diff mbox

[v4,01/10] Language independent bits

Message ID 1395463432-29750-2-git-send-email-sergiodj@redhat.com
State Committed
Headers show

Commit Message

Sergio Durigan Junior March 22, 2014, 4:43 a.m. UTC
This patch does a refactoring on gdb/{parse.c,parser-defs.h,language.*}
in order to remove the `expout*' globals.  It creates a new
structure called `parser_state' which holds those variables per-parser,
and eventually will hold all the global parser variables.

This patch also creates a helper cleanup responsible for resetting the
value of the parser state on each parser.

2014-03-22  Sergio Durigan Junior  <sergiodj@redhat.com>

	* language.c (unk_lang_parser): Add "struct parser_state"
	argument.
	* language.h (struct language_defn) <la_parser>: Likewise.
	* parse.c (expout, expout_size, expout_ptr): Remove variables.
	(initialize_expout): Add "struct parser_state" argument.
	Rewrite function to use the parser state.
	(reallocate_expout, write_exp_elt, write_exp_elt_opcode,
	write_exp_elt_sym, write_exp_elt_block, write_exp_elt_objfile,
	write_exp_elt_longcst, write_exp_elt_dblcst,
	write_exp_elt_decfloatcst, write_exp_elt_type,
	write_exp_elt_intern, write_exp_string, write_exp_string_vector,
	write_exp_bitstring, write_exp_msymbol, mark_struct_expression,
	write_dollar_variable): Likewise.
	(parse_exp_in_context_1): Use parser state.
	(insert_type_address_space): Add "struct parser_state" argument.
	Use parser state.
	(increase_expout_size): New function.
	* parser-defs.h: Forward declare "struct language_defn" and
	"struct parser_state".
	(expout, expout_size, expout_ptr): Remove extern declarations.
	(parse_gdbarch, parse_language): Rewrite macro declarations to
	accept the parser state.
	(struct parser_state): New struct.
	(initialize_expout, reallocate_expout, write_exp_elt_opcode,
	write_exp_elt_sym, write_exp_elt_longcst, write_exp_elt_dblcst,
	write_exp_elt_decfloatcst, write_exp_elt_type,
	write_exp_elt_intern, write_exp_string, write_exp_string_vector,
	write_exp_bitstring, write_exp_elt_block, write_exp_elt_objfile,
	write_exp_msymbol, write_dollar_variable,
	mark_struct_expression, insert_type_address_space): Add "struct
	parser_state" argument.
	(increase_expout_size): New function.
	* utils.c (do_clear_parser_state): New function.
	(make_cleanup_clear_parser_state): Likewise.
	* utils.h (make_cleanup_clear_parser_state): New function
	prototype.
---
 gdb/language.c    |   4 +-
 gdb/language.h    |   3 +-
 gdb/parse.c       | 277 +++++++++++++++++++++++++++---------------------------
 gdb/parser-defs.h |  83 ++++++++++------
 gdb/utils.c       |  18 ++++
 gdb/utils.h       |   4 +
 6 files changed, 217 insertions(+), 172 deletions(-)
diff mbox

Patch

diff --git a/gdb/language.c b/gdb/language.c
index ae0fa15..d5502f2 100644
--- a/gdb/language.c
+++ b/gdb/language.c
@@ -50,7 +50,7 @@  extern void _initialize_language (void);
 
 static void unk_lang_error (char *);
 
-static int unk_lang_parser (void);
+static int unk_lang_parser (struct parser_state *);
 
 static void show_check (char *, int);
 
@@ -694,7 +694,7 @@  default_get_string (struct value *value, gdb_byte **buffer, int *length,
 /* Define the language that is no language.  */
 
 static int
-unk_lang_parser (void)
+unk_lang_parser (struct parser_state *ps)
 {
   return 1;
 }
diff --git a/gdb/language.h b/gdb/language.h
index ded595f..9e95bf2 100644
--- a/gdb/language.h
+++ b/gdb/language.h
@@ -34,6 +34,7 @@  struct ui_file;
 struct value_print_options;
 struct type_print_options;
 struct lang_varobj_ops;
+struct parser_state;
 
 #define MAX_FORTRAN_DIMS  7	/* Maximum number of F77 array dims.  */
 
@@ -164,7 +165,7 @@  struct language_defn
 
     /* Parser function.  */
 
-    int (*la_parser) (void);
+    int (*la_parser) (struct parser_state *);
 
