Extract symbol-writing function from parsers

I noticed that several parsers shared the same code to write a symbol
reference to an expression.  This patch factors this code out into a
new function.

Regression tested on x86-64 Fedora 32.

gdb/ChangeLog
2021-02-05  Tom Tromey  <tom@tromey.com>

	* parser-defs.h (write_exp_symbol_reference): Declare.
	* parse.c (write_exp_symbol_reference): New function.
	* p-exp.y (variable): Use write_exp_symbol_reference.
	* m2-exp.y (variable): Use write_exp_symbol_reference.
	* f-exp.y (variable): Use write_exp_symbol_reference.
	* d-exp.y (PrimaryExpression): Use write_exp_symbol_reference.
	* c-exp.y (variable): Use write_exp_symbol_reference.

8 files changed, 78 insertions, 129 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 07fe6a0..553b5f0 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,13 @@
+2021-02-05  Tom Tromey  <tom@tromey.com>
+
+	* parser-defs.h (write_exp_symbol_reference): Declare.
+	* parse.c (write_exp_symbol_reference): New function.
+	* p-exp.y (variable): Use write_exp_symbol_reference.
+	* m2-exp.y (variable): Use write_exp_symbol_reference.
+	* f-exp.y (variable): Use write_exp_symbol_reference.
+	* d-exp.y (PrimaryExpression): Use write_exp_symbol_reference.
+	* c-exp.y (variable): Use write_exp_symbol_reference.
+
 2021-02-05  Tom de Vries  <tdevries@suse.de>
 
 	PR exp/27265
diff --git a/gdb/c-exp.y b/gdb/c-exp.y
index 71610e9..13b06f3 100644
--- a/gdb/c-exp.y
+++ b/gdb/c-exp.y
@@ -1104,30 +1104,12 @@ variable:	qualified_name
 	|	COLONCOLON name_not_typename
 			{
 			  std::string name = copy_name ($2.stoken);
-			  struct symbol *sym;
-			  struct bound_minimal_symbol msymbol;
-
-			  sym
+			  struct block_symbol sym
 			    = lookup_symbol (name.c_str (),
 					     (const struct block *) NULL,
-					     VAR_DOMAIN, NULL).symbol;
-			  if (sym)
-			    {
-			      write_exp_elt_opcode (pstate, OP_VAR_VALUE);
-			      write_exp_elt_block (pstate, NULL);
-			      write_exp_elt_sym (pstate, sym);
-			      write_exp_elt_opcode (pstate, OP_VAR_VALUE);
-			      break;
-			    }
-
-			  msymbol = lookup_bound_minimal_symbol (name.c_str ());
-			  if (msymbol.minsym != NULL)
-			    write_exp_msymbol (pstate, msymbol);
-			  else if (!have_full_symbols () && !have_partial_symbols ())
-			    error (_("No symbol table is loaded.  Use the \"file\" command."));
-			  else
-			    error (_("No symbol \"%s\" in current context."),
-				   name.c_str ());
+					     VAR_DOMAIN, NULL);
+			  write_exp_symbol_reference (pstate, name.c_str (),
+						      sym);
 			}
 	;
 
