From 0e9ae10f5f97824067365af4813b843973297573 Mon Sep 17 00:00:00 2001 From: Sergio Durigan Junior Date: Mon, 13 Nov 2017 01:05:57 -0500 Subject: [PATCH] Convert SystemTap probe interface to C++ (and perform some cleanups) This patch converts the SystemTap probe interface (gdb/stap-probe.[ch]) to C++, and also performs some cleanups that were on my TODO list for a while. The main changes were the conversion of 'struct stap_probe' to 'class stap_probe', and a new 'class stap_static_probe_ops' to replace the use of 'stap_probe_ops'. Both classes implement the virtual methods exported by their parents, 'class probe' and 'class static_probe_ops', respectively. I believe it's now a bit simpler to understand the logic behind the stap-probe interface. There are several helper functions used to parse parts of a stap probe, and since they are generic and don't need to know about the probe they're working on, I decided to leave them as simple static functions (instead of e.g. converting them to class methods). I've also converted a few uses of "VEC" to "std::vector", which makes the code simpler and easier to maintain. And, as usual, some cleanups here and there. Even though I'm sending a series of patches, they need to be tested and committed as a single unit, because of inter-dependencies. But it should be easier to review in separate logical units. I've regtested this patch on BuildBot, no regressions found. gdb/ChangeLog: 2017-11-22 Sergio Durigan Junior Simon Marchi * stap-probe.c (struct probe_ops stap_probe_ops): Delete variable. (struct stap_probe_arg) : New constructor. : Change type to 'expression_up'. (stap_probe_arg_s): Delete type and VEC. (struct stap_probe): Delete. Replace by... (class stap_static_probe_ops): ...this and... (class stap_probe): ...this. Rename variables to add 'm_' prefix. Do not use 'union' for arguments anymore. (stap_get_expected_argument_type): Receive probe name instead of 'struct stap_probe'. Adjust code. (stap_parse_probe_arguments): Rename to... (stap_probe::parse_arguments): ...this. Adjust code to reflect change. (stap_get_probe_address): Rename to... (stap_probe::get_relocated_address): ...this. Adjust code to reflect change. (stap_get_probe_argument_count): Rename to... (stap_probe::get_argument_count): ...this. Adjust code to reflect change. (stap_get_arg): Rename to... (stap_probe::get_arg_by_number'): ...this. Adjust code to reflect change. (can_evaluate_probe_arguments): Rename to... (stap_probe::can_evaluate_arguments): ...this. Adjust code to reflect change. (stap_evaluate_probe_argument): Rename to... (stap_probe::evaluate_argument): ...this. Adjust code to reflect change. (stap_compile_to_ax): Rename to... (stap_probe::compile_to_ax): ...this. Adjust code to reflect change. (stap_probe_destroy): Delete. (stap_modify_semaphore): Adjust comment. (stap_set_semaphore): Rename to... (stap_probe::set_semaphore): ...this. Adjust code to reflect change. (stap_clear_semaphore): Rename to... (stap_probe::clear_semaphore): ...this. Adjust code to reflect change. (stap_probe::get_static_ops): New method. (handle_stap_probe): Adjust code to create instance of 'stap_probe'. (stap_get_probes): Rename to... (stap_static_probe_ops::get_probes): ...this. Adjust code to reflect change. (stap_probe_is_linespec): Rename to... (stap_static_probe_ops::is_linespec): ...this. Adjust code to reflect change. (stap_type_name): Rename to... (stap_static_probe_ops::type_name): ...this. Adjust code to reflect change. (stap_gen_info_probes_table_header): Rename to... (stap_static_probe_ops::gen_info_probes_table_header): ...this. Adjust code to reflect change. (stap_gen_info_probes_table_values): Rename to... (stap_probe::gen_info_probes_table_values): ...this. Adjust code to reflect change. (struct probe_ops stap_probe_ops): Delete. (info_probes_stap_command): Use 'info_probes_for_spops' instead of 'info_probes_for_ops'. (_initialize_stap_probe): Use 'all_static_probe_ops' instead of 