gdb: pass frames as `const frame_info_ptr &`

We currently pass frames to function by value, as `frame_info_ptr`.
This is somewhat expensive:

 - the size of `frame_info_ptr` is 64 bytes, which is a bit big to pass
   by value
 - the constructors and destructor link/unlink the object in the global
   `frame_info_ptr::frame_list` list.  This is an `intrusive_list`, so
   it's not so bad: it's just assigning a few points, there's no memory
   allocation as if it was `std::list`, but still it's useless to do
   that over and over.

As suggested by Tom Tromey, change many function signatures to accept
`const frame_info_ptr &` instead of `frame_info_ptr`.

Some functions reassign their `frame_info_ptr` parameter, like:

  void
  the_func (frame_info_ptr frame)
  {
    for (; frame != nullptr; frame = get_prev_frame (frame))
      {
        ...
      }
  }

I wondered what to do about them, do I leave them as-is or change them
(and need to introduce a separate local variable that can be
re-assigned).  I opted for the later for consistency.  It might not be
clear why some functions take `const frame_info_ptr &` while others take
`frame_info_ptr`.  Also, if a function took a `frame_info_ptr` because
it did re-assign its parameter, I doubt that we would think to change it
to `const frame_info_ptr &` should the implementation change such that
it doesn't need to take `frame_info_ptr` anymore.  It seems better to
have a simple rule and apply it everywhere.

Change-Id: I59d10addef687d157f82ccf4d54f5dde9a963fd0
Approved-By: Andrew Burgess <aburgess@redhat.com>

10 files changed, 94 insertions, 93 deletions

diff --git a/gdb/dwarf2/ada-imported.c b/gdb/dwarf2/ada-imported.c
index 1a0bc1d..065e2b9 100644
--- a/gdb/dwarf2/ada-imported.c
+++ b/gdb/dwarf2/ada-imported.c
@@ -32,7 +32,7 @@ get_imported_name (const struct symbol *sym)
 /* Implement the read_variable method from symbol_computed_ops.  */
 
 static struct value *
-ada_imported_read_variable (struct symbol *symbol, frame_info_ptr frame)
+ada_imported_read_variable (struct symbol *symbol, const frame_info_ptr &frame)
 {
   const char *name = get_imported_name (symbol);
   bound_minimal_symbol minsym = lookup_minimal_symbol_linkage (name, false);
diff --git a/gdb/dwarf2/call-site.h b/gdb/dwarf2/call-site.h
index 5434c84..0a0c7e8 100644
--- a/gdb/dwarf2/call-site.h
+++ b/gdb/dwarf2/call-site.h
@@ -94,7 +94,7 @@ struct call_site_target
 
   void iterate_over_addresses (struct gdbarch *call_site_gdbarch,
 			       const struct call_site *call_site,
-			       frame_info_ptr caller_frame,
+			       const frame_info_ptr &caller_frame,
 			       iterate_ftype callback) const;
 
 private:
@@ -201,7 +201,7 @@ struct call_site
      throw NO_ENTRY_VALUE_ERROR.  */
 
   void iterate_over_addresses (struct gdbarch *call_site_gdbarch,
-			       frame_info_ptr caller_frame,
+			       const frame_info_ptr &caller_frame,
 			       call_site_target::iterate_ftype callback)
     const
   {
diff --git a/gdb/dwarf2/expr.c b/gdb/dwarf2/expr.c
index 9cfae10..d0256e7 100644
--- a/gdb/dwarf2/expr.c
+++ b/gdb/dwarf2/expr.c
@@ -49,7 +49,7 @@ static const registry<gdbarch>::key<dwarf_gdbarch_types> dwarf_arch_cookie;
 /* Ensure that a FRAME is defined, throw an exception otherwise.  */
 
 static void
-ensure_have_frame (frame_info_ptr frame, const char *op_name)
+ensure_have_frame (const frame_info_ptr &frame, const char *op_name)
 {
   if (frame == nullptr)
     throw_error (GENERIC_ERROR,
@@ -78,7 +78,7 @@ bits_to_bytes (ULONGEST start, ULONGEST n_bits)
 /* See expr.h.  */
 
 CORE_ADDR
-read_addr_from_reg (frame_info_ptr frame, int reg)
+read_addr_from_reg (const frame_info_ptr &frame, int reg)
 {
   struct gdbarch *gdbarch = get_frame_arch (frame);
   int regnum = dwarf_reg_to_regnum_or_error (gdbarch, reg);
@@ -112,7 +112,7 @@ static piece_closure *
 allocate_piece_closure (dwarf2_per_cu_data *per_cu,
 			dwarf2_per_objfile *per_objfile,
 			std::vector<dwarf_expr_piece> &&pieces,
-			frame_info_ptr frame)
+			const frame_info_ptr &frame)
 {
   piece_closure *c = new piece_closure;
 