     /* Parser error function.  */
 
diff --git a/gdb/parse.c b/gdb/parse.c
index c6e25a9..b0da2ef 100644
--- a/gdb/parse.c
+++ b/gdb/parse.c
@@ -67,9 +67,6 @@  const struct exp_descriptor exp_descriptor_standard =
   };
 
 /* Global variables declared in parser-defs.h (and commented there).  */
-struct expression *expout;
-int expout_size;
-int expout_ptr;
 const struct block *expression_context_block;
 CORE_ADDR expression_context_pc;
 const struct block *innermost_block;
@@ -185,118 +182,121 @@  free_funcalls (void *ignore)
     }
 }
 
-/* This page contains the functions for adding data to the struct expression
-   being constructed.  */
 
 /* See definition in parser-defs.h.  */
 
 void
-initialize_expout (int initial_size, const struct language_defn *lang,
+initialize_expout (struct parser_state *ps, size_t initial_size,
+		   const struct language_defn *lang,
 		   struct gdbarch *gdbarch)
 {
-  expout_size = initial_size;
-  expout_ptr = 0;
-  expout = xmalloc (sizeof (struct expression)
-		    + EXP_ELEM_TO_BYTES (expout_size));
-  expout->language_defn = lang;
-  expout->gdbarch = gdbarch;
+  ps->expout_size = initial_size;
+  ps->expout_ptr = 0;
+  ps->expout = xmalloc (sizeof (struct expression)
+			+ EXP_ELEM_TO_BYTES (ps->expout_size));
+  ps->expout->language_defn = lang;
+  ps->expout->gdbarch = gdbarch;
 }
 
 /* See definition in parser-defs.h.  */
 
 void
-reallocate_expout (void)
+reallocate_expout (struct parser_state *ps)
 {
   /* Record the actual number of expression elements, and then
      reallocate the expression memory so that we free up any
      excess elements.  */
 
-  expout->nelts = expout_ptr;
-  expout = xrealloc ((char *) expout,
-		     sizeof (struct expression)
-		     + EXP_ELEM_TO_BYTES (expout_ptr));
+  ps->expout->nelts = ps->expout_ptr;
+  ps->expout = (struct expression *)
+     xrealloc (ps->expout,
+	       sizeof (struct expression)
+	       + EXP_ELEM_TO_BYTES (ps->expout_ptr));
 }
 
+/* This page contains the functions for adding data to the struct expression
+   being constructed.  */
+
 /* Add one element to the end of the expression.  */
 
 /* To avoid a bug in the Sun 4 compiler, we pass things that can fit into
    a register through here.  */
 
 static void
-write_exp_elt (const union exp_element *expelt)
+write_exp_elt (struct parser_state *ps, const union exp_element *expelt)
 {
-  if (expout_ptr >= expout_size)
+  if (ps->expout_ptr >= ps->expout_size)
     {
-      expout_size *= 2;
-      expout = (struct expression *)
-	xrealloc ((char *) expout, sizeof (struct expression)
-		  + EXP_ELEM_TO_BYTES (expout_size));
+      ps->expout_size *= 2;
+      ps->expout = (struct expression *)
+	xrealloc (ps->expout, sizeof (struct expression)
+		  + EXP_ELEM_TO_BYTES (ps->expout_size));
     }
-  expout->elts[expout_ptr++] = *expelt;
+  ps->expout->elts[ps->expout_ptr++] = *expelt;
 }
 
 void
-write_exp_elt_opcode (enum exp_opcode expelt)
+write_exp_elt_opcode (struct parser_state *ps, enum exp_opcode expelt)
 {
   union exp_element tmp;
 
   memset (&tmp, 0, sizeof (union exp_element));
   tmp.opcode = expelt;
-  write_exp_elt (&tmp);
+  write_exp_elt (ps, &tmp);
 }
 
 void
-write_exp_elt_sym (struct symbol *expelt)
+write_exp_elt_sym (struct parser_state *ps, struct symbol *expelt)
 {
   union exp_element tmp;
 
   memset (&tmp, 0, sizeof (union exp_element));
   tmp.symbol = expelt;
-  write_exp_elt (&tmp);
+  write_exp_elt (ps, &tmp);
 }
 
 void
-write_exp_elt_block (const struct block *b)
+write_exp_elt_block (struct parser_state *ps, const struct block *b)
 {
   union exp_element tmp;
 
   memset (&tmp, 0, sizeof (union exp_element));
   tmp.block = b;
-  write_exp_elt (&tmp);
+  write_exp_elt (ps, &tmp);
 }
 