diff --git a/gdb/d-exp.y b/gdb/d-exp.y
index 35cd074..c432f22 100644
--- a/gdb/d-exp.y
+++ b/gdb/d-exp.y
@@ -464,7 +464,6 @@ PrimaryExpression:
 			     been resolved, it's not likely to be found.  */
 			  if (type->code () == TYPE_CODE_MODULE)
 			    {
-			      struct bound_minimal_symbol msymbol;
 			      struct block_symbol sym;
 			      const char *type_name = TYPE_SAFE_NAME (type);
 			      int type_name_len = strlen (type_name);
@@ -477,35 +476,23 @@ PrimaryExpression:
 				lookup_symbol (name.c_str (),
 					       (const struct block *) NULL,
 					       VAR_DOMAIN, NULL);
-			      if (sym.symbol)
-				{
-				  write_exp_elt_opcode (pstate, OP_VAR_VALUE);
-				  write_exp_elt_block (pstate, sym.block);
-				  write_exp_elt_sym (pstate, sym.symbol);
-				  write_exp_elt_opcode (pstate, OP_VAR_VALUE);
-				  break;
-				}
-
-			      msymbol = lookup_bound_minimal_symbol (name.c_str ());
-			      if (msymbol.minsym != NULL)
-				write_exp_msymbol (pstate, msymbol);
-			      else if (!have_full_symbols () && !have_partial_symbols ())
-				error (_("No symbol table is loaded.  Use the \"file\" command."));
-			      else
-				error (_("No symbol \"%s\" in current context."),
-				       name.c_str ());
+			      write_exp_symbol_reference (pstate,
+							  name.c_str (),
+							  sym);
+			    }
+			  else
+			    {
+			      /* Check if the qualified name resolves as a member
+				 of an aggregate or an enum type.  */
+			      if (!type_aggregate_p (type))
+				error (_("`%s' is not defined as an aggregate type."),
+				       TYPE_SAFE_NAME (type));
+
+			      write_exp_elt_opcode (pstate, OP_SCOPE);
+			      write_exp_elt_type (pstate, type);
+			      write_exp_string (pstate, $3);
+			      write_exp_elt_opcode (pstate, OP_SCOPE);
 			    }
-
-			  /* Check if the qualified name resolves as a member
-			     of an aggregate or an enum type.  */
-			  if (!type_aggregate_p (type))
-			    error (_("`%s' is not defined as an aggregate type."),
-				   TYPE_SAFE_NAME (type));
-
-			  write_exp_elt_opcode (pstate, OP_SCOPE);
-			  write_exp_elt_type (pstate, type);
-			  write_exp_string (pstate, $3);
-			  write_exp_elt_opcode (pstate, OP_SCOPE);
 			}
 |	DOLLAR_VARIABLE
 		{ write_dollar_variable (pstate, $1); }
diff --git a/gdb/f-exp.y b/gdb/f-exp.y
index 3b0f23d..92a70b4 100644
--- a/gdb/f-exp.y
+++ b/gdb/f-exp.y
@@ -540,32 +540,9 @@ exp	:	STRING_LITERAL
 
 variable:	name_not_typename
 			{ struct block_symbol sym = $1.sym;
-
-			  if (sym.symbol)
-			    {
-			      if (symbol_read_needs_frame (sym.symbol))
-				pstate->block_tracker->update (sym);
-			      write_exp_elt_opcode (pstate, OP_VAR_VALUE);
-			      write_exp_elt_block (pstate, sym.block);
-			      write_exp_elt_sym (pstate, sym.symbol);
-			      write_exp_elt_opcode (pstate, OP_VAR_VALUE);
-			      break;
-			    }
-			  else
-			    {
-			      struct bound_minimal_symbol msymbol;
-			      std::string arg = copy_name ($1.stoken);
-
-			      msymbol =
-				lookup_bound_minimal_symbol (arg.c_str ());
-			      if (msymbol.minsym != NULL)
-				write_exp_msymbol (pstate, msymbol);
-			      else if (!have_full_symbols () && !have_partial_symbols ())
-				error (_("No symbol table is loaded.  Use the \"file\" command."));
-			      else
-				error (_("No symbol \"%s\" in current context."),
-				       arg.c_str ());
-			    }
+			  std::string name = copy_name ($1.stoken);
+			  write_exp_symbol_reference (pstate, name.c_str (),
+						      sym);
 			}
 	;
 
diff --git a/gdb/m2-exp.y b/gdb/m2-exp.y
index 717c6e6..68bae48 100644
--- a/gdb/m2-exp.y
+++ b/gdb/m2-exp.y
@@ -561,37 +561,15 @@ variable:	NAME
 			{ struct block_symbol sym;
 			  struct field_of_this_result is_a_field_of_this;
 
+			  std::string name = copy_name ($1);
 			  sym
-			    = lookup_symbol (copy_name ($1).c_str (),
+			    = lookup_symbol (name.c_str (),
 					     pstate->expression_context_block,
 					     VAR_DOMAIN,
 					     &is_a_field_of_this);
 
-			  if (sym.symbol)
-			    {
-			      if (symbol_read_needs_frame (sym.symbol))
-				pstate->block_tracker->update (sym);
-
-			      write_exp_elt_opcode (pstate, OP_VAR_VALUE);
-			      write_exp_elt_block (pstate, sym.block);
-			      write_exp_elt_sym (pstate, sym.symbol);
-			      write_exp_elt_opcode (pstate, OP_VAR_VALUE);
-			    }
-			  else
-			    {
-			      struct bound_minimal_symbol msymbol;
-			      std::string arg = copy_name ($1);
-
-			      msymbol =
-				lookup_bound_minimal_symbol (arg.c_str ());
-			      if (msymbol.minsym != NULL)
-				write_exp_msymbol (pstate, msymbol);
-			      else if (!have_full_symbols () && !have_partial_symbols ())
-				error (_("No symbol table is loaded.  Use the \"symbol-file\" command."));
-			      else
-				error (_("No symbol \"%s\" in current context."),
-				       arg.c_str ());
-			    }
+			  write_exp_symbol_reference (pstate, name.c_str (),
+						      sym);
 			}
 	;
 
