[PATCH] Change parameters to language_defn::post_parser

[Tom Tromey]

In the expression rewrite, Ada type resolution will be done at parse
time rather than in a post-parse pass.  At this point,
language_defn::post_parser will be removed.  However, for this to
work, the information available to post_parser must be made available
during the actual parse.

This patch refactors this code slightly to make this possible.  In
particular, "void_context_p" is passed to the parser_state
constructor, and the parser state is then passed to the post_parser
method.

gdb/ChangeLog
2020-12-14  Tom Tromey  <tom@tromey.com>

	* rust-exp.y (rust_lex_tests): Update.
	* parser-defs.h (parser_state): Add void_p parameter.
	<void_context_p>: New member.
	* parse.c (parse_exp_in_context): Update.
	* language.h (language_defn::post_parser): Remove void_context_p,
	completing, tracker parameters.  Add parser state.
	* ada-lang.c (ada_language::post_parser): Update.
---
 gdb/ChangeLog     | 10 ++++++++++
 gdb/ada-lang.c    |  9 +++++----
 gdb/language.h    | 12 ++++--------
 gdb/parse.c       |  4 ++--
 gdb/parser-defs.h |  9 +++++++--
 gdb/rust-exp.y    |  2 +-
 6 files changed, 29 insertions(+), 17 deletions(-)

diff --git a/gdb/ada-lang.c b/gdb/ada-lang.c
index 564cdbee13c..476c3ae8320 100644
--- a/gdb/ada-lang.c
+++ b/gdb/ada-lang.c
@@ -14163,16 +14163,17 @@ class ada_language : public language_defn
      A null CONTEXT_TYPE indicates that a non-void return type is
      preferred.  May change (expand) *EXP.  */
 
-  void post_parser (expression_up *expp, int void_context_p, int completing,
-		    innermost_block_tracker *tracker) const override
+  void post_parser (expression_up *expp, struct parser_state *ps)
+    const override
   {
     struct type *context_type = NULL;
     int pc = 0;
 
-    if (void_context_p)
+    if (ps->void_context_p)
       context_type = builtin_type ((*expp)->gdbarch)->builtin_void;
 
-    resolve_subexp (expp, &pc, 1, context_type, completing, tracker);
+    resolve_subexp (expp, &pc, 1, context_type, ps->parse_completion,
+		    ps->block_tracker);
   }
 
   /* See language.h.  */
diff --git a/gdb/language.h b/gdb/language.h
index e955340440d..73ddd24f228 100644
--- a/gdb/language.h
+++ b/gdb/language.h
@@ -522,14 +522,10 @@ struct language_defn
   /* Given an expression *EXPP created by prefixifying the result of
      la_parser, perform any remaining processing necessary to complete its
      translation.  *EXPP may change; la_post_parser is responsible for
-     releasing its previous contents, if necessary.  If VOID_CONTEXT_P,
-     then no value is expected from the expression.  If COMPLETING is
-     non-zero, then the expression has been parsed for completion, not
-     evaluation.  */
-
-  virtual void post_parser (expression_up *expp, int void_context_p,
-			    int completing,
-			    innermost_block_tracker *tracker) const
+     releasing its previous contents, if necessary.  */
+
+  virtual void post_parser (expression_up *expp, struct parser_state *ps)
+    const
   {
     /* By default the post-parser does nothing.  */
   }
diff --git a/gdb/parse.c b/gdb/parse.c
index 73d82e64a87..b160c2deadb 100644
--- a/gdb/parse.c
+++ b/gdb/parse.c
@@ -1113,7 +1113,7 @@ parse_exp_in_context (const char **stringptr, CORE_ADDR pc,
 
   parser_state ps (lang, get_current_arch (), expression_context_block,
 		   expression_context_pc, comma, *stringptr,
-		   cstate != nullptr, tracker);
+		   cstate != nullptr, tracker, void_context_p);
 
   scoped_restore_current_language lang_saver;
   set_language (lang->la_language);
@@ -1147,7 +1147,7 @@ parse_exp_in_context (const char **stringptr, CORE_ADDR pc,
   if (out_subexp)
     *out_subexp = subexp;
 
-  lang->post_parser (&result, void_context_p, ps.parse_completion, tracker);
+  lang->post_parser (&result, &ps);
 
   if (expressiondebug)
     dump_prefix_expression (result.get (), gdb_stdlog);
diff --git a/gdb/parser-defs.h b/gdb/parser-defs.h
index 17216057b18..072e9468257 100644
--- a/gdb/parser-defs.h
+++ b/gdb/parser-defs.h
@@ -109,14 +109,16 @@ struct parser_state : public expr_builder
 		int comma,
 		const char *input,
 		int completion,
-		innermost_block_tracker *tracker)
+		innermost_block_tracker *tracker,
+		int void_p)
     : expr_builder (lang, gdbarch),
       expression_context_block (context_block),
       expression_context_pc (context_pc),
       comma_terminates (comma),
       lexptr (input),
       parse_completion (completion),
-      block_tracker (tracker)
+      block_tracker (tracker),
+      void_context_p (void_p)
   {
   }
 
@@ -192,6 +194,9 @@ struct parser_state : public expr_builder
   /* The innermost block tracker.  */
   innermost_block_tracker *block_tracker;
 
+  /* True if no value is expected from the expression.  */
+  int void_context_p;
+
 private:
 
   /* Data structure for saving values of arglist_len for function calls whose
diff --git a/gdb/rust-exp.y b/gdb/rust-exp.y
index 1207d1d6f42..4879812c014 100644
--- a/gdb/rust-exp.y
+++ b/gdb/rust-exp.y
@@ -2732,7 +2732,7 @@ rust_lex_tests (void)
 
   /* Set up dummy "parser", so that rust_type works.  */
   struct parser_state ps (language_def (language_rust), target_gdbarch (),
-			  nullptr, 0, 0, nullptr, 0, nullptr);
+			  nullptr, 0, 0, nullptr, 0, nullptr, 0);
   rust_parser parser (&ps);
 
   rust_lex_test_one (&parser, "", 0);
-- 
2.17.2