 void
-write_exp_elt_objfile (struct objfile *objfile)
+write_exp_elt_objfile (struct parser_state *ps, struct objfile *objfile)
 {
   union exp_element tmp;
 
   memset (&tmp, 0, sizeof (union exp_element));
   tmp.objfile = objfile;
-  write_exp_elt (&tmp);
+  write_exp_elt (ps, &tmp);
 }
 
 void
-write_exp_elt_longcst (LONGEST expelt)
+write_exp_elt_longcst (struct parser_state *ps, LONGEST expelt)
 {
   union exp_element tmp;
 
   memset (&tmp, 0, sizeof (union exp_element));
   tmp.longconst = expelt;
-  write_exp_elt (&tmp);
+  write_exp_elt (ps, &tmp);
 }
 
 void
-write_exp_elt_dblcst (DOUBLEST expelt)
+write_exp_elt_dblcst (struct parser_state *ps, DOUBLEST expelt)
 {
   union exp_element tmp;
 
   memset (&tmp, 0, sizeof (union exp_element));
   tmp.doubleconst = expelt;
-  write_exp_elt (&tmp);
+  write_exp_elt (ps, &tmp);
 }
 
 void
-write_exp_elt_decfloatcst (gdb_byte expelt[16])
+write_exp_elt_decfloatcst (struct parser_state *ps, gdb_byte expelt[16])
 {
   union exp_element tmp;
   int index;
@@ -304,27 +304,27 @@  write_exp_elt_decfloatcst (gdb_byte expelt[16])
   for (index = 0; index < 16; index++)
     tmp.decfloatconst[index] = expelt[index];
 
-  write_exp_elt (&tmp);
+  write_exp_elt (ps, &tmp);
 }
 
 void
-write_exp_elt_type (struct type *expelt)
+write_exp_elt_type (struct parser_state *ps, struct type *expelt)
 {
   union exp_element tmp;
 
   memset (&tmp, 0, sizeof (union exp_element));
   tmp.type = expelt;
-  write_exp_elt (&tmp);
+  write_exp_elt (ps, &tmp);
 }
 
 void
-write_exp_elt_intern (struct internalvar *expelt)
+write_exp_elt_intern (struct parser_state *ps, struct internalvar *expelt)
 {
   union exp_element tmp;
 
   memset (&tmp, 0, sizeof (union exp_element));
   tmp.internalvar = expelt;
-  write_exp_elt (&tmp);
+  write_exp_elt (ps, &tmp);
 }
 
 /* Add a string constant to the end of the expression.
@@ -349,10 +349,10 @@  write_exp_elt_intern (struct internalvar *expelt)
 
 
 void
-write_exp_string (struct stoken str)
+write_exp_string (struct parser_state *ps, struct stoken str)
 {
   int len = str.length;
-  int lenelt;
+  size_t lenelt;
   char *strdata;
 
   /* Compute the number of expression elements required to hold the string
@@ -362,28 +362,19 @@  write_exp_string (struct stoken str)
 
   lenelt = 2 + BYTES_TO_EXP_ELEM (len + 1);
 
-  /* Ensure that we have enough available expression elements to store
-     everything.  */
-
-  if ((expout_ptr + lenelt) >= expout_size)
-    {
-      expout_size = max (expout_size * 2, expout_ptr + lenelt + 10);
-      expout = (struct expression *)
-	xrealloc ((char *) expout, (sizeof (struct expression)
-				    + EXP_ELEM_TO_BYTES (expout_size)));
-    }
+  increase_expout_size (ps, lenelt);
 
   /* Write the leading length expression element (which advances the current
      expression element index), then write the string constant followed by a
      terminating null byte, and then write the trailing length expression
      element.  */
 
-  write_exp_elt_longcst ((LONGEST) len);
-  strdata = (char *) &expout->elts[expout_ptr];
+  write_exp_elt_longcst (ps, (LONGEST) len);
+  strdata = (char *) &ps->expout->elts[ps->expout_ptr];
   memcpy (strdata, str.ptr, len);
   *(strdata + len) = '\0';
-  expout_ptr += lenelt - 2;
-  write_exp_elt_longcst ((LONGEST) len);
+  ps->expout_ptr += lenelt - 2;
+  write_exp_elt_longcst (ps, (LONGEST) len);
 }
 
 /* Add a vector of string constants to the end of the expression.
@@ -400,9 +391,11 @@  write_exp_string (struct stoken str)
    long constant, followed by the contents of the string.  */
 
 void
-write_exp_string_vector (int type, struct stoken_vector *vec)
+write_exp_string_vector (struct parser_state *ps, int type,
+			 struct stoken_vector *vec)
 {
-  int i, n_slots, len;
+  int i, len;
+  size_t n_slots;
 