@@ -1076,7 +1076,7 @@ dwarf_expr_context::fetch_result (struct type *type, struct type *subobj_type,
 
 value *
 dwarf_expr_context::evaluate (const gdb_byte *addr, size_t len, bool as_lval,
-			      dwarf2_per_cu_data *per_cu, frame_info_ptr frame,
+			      dwarf2_per_cu_data *per_cu, const frame_info_ptr &frame,
 			      const struct property_addr_info *addr_info,
 			      struct type *type, struct type *subobj_type,
 			      LONGEST subobj_offset)
diff --git a/gdb/dwarf2/expr.h b/gdb/dwarf2/expr.h
index 6acd078..b02cc53 100644
--- a/gdb/dwarf2/expr.h
+++ b/gdb/dwarf2/expr.h
@@ -137,7 +137,7 @@ struct dwarf_expr_context
      The ADDR_INFO property can be specified to override the range of
      memory addresses with the passed in buffer.  */
   value *evaluate (const gdb_byte *addr, size_t len, bool as_lval,
-		   dwarf2_per_cu_data *per_cu, frame_info_ptr frame,
+		   dwarf2_per_cu_data *per_cu, const frame_info_ptr &frame,
 		   const struct property_addr_info *addr_info = nullptr,
 		   struct type *type = nullptr,
 		   struct type *subobj_type = nullptr,
@@ -256,7 +256,7 @@ private:
 
 /* Return the value of register number REG (a DWARF register number),
    read as an address in a given FRAME.  */
-CORE_ADDR read_addr_from_reg (frame_info_ptr frame, int reg);
+CORE_ADDR read_addr_from_reg (const frame_info_ptr &frame, int reg);
 
 void dwarf_expr_require_composition (const gdb_byte *, const gdb_byte *,
 				     const char *);
diff --git a/gdb/dwarf2/frame-tailcall.c b/gdb/dwarf2/frame-tailcall.c
index 27a820a..2f6400d 100644
--- a/gdb/dwarf2/frame-tailcall.c
+++ b/gdb/dwarf2/frame-tailcall.c
@@ -90,7 +90,7 @@ cache_eq (const void *arg1, const void *arg2)
    tailcall_cache.  */
 
 static struct tailcall_cache *
-cache_new_ref1 (frame_info_ptr next_bottom_frame)
+cache_new_ref1 (const frame_info_ptr &next_bottom_frame)
 {
   struct tailcall_cache *cache = XCNEW (struct tailcall_cache);
   void **slot;
@@ -137,7 +137,7 @@ cache_unref (struct tailcall_cache *cache)
    return 0.  */
 
 static int
-frame_is_tailcall (frame_info_ptr fi)
+frame_is_tailcall (const frame_info_ptr &fi)
 {
   return frame_unwinder_is (fi, &dwarf2_tailcall_frame_unwind);
 }
@@ -146,12 +146,13 @@ frame_is_tailcall (frame_info_ptr fi)
    call chain.  Otherwise return NULL.  No new reference is created.  */
 
 static struct tailcall_cache *
-cache_find (frame_info_ptr fi)
+cache_find (const frame_info_ptr &initial_fi)
 {
   struct tailcall_cache *cache;
   struct tailcall_cache search;
   void **slot;
 
+  frame_info_ptr fi = initial_fi;
   while (frame_is_tailcall (fi))
     {
       fi = get_next_frame (fi);
@@ -173,7 +174,7 @@ cache_find (frame_info_ptr fi)
    If THIS_FRAME is CACHE-> NEXT_BOTTOM_FRAME return -1.  */
 
 static int
-existing_next_levels (frame_info_ptr this_frame,
+existing_next_levels (const frame_info_ptr &this_frame,
 		      struct tailcall_cache *cache)
 {
   int retval = (frame_relative_level (this_frame)
@@ -210,7 +211,7 @@ pretended_chain_levels (struct call_site_chain *chain)
    Specific virtual tail call frames are tracked by INLINE_DEPTH.  */
 
 static void
-tailcall_frame_this_id (frame_info_ptr this_frame, void **this_cache,
+tailcall_frame_this_id (const frame_info_ptr &this_frame, void **this_cache,
 			struct frame_id *this_id)
 {
   struct tailcall_cache *cache = (struct tailcall_cache *) *this_cache;
@@ -232,7 +233,7 @@ tailcall_frame_this_id (frame_info_ptr this_frame, void **this_cache,
    CACHE.  */
 
 static CORE_ADDR
-pretend_pc (frame_info_ptr this_frame, struct tailcall_cache *cache)
+pretend_pc (const frame_info_ptr &this_frame, struct tailcall_cache *cache)
 {
   int next_levels = existing_next_levels (this_frame, cache);
   struct call_site_chain *chain = cache->chain;
@@ -264,7 +265,7 @@ pretend_pc (frame_info_ptr this_frame, struct tailcall_cache *cache)
    frames unwind the NULL case differently.  */
 