'all_probe_ops'. --- gdb/ChangeLog | 67 ++++++ gdb/stap-probe.c | 534 +++++++++++++++++++++++------------------------ 2 files changed, 328 insertions(+), 273 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 2121e3ec66..b385f5456f 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,70 @@ +2017-11-22 Sergio Durigan Junior + Simon Marchi + + * stap-probe.c (struct probe_ops stap_probe_ops): Delete + variable. + (struct stap_probe_arg) : New constructor. + : Change type to 'expression_up'. + (stap_probe_arg_s): Delete type and VEC. + (struct stap_probe): Delete. Replace by... + (class stap_static_probe_ops): ...this and... + (class stap_probe): ...this. Rename variables to add 'm_' + prefix. Do not use 'union' for arguments anymore. + (stap_get_expected_argument_type): Receive probe name instead + of 'struct stap_probe'. Adjust code. + (stap_parse_probe_arguments): Rename to... + (stap_probe::parse_arguments): ...this. Adjust code to + reflect change. + (stap_get_probe_address): Rename to... + (stap_probe::get_relocated_address): ...this. Adjust code + to reflect change. + (stap_get_probe_argument_count): Rename to... + (stap_probe::get_argument_count): ...this. Adjust code + to reflect change. + (stap_get_arg): Rename to... + (stap_probe::get_arg_by_number'): ...this. Adjust code to + reflect change. + (can_evaluate_probe_arguments): Rename to... + (stap_probe::can_evaluate_arguments): ...this. Adjust code + to reflect change. + (stap_evaluate_probe_argument): Rename to... + (stap_probe::evaluate_argument): ...this. Adjust code + to reflect change. + (stap_compile_to_ax): Rename to... + (stap_probe::compile_to_ax): ...this. Adjust code to + reflect change. + (stap_probe_destroy): Delete. + (stap_modify_semaphore): Adjust comment. + (stap_set_semaphore): Rename to... + (stap_probe::set_semaphore): ...this. Adjust code to reflect + change. + (stap_clear_semaphore): Rename to... + (stap_probe::clear_semaphore): ...this. Adjust code to + reflect change. + (stap_probe::get_static_ops): New method. + (handle_stap_probe): Adjust code to create instance of + 'stap_probe'. + (stap_get_probes): Rename to... + (stap_static_probe_ops::get_probes): ...this. Adjust code to + reflect change. + (stap_probe_is_linespec): Rename to... + (stap_static_probe_ops::is_linespec): ...this. Adjust code to + reflect change. + (stap_type_name): Rename to... + (stap_static_probe_ops::type_name): ...this. Adjust code to + reflect change. + (stap_gen_info_probes_table_header): Rename to... + (stap_static_probe_ops::gen_info_probes_table_header): + ...this. Adjust code to reflect change. + (stap_gen_info_probes_table_values): Rename to... + (stap_probe::gen_info_probes_table_values): ...this. Adjust + code to reflect change. + (struct probe_ops stap_probe_ops): Delete. + (info_probes_stap_command): Use 'info_probes_for_spops' + instead of 'info_probes_for_ops'. + (_initialize_stap_probe): Use 'all_static_probe_ops' instead + of 'all_probe_ops'. + 2017-11-22 Sergio Durigan Junior * break-catch-throw.c (fetch_probe_arguments): Use diff --git a/gdb/stap-probe.c b/gdb/stap-probe.c index 6fa0d20280..63100c9fb3 100644 --- a/gdb/stap-probe.c +++ b/gdb/stap-probe.c @@ -45,10 +45,6 @@ #define STAP_BASE_SECTION_NAME ".stapsdt.base" -/* Forward declaration. */ - -extern const struct probe_ops stap_probe_ops; - /* Should we display debug information for the probe's argument expression parsing? */ @@ -85,6 +81,12 @@ enum stap_arg_bitness struct stap_probe_arg { + /* Constructor for stap_probe_arg. */ + stap_probe_arg (enum stap_arg_bitness bitness_, struct type *atype_, + expression_up &&aexpr_) + : bitness (bitness_), atype (atype_), aexpr (std::move (aexpr_)) + {} + /* The bitness of this argument. */ enum stap_arg_bitness bitness; @@ -92,35 +94,134 @@ struct stap_probe_arg struct type *atype; /* The argument converted to an internal GDB expression. */ - struct expression *aexpr; + expression_up aexpr; }; -typedef struct stap_probe_arg