   /* Compute the size.  We compute the size in number of slots to
      avoid issues with string padding.  */
@@ -421,28 +414,22 @@  write_exp_string_vector (int type, struct stoken_vector *vec)
   len = EXP_ELEM_TO_BYTES (n_slots) - 1;
 
   n_slots += 4;
-  if ((expout_ptr + n_slots) >= expout_size)
-    {
-      expout_size = max (expout_size * 2, expout_ptr + n_slots + 10);
-      expout = (struct expression *)
-	xrealloc ((char *) expout, (sizeof (struct expression)
-				    + EXP_ELEM_TO_BYTES (expout_size)));
-    }
+  increase_expout_size (ps, n_slots);
 
-  write_exp_elt_opcode (OP_STRING);
-  write_exp_elt_longcst (len);
-  write_exp_elt_longcst (type);
+  write_exp_elt_opcode (ps, OP_STRING);
+  write_exp_elt_longcst (ps, len);
+  write_exp_elt_longcst (ps, type);
 
   for (i = 0; i < vec->len; ++i)
     {
-      write_exp_elt_longcst (vec->tokens[i].length);
-      memcpy (&expout->elts[expout_ptr], vec->tokens[i].ptr,
+      write_exp_elt_longcst (ps, vec->tokens[i].length);
+      memcpy (&ps->expout->elts[ps->expout_ptr], vec->tokens[i].ptr,
 	      vec->tokens[i].length);
-      expout_ptr += BYTES_TO_EXP_ELEM (vec->tokens[i].length);
+      ps->expout_ptr += BYTES_TO_EXP_ELEM (vec->tokens[i].length);
     }
 
-  write_exp_elt_longcst (len);
-  write_exp_elt_opcode (OP_STRING);
+  write_exp_elt_longcst (ps, len);
+  write_exp_elt_opcode (ps, OP_STRING);
 }
 
 /* Add a bitstring constant to the end of the expression.
@@ -457,11 +444,11 @@  write_exp_string_vector (int type, struct stoken_vector *vec)
    either end of the bitstring.  */
 
 void
-write_exp_bitstring (struct stoken str)
+write_exp_bitstring (struct parser_state *ps, struct stoken str)
 {
   int bits = str.length;	/* length in bits */
   int len = (bits + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT;
-  int lenelt;
+  size_t lenelt;
   char *strdata;
 
   /* Compute the number of expression elements required to hold the bitstring,
@@ -470,33 +457,25 @@  write_exp_bitstring (struct stoken str)
 
   lenelt = 2 + BYTES_TO_EXP_ELEM (len);
 
-  /* Ensure that we have enough available expression elements to store
-     everything.  */
-
-  if ((expout_ptr + lenelt) >= expout_size)
-    {
-      expout_size = max (expout_size * 2, expout_ptr + lenelt + 10);
-      expout = (struct expression *)
-	xrealloc ((char *) expout, (sizeof (struct expression)
-				    + EXP_ELEM_TO_BYTES (expout_size)));
-    }
+  increase_expout_size (ps, lenelt);
 
   /* Write the leading length expression element (which advances the current
      expression element index), then write the bitstring constant, and then
      write the trailing length expression element.  */
 
-  write_exp_elt_longcst ((LONGEST) bits);
-  strdata = (char *) &expout->elts[expout_ptr];
+  write_exp_elt_longcst (ps, (LONGEST) bits);
+  strdata = (char *) &ps->expout->elts[ps->expout_ptr];
   memcpy (strdata, str.ptr, len);
-  expout_ptr += lenelt - 2;
-  write_exp_elt_longcst ((LONGEST) bits);
+  ps->expout_ptr += lenelt - 2;
+  write_exp_elt_longcst (ps, (LONGEST) bits);
 }
 
 /* Add the appropriate elements for a minimal symbol to the end of
    the expression.  */
 
 void
-write_exp_msymbol (struct bound_minimal_symbol bound_msym)
+write_exp_msymbol (struct parser_state *ps,
+		   struct bound_minimal_symbol bound_msym)
 {
   struct minimal_symbol *msymbol = bound_msym.minsym;
   struct objfile *objfile = bound_msym.objfile;
@@ -536,62 +515,62 @@  write_exp_msymbol (struct bound_minimal_symbol bound_msym)
   if (overlay_debugging)
     addr = symbol_overlayed_address (addr, section);
 
