit value. */
-extern void ax_ext PARAMS ((struct agent_expr * EXPR, int N));
+extern void ax_ext (struct agent_expr *EXPR, int N);
/* Append a zero-extension instruction to EXPR, to extend an N-bit value. */
-extern void ax_zero_ext PARAMS ((struct agent_expr * EXPR, int N));
+extern void ax_zero_ext (struct agent_expr *EXPR, int N);
/* Append a trace_quick instruction to EXPR, to record N bytes. */
-extern void ax_trace_quick PARAMS ((struct agent_expr * EXPR, int N));
+extern void ax_trace_quick (struct agent_expr *EXPR, int N);
/* Append a goto op to EXPR. OP is the actual op (must be aop_goto or
aop_if_goto). We assume we don't know the target offset yet,
for the target, and return the offset in EXPR of that space, so we
can backpatch it once we do know the target offset. Use ax_label
to do the backpatching. */
-extern int ax_goto PARAMS ((struct agent_expr * EXPR, enum agent_op OP));
+extern int ax_goto (struct agent_expr *EXPR, enum agent_op OP);
/* Suppose a given call to ax_goto returns some value PATCH. When you
know the offset TARGET that goto should jump to, call
ax_label (EXPR, PATCH, TARGET)
to patch TARGET into the ax_goto instruction. */
-extern void ax_label PARAMS ((struct agent_expr * EXPR, int patch, int target));
+extern void ax_label (struct agent_expr *EXPR, int patch, int target);
/* Assemble code to push a constant on the stack. */
-extern void ax_const_l PARAMS ((struct agent_expr * EXPR, LONGEST l));
-extern void ax_const_d PARAMS ((struct agent_expr * EXPR, LONGEST d));
+extern void ax_const_l (struct agent_expr *EXPR, LONGEST l);
+extern void ax_const_d (struct agent_expr *EXPR, LONGEST d);
/* Assemble code to push the value of register number REG on the
stack. */
-extern void ax_reg PARAMS ((struct agent_expr * EXPR, int REG));
+extern void ax_reg (struct agent_expr *EXPR, int REG);
+
+/* Add the given register to the register mask of the expression. */
+extern void ax_reg_mask (struct agent_expr *ax, int reg);
+
+/* Assemble code to operate on a trace state variable. */
+extern void ax_tsv (struct agent_expr *expr, enum agent_op op, int num);
+
+/* Append a string to the bytecode stream. */
+extern void ax_string (struct agent_expr *x, const char *str, int slen);
\f
/* Functions for printing out expressions, and otherwise debugging
things. */
/* Disassemble the expression EXPR, writing to F. */
-extern void ax_print PARAMS ((GDB_FILE * f, struct agent_expr * EXPR));
+extern void ax_print (struct ui_file *f, struct agent_expr * EXPR);
/* An entry in the opcode map. */
struct aop_map
/* The name of the opcode. Null means that this entry is not a
valid opcode --- a hole in the opcode space. */
- char *name;
+ const char *name;
/* All opcodes take no operands from the bytecode stream, or take
unsigned integers of various sizes. If this is a positive number
/* Map of the bytecodes, indexed by bytecode number. */
extern struct aop_map aop_map[];
-/* Different kinds of flaws an agent expression might have, as
- detected by agent_reqs. */
-enum agent_flaws
- {
- agent_flaw_none = 0, /* code is good */
-
- /* There is an invalid instruction in the stream. */
- agent_flaw_bad_instruction,
-
- /* There is an incomplete instruction at the end of the expression. */
- agent_flaw_incomplete_instruction,
-
- /* agent_reqs was unable to prove that every jump target is to a
- valid offset. Valid offsets are within the bounds of the
- expression, and to a valid instruction boundary. */
- agent_flaw_bad_jump,
-
- /* agent_reqs was unable to prove to its satisfaction that, for each
- jump target location, the stack will have the same height whether
- that location is reached via a jump or by straight execution. */
- agent_flaw_height_mismatch,
-
- /* agent_reqs was unable to prove that every instruction following
- an unconditional jump was the target of some other jump. */
- agent_flaw_hole
- };
-
-/* Structure describing the requirements of a bytecode expression. */
-struct agent_reqs
- {
-
- /* If the following is not equal to agent_flaw_none, the rest of the
- information in this structure is suspect. */
- enum agent_flaws flaw;
-
- /* Number of elements left on stack at end; may be negative if expr
- only consumes elements. */
- int final_height;
-
- /* Maximum and minimum stack height, relative to initial height. */
- int max_height, min_height;
-
- /* Largest `ref' or `const' opcode used, in bits. Zero means the
- expression has no such instructions. */
- int max_data_size;
-
- /* Bit vector of registers used. Register R is used iff
-
- reg_mask[R / 8] & (1 << (R % 8))
-
- is non-zero. Note! You may not assume that this bitmask is long
- enough to hold bits for all the registers of the machine; the
- agent expression code has no idea how many registers the machine
- has. However, the bitmask is reg_mask_len bytes long, so the
- valid register numbers run from 0 to reg_mask_len * 8 - 1.
-
- We're assuming eight-bit bytes. So sue me.
-
- The caller should free reg_list when done. */
- int reg_mask_len;
- unsigned char *reg_mask;
- };
-
+/* Given an agent expression AX, analyze and update its requirements. */
-/* Given an agent expression AX, fill in an agent_reqs structure REQS
- describing it. */
-extern void ax_reqs PARAMS ((struct agent_expr * ax,
- struct agent_reqs * reqs));
+extern void ax_reqs (struct agent_expr *ax);
-#endif /* AGENTEXPR_H */
+#endif /* AX_H */
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