[PATCHv2 2/3] gdb: merge error handling from different expression parsers

[Andrew Burgess <aburgess@redhat.com>]

Many (all?) of the expression parsers implement yyerror to handle
parser errors, and all of these functions are basically identical.

This commit adds a new parser_state::parse_error() function, which
implements the common error handling code, this function can then be
called from all the different yyerror functions.

The benefit of this is that (in a future commit) I can improve the
error output, and all the expression parsers will benefit.

This commit is pure refactoring though, and so, there should be no
user visible changes after this commit.
---
 gdb/ada-exp.y     |  2 +-
 gdb/c-exp.y       |  5 +----
 gdb/d-exp.y       |  5 +----
 gdb/f-exp.y       |  5 +----
 gdb/go-exp.y      |  5 +----
 gdb/m2-exp.y      |  5 +----
 gdb/p-exp.y       |  5 +----
 gdb/parse.c       | 11 +++++++++++
 gdb/parser-defs.h |  5 +++++
 9 files changed, 23 insertions(+), 25 deletions(-)

diff --git a/gdb/ada-exp.y b/gdb/ada-exp.y
index fcb5aa4379b..2a1cff50887 100644
--- a/gdb/ada-exp.y
+++ b/gdb/ada-exp.y
@@ -1212,7 +1212,7 @@ ada_parse (struct parser_state *par_state)
 static void
 yyerror (const char *msg)
 {
-  error (_("Error in expression, near `%s'."), pstate->lexptr);
+  pstate->parse_error (msg);
 }
 
 /* Emit expression to access an instance of SYM, in block BLOCK (if
diff --git a/gdb/c-exp.y b/gdb/c-exp.y
index 2b4c21850d3..6697b3b2278 100644
--- a/gdb/c-exp.y
+++ b/gdb/c-exp.y
@@ -3482,8 +3482,5 @@ c_print_token (FILE *file, int type, YYSTYPE value)
 static void
 yyerror (const char *msg)
 {
-  if (pstate->prev_lexptr)
-    pstate->lexptr = pstate->prev_lexptr;
-
-  error (_("A %s in expression, near `%s'."), msg, pstate->lexptr);
+  pstate->parse_error (msg);
 }
diff --git a/gdb/d-exp.y b/gdb/d-exp.y
index e2507982d50..627c681d895 100644
--- a/gdb/d-exp.y
+++ b/gdb/d-exp.y
@@ -1631,9 +1631,6 @@ d_parse (struct parser_state *par_state)
 static void
 yyerror (const char *msg)
 {
-  if (pstate->prev_lexptr)
-    pstate->lexptr = pstate->prev_lexptr;
-
-  error (_("A %s in expression, near `%s'."), msg, pstate->lexptr);
+  pstate->parse_error (msg);
 }
 
diff --git a/gdb/f-exp.y b/gdb/f-exp.y
index e4e2171d641..88a95bccb11 100644
--- a/gdb/f-exp.y
+++ b/gdb/f-exp.y
@@ -1736,8 +1736,5 @@ f_language::parser (struct parser_state *par_state) const
 static void
 yyerror (const char *msg)
 {
-  if (pstate->prev_lexptr)
-    pstate->lexptr = pstate->prev_lexptr;
-
-  error (_("A %s in expression, near `%s'."), msg, pstate->lexptr);
+  pstate->parse_error (msg);
 }
diff --git a/gdb/go-exp.y b/gdb/go-exp.y
index c9b9c0b1ab7..561a3bef1b0 100644
--- a/gdb/go-exp.y
+++ b/gdb/go-exp.y
@@ -1545,8 +1545,5 @@ go_language::parser (struct parser_state *par_state) const
 static void
 yyerror (const char *msg)
 {
-  if (pstate->prev_lexptr)
-    pstate->lexptr = pstate->prev_lexptr;
-
-  error (_("A %s in expression, near `%s'."), msg, pstate->lexptr);
+  pstate->parse_error (msg);
 }
diff --git a/gdb/m2-exp.y b/gdb/m2-exp.y
index 092a8be248d..9a8767f5ac7 100644
--- a/gdb/m2-exp.y
+++ b/gdb/m2-exp.y
@@ -1006,8 +1006,5 @@ m2_language::parser (struct parser_state *par_state) const
 static void
 yyerror (const char *msg)
 {
-  if (pstate->prev_lexptr)
-    pstate->lexptr = pstate->prev_lexptr;
-
-  error (_("A %s in expression, near `%s'."), msg, pstate->lexptr);
+  pstate->parse_error (msg);
 }
diff --git a/gdb/p-exp.y b/gdb/p-exp.y
index b0f334897ad..9dfa8c5fd4f 100644
--- a/gdb/p-exp.y
+++ b/gdb/p-exp.y
@@ -1660,8 +1660,5 @@ pascal_language::parser (struct parser_state *par_state) const
 static void
 yyerror (const char *msg)
 {
-  if (pstate->prev_lexptr)
-    pstate->lexptr = pstate->prev_lexptr;
-
-  error (_("A %s in expression, near `%s'."), msg, pstate->lexptr);
+  pstate->parse_error (msg);
 }
diff --git a/gdb/parse.c b/gdb/parse.c
index b57d112fafd..efac0dee1af 100644
--- a/gdb/parse.c
+++ b/gdb/parse.c
@@ -244,6 +244,17 @@ parser_state::push_dollar (struct stoken str)
     (create_internalvar (copy.c_str () + 1));
 }
 
+/* See parser-defs.h.  */
+
+void
+parser_state::parse_error (const char *msg)
+{
+  if (this->prev_lexptr)
+    this->lexptr = this->prev_lexptr;
+
+  error (_("A %s in expression, near `%s'."), msg, this->lexptr);
+}
+
 \f
 
 const char *
diff --git a/gdb/parser-defs.h b/gdb/parser-defs.h
index 93ebdf5c061..4d40245228b 100644
--- a/gdb/parser-defs.h
+++ b/gdb/parser-defs.h
@@ -262,6 +262,11 @@ struct parser_state : public expr_builder
     push (expr::make_operation<T> (std::move (lhs), std::move (rhs)));
   }
 
+  /* Function called from various the various parsers yyerror functions to
+     throw an error.  The error will include a message identifying the
+     location of the error within the current expression.  */
+  void parse_error (const char *msg);
+
   /* If this is nonzero, this block is used as the lexical context for
      symbol names.  */
 
-- 
2.25.4