-  write_exp_elt_opcode (OP_LONG);
+  write_exp_elt_opcode (ps, OP_LONG);
   /* Let's make the type big enough to hold a 64-bit address.  */
-  write_exp_elt_type (objfile_type (objfile)->builtin_core_addr);
-  write_exp_elt_longcst ((LONGEST) addr);
-  write_exp_elt_opcode (OP_LONG);
+  write_exp_elt_type (ps, objfile_type (objfile)->builtin_core_addr);
+  write_exp_elt_longcst (ps, (LONGEST) addr);
+  write_exp_elt_opcode (ps, OP_LONG);
 
   if (section && section->the_bfd_section->flags & SEC_THREAD_LOCAL)
     {
-      write_exp_elt_opcode (UNOP_MEMVAL_TLS);
-      write_exp_elt_objfile (objfile);
-      write_exp_elt_type (objfile_type (objfile)->nodebug_tls_symbol);
-      write_exp_elt_opcode (UNOP_MEMVAL_TLS);
+      write_exp_elt_opcode (ps, UNOP_MEMVAL_TLS);
+      write_exp_elt_objfile (ps, objfile);
+      write_exp_elt_type (ps, objfile_type (objfile)->nodebug_tls_symbol);
+      write_exp_elt_opcode (ps, UNOP_MEMVAL_TLS);
       return;
     }
 
-  write_exp_elt_opcode (UNOP_MEMVAL);
+  write_exp_elt_opcode (ps, UNOP_MEMVAL);
   switch (type)
     {
     case mst_text:
     case mst_file_text:
     case mst_solib_trampoline:
-      write_exp_elt_type (objfile_type (objfile)->nodebug_text_symbol);
+      write_exp_elt_type (ps, objfile_type (objfile)->nodebug_text_symbol);
       break;
 
     case mst_text_gnu_ifunc:
-      write_exp_elt_type (objfile_type (objfile)
-					       ->nodebug_text_gnu_ifunc_symbol);
+      write_exp_elt_type (ps, objfile_type (objfile)
+			  ->nodebug_text_gnu_ifunc_symbol);
       break;
 
     case mst_data:
     case mst_file_data:
     case mst_bss:
     case mst_file_bss:
-      write_exp_elt_type (objfile_type (objfile)->nodebug_data_symbol);
+      write_exp_elt_type (ps, objfile_type (objfile)->nodebug_data_symbol);
       break;
 
     case mst_slot_got_plt:
-      write_exp_elt_type (objfile_type (objfile)->nodebug_got_plt_symbol);
+      write_exp_elt_type (ps, objfile_type (objfile)->nodebug_got_plt_symbol);
       break;
 
     default:
-      write_exp_elt_type (objfile_type (objfile)->nodebug_unknown_symbol);
+      write_exp_elt_type (ps, objfile_type (objfile)->nodebug_unknown_symbol);
       break;
     }
-  write_exp_elt_opcode (UNOP_MEMVAL);
+  write_exp_elt_opcode (ps, UNOP_MEMVAL);
 }
 
 /* Mark the current index as the starting location of a structure
    expression.  This is used when completing on field names.  */
 
 void
-mark_struct_expression (void)
+mark_struct_expression (struct parser_state *ps)
 {
   gdb_assert (parse_completion
 	      && expout_tag_completion_type == TYPE_CODE_UNDEF);
-  expout_last_struct = expout_ptr;
+  expout_last_struct = ps->expout_ptr;
 }
 
 /* Indicate that the current parser invocation is completing a tag.
@@ -638,7 +617,7 @@  mark_completion_tag (enum type_code tag, const char *ptr, int length)
    value in the value history, I.e. $$1  */
 
 void
-write_dollar_variable (struct stoken str)
+write_dollar_variable (struct parser_state *ps, struct stoken str)
 {
   struct symbol *sym = NULL;
   struct bound_minimal_symbol msym;
@@ -676,7 +655,7 @@  write_dollar_variable (struct stoken str)
 