stap_probe_arg_s; -DEF_VEC_O (stap_probe_arg_s); +/* Class that implements the static probe methods for "stap" probes. */ -struct stap_probe +class stap_static_probe_ops : public static_probe_ops { - /* Generic information about the probe. This shall be the first element - of this struct, in order to maintain binary compatibility with the - `struct probe' and be able to fully abstract it. */ - struct probe p; +public: + /* See probe.h. */ + bool is_linespec (const char **linespecp) const override; + /* See probe.h. */ + void get_probes (std::vector *probesp, + struct objfile *objfile) const override; + + /* See probe.h. */ + const char *type_name () const override; + + /* See probe.h. */ + std::vector gen_info_probes_table_header + () const override; +}; + +/* SystemTap static_probe_ops. */ + +const stap_static_probe_ops stap_static_probe_ops; + +class stap_probe : public probe +{ +public: + /* Constructor for stap_probe. */ + stap_probe (std::string &&name_, std::string &&provider_, CORE_ADDR address_, + struct gdbarch *arch_, CORE_ADDR sem_addr, const char *args_text) + : probe (std::move (name_), std::move (provider_), address_, arch_), + m_sem_addr (sem_addr), + m_have_parsed_args (false), m_unparsed_args_text (args_text) + {} + + /* See probe.h. */ + CORE_ADDR get_relocated_address (struct objfile *objfile) override; + + /* See probe.h. */ + unsigned get_argument_count (struct frame_info *frame) override; + + /* See probe.h. */ + bool can_evaluate_arguments () const override; + + /* See probe.h. */ + struct value *evaluate_argument (unsigned n, + struct frame_info *frame) override; + + /* See probe.h. */ + void compile_to_ax (struct agent_expr *aexpr, + struct axs_value *axs_value, + unsigned n) override; + + /* See probe.h. */ + void set_semaphore (struct objfile *objfile, + struct gdbarch *gdbarch) override; + + /* See probe.h. */ + void clear_semaphore (struct objfile *objfile, + struct gdbarch *gdbarch) override; + + /* See probe.h. */ + const static_probe_ops *get_static_ops () const override; + + /* See probe.h. */ + std::vector gen_info_probes_table_values () const override; + + /* Return argument N of probe. + + If the probe's arguments have not been parsed yet, parse them. If + there are no arguments, throw an exception (error). Otherwise, + return the requested argument. */ + struct stap_probe_arg *get_arg_by_number (unsigned n, + struct gdbarch *gdbarch) + { + if (!m_have_parsed_args) + this->parse_arguments (gdbarch); + + gdb_assert (m_have_parsed_args); + if (m_parsed_args.empty ()) + internal_error (__FILE__, __LINE__, + _("Probe '%s' apparently does not have arguments, but \n" + "GDB is requesting its argument number %u anyway. " + "This should not happen. Please report this bug."), + this->get_name ().c_str (), n); + + if (n > m_parsed_args.size ()) + internal_error (__FILE__, __LINE__, + _("Probe '%s' has %d arguments, but GDB is requesting\n" + "argument %u. This should not happen. Please\n" + "report this bug."), + this->get_name ().c_str (), + (int) m_parsed_args.size (), n); + + return &m_parsed_args[n]; + } + + /* Function which parses an argument string from the probe, + correctly splitting the arguments and storing their information + in properly ways. + + Consider the following argument string (x86 syntax): + + `4@%eax 4@$10' + + We have two arguments, `%eax' and `$10', both with 32-bit + unsigned bitness. This function basically handles them, properly + filling some structures with this information. */ + void parse_arguments (struct gdbarch *gdbarch); + +private: /* If the probe has a semaphore associated, then this is the value of it, relative to SECT_OFF_DATA. */ - CORE_ADDR sem_addr; + CORE_ADDR m_sem_addr; - /* One if the arguments have been parsed. */ - unsigned int args_parsed : 1; + /* True if the arguments have been parsed. */ + bool m_have_parsed_args; - union - { - const char *text; + /* The text version of the probe's arguments, unparsed. */ + const char *m_unparsed_args_text; - /* Information about each argument. This is an array of `stap_probe_arg', - with each entry representing one argument. */ - VEC (stap_probe_arg_s) *vec; - } - args_u; + /* Information about each argument. This is an array of `stap_probe_arg', + with each entry representing one argument. This is only valid if + M_ARGS_PARSED is true. */ + std::vector m_parsed_args; }; /* When parsing the arguments, we have to establish different precedences @@ -326,7 +427,7 @@ stap_get_opcode (const char **s) static struct type * stap_get_expected_argument_type (struct gdbarch *gdbarch, enum stap_arg_bitness b, - const struct stap_probe *probe) + const char *probe_name) { switch (b) { @@ -361,8 +462,7 @@ stap_get_expected_argument_type (struct gdbarch *gdbarch, return builtin_type (gdbarch)->builtin_uint64; default: - error (_("Undefined bitness for probe '%s'."), - probe->p.name); + error (_("Undefined bitness for probe '%s'."), probe_name); break; } } @@ -1039,10 +1139,10 @@ stap_parse_argument_1 (struct stap_parse_info *p, int has_lhs, - If we find an operator, we skip it. This function can also call a special function that will try to match - unknown tokens. It will return 1 if the argument has been parsed - successfully, or zero otherwise. */ + unknown tokens. It will return the expression_up generated from + parsing the argument. */ -static struct expression * +static expression_up stap_parse_argument (const char **arg, struct type *atype, struct gdbarch *gdbarch) { @@ -1078,41 +1178,27 @@ stap_parse_argument (const char **arg, struct type *atype, *arg = p.arg; /* We can safely return EXPOUT here. */ - return p.pstate.expout; + return expression_up (p.pstate.expout); } -/* Function which parses an argument string from PROBE, correctly splitting - the arguments and storing their information in properly ways. - - Consider the following argument string (x86 syntax): - - `4@%eax 4@$10' +/* Implementation of 'parse_arguments' method. */ - We have two arguments, `%eax' and `$10', both with 32-bit unsigned bitness. - This function basically handles them, properly filling some structures with - this information. */ - -static void -stap_parse_probe_arguments (struct stap_probe *probe, struct gdbarch *gdbarch) +void +stap_probe::parse_arguments (struct gdbarch *gdbarch) { const char *cur; - gdb_assert (!probe->args_parsed); - cur = probe->args_u.text; - probe->args_parsed = 1; - probe->args_u.vec = NULL; + gdb_assert (!m_have_parsed_args); + cur = m_unparsed_args_text; + m_have_parsed_args = true; if (cur == NULL || *cur == '\0' || *cur == ':') return; while (*cur != '\0') { - struct stap_probe_arg arg; - enum stap_arg_bitness b; - int got_minus = 0; - struct expression *expr; - - memset (&arg, 0, sizeof (arg)); + enum stap_arg_bitness bitness; + bool got_minus = false; /* We expect to find something like: @@ -1128,30 +1214,30 @@ stap_parse_probe_arguments (struct stap_probe *probe, struct gdbarch *gdbarch) { /* Discard the `-'. */ ++cur; - got_minus = 1; + got_minus = true; } /* Defining the bitness. */ switch (*cur) { case '1': - b = (got_minus ? STAP_ARG_BITNESS_8BIT_SIGNED - : STAP_ARG_BITNESS_8BIT_UNSIGNED); + bitness = (got_minus ? STAP_ARG_BITNESS_8BIT_SIGNED + : STAP_ARG_BITNESS_8BIT_UNSIGNED); break; case '2': - b = (got_minus ? STAP_ARG_BITNESS_16BIT_SIGNED - : STAP_ARG_BITNESS_16BIT_UNSIGNED); + bitness = (got_minus ? STAP_ARG_BITNESS_16BIT_SIGNED + : STAP_ARG_BITNESS_16BIT_UNSIGNED); break; case '4': - b = (got_minus ? STAP_ARG_BITNESS_32BIT_SIGNED - : STAP_ARG_BITNESS_32BIT_UNSIGNED); + bitness = (got_minus ? STAP_ARG_BITNESS_32BIT_SIGNED + : STAP_ARG_BITNESS_32BIT_UNSIGNED); break; case '8': - b = (got_minus ? STAP_ARG_BITNESS_64BIT_SIGNED - : STAP_ARG_BITNESS_64BIT_UNSIGNED); + bitness = (got_minus ? STAP_ARG_BITNESS_64BIT_SIGNED + : STAP_ARG_BITNESS_64BIT_UNSIGNED); break; default: @@ -1159,67 +1245,60 @@ stap_parse_probe_arguments (struct stap_probe *probe, struct gdbarch *gdbarch) /* We