change probes to be program-space-independent

This changes the probes to be independent of the program space.

After this, when a probe's address is needed, it is determined by
applying offsets at the point of use.

This introduces a bound_probe object, similar to bound minimal
symbols.  Objects of this type are used when it's necessary to pass a
probe and its corresponding objfile.

This removes the backlink from probe to objfile, which was primarily
used to fetch the architecture to use.

This adds a get_probe_address function which calls a probe method to
compute the probe's relocated address.  Similarly, it adds an objfile
parameter to the semaphore methods so they can do the relocation
properly as well.

2014-03-03  Tom Tromey  <tromey@redhat.com>

	* break-catch-throw.c (fetch_probe_arguments): Use bound probes.
	* breakpoint.c (create_longjmp_master_breakpoint): Use
	get_probe_address.
	(add_location_to_breakpoint, bkpt_probe_insert_location)
	(bkpt_probe_remove_location): Update.
	* breakpoint.h (struct bp_location) <probe>: Now a bound_probe.
	* elfread.c (elf_symfile_relocate_probe): Remove.
	(elf_probe_fns): Update.
	(insert_exception_resume_breakpoint): Change type of "probe"
	parameter to bound_probe.
	(check_exception_resume): Update.
	* objfiles.c (objfile_relocate1): Don't relocate probes.
	* probe.c (bound_probe_s): New typedef.
	(parse_probes): Use get_probe_address.  Set sal's objfile.
	(find_probe_by_pc): Return a bound_probe.
	(collect_probes): Return a VEC(bound_probe_s).
	(compare_probes): Update.
	(gen_ui_out_table_header_info): Change type of "probes"
	parameter.  Update.
	(info_probes_for_ops): Update.
	(get_probe_address): New function.
	(probe_safe_evaluate_at_pc): Update.
	* probe.h (struct probe_ops) <get_probe_address>: New field.
	<set_semaphore, clear_semaphore>: Add objfile parameter.
	(struct probe) <objfile>: Remove field.
	<arch>: New field.
	<address>: Update comment.
	(struct bound_probe): New.
	(find_probe_by_pc): Return a bound_probe.
	(get_probe_address): Declare.
	* solib-svr4.c (struct probe_and_action) <address>: New field.
	(hash_probe_and_action, equal_probe_and_action): Update.
	(register_solib_event_probe): Add address parameter.
	(solib_event_probe_at): Update.
	(svr4_create_probe_breakpoints): Add objfile parameter.  Use
	get_probe_address.
	* stap-probe.c (struct stap_probe) <sem_addr>: Update comment.
	(stap_get_probe_address): New function.
	(stap_can_evaluate_probe_arguments, compute_probe_arg)
	(compile_probe_arg): Update.
	(stap_set_semaphore, stap_clear_semaphore): Compute semaphore's
	address.
	(handle_stap_probe): Don't relocate the probe.
	(stap_relocate): Remove.
	(stap_gen_info_probes_table_values): Update.
	(stap_probe_ops): Remove stap_relocate.
	* symfile-debug.c (debug_sym_relocate_probe): Remove.
	(debug_sym_probe_fns): Update.
	* symfile.h (struct sym_probe_fns) <sym_relocate_probe>: Remove.
	* symtab.c (init_sal): Use memset.
	* symtab.h (struct symtab_and_line) <objfile>: New field.
	* tracepoint.c (start_tracing, stop_tracing): Update.

1 files changed, 37 insertions, 12 deletions

diff --git a/gdb/probe.h b/gdb/probe.h
index 38cc950..aa8aba8 100644
--- a/gdb/probe.h
+++ b/gdb/probe.h
@@ -64,10 +64,11 @@ struct probe_ops
 
     void (*get_probes) (VEC (probe_p) **probes, struct objfile *objfile);
 
-    /* Function used to relocate addresses from PROBE according to some DELTA
-       provided.  */
+    /* Compute the probe's relocated address.  OBJFILE is the objfile
+       in which the probe originated.  */
 
-    void (*relocate) (struct probe *probe, CORE_ADDR delta);
+    CORE_ADDR (*get_probe_address) (struct probe *probe,
+				    struct objfile *objfile);
 
     /* Return the number of arguments of PROBE.  */
 
@@ -97,13 +98,15 @@ struct probe_ops
        sense if the probe has a concept of semaphore associated to a
        probe.  */
 
-    void (*set_semaphore) (struct probe *probe, struct gdbarch *gdbarch);
+    void (*set_semaphore) (struct probe *probe, struct objfile *objfile,
+			   struct gdbarch *gdbarch);
 
     /* Clear the semaphore associated with the PROBE.  This function only
        makes sense if the probe has a concept of semaphore associated to
        a probe.  */
 
-    void (*clear_semaphore) (struct probe *probe, struct gdbarch *gdbarch);
+    void (*clear_semaphore) (struct probe *probe, struct objfile *objfile,
+			     struct gdbarch *gdbarch);
 
     /* Function called to destroy PROBE's specific data.  This function
        shall not free PROBE itself.  */
@@ -166,10 +169,8 @@ struct probe
     /* The operations associated with this probe.  */
     const struct probe_ops *pops;
 
-    /* The objfile which contains this probe.  Even if the probe is also
-       present in a separate debug objfile, this variable always points to
-       the non-separate debug objfile.  */
-    struct objfile *objfile;
+    /* The probe's architecture.  */
+    struct gdbarch *arch;
 
     /* The name of the probe.  */
     const char *name;
@@ -178,10 +179,27 @@ struct probe
        the objfile which contains the probe.  */
     const char *provider;
 
-    /* The address where the probe is inserted.  */
+    /* The address where the probe is inserted, relative to
+       SECT_OFF_TEXT.  */
     CORE_ADDR address;
   };
 
+/* A bound probe holds a pointer to a probe and a pointer to the
+   probe's defining objfile.  This is needed because probes are
+   independent of the program space and thus require relocation at
+   their point of use.  */
+
+struct bound_probe
+  {
+    /* The probe.  */
+
+    struct probe *probe;
+
+    /* The objfile in which the probe originated.  */
+
+    struct objfile *objfile;
+  };
+
 /* A helper for linespec that decodes a probe specification.  It returns a
    symtabs_and_lines object and updates *ARGPTR or throws an error.  */
 
@@ -194,9 +212,10 @@ extern struct symtabs_and_lines parse_probes (char **argptr,
 extern void register_probe_ops (struct probe *probe);
 
 /* Given a PC, find an associated probe.  If a probe is found, return
-   it.  If no probe is found, return NULL.  */
+   it.  If no probe is found, return a bound probe whose fields are
+   both NULL.  */
 
-extern struct probe *find_probe_by_pc (CORE_ADDR pc);
+extern struct bound_probe find_probe_by_pc (CORE_ADDR pc);
 
 /* Search OBJFILE for a probe with the given PROVIDER, NAME.  Return a
    VEC of all probes that were found.  If no matching probe is found,
@@ -221,6 +240,12 @@ extern void info_probes_for_ops (char *arg, int from_tty,
 
 extern struct cmd_list_element **info_probes_cmdlist_get (void);
 
+/* Compute the probe's relocated address.  OBJFILE is the objfile in
+   which the probe originated.  */
+
+extern CORE_ADDR get_probe_address (struct probe *probe,
+				    struct objfile *objfile);
+
 /* Return the argument count of the specified probe.  */
 
 extern unsigned get_probe_argument_count (struct probe *probe,