   /* Handle tokens that refer to machine registers:
      $ followed by a register name.  */
-  i = user_reg_map_name_to_regnum (parse_gdbarch,
+  i = user_reg_map_name_to_regnum (parse_gdbarch (ps),
 				   str.ptr + 1, str.length - 1);
   if (i >= 0)
     goto handle_register;
@@ -686,9 +665,9 @@  write_dollar_variable (struct stoken str)
   isym = lookup_only_internalvar (copy_name (str) + 1);
   if (isym)
     {
-      write_exp_elt_opcode (OP_INTERNALVAR);
-      write_exp_elt_intern (isym);
-      write_exp_elt_opcode (OP_INTERNALVAR);
+      write_exp_elt_opcode (ps, OP_INTERNALVAR);
+      write_exp_elt_intern (ps, isym);
+      write_exp_elt_opcode (ps, OP_INTERNALVAR);
       return;
     }
 
@@ -699,36 +678,36 @@  write_dollar_variable (struct stoken str)
 		       VAR_DOMAIN, NULL);
   if (sym)
     {
-      write_exp_elt_opcode (OP_VAR_VALUE);
-      write_exp_elt_block (block_found);	/* set by lookup_symbol */
-      write_exp_elt_sym (sym);
-      write_exp_elt_opcode (OP_VAR_VALUE);
+      write_exp_elt_opcode (ps, OP_VAR_VALUE);
+      write_exp_elt_block (ps, block_found);	/* set by lookup_symbol */
+      write_exp_elt_sym (ps, sym);
+      write_exp_elt_opcode (ps, OP_VAR_VALUE);
       return;
     }
   msym = lookup_bound_minimal_symbol (copy_name (str));
   if (msym.minsym)
     {
-      write_exp_msymbol (msym);
+      write_exp_msymbol (ps, msym);
       return;
     }
 
   /* Any other names are assumed to be debugger internal variables.  */
 
-  write_exp_elt_opcode (OP_INTERNALVAR);
-  write_exp_elt_intern (create_internalvar (copy_name (str) + 1));
-  write_exp_elt_opcode (OP_INTERNALVAR);
+  write_exp_elt_opcode (ps, OP_INTERNALVAR);
+  write_exp_elt_intern (ps, create_internalvar (copy_name (str) + 1));
+  write_exp_elt_opcode (ps, OP_INTERNALVAR);
   return;
 handle_last:
-  write_exp_elt_opcode (OP_LAST);
-  write_exp_elt_longcst ((LONGEST) i);
-  write_exp_elt_opcode (OP_LAST);
+  write_exp_elt_opcode (ps, OP_LAST);
+  write_exp_elt_longcst (ps, (LONGEST) i);
+  write_exp_elt_opcode (ps, OP_LAST);
   return;
 handle_register:
-  write_exp_elt_opcode (OP_REGISTER);
+  write_exp_elt_opcode (ps, OP_REGISTER);
   str.length--;
   str.ptr++;
-  write_exp_string (str);
-  write_exp_elt_opcode (OP_REGISTER);
+  write_exp_string (ps, str);
+  write_exp_elt_opcode (ps, OP_REGISTER);
   return;
 }
 
@@ -1161,6 +1140,7 @@  parse_exp_in_context_1 (const char **stringptr, CORE_ADDR pc,
   volatile struct gdb_exception except;
   struct cleanup *old_chain, *inner_chain;
   const struct language_defn *lang = NULL;
+  struct parser_state ps;
   int subexp;
 
   lexptr = *stringptr;
@@ -1233,47 +1213,48 @@  parse_exp_in_context_1 (const char **stringptr, CORE_ADDR pc,
      While we need CURRENT_LANGUAGE to be set to LANG (for lookup_symbol
      and others called from *.y) ensure CURRENT_LANGUAGE gets restored
      to the value matching SELECTED_FRAME as set by get_current_arch.  */
-  initialize_expout (10, lang, get_current_arch ());
+
+  initialize_expout (&ps, 10, lang, get_current_arch ());
   inner_chain = make_cleanup_restore_current_language ();
   set_language (lang->la_language);
 
   TRY_CATCH (except, RETURN_MASK_ALL)
     {
-      if (lang->la_parser ())
+      if (lang->la_parser (&ps))
         lang->la_error (NULL);
     }
   if (except.reason < 0)
     {
       if (! parse_completion)
 	{
-	  xfree (expout);
+	  xfree (ps.expout);
 	  throw_exception (except);
 	}
     }
 
-  reallocate_expout ();
+  reallocate_expout (&ps);
 
   /* Convert expression from postfix form as generated by yacc
      parser, to a prefix form.  */
 
   if (expressiondebug)
-    dump_raw_expression (expout, gdb_stdlog,
+    dump_raw_expression (ps.expout, gdb_stdlog,
 			 "before conversion to prefix form");
 
-  subexp = prefixify_expression (expout);
+  subexp = prefixify_expression (ps.expout);
   if (out_subexp)
     *out_subexp = subexp;
 
