diff options
Diffstat (limited to 'gdb/ax.h')
| -rw-r--r-- | gdb/ax.h | 148 |
1 files changed, 78 insertions, 70 deletions
@@ -51,6 +51,33 @@ to the host GDB. */ +/* Different kinds of flaws an agent expression might have, as + detected by ax_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, + + /* 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. */ /* The type of an element of the agent expression stack. @@ -67,14 +94,56 @@ union agent_val /* A buffer containing a agent expression. */ struct 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; + }; /* The actual values of the various bytecode operations. @@ -143,7 +212,7 @@ enum agent_op /* Functions for building expressions. */ /* Allocate a new, empty agent expression. */ -extern struct agent_expr *new_agent_expr (CORE_ADDR); +extern struct agent_expr *new_agent_expr (struct gdbarch *, CORE_ADDR); /* Free a agent expression. */ extern void free_agent_expr (struct agent_expr *); @@ -186,6 +255,9 @@ extern void ax_const_d (struct agent_expr *EXPR, LONGEST d); stack. */ 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); @@ -226,72 +298,8 @@ struct aop_map /* 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 (struct agent_expr *ax, struct agent_reqs *reqs); +extern void ax_reqs (struct agent_expr *ax); #endif /* AGENTEXPR_H */ |