 struct value *
-dwarf2_tailcall_prev_register_first (frame_info_ptr this_frame,
+dwarf2_tailcall_prev_register_first (const frame_info_ptr &this_frame,
 				     void **tailcall_cachep, int regnum)
 {
   struct gdbarch *this_gdbarch = get_frame_arch (this_frame);
@@ -294,7 +295,7 @@ dwarf2_tailcall_prev_register_first (frame_info_ptr this_frame,
    dwarf2_tailcall_prev_register_first.  */
 
 static struct value *
-tailcall_frame_prev_register (frame_info_ptr this_frame,
+tailcall_frame_prev_register (const frame_info_ptr &this_frame,
 			       void **this_cache, int regnum)
 {
   struct tailcall_cache *cache = (struct tailcall_cache *) *this_cache;
@@ -316,7 +317,7 @@ tailcall_frame_prev_register (frame_info_ptr this_frame,
 
 static int
 tailcall_frame_sniffer (const struct frame_unwind *self,
-			 frame_info_ptr this_frame, void **this_cache)
+			 const frame_info_ptr &this_frame, void **this_cache)
 {
   frame_info_ptr next_frame;
   int next_levels;
@@ -363,7 +364,7 @@ tailcall_frame_sniffer (const struct frame_unwind *self,
    address pushed on the stack.  */
 
 void
-dwarf2_tailcall_sniffer_first (frame_info_ptr this_frame,
+dwarf2_tailcall_sniffer_first (const frame_info_ptr &this_frame,
 			       void **tailcall_cachep,
 			       const LONGEST *entry_cfa_sp_offsetp)
 {
@@ -458,7 +459,7 @@ tailcall_frame_dealloc_cache (frame_info *self, void *this_cache)
    call frames have gdbarch of the bottom (callee) frame.  */
 
 static struct gdbarch *
-tailcall_frame_prev_arch (frame_info_ptr this_frame,
+tailcall_frame_prev_arch (const frame_info_ptr &this_frame,
 			  void **this_prologue_cache)
 {
   struct tailcall_cache *cache = (struct tailcall_cache *) *this_prologue_cache;
diff --git a/gdb/dwarf2/frame-tailcall.h b/gdb/dwarf2/frame-tailcall.h
index b0809c8..3f49487 100644
--- a/gdb/dwarf2/frame-tailcall.h
+++ b/gdb/dwarf2/frame-tailcall.h
@@ -26,12 +26,12 @@ struct frame_unwind;
 /* The tail call frame unwinder.  */
 
 extern void
-  dwarf2_tailcall_sniffer_first (frame_info_ptr this_frame,
+  dwarf2_tailcall_sniffer_first (const frame_info_ptr &this_frame,
 				 void **tailcall_cachep,
 				 const LONGEST *entry_cfa_sp_offsetp);
 
 extern struct value *
-  dwarf2_tailcall_prev_register_first (frame_info_ptr this_frame,
+  dwarf2_tailcall_prev_register_first (const frame_info_ptr &this_frame,
 				       void **tailcall_cachep, int regnum);
 
 extern const struct frame_unwind dwarf2_tailcall_frame_unwind;
diff --git a/gdb/dwarf2/frame.c b/gdb/dwarf2/frame.c
index fc6704f..530513c 100644
--- a/gdb/dwarf2/frame.c
+++ b/gdb/dwarf2/frame.c
@@ -233,7 +233,7 @@ register %s (#%d) at %s"),
 
 static CORE_ADDR
 execute_stack_op (const gdb_byte *exp, ULONGEST len, int addr_size,
-		  frame_info_ptr this_frame, CORE_ADDR initial,
+		  const frame_info_ptr &this_frame, CORE_ADDR initial,
 		  int initial_in_stack_memory, dwarf2_per_objfile *per_objfile)
 {
   dwarf_expr_context ctx (per_objfile, addr_size);
@@ -589,17 +589,17 @@ execute_cfa_program_test (struct gdbarch *gdbarch)
 static void dwarf2_frame_default_init_reg (struct gdbarch *gdbarch,
 					   int regnum,
 					   struct dwarf2_frame_state_reg *reg,
-					   frame_info_ptr this_frame);
+					   const frame_info_ptr &this_frame);
 
 struct dwarf2_frame_ops
 {
   /* Pre-initialize the register state REG for register REGNUM.  */
   void (*init_reg) (struct gdbarch *, int, struct dwarf2_frame_state_reg *,
-		    frame_info_ptr)
+		    const frame_info_ptr &)
     = dwarf2_frame_default_init_reg;
 
   /* Check whether the THIS_FRAME is a signal trampoline.  */
-  int (*signal_frame_p) (struct gdbarch *, frame_info_ptr) = nullptr;
+  int (*signal_frame_p) (struct gdbarch *, const frame_info_ptr &) = nullptr;
 