-  lang->la_post_parser (&expout, void_context_p);
+  lang->la_post_parser (&ps.expout, void_context_p);
 
   if (expressiondebug)
-    dump_prefix_expression (expout, gdb_stdlog);
+    dump_prefix_expression (ps.expout, gdb_stdlog);
 
   do_cleanups (inner_chain);
   discard_cleanups (old_chain);
 
   *stringptr = lexptr;
-  return expout;
+  return ps.expout;
 }
 
 /* Parse STRING as an expression, and complain if this fails
@@ -1512,7 +1493,7 @@  push_type_int (int n)
    item.  */
 
 void
-insert_type_address_space (char *string)
+insert_type_address_space (struct parser_state *pstate, char *string)
 {
   union type_stack_elt element;
   int slot;
@@ -1527,7 +1508,8 @@  insert_type_address_space (char *string)
 
   element.piece = tp_space_identifier;
   insert_into_type_stack (slot, element);
-  element.int_val = address_space_name_to_int (parse_gdbarch, string);
+  element.int_val = address_space_name_to_int (parse_gdbarch (pstate),
+					       string);
   insert_into_type_stack (slot, element);
 }
 
@@ -1909,6 +1891,21 @@  exp_uses_objfile (struct expression *exp, struct objfile *objfile)
   return exp_iterate (exp, exp_uses_objfile_iter, objfile);
 }
 
+/* See definition in parser-defs.h.  */
+
+void
+increase_expout_size (struct parser_state *ps, size_t lenelt)
+{
+  if ((ps->expout_ptr + lenelt) >= ps->expout_size)
+    {
+      ps->expout_size = max (ps->expout_size * 2,
+			     ps->expout_ptr + lenelt + 10);
+      ps->expout = (struct expression *)
+	xrealloc (ps->expout, (sizeof (struct expression)
+			       + EXP_ELEM_TO_BYTES (ps->expout_size)));
+    }
+}
+
 void
 _initialize_parse (void)
 {
diff --git a/gdb/parser-defs.h b/gdb/parser-defs.h
index c3f2607..97c53b9 100644
--- a/gdb/parser-defs.h
+++ b/gdb/parser-defs.h
@@ -28,15 +28,29 @@ 
 #include "expression.h"
 
 struct block;
+struct language_defn;
+struct internalvar;
 
 extern int parser_debug;
 
-extern struct expression *expout;
-extern int expout_size;
-extern int expout_ptr;
+#define parse_gdbarch(ps) ((ps)->expout->gdbarch)
+#define parse_language(ps) ((ps)->expout->language_defn)
 
-#define parse_gdbarch (expout->gdbarch)
-#define parse_language (expout->language_defn)
+struct parser_state
+{
+  /* The expression related to this parser state.  */
+
+  struct expression *expout;
+
+  /* The size of the expression above.  */
+
+  size_t expout_size;
+
+  /* The number of elements already in the expression.  This is used
+     to know where to put new elements.  */
+
+  size_t expout_ptr;
+};
 
 /* If this is nonzero, this block is used as the lexical context
    for symbol names.  */
@@ -148,19 +162,21 @@  struct type_stack
 };
 
 /* Helper function to initialize the expout, expout_size, expout_ptr
-   trio before it is used to store expression elements created during
-   the parsing of an expression.  INITIAL_SIZE is the initial size of
+   trio inside PS before it is used to store expression elements created
+   during the parsing of an expression.  INITIAL_SIZE is the initial size of
    the expout array.  LANG is the language used to parse the expression.
    And GDBARCH is the gdbarch to use during parsing.  */
 
-extern void initialize_expout (int, const struct language_defn *,
-			       struct gdbarch *);
+extern void initialize_expout (struct parser_state *ps,
+			       size_t initial_size,
+			       const struct language_defn *lang,
+			       struct gdbarch *gdbarch);
 
-/* Helper function that frees any unsed space in the expout array.
-   It is generally used when the parser has just been parsed and
-   created.  */
+/* Helper function that reallocates the EXPOUT inside PS in order to
+   eliminate any unused space.  It is generally used when the expression
+   has just been parsed and created.  */
 
-extern void reallocate_expout (void);
+extern void reallocate_expout (struct parser_state *ps);
 
 /* Reverse an expression from suffix form (in which it is constructed)
    to prefix form (in which we can conveniently print or execute it).
@@ -171,35 +187,38 @@  extern void reallocate_expout (void);
 
 extern int prefixify_expression (struct expression *expr);
 
