gdb: use bool in frame code

Change instances of int variables and return values used as boolean
values to use the bool type.

Shorten the comments of a few functions, because I think they go a bit
too much in implementation details, which appear out of date anyway.

Make other misc changes to the functions that are already being changed,
such as using nullptr instead of NULL, dropping `struct` keywords and
declaring variables when first used.

gdb/ChangeLog:

	* frame.h (frame_id_p): Return bool.
	(frame_id_artificial_p): Return bool.
	(frame_id_eq): Return bool.
	(has_stack_frames): Return bool.
	(get_selected_frame): Fix typo in comment.
	(get_frame_pc_if_available): Return bool.
	(get_frame_address_in_block_if_available): Return bool.
	(get_frame_func_if_available): Return bool.
	(read_frame_register_unsigned): Return bool.
	(get_frame_register_bytes): Return bool.
	(safe_frame_unwind_memory): Return bool.
	(deprecated_frame_register_read): Return bool.
	(frame_unwinder_is): Return bool.
	* frame.c (struct frame_info) <prev_arch::p>: Change type to
	bool.
	<this_id::p>: Likewise.
	<prev_p>: Likewise.
	(frame_stash_add): Return bool.
	(get_frame_id): Use bool.
	(frame_id_build_special) Use bool.
	(frame_id_build_unavailable_stack): Use bool.
	(frame_id_build): Use bool.
	(frame_id_p): Return bool, use true/false instead of 1/0.
	(frame_id_artificial_p): Likewise.
	(frame_id_eq): Likewise.
	(frame_id_inner): Likewise.
	(get_frame_func_if_available): Likewise.
	(read_frame_register_unsigned): Likewise.
	(deprecated_frame_register_read): Likewise.
	(get_frame_register_bytes): Likewise.
	(has_stack_frames): Likewise.
	(inside_main_func): Likewise.
	(inside_entry_func): Likewise.
	(get_frame_pc_if_available): Likewise.
	(get_frame_address_in_block_if_available): Likewise.
	(frame_unwinder_is): Likewise.
	(safe_frame_unwind_memory): Likewise.
	(frame_unwind_arch): Likewise.

Change-Id: I6121fa56739b688be79d73d087d76b268ba5a46a

1 files changed, 27 insertions, 33 deletions

diff --git a/gdb/frame.h b/gdb/frame.h
index 8d029cc..1c6afad 100644
--- a/gdb/frame.h
+++ b/gdb/frame.h
@@ -45,8 +45,8 @@
    strongly hinting at its unsafeness)
 
    safe_....(): Safer version of various functions, doesn't throw an
-   error (leave this for later?).  Returns non-zero / non-NULL if the
-   request succeeds, zero / NULL otherwize.
+   error (leave this for later?).  Returns true / non-NULL if the request
+   succeeds, false / NULL otherwise.
 
    Suffixes:
 
@@ -236,19 +236,16 @@ extern struct frame_id
    as the special identifier address are set to indicate wild cards.  */
 extern struct frame_id frame_id_build_wild (CORE_ADDR stack_addr);
 
-/* Returns non-zero when L is a valid frame (a valid frame has a
-   non-zero .base).  The outermost frame is valid even without an
-   ID.  */
-extern int frame_id_p (struct frame_id l);
+/* Returns true when L is a valid frame.  */
+extern bool frame_id_p (frame_id l);
 
-/* Returns non-zero when L is a valid frame representing a frame made up by GDB
+/* Returns true when L is a valid frame representing a frame made up by GDB
    without stack data representation in inferior, such as INLINE_FRAME or
    TAILCALL_FRAME.  */
-extern int frame_id_artificial_p (struct frame_id l);
+extern bool frame_id_artificial_p (frame_id l);
 
-/* Returns non-zero when L and R identify the same frame, or, if
-   either L or R have a zero .func, then the same frame base.  */
-extern int frame_id_eq (struct frame_id l, struct frame_id r);
+/* Returns true when L and R identify the same frame.  */
+extern bool frame_id_eq (frame_id l, frame_id r);
 
 /* Write the internal representation of a frame ID on the specified
    stream.  */
@@ -303,7 +300,7 @@ extern struct frame_info *get_current_frame (void);
 /* Does the current target interface have enough state to be able to
    query the current inferior for frame info, and is the inferior in a
    state where that is possible?  */
-extern int has_stack_frames (void);
+extern bool has_stack_frames ();
 
 /* Invalidates the frame cache (this function should have been called
    invalidate_cached_frames).
@@ -317,7 +314,7 @@ extern void reinit_frame_cache (void);
 /* On demand, create the selected frame and then return it.  If the
    selected frame can not be created, this function prints then throws
    an error.  When MESSAGE is non-NULL, use it for the error message,
-   otherwize use a generic error message.  */
+   otherwise use a generic error message.  */
 /* FIXME: cagney/2002-11-28: At present, when there is no selected
    frame, this function always returns the current (inner most) frame.
    It should instead, when a thread has previously had its frame
@@ -367,8 +364,7 @@ extern CORE_ADDR get_frame_pc (struct frame_info *);
 /* Same as get_frame_pc, but return a boolean indication of whether
    the PC is actually available, instead of throwing an error.  */
 