   /* Convert .eh_frame register number to DWARF register number, or
      adjust .debug_frame register number.  */
@@ -625,7 +625,7 @@ get_frame_ops (struct gdbarch *gdbarch)
 static void
 dwarf2_frame_default_init_reg (struct gdbarch *gdbarch, int regnum,
 			       struct dwarf2_frame_state_reg *reg,
-			       frame_info_ptr this_frame)
+			       const frame_info_ptr &this_frame)
 {
   /* If we have a register that acts as a program counter, mark it as
      a destination for the return address.  If we have a register that
@@ -666,7 +666,7 @@ void
 dwarf2_frame_set_init_reg (struct gdbarch *gdbarch,
 			   void (*init_reg) (struct gdbarch *, int,
 					     struct dwarf2_frame_state_reg *,
-					     frame_info_ptr))
+					     const frame_info_ptr &))
 {
   struct dwarf2_frame_ops *ops = get_frame_ops (gdbarch);
 
@@ -678,7 +678,7 @@ dwarf2_frame_set_init_reg (struct gdbarch *gdbarch,
 static void
 dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum,
 		       struct dwarf2_frame_state_reg *reg,
-		       frame_info_ptr this_frame)
+		       const frame_info_ptr &this_frame)
 {
   struct dwarf2_frame_ops *ops = get_frame_ops (gdbarch);
 
@@ -691,7 +691,7 @@ dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum,
 void
 dwarf2_frame_set_signal_frame_p (struct gdbarch *gdbarch,
 				 int (*signal_frame_p) (struct gdbarch *,
-							frame_info_ptr))
+							const frame_info_ptr &))
 {
   struct dwarf2_frame_ops *ops = get_frame_ops (gdbarch);
 
@@ -703,7 +703,7 @@ dwarf2_frame_set_signal_frame_p (struct gdbarch *gdbarch,
 
 static int
 dwarf2_frame_signal_frame_p (struct gdbarch *gdbarch,
-			     frame_info_ptr this_frame)
+			     const frame_info_ptr &this_frame)
 {
   struct dwarf2_frame_ops *ops = get_frame_ops (gdbarch);
 
@@ -890,7 +890,7 @@ struct dwarf2_frame_cache
 };
 
 static struct dwarf2_frame_cache *
-dwarf2_frame_cache (frame_info_ptr this_frame, void **this_cache)
+dwarf2_frame_cache (const frame_info_ptr &this_frame, void **this_cache)
 {
   struct gdbarch *gdbarch = get_frame_arch (this_frame);
   const int num_regs = gdbarch_num_cooked_regs (gdbarch);
@@ -1120,7 +1120,7 @@ incomplete CFI data; unspecified registers (e.g., %s) at %s"),
 }
 
 static enum unwind_stop_reason
-dwarf2_frame_unwind_stop_reason (frame_info_ptr this_frame,
+dwarf2_frame_unwind_stop_reason (const frame_info_ptr &this_frame,
 				 void **this_cache)
 {
   struct dwarf2_frame_cache *cache
@@ -1136,7 +1136,7 @@ dwarf2_frame_unwind_stop_reason (frame_info_ptr this_frame,
 }
 
 static void
-dwarf2_frame_this_id (frame_info_ptr this_frame, void **this_cache,
+dwarf2_frame_this_id (const frame_info_ptr &this_frame, void **this_cache,
 		      struct frame_id *this_id)
 {
   struct dwarf2_frame_cache *cache =
@@ -1151,7 +1151,7 @@ dwarf2_frame_this_id (frame_info_ptr this_frame, void **this_cache,
 }
 
 static struct value *
-dwarf2_frame_prev_register (frame_info_ptr this_frame, void **this_cache,
+dwarf2_frame_prev_register (const frame_info_ptr &this_frame, void **this_cache,
 			    int regnum)
 {
   struct gdbarch *gdbarch = get_frame_arch (this_frame);
@@ -1253,7 +1253,7 @@ dwarf2_frame_prev_register (frame_info_ptr this_frame, void **this_cache,
 /* See frame.h.  */
 
 void *
-dwarf2_frame_get_fn_data (frame_info_ptr this_frame, void **this_cache,
+dwarf2_frame_get_fn_data (const frame_info_ptr &this_frame, void **this_cache,
 			  fn_prev_register cookie)
 {
   struct dwarf2_frame_fn_data *fn_data = nullptr;
@@ -1271,7 +1271,7 @@ dwarf2_frame_get_fn_data (frame_info_ptr this_frame, void **this_cache,
 /* See frame.h.  */
 