-extern void write_exp_elt_opcode (enum exp_opcode);
+extern void write_exp_elt_opcode (struct parser_state *, enum exp_opcode);
 
-extern void write_exp_elt_sym (struct symbol *);
+extern void write_exp_elt_sym (struct parser_state *, struct symbol *);
 
-extern void write_exp_elt_longcst (LONGEST);
+extern void write_exp_elt_longcst (struct parser_state *, LONGEST);
 
-extern void write_exp_elt_dblcst (DOUBLEST);
+extern void write_exp_elt_dblcst (struct parser_state *, DOUBLEST);
 
-extern void write_exp_elt_decfloatcst (gdb_byte *);
+extern void write_exp_elt_decfloatcst (struct parser_state *, gdb_byte *);
 
-extern void write_exp_elt_type (struct type *);
+extern void write_exp_elt_type (struct parser_state *, struct type *);
 
-extern void write_exp_elt_intern (struct internalvar *);
+extern void write_exp_elt_intern (struct parser_state *, struct internalvar *);
 
-extern void write_exp_string (struct stoken);
+extern void write_exp_string (struct parser_state *, struct stoken);
 
-void write_exp_string_vector (int type, struct stoken_vector *vec);
+void write_exp_string_vector (struct parser_state *, int type,
+			      struct stoken_vector *vec);
 
-extern void write_exp_bitstring (struct stoken);
+extern void write_exp_bitstring (struct parser_state *, struct stoken);
 
-extern void write_exp_elt_block (const struct block *);
+extern void write_exp_elt_block (struct parser_state *, const struct block *);
 
-extern void write_exp_elt_objfile (struct objfile *objfile);
+extern void write_exp_elt_objfile (struct parser_state *,
+				   struct objfile *objfile);
 
-extern void write_exp_msymbol (struct bound_minimal_symbol);
+extern void write_exp_msymbol (struct parser_state *,
+			       struct bound_minimal_symbol);
 
-extern void write_dollar_variable (struct stoken str);
+extern void write_dollar_variable (struct parser_state *, struct stoken str);
 
-extern void mark_struct_expression (void);
+extern void mark_struct_expression (struct parser_state *);
 
 extern const char *find_template_name_end (const char *);
 
@@ -215,7 +234,7 @@  extern void push_type (enum type_pieces);
 
 extern void push_type_int (int);
 
-extern void insert_type_address_space (char *);
+extern void insert_type_address_space (struct parser_state *, char *);
 
 extern enum type_pieces pop_type (void);
 
@@ -375,5 +394,11 @@  extern int exp_uses_objfile (struct expression *exp, struct objfile *objfile);
 extern void mark_completion_tag (enum type_code, const char *ptr,
 				 int length);
 
+/* Reallocate the `expout' pointer inside PS so that it can accommodate
+   at least LENELT expression elements.  This function does nothing if
+   there is enough room for the elements.  */
+
+extern void increase_expout_size (struct parser_state *ps, size_t lenelt);
+
 #endif /* PARSER_DEFS_H */
 
diff --git a/gdb/utils.c b/gdb/utils.c
index 364470c..a8a7cb3 100644
--- a/gdb/utils.c
+++ b/gdb/utils.c
@@ -466,6 +466,24 @@  make_cleanup_restore_current_language (void)
 		       (void *) (uintptr_t) saved_lang);
 }
 
+/* Helper function for make_cleanup_clear_parser_state.  */
+
+static void
+do_clear_parser_state (void *ptr)
+{
+  struct parser_state **p = (struct parser_state **) ptr;
+
+  *p = NULL;
+}
+
+/* Clean (i.e., set to NULL) the parser state variable P.  */
+
+struct cleanup *
+make_cleanup_clear_parser_state (struct parser_state **p)
+{
+  return make_cleanup (do_clear_parser_state, (void *) p);
+}
+
 /* This function is useful for cleanups.
    Do
 
diff --git a/gdb/utils.h b/gdb/utils.h
index d6df2ee..33371ac 100644
--- a/gdb/utils.h
+++ b/gdb/utils.h
@@ -115,6 +115,10 @@  extern struct cleanup *make_cleanup_restore_current_language (void);
 
 extern struct cleanup *make_cleanup_htab_delete (htab_t htab);
 
+struct parser_state;
+extern struct cleanup *make_cleanup_clear_parser_state
+  (struct parser_state **p);
+
 extern void free_current_contents (void *);
 
 extern void init_page_info (void);