have an error, because we don't expect anything except 1, 2, 4 and 8. */ warning (_("unrecognized bitness %s%c' for probe `%s'"), - got_minus ? "`-" : "`", *cur, probe->p.name); + got_minus ? "`-" : "`", *cur, + this->get_name ().c_str ()); return; } } - - arg.bitness = b; - /* Discard the number and the `@' sign. */ cur += 2; } else - arg.bitness = STAP_ARG_BITNESS_UNDEFINED; + bitness = STAP_ARG_BITNESS_UNDEFINED; - arg.atype = stap_get_expected_argument_type (gdbarch, arg.bitness, - probe); + struct type *atype + = stap_get_expected_argument_type (gdbarch, bitness, + this->get_name ().c_str ()); - expr = stap_parse_argument (&cur, arg.atype, gdbarch); + expression_up expr = stap_parse_argument (&cur, atype, gdbarch); if (stap_expression_debug) - dump_raw_expression (expr, gdb_stdlog, + dump_raw_expression (expr.get (), gdb_stdlog, "before conversion to prefix form"); - prefixify_expression (expr); + prefixify_expression (expr.get ()); if (stap_expression_debug) - dump_prefix_expression (expr, gdb_stdlog); + dump_prefix_expression (expr.get (), gdb_stdlog); - arg.aexpr = expr; + m_parsed_args.emplace_back (bitness, atype, std::move (expr)); /* Start it over again. */ cur = skip_spaces (cur); - - VEC_safe_push (stap_probe_arg_s, probe->args_u.vec, &arg); } } -/* Implementation of the get_probe_address method. */ +/* Implementation of the get_relocated_address method. */ -static CORE_ADDR -stap_get_probe_address (struct probe *probe, struct objfile *objfile) +CORE_ADDR +stap_probe::get_relocated_address (struct objfile *objfile) { - return probe->address + ANOFFSET (objfile->section_offsets, - SECT_OFF_DATA (objfile)); + return this->get_address () + ANOFFSET (objfile->section_offsets, + SECT_OFF_DATA (objfile)); } /* Given PROBE, returns the number of arguments present in that probe's argument string. */ -static unsigned -stap_get_probe_argument_count (struct probe *probe_generic, - struct frame_info *frame) +unsigned +stap_probe::get_argument_count (struct frame_info *frame) { - struct stap_probe *probe = (struct stap_probe *) probe_generic; struct gdbarch *gdbarch = get_frame_arch (frame); - gdb_assert (probe_generic->pops == &stap_probe_ops); - - if (!probe->args_parsed) + if (!m_have_parsed_args) { - if (can_evaluate_probe_arguments (probe_generic)) - stap_parse_probe_arguments (probe, gdbarch); + if (this->can_evaluate_arguments ()) + this->parse_arguments (gdbarch); else { static int have_warned_stap_incomplete = 0; @@ -1234,13 +1313,12 @@ stap_get_probe_argument_count (struct probe *probe_generic, } /* Marking the arguments as "already parsed". */ - probe->args_u.vec = NULL; - probe->args_parsed = 1; + m_have_parsed_args = true; } } - gdb_assert (probe->args_parsed); - return VEC_length (stap_probe_arg_s, probe->args_u.vec); + gdb_assert (m_have_parsed_args); + return m_parsed_args.size (); } /* Return 1 if OP is a valid operator inside a probe argument, or zero @@ -1279,36 +1357,12 @@ stap_is_operator (const char *op) return ret; } -/* Return argument N of probe PROBE. +/* Implement the `can_evaluate_arguments' method. */ - If the probe's arguments have not been parsed yet, parse them. If - there are no arguments, throw an exception (error). Otherwise, - return the requested argument. */ - -static struct stap_probe_arg * -stap_get_arg (struct stap_probe *probe, unsigned n, struct gdbarch *gdbarch) -{ - if (!probe->args_parsed) - stap_parse_probe_arguments (probe, gdbarch); - - gdb_assert (probe->args_parsed); - if (probe->args_u.vec == NULL) - internal_error (__FILE__, __LINE__, - _("Probe '%s' apparently does not have arguments, but \n" - "GDB is requesting its argument number %u anyway. " - "This should not happen. Please report this bug."), - probe->p.name, n); - - return VEC_index (stap_probe_arg_s, probe->args_u.vec, n); -} - -/* Implement the `can_evaluate_probe_arguments' method of probe_ops. */ - -static int -stap_can_evaluate_probe_arguments (struct probe *probe_generic) +bool +stap_probe::can_evaluate_arguments () const { - struct stap_probe *stap_probe = (struct stap_probe *) probe_generic; - struct gdbarch *gdbarch = stap_probe->p.arch; + struct gdbarch *gdbarch = this->get_gdbarch (); /* For SystemTap probes, we have to guarantee that the method stap_is_single_operand is defined on gdbarch. If it is not, then it @@ -1319,71 +1373,42 @@ stap_can_evaluate_probe_arguments (struct probe *probe_generic) /* Evaluate the probe's argument N (indexed from 0), returning a value corresponding to it. Assertion is thrown if N does not exist. */ -static struct value * -stap_evaluate_probe_argument (struct probe *probe_generic, unsigned n, - struct frame_info *frame) +struct value * +stap_probe::evaluate_argument (unsigned n, struct frame_info *frame) { - struct stap_probe *stap_probe = (struct stap_probe *) probe_generic; - struct gdbarch *gdbarch = get_frame_arch (frame); struct stap_probe_arg *arg; int pos = 0; + struct gdbarch *gdbarch = get_frame_arch (frame); - gdb_assert (probe_generic->pops == &stap_probe_ops); - - arg = stap_get_arg (stap_probe, n, gdbarch); - return evaluate_subexp_standard (arg->atype, arg->aexpr, &pos, EVAL_NORMAL); + arg = this->get_arg_by_number (n, gdbarch); + return evaluate_subexp_standard (arg->atype, arg->aexpr.get (), &pos, + EVAL_NORMAL); } /* Compile the probe's argument N (indexed from 0) to agent expression. Assertion is thrown if N does not exist. */ -static void -stap_compile_to_ax (struct probe *probe_generic, struct agent_expr *expr, - struct axs_value *value, unsigned n) +void +stap_probe::compile_to_ax (struct agent_expr *expr, struct axs_value *value, + unsigned n) { - struct stap_probe *stap_probe = (struct stap_probe *) probe_generic; struct stap_probe_arg *arg; union exp_element *pc; - gdb_assert (probe_generic->pops == &stap_probe_ops); - - arg = stap_get_arg (stap_probe, n, expr->gdbarch); + arg = this->get_arg_by_number (n, expr->gdbarch); pc = arg->aexpr->elts; - gen_expr (arg->aexpr, &pc, expr, value); + gen_expr (arg->aexpr.get (), &pc, expr, value); require_rvalue (expr, value); value->type = arg->atype; } - -/* Destroy (free) the data related to PROBE. PROBE memory itself is not feed - as it is allocated on an obstack. */ - -static void -stap_probe_destroy (struct probe *probe_generic) -{ - struct stap_probe *probe = (struct stap_probe *) probe_generic; - - gdb_assert (probe_generic->pops == &stap_probe_ops); - - if (probe->args_parsed) - { - struct stap_probe_arg *arg; - int ix; - - for (ix = 0; VEC_iterate (stap_probe_arg_s, probe->args_u.vec, ix, arg); - ++ix) - xfree (arg->aexpr); - VEC_free (stap_probe_arg_s, probe->args_u.vec); - } -} - /* Set or clear a SystemTap semaphore. ADDRESS is the semaphore's - address. SET is zero if the semaphore should be cleared, or one - if it should be set. This is a helper function for `stap_semaphore_down' - and `stap_semaphore_up'. */ + address. SET is zero if the semaphore should be cleared, or one if + it should be set. This is a helper function for + 'stap_probe::set_semaphore' and 'stap_probe::clear_semaphore'. */ static void stap_modify_semaphore (CORE_ADDR address, int set, struct gdbarch *gdbarch) @@ -1419,41 +1444,47 @@ stap_modify_semaphore (CORE_ADDR address, int set, struct gdbarch *gdbarch) warning (_("Could not write the value of a SystemTap semaphore.")); } -/* Set a SystemTap semaphore. SEM is the semaphore's address. Semaphores - act as reference counters, so calls to this function must be paired with - calls to `stap_semaphore_down'. +/* Implementation of the 'set_semaphore' method. - This function and `stap_semaphore_down' race with another tool changing - the probes, but that is too rare to care. */ + SystemTap semaphores act as reference counters, so calls to this + function must be paired with calls to 'clear_semaphore'. -static void -stap_set_semaphore (struct probe *probe_generic, struct objfile *objfile, - struct gdbarch *gdbarch) + This function and 'clear_semaphore' race