diff options
| -rw-r--r-- | gdb/ChangeLog | 13 | ||||
| -rw-r--r-- | gdb/target.c | 121 | ||||
| -rw-r--r-- | gdb/target.h | 47 |
3 files changed, 119 insertions, 62 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index a8da90b..424b7af 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,18 @@ 2018-06-07 Pedro Alves <palves@redhat.com> + * target.h (target_ops) <beneath>: Now a method. All references + updated. + (class target_stack): New. + * target.c (g_target_stack): New. + (g_current_top_target): Delete. + (current_top_target): Get the top target out of g_target_stack. + (target_stack::push, target_stack::unpush): New. + (push_target, unpush_target): Reimplement. + (target_is_pushed): Reimplement in terms of g_target_stack. + (target_ops::beneath, target_stack::find_beneath): New. + +2018-06-07 Pedro Alves <palves@redhat.com> + * target.h (find_target_beneath): Delete declaration. * target.c (find_target_beneath): Delete definition. * aix-thread.c: All callers of find_target_beneath adjusted to diff --git a/gdb/target.c b/gdb/target.c index cc4f81e..a1fe8f9 100644 --- a/gdb/target.c +++ b/gdb/target.c @@ -119,16 +119,18 @@ static std::unordered_map<const target_info *, target_open_ftype *> static struct target_ops *the_dummy_target; static struct target_ops *the_debug_target; +/* The target stack. */ + +static target_stack g_target_stack; + /* Top of target stack. */ /* The target structure we are currently using to talk to a process or file or whatever "inferior" we have. */ -static target_ops *g_current_top_target; - target_ops * current_top_target () { - return g_current_top_target; + return g_target_stack.top (); } /* Command list for target. */ @@ -631,50 +633,47 @@ default_execution_direction (struct target_ops *self) to_execution_direction must be implemented for reverse async"); } -/* Push a new target type into the stack of the existing target accessors, - possibly superseding some of the existing accessors. - - Rather than allow an empty stack, we always have the dummy target at - the bottom stratum, so we can call the function vectors without - checking them. */ +/* See target.h. */ void -push_target (struct target_ops *t) +target_stack::push (target_ops *t) { - struct target_ops **cur; - - /* Find the proper stratum to install this target in. */ - for (cur = &g_current_top_target; (*cur) != NULL; cur = &(*cur)->m_beneath) + /* If there's already a target at this stratum, remove it. */ + if (m_stack[t->to_stratum] != NULL) { - if ((int) (t->to_stratum) >= (int) (*cur)->to_stratum) - break; + target_ops *prev = m_stack[t->to_stratum]; + m_stack[t->to_stratum] = NULL; + target_close (prev); } - /* If there's already targets at this stratum, remove them. */ - /* FIXME: cagney/2003-10-15: I think this should be popping all - targets to CUR, and not just those at this stratum level. */ - while ((*cur) != NULL && t->to_stratum == (*cur)->to_stratum) - { - /* There's already something at this stratum level. Close it, - and un-hook it from the stack. */ - struct target_ops *tmp = (*cur); + /* Now add the new one. */ + m_stack[t->to_stratum] = t; - (*cur) = (*cur)->m_beneath; - tmp->m_beneath = NULL; - target_close (tmp); - } + if (m_top < t->to_stratum) + m_top = t->to_stratum; +} + +/* See target.h. */ - /* We have removed all targets in our stratum, now add the new one. */ - t->m_beneath = (*cur); - (*cur) = t; +void +push_target (struct target_ops *t) +{ + g_target_stack.push (t); } -/* Remove a target_ops vector from the stack, wherever it may be. - Return how many times it was removed (0 or 1). */ +/* See target.h. */ int unpush_target (struct target_ops *t) { + return g_target_stack.unpush (t); +} + +/* See target.h. */ + +bool +target_stack::unpush (target_ops *t) +{ struct target_ops **cur; struct target_ops *tmp; @@ -682,31 +681,30 @@ unpush_target (struct target_ops *t) internal_error (__FILE__, __LINE__, _("Attempt to unpush the dummy target")); - /* Look for the specified target. Note that we assume that a target - can only occur once in the target stack. */ + gdb_assert (t != NULL); + + /* Look for the specified target. Note that a target can only occur + once in the target stack. */ - for (cur = &g_current_top_target; (*cur) != NULL; cur = &(*cur)->m_beneath) + if (m_stack[t->to_stratum] != t) { - if ((*cur) == t) - break; + /* If T wasn't pushed, quit. Only open targets should be + closed. */ + return false; } - /* If we don't find target_ops, quit. Only open targets should be - closed. */ - if ((*cur) == NULL) - return 0; - /* Unchain the target. */ - tmp = (*cur); - (*cur) = (*cur)->m_beneath; - tmp->m_beneath = NULL; + m_stack[t->to_stratum] = NULL; + + if (m_top == t->to_stratum) + m_top = t->beneath ()->to_stratum; /* Finally close the target. Note we do this after unchaining, so any target method calls from within the target_close implementation don't end up in T anymore. */ target_close (t); - return 1; + return true; } /* Unpush TARGET and assert that it worked. */ @@ -751,13 +749,7 @@ pop_all_targets (void) int target_is_pushed (struct target_ops *t) { - for (target_ops *cur = current_top_target (); - cur != NULL; - cur = cur->beneath ()) - if (cur == t) - return 1; - - return 0; + return g_target_stack.is_pushed (t); } /* Default implementation of to_get_thread_local_address. */ @@ -2625,7 +2617,7 @@ target_thread_address_space (ptid_t ptid) target_ops * target_ops::beneath () const { - return m_beneath; + return g_target_stack.find_beneath (this); } void @@ -3213,16 +3205,25 @@ default_thread_architecture (struct target_ops *ops, ptid_t ptid) /* See target.h. */ -struct target_ops * -find_target_at (enum strata stratum) +target_ops * +target_stack::find_beneath (const target_ops *t) const { - for (target_ops *t = current_top_target (); t != NULL; t = t->beneath ()) - if (t->to_stratum == stratum) - return t; + /* Look for a non-empty slot at stratum levels beneath T's. */ + for (int stratum = t->to_stratum - 1; stratum >= 0; --stratum) + if (m_stack[stratum] != NULL) + return m_stack[stratum]; return NULL; } +/* See target.h. */ + +struct target_ops * +find_target_at (enum strata stratum) +{ + return g_target_stack.at (stratum); +} + /* See target.h */ diff --git a/gdb/target.h b/gdb/target.h index 9dd29a6..18c4a84 100644 --- a/gdb/target.h +++ b/gdb/target.h @@ -61,7 +61,11 @@ struct inferior; of variables any more (the file target is handling them and they never get to the process target). So when you push a file target, it goes into the file stratum, which is always below the process - stratum. */ + stratum. + + Note that rather than allow an empty stack, we always have the + dummy target at the bottom stratum, so we can call the target + methods without checking them. */ #include "target/target.h" #include "target/resume.h" @@ -425,7 +429,6 @@ struct target_info struct target_ops { /* To the target under this one. */ - target_ops *m_beneath; target_ops *beneath () const; /* Free resources associated with the target. Note that singleton @@ -1268,6 +1271,46 @@ extern void set_native_target (target_ops *target); NULL. */ extern target_ops *get_native_target (); +/* Type that manages a target stack. See description of target stacks + and strata at the top of the file. */ + +class target_stack +{ +public: + target_stack () = default; + DISABLE_COPY_AND_ASSIGN (target_stack); + + /* Push a new target into the stack of the existing target + accessors, possibly superseding some existing accessor. */ + void push (target_ops *t); + + /* Remove a target from the stack, wherever it may be. Return true + if it was removed, false otherwise. */ + bool unpush (target_ops *t); + + /* Returns true if T is pushed on the target stack. */ + bool is_pushed (target_ops *t) const + { return at (t->to_stratum) == t; } + + /* Return the target at STRATUM. */ + target_ops *at (strata stratum) const { return m_stack[stratum]; } + + /* Return the target at the top of the stack. */ + target_ops *top () const { return at (m_top); } + + /* Find the next target down the stack from the specified target. */ + target_ops *find_beneath (const target_ops *t) const; + +private: + /* The stratum of the top target. */ + enum strata m_top {}; + + /* The stack, represented as an array, with one slot per stratum. + If no target is pushed at some stratum, the corresponding slot is + null. */ + target_ops *m_stack[(int) debug_stratum + 1] {}; +}; + /* The ops structure for our "current" target process. This should never be NULL. If there is no target, it points to the dummy_target. */ |