 void *
-dwarf2_frame_allocate_fn_data (frame_info_ptr this_frame, void **this_cache,
+dwarf2_frame_allocate_fn_data (const frame_info_ptr &this_frame, void **this_cache,
 			       fn_prev_register cookie, unsigned long size)
 {
   struct dwarf2_frame_fn_data *fn_data = nullptr;
@@ -1307,7 +1307,7 @@ dwarf2_frame_dealloc_cache (frame_info *self, void *this_cache)
 
 static int
 dwarf2_frame_sniffer (const struct frame_unwind *self,
-		      frame_info_ptr this_frame, void **this_cache)
+		      const frame_info_ptr &this_frame, void **this_cache)
 {
   if (!dwarf2_frame_unwinders_enabled_p)
     return 0;
@@ -1383,7 +1383,7 @@ dwarf2_append_unwinders (struct gdbarch *gdbarch)
    response to the "info frame" command.  */
 
 static CORE_ADDR
-dwarf2_frame_base_address (frame_info_ptr this_frame, void **this_cache)
+dwarf2_frame_base_address (const frame_info_ptr &this_frame, void **this_cache)
 {
   struct dwarf2_frame_cache *cache =
     dwarf2_frame_cache (this_frame, this_cache);
@@ -1400,7 +1400,7 @@ static const struct frame_base dwarf2_frame_base =
 };
 
 const struct frame_base *
-dwarf2_frame_base_sniffer (frame_info_ptr this_frame)
+dwarf2_frame_base_sniffer (const frame_info_ptr &this_frame)
 {
   CORE_ADDR block_addr = get_frame_address_in_block (this_frame);
 
@@ -1415,8 +1415,10 @@ dwarf2_frame_base_sniffer (frame_info_ptr this_frame)
    DW_OP_call_frame_cfa.  */
 
 CORE_ADDR
-dwarf2_frame_cfa (frame_info_ptr this_frame)
+dwarf2_frame_cfa (const frame_info_ptr &initial_this_frame)
 {
+  frame_info_ptr this_frame = initial_this_frame;
+
   if (frame_unwinder_is (this_frame, &record_btrace_tailcall_frame_unwind)
       || frame_unwinder_is (this_frame, &record_btrace_frame_unwind))
     throw_error (NOT_AVAILABLE_ERROR,
diff --git a/gdb/dwarf2/frame.h b/gdb/dwarf2/frame.h
index 1ef35ee..2167310 100644
--- a/gdb/dwarf2/frame.h
+++ b/gdb/dwarf2/frame.h
@@ -66,7 +66,7 @@ enum dwarf2_frame_reg_rule
 
 /* Register state.  */
 
-typedef struct value *(*fn_prev_register) (frame_info_ptr this_frame,
+typedef struct value *(*fn_prev_register) (const frame_info_ptr &this_frame,
 					   void **this_cache, int regnum);
 
 struct dwarf2_frame_state_reg
@@ -207,18 +207,17 @@ extern bool dwarf2_frame_unwinders_enabled_p;
 /* Set the architecture-specific register state initialization
    function for GDBARCH to INIT_REG.  */
 
-extern void dwarf2_frame_set_init_reg (struct gdbarch *gdbarch,
-				       void (*init_reg) (struct gdbarch *, int,
-					     struct dwarf2_frame_state_reg *,
-					     frame_info_ptr));
+extern void dwarf2_frame_set_init_reg (
+  gdbarch *gdbarch, void (*init_reg) (struct gdbarch *, int,
+				      dwarf2_frame_state_reg *,
+				      const frame_info_ptr &));
 
 /* Set the architecture-specific signal trampoline recognition
    function for GDBARCH to SIGNAL_FRAME_P.  */
 
-extern void
-  dwarf2_frame_set_signal_frame_p (struct gdbarch *gdbarch,
-				   int (*signal_frame_p) (struct gdbarch *,
-							  frame_info_ptr));
+extern void dwarf2_frame_set_signal_frame_p
+  (gdbarch *gdbarch, int (*signal_frame_p) (struct gdbarch *,
+			  const frame_info_ptr &));
 
 /* Set the architecture-specific adjustment of .eh_frame and .debug_frame
    register numbers.  */
@@ -236,11 +235,11 @@ void dwarf2_append_unwinders (struct gdbarch *gdbarch);
    NULL if it can't be handled by the DWARF CFI frame unwinder.  */
 
 extern const struct frame_base *
-  dwarf2_frame_base_sniffer (frame_info_ptr this_frame);
+  dwarf2_frame_base_sniffer (const frame_info_ptr &this_frame);
 
 /* Compute the DWARF CFA for a frame.  */
 
-CORE_ADDR dwarf2_frame_cfa (frame_info_ptr this_frame);
+CORE_ADDR dwarf2_frame_cfa (const frame_info_ptr &this_frame);
 
 /* Find the CFA information for PC.
 