-extern int get_frame_pc_if_available (struct frame_info *frame,
-				      CORE_ADDR *pc);
+extern bool get_frame_pc_if_available (frame_info *frame, CORE_ADDR *pc);
 
 /* An address (not necessarily aligned to an instruction boundary)
    that falls within THIS frame's code block.
@@ -390,9 +386,8 @@ extern CORE_ADDR get_frame_address_in_block (struct frame_info *this_frame);
    PC is unavailable, it will not be), instead of possibly throwing an
    error trying to read an unavailable PC.  */
 
-extern int
-  get_frame_address_in_block_if_available (struct frame_info *this_frame,
-					   CORE_ADDR *pc);
+extern bool get_frame_address_in_block_if_available (frame_info *this_frame,
+						     CORE_ADDR *pc);
 
 /* The frame's inner-most bound.  AKA the stack-pointer.  Confusingly
    known as top-of-stack.  */
@@ -409,7 +404,7 @@ extern CORE_ADDR get_frame_func (struct frame_info *fi);
    will not be), instead of possibly throwing an error trying to read
    an unavailable PC.  */
 
-extern int get_frame_func_if_available (struct frame_info *fi, CORE_ADDR *);
+extern bool get_frame_func_if_available (frame_info *fi, CORE_ADDR *);
 
 /* Closely related to the resume address, various symbol table
    attributes that are determined by the PC.  Note that for a normal
@@ -597,8 +592,8 @@ extern ULONGEST get_frame_register_unsigned (struct frame_info *frame,
    get_frame_register_value, that do not throw if the result is
    optimized out or unavailable.  */
 
-extern int read_frame_register_unsigned (struct frame_info *frame,
-					 int regnum, ULONGEST *val);
+extern bool read_frame_register_unsigned (frame_info *frame,
+					  int regnum, ULONGEST *val);
 
 /* Get the value of the register that belongs to this FRAME.  This
    function is a wrapper to the call sequence ``frame_register_unwind
@@ -621,10 +616,10 @@ extern void put_frame_register (struct frame_info *frame, int regnum,
    in frame FRAME, starting at OFFSET, into BUF.  If the register
    contents are optimized out or unavailable, set *OPTIMIZEDP,
    *UNAVAILABLEP accordingly.  */
-extern int get_frame_register_bytes (struct frame_info *frame, int regnum,
-				     CORE_ADDR offset, int len,
-				     gdb_byte *myaddr,
-				     int *optimizedp, int *unavailablep);
+extern bool get_frame_register_bytes (frame_info *frame, int regnum,
+				      CORE_ADDR offset, int len,
+				      gdb_byte *myaddr,
+				      int *optimizedp, int *unavailablep);
 
 /* Write LEN bytes to one or multiple registers starting with REGNUM
    in frame FRAME, starting at OFFSET, into BUF.  */
@@ -662,10 +657,10 @@ extern LONGEST get_frame_memory_signed (struct frame_info *this_frame,
 extern ULONGEST get_frame_memory_unsigned (struct frame_info *this_frame,
 					   CORE_ADDR memaddr, int len);
 
-/* Same as above, but return non-zero when the entire memory read
-   succeeds, zero otherwize.  */
-extern int safe_frame_unwind_memory (struct frame_info *this_frame,
-				     CORE_ADDR addr, gdb_byte *buf, int len);
+/* Same as above, but return true zero when the entire memory read
+   succeeds, false otherwise.  */
+extern bool safe_frame_unwind_memory (frame_info *this_frame, CORE_ADDR addr,
+				      gdb_byte *buf, int len);
 
 /* Return this frame's architecture.  */
 extern struct gdbarch *get_frame_arch (struct frame_info *this_frame);
@@ -772,8 +767,8 @@ extern void print_frame_info (const frame_print_options &fp_opts,
 
 extern struct frame_info *block_innermost_frame (const struct block *);
 
-extern int deprecated_frame_register_read (struct frame_info *frame, int regnum,
-				gdb_byte *buf);
+extern bool deprecated_frame_register_read (frame_info *frame, int regnum,
+					    gdb_byte *buf);
 
 /* From stack.c.  */
 
@@ -907,8 +902,7 @@ extern struct frame_info *create_new_frame (CORE_ADDR base, CORE_ADDR pc);
 /* Return true if the frame unwinder for frame FI is UNWINDER; false
    otherwise.  */
 
-extern int frame_unwinder_is (struct frame_info *fi,
-			      const struct frame_unwind *unwinder);
+extern bool frame_unwinder_is (frame_info *fi, const frame_unwind *unwinder);
 
 /* Return the language of FRAME.  */