diff --git a/gdb/p-exp.y b/gdb/p-exp.y
index 5a43e89..b025ac3 100644
--- a/gdb/p-exp.y
+++ b/gdb/p-exp.y
@@ -691,33 +691,12 @@ variable:	qualified_name
 	|	COLONCOLON name
 			{
 			  std::string name = copy_name ($2);
-			  struct symbol *sym;
-			  struct bound_minimal_symbol msymbol;
-
-			  sym =
-			    lookup_symbol (name.c_str (),
-					   (const struct block *) NULL,
-					   VAR_DOMAIN, NULL).symbol;
-			  if (sym)
-			    {
-			      write_exp_elt_opcode (pstate, OP_VAR_VALUE);
-			      write_exp_elt_block (pstate, NULL);
-			      write_exp_elt_sym (pstate, sym);
-			      write_exp_elt_opcode (pstate, OP_VAR_VALUE);
-			      break;
-			    }
 
-			  msymbol
-			    = lookup_bound_minimal_symbol (name.c_str ());
-			  if (msymbol.minsym != NULL)
-			    write_exp_msymbol (pstate, msymbol);
-			  else if (!have_full_symbols ()
-				   && !have_partial_symbols ())
-			    error (_("No symbol table is loaded.  "
-				   "Use the \"file\" command."));
-			  else
-			    error (_("No symbol \"%s\" in current context."),
-				   name.c_str ());
+			  struct block_symbol sym
+			    = lookup_symbol (name.c_str (), nullptr,
+					     VAR_DOMAIN, nullptr);
+			  write_exp_symbol_reference (pstate, name.c_str (),
+						      sym);
 			}
 	;
 
diff --git a/gdb/parse.c b/gdb/parse.c
index 933960f..08fde89 100644
--- a/gdb/parse.c
+++ b/gdb/parse.c
@@ -650,6 +650,32 @@ handle_register:
   return;
 }
 
+/* See parser-defs.h.  */
+
+void
+write_exp_symbol_reference (struct parser_state *pstate, const char *name,
+			    struct block_symbol sym)
+{
+  if (sym.symbol != nullptr)
+    {
+      if (symbol_read_needs_frame (sym.symbol))
+	pstate->block_tracker->update (sym);
+      write_exp_elt_opcode (pstate, OP_VAR_VALUE);
+      write_exp_elt_block (pstate, NULL);
+      write_exp_elt_sym (pstate, sym.symbol);
+      write_exp_elt_opcode (pstate, OP_VAR_VALUE);
+    }
+  else
+    {
+      struct bound_minimal_symbol msymbol = lookup_bound_minimal_symbol (name);
+      if (msymbol.minsym != NULL)
+	write_exp_msymbol (pstate, msymbol);
+      else if (!have_full_symbols () && !have_partial_symbols ())
+	error (_("No symbol table is loaded.  Use the \"file\" command."));
+      else
+	error (_("No symbol \"%s\" in current context."), name);
+    }
+}
 
 const char *
 find_template_name_end (const char *p)
diff --git a/gdb/parser-defs.h b/gdb/parser-defs.h
index 5ff5d52..466230e 100644
--- a/gdb/parser-defs.h
+++ b/gdb/parser-defs.h
@@ -334,6 +334,16 @@ extern void write_exp_msymbol (struct expr_builder *,
 
 extern void write_dollar_variable (struct parser_state *, struct stoken str);
 
+/* Write a reference to a symbol to the expression being built in PS.
+   NAME is the name of the symbol to write; SYM is the symbol.  If SYM
+   is nullptr (meaning the 'symbol' member), a minimal symbol will be
+   searched for and used if available.  Throws an exception if SYM is
+   nullptr and no minimal symbol can be found.  */
+
+extern void write_exp_symbol_reference (struct parser_state *ps,
+					const char *name,
+					struct block_symbol sym);
+
 extern const char *find_template_name_end (const char *);
 
 extern std::string copy_name (struct stoken);