@@ -276,7 +275,7 @@ extern int dwarf2_fetch_cfa_info (struct gdbarch *gdbarch, CORE_ADDR pc,
    COOKIE is the key for the prev_function implementation.
    SIZE is the size of the custom data object to allocate.  */
 
-extern void *dwarf2_frame_allocate_fn_data (frame_info_ptr this_frame,
+extern void *dwarf2_frame_allocate_fn_data (const frame_info_ptr &this_frame,
 					    void **this_cache,
 					    fn_prev_register cookie,
 					    unsigned long size);
@@ -291,7 +290,7 @@ extern void *dwarf2_frame_allocate_fn_data (frame_info_ptr this_frame,
    THIS_CACHE is the dwarf2 cache object to store the pointer on.
    COOKIE is the key for the prev_function implementation.  */
 
-extern void *dwarf2_frame_get_fn_data (frame_info_ptr this_frame,
+extern void *dwarf2_frame_get_fn_data (const frame_info_ptr &this_frame,
 				       void **this_cache,
 				       fn_prev_register cookie);
 
diff --git a/gdb/dwarf2/loc.c b/gdb/dwarf2/loc.c
index 0f0d14f..203ad53 100644
--- a/gdb/dwarf2/loc.c
+++ b/gdb/dwarf2/loc.c
@@ -48,7 +48,7 @@
 #include "gdbsupport/byte-vector.h"
 
 static struct value *dwarf2_evaluate_loc_desc_full
-  (struct type *type, frame_info_ptr frame, const gdb_byte *data,
+  (struct type *type, const frame_info_ptr &frame, const gdb_byte *data,
    size_t size, dwarf2_per_cu_data *per_cu, dwarf2_per_objfile *per_objfile,
    struct type *subobj_type, LONGEST subobj_byte_offset, bool as_lval = true);
 
@@ -503,7 +503,7 @@ locexpr_find_frame_base_location (struct symbol *framefunc, CORE_ADDR pc,
    LOC_BLOCK functions using a DWARF expression as its DW_AT_frame_base.  */
 
 static CORE_ADDR
-locexpr_get_frame_base (struct symbol *framefunc, frame_info_ptr frame)
+locexpr_get_frame_base (struct symbol *framefunc, const frame_info_ptr &frame)
 {
   struct gdbarch *gdbarch;
   struct type *type;
@@ -561,7 +561,7 @@ loclist_find_frame_base_location (struct symbol *framefunc, CORE_ADDR pc,
    LOC_BLOCK functions using a DWARF location list as its DW_AT_frame_base.  */
 
 static CORE_ADDR
-loclist_get_frame_base (struct symbol *framefunc, frame_info_ptr frame)
+loclist_get_frame_base (struct symbol *framefunc, const frame_info_ptr &frame)
 {
   struct gdbarch *gdbarch;
   struct type *type;
@@ -649,11 +649,10 @@ show_entry_values_debug (struct ui_file *file, int from_tty,
 /* See gdbtypes.h.  */
 
 void
-call_site_target::iterate_over_addresses
-     (struct gdbarch *call_site_gdbarch,
-      const struct call_site *call_site,
-      frame_info_ptr caller_frame,
-      iterate_ftype callback) const
+call_site_target::iterate_over_addresses (gdbarch *call_site_gdbarch,
+					  const call_site *call_site,
+					  const frame_info_ptr &caller_frame,
+					  iterate_ftype callback) const
 {
   switch (m_loc_kind)
     {
@@ -1138,9 +1137,9 @@ call_site_parameter_matches (struct call_site_parameter *parameter,
 /* See loc.h.  */
 
 struct call_site_parameter *
-dwarf_expr_reg_to_entry_parameter (frame_info_ptr frame,
-				   enum call_site_parameter_kind kind,
-				   union call_site_parameter_u kind_u,
+dwarf_expr_reg_to_entry_parameter (const frame_info_ptr &initial_frame,
+				   call_site_parameter_kind kind,
+				   call_site_parameter_u kind_u,
 				   dwarf2_per_cu_data **per_cu_return,
 				   dwarf2_per_objfile **per_objfile_return)
 {
@@ -1152,6 +1151,7 @@ dwarf_expr_reg_to_entry_parameter (frame_info_ptr frame,
   /* Initialize it just to avoid a GCC false warning.  */
   struct call_site_parameter *parameter = NULL;
   CORE_ADDR target_addr;
+  frame_info_ptr frame = initial_frame;
 
   while (get_frame_type (frame) == INLINE_FRAME)
     {
@@ -1263,7 +1263,7 @@ dwarf_expr_reg_to_entry_parameter (frame_info_ptr frame,
 static struct value *
 dwarf_entry_parameter_to_value (struct call_site_parameter *parameter,
 				CORE_ADDR deref_size, struct type *type,
-				frame_info_ptr caller_frame,
+				const frame_info_ptr &caller_frame,
 				dwarf2_per_cu_data *per_cu,
 				dwarf2_per_objfile *per_objfile)
 {
@@ -1339,7 +1339,7 @@ static const struct lval_funcs entry_data_value_funcs =
 