with another tool + changing the probes, but that is too rare to care. */ + +void +stap_probe::set_semaphore (struct objfile *objfile, struct gdbarch *gdbarch) { - struct stap_probe *probe = (struct stap_probe *) probe_generic; - CORE_ADDR addr; + stap_modify_semaphore (this->get_relocated_address (objfile), 1, gdbarch); +} - gdb_assert (probe_generic->pops == &stap_probe_ops); +/* Implementation of the 'clear_semaphore' method. */ - addr = (probe->sem_addr - + ANOFFSET (objfile->section_offsets, SECT_OFF_DATA (objfile))); - stap_modify_semaphore (addr, 1, gdbarch); +void +stap_probe::clear_semaphore (struct objfile *objfile, struct gdbarch *gdbarch) +{ + stap_modify_semaphore (this->get_relocated_address (objfile), 0, gdbarch); } -/* Clear a SystemTap semaphore. SEM is the semaphore's address. */ +/* Implementation of the 'get_static_ops' method. */ -static void -stap_clear_semaphore (struct probe *probe_generic, struct objfile *objfile, - struct gdbarch *gdbarch) +const static_probe_ops * +stap_probe::get_static_ops () const +{ + return &stap_static_probe_ops; +} + +/* Implementation of the 'gen_info_probes_table_values' method. */ + +std::vector +stap_probe::gen_info_probes_table_values () const { - struct stap_probe *probe = (struct stap_probe *) probe_generic; - CORE_ADDR addr; + const char *val = NULL; - gdb_assert (probe_generic->pops == &stap_probe_ops); + if (m_sem_addr != 0) + val = print_core_address (this->get_gdbarch (), m_sem_addr); - addr = (probe->sem_addr - + ANOFFSET (objfile->section_offsets, SECT_OFF_DATA (objfile))); - stap_modify_semaphore (addr, 0, gdbarch); + return std::vector { val }; } /* Helper function that parses the information contained in a @@ -1478,21 +1509,14 @@ handle_stap_probe (struct objfile *objfile, struct sdt_note *el, int size = bfd_get_arch_size (abfd) / 8; struct gdbarch *gdbarch = get_objfile_arch (objfile); struct type *ptr_type = builtin_type (gdbarch)->builtin_data_ptr; - CORE_ADDR base_ref; - const char *probe_args = NULL; - struct stap_probe *ret; - - ret = XOBNEW (&objfile->per_bfd->storage_obstack, struct stap_probe); - ret->p.pops = &stap_probe_ops; - ret->p.arch = gdbarch; /* Provider and the name of the probe. */ - ret->p.provider = (char *) &el->data[3 * size]; - ret->p.name = ((const char *) - memchr (ret->p.provider, '\0', - (char *) el->data + el->size - ret->p.provider)); + const char *provider = (const char *) &el->data[3 * size]; + const char *name = ((const char *) + memchr (provider, '\0', + (char *) el->data + el->size - provider)); /* Making sure there is a name. */ - if (ret->p.name == NULL) + if (name == NULL) { complaint (&symfile_complaints, _("corrupt probe name when " "reading `%s'"), @@ -1503,32 +1527,32 @@ handle_stap_probe (struct objfile *objfile, struct sdt_note *el, return; } else - ++ret->p.name; + ++name; /* Retrieving the probe's address. */ - ret->p.address = extract_typed_address (&el->data[0], ptr_type); + CORE_ADDR address = extract_typed_address (&el->data[0], ptr_type); /* Link-time sh_addr of `.stapsdt.base' section. */ - base_ref = extract_typed_address (&el->data[size], ptr_type); + CORE_ADDR base_ref = extract_typed_address (&el->data[size], ptr_type); /* Semaphore address. */ - ret->sem_addr = extract_typed_address (&el->data[2 * size], ptr_type); + CORE_ADDR sem_addr = extract_typed_address (&el->data[2 * size], ptr_type); - ret->p.address += base - base_ref; - if (ret->sem_addr != 0) - ret->sem_addr += base - base_ref; + address += base - base_ref; + if (sem_addr != 0) + sem_addr += base - base_ref; /* Arguments. We can only extract the argument format if there is a valid name for this probe. */ - probe_args = ((const char*) - memchr (ret->p.name, '\0', - (char *) el->data + el->size - ret->p.name)); + const char *probe_args = ((const char*) + memchr (name, '\0', + (char *) el->data + el->size - name)); if (probe_args != NULL) ++probe_args; if (probe_args == NULL - || (memchr (probe_args, '\0', (char *) el->data + el->size - ret->p.name) + || (memchr (probe_args, '\0', (char *) el->data + el->size - name) != el->data + el->size - 1)) { complaint (&symfile_complaints, _("corrupt probe argument when " @@ -1539,11 +1563,11 @@ handle_stap_probe (struct objfile *objfile, struct sdt_note *el, return; } - ret->args_parsed = 0; - ret->args_u.text = probe_args; + stap_probe *ret = new stap_probe (std::string (name), std::string (provider), + address, gdbarch, sem_addr, probe_args); /* Successfully created probe. */ - probesp->push_back ((struct probe *) ret); + probesp->push_back (ret); } /* Helper function which tries to find the base address of the SystemTap @@ -1584,11 +1608,21 @@ get_stap_base_address (bfd *obfd, bfd_vma *base) return 1; } -/* Helper function for `elf_get_probes', which gathers information about all - SystemTap probes from OBJFILE. */ +/* Implementation of the 'is_linespec' method. */ -static void -stap_get_probes (std::vector *probesp, struct objfile *objfile) +bool +stap_static_probe_ops::is_linespec (const char **linespecp) const +{ + static const char *const keywords[] = { "-pstap", "-probe-stap", NULL }; + + return probe_is_linespec_by_keyword (linespecp, keywords); +} + +/* Implementation of the 'get_probes' method. */ + +void +stap_static_probe_ops::get_probes (std::vector *probesp, + struct objfile *objfile) const { /* If we are here, then this is the first time we are parsing the SystemTap probe's information. We basically have to count how many @@ -1640,83 +1674,37 @@ stap_get_probes (std::vector *probesp, struct objfile *objfile) /* Implementation of the type_name method. */ -static const char * -stap_type_name (struct probe *probe) +const char * +stap_static_probe_ops::type_name () const { - gdb_assert (probe->pops == &stap_probe_ops); return "stap"; } -static int -stap_probe_is_linespec (const char **linespecp) -{ - static const char *const keywords[] = { "-pstap", "-probe-stap", NULL }; +/* Implementation of the 'gen_info_probes_table_header' method. */ - return probe_is_linespec_by_keyword (linespecp, keywords); -} - -static void -stap_gen_info_probes_table_header (VEC (info_probe_column_s) **heads) +std::vector +stap_static_probe_ops::gen_info_probes_table_header () const { - info_probe_column_s stap_probe_column; + struct info_probe_column stap_probe_column; stap_probe_column.field_name = "semaphore"; stap_probe_column.print_name = _("Semaphore"); - VEC_safe_push (info_probe_column_s, *heads, &stap_probe_column); + return std::vector { stap_probe_column }; } -static void -stap_gen_info_probes_table_values (struct probe *probe_generic, - VEC (const_char_ptr) **ret) -{ - struct stap_probe *probe = (struct stap_probe *) probe_generic; - struct gdbarch *gdbarch; - const char *val = NULL; - - gdb_assert (probe_generic->pops == &stap_probe_ops); - - gdbarch = probe->p.arch; - - if (probe->sem_addr != 0) - val = print_core_address (gdbarch, probe->sem_addr); - - VEC_safe_push (const_char_ptr, *ret, val); -} - -/* SystemTap probe_ops. */ - -const struct probe_ops stap_probe_ops = -{ - stap_probe_is_linespec, - stap_get_probes, - stap_get_probe_address, - stap_get_probe_argument_count, - stap_can_evaluate_probe_arguments, - stap_evaluate_probe_argument, - stap_compile_to_ax, - stap_set_semaphore, - stap_clear_semaphore, - stap_probe_destroy, - stap_type_name, - stap_gen_info_probes_table_header, - stap_gen_info_probes_table_values, - NULL, /* enable_probe */ - NULL /* disable_probe */ -}; - /* Implementation of the `info probes stap' command. */ static void info_probes_stap_command (const char *arg, int from_tty) { - info_probes_for_ops (arg, from_tty, &stap_probe_ops); + info_probes_for_spops (arg, from_tty, &stap_static_probe_ops); } void _initialize_stap_probe (void) { - all_probe_ops.push_back (&stap_probe_ops); + all_static_probe_ops.push_back (&stap_static_probe_ops); add_setshow_zuinteger_cmd ("stap-expression", class_maintenance, &stap_expression_debug, -- 2.34.1