 /* See dwarf2/loc.h.  */
 struct value *
-value_of_dwarf_reg_entry (struct type *type, frame_info_ptr frame,
+value_of_dwarf_reg_entry (struct type *type, const frame_info_ptr &frame,
 			  enum call_site_parameter_kind kind,
 			  union call_site_parameter_u kind_u)
 {
@@ -1395,7 +1395,7 @@ value_of_dwarf_reg_entry (struct type *type, frame_info_ptr frame,
    cannot resolve the parameter for any reason.  */
 
 static struct value *
-value_of_dwarf_block_entry (struct type *type, frame_info_ptr frame,
+value_of_dwarf_block_entry (struct type *type, const frame_info_ptr &frame,
 			    const gdb_byte *block, size_t block_len)
 {
   union call_site_parameter_u kind_u;
@@ -1456,7 +1456,7 @@ struct value *
 indirect_synthetic_pointer (sect_offset die, LONGEST byte_offset,
 			    dwarf2_per_cu_data *per_cu,
 			    dwarf2_per_objfile *per_objfile,
-			    frame_info_ptr frame, struct type *type,
+			    const frame_info_ptr &frame, struct type *type,
 			    bool resolve_abstract_p)
 {
   /* Fetch the location expression of the DIE we're pointing to.  */
@@ -1496,7 +1496,7 @@ indirect_synthetic_pointer (sect_offset die, LONGEST byte_offset,
    SUBOBJ_BYTE_OFFSET within the variable of type TYPE.  */
 
 static struct value *
-dwarf2_evaluate_loc_desc_full (struct type *type, frame_info_ptr frame,
+dwarf2_evaluate_loc_desc_full (struct type *type, const frame_info_ptr &frame,
 			       const gdb_byte *data, size_t size,
 			       dwarf2_per_cu_data *per_cu,
 			       dwarf2_per_objfile *per_objfile,
@@ -1561,7 +1561,7 @@ dwarf2_evaluate_loc_desc_full (struct type *type, frame_info_ptr frame,
    passes 0 as the byte_offset.  */
 
 struct value *
-dwarf2_evaluate_loc_desc (struct type *type, frame_info_ptr frame,
+dwarf2_evaluate_loc_desc (struct type *type, const frame_info_ptr &frame,
 			  const gdb_byte *data, size_t size,
 			  dwarf2_per_cu_data *per_cu,
 			  dwarf2_per_objfile *per_objfile, bool as_lval)
@@ -1584,7 +1584,7 @@ dwarf2_evaluate_loc_desc (struct type *type, frame_info_ptr frame,
 
 static int
 dwarf2_locexpr_baton_eval (const struct dwarf2_locexpr_baton *dlbaton,
-			   frame_info_ptr frame,
+			   const frame_info_ptr &frame,
 			   const struct property_addr_info *addr_stack,
 			   CORE_ADDR *valp,
 			   gdb::array_view<CORE_ADDR> push_values,
@@ -1644,9 +1644,9 @@ dwarf2_locexpr_baton_eval (const struct dwarf2_locexpr_baton *dlbaton,
 /* See dwarf2/loc.h.  */
 
 bool
-dwarf2_evaluate_property (const struct dynamic_prop *prop,
-			  frame_info_ptr frame,
-			  const struct property_addr_info *addr_stack,
+dwarf2_evaluate_property (const dynamic_prop *prop,
+			  const frame_info_ptr &initial_frame,
+			  const property_addr_info *addr_stack,
 			  CORE_ADDR *value,
 			  gdb::array_view<CORE_ADDR> push_values)
 {
@@ -1657,6 +1657,7 @@ dwarf2_evaluate_property (const struct dynamic_prop *prop,
      Without this here this could happen if the code below selects a
      frame.  */
   scoped_restore_current_language save_language;
+  frame_info_ptr frame = initial_frame;
 
   if (frame == NULL && has_stack_frames ())
     frame = get_selected_frame (NULL);
@@ -3051,7 +3052,7 @@ dwarf2_compile_expr_to_ax (struct agent_expr *expr, struct axs_value *loc,
 /* Return the value of SYMBOL in FRAME using the DWARF-2 expression
    evaluator to calculate the location.  */
 static struct value *
-locexpr_read_variable (struct symbol *symbol, frame_info_ptr frame)
+locexpr_read_variable (struct symbol *symbol, const frame_info_ptr &frame)
 {
   struct dwarf2_locexpr_baton *dlbaton
     = (struct dwarf2_locexpr_baton *) SYMBOL_LOCATION_BATON (symbol);
@@ -3069,7 +3070,7 @@ locexpr_read_variable (struct symbol *symbol, frame_info_ptr frame)
    will be thrown.  */
 
 static struct value *
-locexpr_read_variable_at_entry (struct symbol *symbol, frame_info_ptr frame)
+locexpr_read_variable_at_entry (struct symbol *symbol, const frame_info_ptr &frame)
 {
   struct dwarf2_locexpr_baton *dlbaton
     = (struct dwarf2_locexpr_baton *) SYMBOL_LOCATION_BATON (symbol);
@@ -3884,7 +3885,7 @@ const struct symbol_computed_ops dwarf2_locexpr_funcs = {
 /* Return the value of SYMBOL in FRAME using the DWARF-2 expression
    evaluator to calculate the location.  */
 static struct value *
-loclist_read_variable (struct symbol *symbol, frame_info_ptr frame)
+loclist_read_variable (struct symbol *symbol, const frame_info_ptr &frame)
 {
   struct dwarf2_loclist_baton *dlbaton
     = (struct dwarf2_loclist_baton *) SYMBOL_LOCATION_BATON (symbol);
@@ -3909,7 +3910,7 @@ loclist_read_variable (struct symbol *symbol, frame_info_ptr frame)
    if it cannot resolve the parameter for any reason.  */
 
 static struct value *
-loclist_read_variable_at_entry (struct symbol *symbol, frame_info_ptr frame)
+loclist_read_variable_at_entry (struct symbol *symbol, const frame_info_ptr &frame)
 {
   struct dwarf2_loclist_baton *dlbaton
     = (struct dwarf2_loclist_baton *) SYMBOL_LOCATION_BATON (symbol);
diff --git a/gdb/dwarf2/loc.h b/gdb/dwarf2/loc.h
index fb98e26..4fb7436 100644
--- a/gdb/dwarf2/loc.h
+++ b/gdb/dwarf2/loc.h
@@ -65,9 +65,9 @@ value *compute_var_value (const char *name);
    Function always returns non-NULL, it throws NO_ENTRY_VALUE_ERROR
    otherwise.  */
 
-struct call_site_parameter *dwarf_expr_reg_to_entry_parameter
-  (frame_info_ptr frame, enum call_site_parameter_kind kind,
-   union call_site_parameter_u kind_u, dwarf2_per_cu_data **per_cu_return,
+call_site_parameter *dwarf_expr_reg_to_entry_parameter
+  (const frame_info_ptr &frame, call_site_parameter_kind kind,
+   call_site_parameter_u kind_u, dwarf2_per_cu_data **per_cu_return,
    dwarf2_per_objfile **per_objfile_return);
 
 
@@ -76,13 +76,11 @@ struct call_site_parameter *dwarf_expr_reg_to_entry_parameter
    of FRAME.  AS_LVAL defines if the resulting struct value is expected to
    be a value or a location description.  */
 
-struct value *dwarf2_evaluate_loc_desc (struct type *type,
-					frame_info_ptr frame,
-					const gdb_byte *data,
-					size_t size,
-					dwarf2_per_cu_data *per_cu,
-					dwarf2_per_objfile *per_objfile,
-					bool as_lval = true);
+value *dwarf2_evaluate_loc_desc (type *type, const frame_info_ptr &frame,
+				 const gdb_byte *data, size_t size,
+				 dwarf2_per_cu_data *per_cu,
+				 dwarf2_per_objfile *per_objfile,
+				 bool as_lval = true);
 
 /* A chain of addresses that might be needed to resolve a dynamic
    property.  */
@@ -121,8 +119,8 @@ struct property_addr_info
    bottom of the stack.  */
 
 bool dwarf2_evaluate_property (const struct dynamic_prop *prop,
-			       frame_info_ptr frame,
-			       const struct property_addr_info *addr_stack,
+			       const frame_info_ptr &frame,
+			       const property_addr_info *addr_stack,
 			       CORE_ADDR *value,
 			       gdb::array_view<CORE_ADDR> push_values = {});
 
@@ -296,7 +294,7 @@ extern void invalid_synthetic_pointer ();
 
 extern struct value *indirect_synthetic_pointer
   (sect_offset die, LONGEST byte_offset, dwarf2_per_cu_data *per_cu,
-   dwarf2_per_objfile *per_objfile, frame_info_ptr frame,
+   dwarf2_per_objfile *per_objfile, const frame_info_ptr &frame,
    struct type *type, bool resolve_abstract_p = false);
 
 /* Read parameter of TYPE at (callee) FRAME's function entry.  KIND and KIND_U
@@ -307,7 +305,7 @@ extern struct value *indirect_synthetic_pointer
    it cannot resolve the parameter for any reason.  */
 
 extern struct value *value_of_dwarf_reg_entry (struct type *type,
-					       struct frame_info_ptr frame,
+					       const frame_info_ptr &frame,
 					       enum call_site_parameter_kind kind,
 					       union call_site_parameter_u kind_u);
 #endif /* DWARF2LOC_H */