First commit of scratch/correct-warning-pos.

This branch is intended to generate correct position information in warning
and error messages from the byte compiler, and is intended thereby to fix bugs

It introduces a new mechanism, the symbol with position.  This is taken over
from the previous git branch scratch/accurate-warning-pos which was abandoned
for being too slow.  The main difference in the current branch is that the
symbol `nil' is never given a position, thus speeding up NILP markedly.

* lisp/emacs-lisp/byte-opt.el (byte-compile-inline-expand)
(byte-optimize-form-code-walker, byte-optimize-let-form, byte-optimize-while)
(byte-optimize-apply): Use byte-compile-warn-x in place of byte-compile-warn.

* lisp/emacs-lisp/bytecomp.el (byte-compile--form-stack): New variable.
(byte-compile-strip-s-p-1, byte-compile-strip-symbol-positions): New
functions.
(byte-compile-recurse-toplevel, byte-compile-initial-macro-environment)
(byte-compile-preprocess, byte-compile-macroexpand-declare-function): Bind
print-symbols-bare to non-nil.
(byte-compile--first-symbol, byte-compile--warning-source-offset): New
functions.
(byte-compile-warning-prefix): Modify to output two sets of position
information, the old (incorrect) set and the new set.
(byte-compile-warn): Strip positions from symbols before outputting.
(byte-compile-warn-x): New function which outputs a correct position supplied
in an argument.
(byte-compile-warn-obsolete, byte-compile-emit-callargs-warn)
(byte-compile-format-warn, byte-compile-nogroup-warn)
(byte-compile-arglist-warn, byte-compile-docstring-length-warn)
(byte-compile-warn-about-unresolved-functions, byte-compile-file)
(byte-compile--check-prefixed-var, byte-compile--declare-var)
(byte-compile-file-form-defvar-function, byte-compile-file-form-defmumble)
(byte-compile-check-lambda-list, byte-compile--warn-lexical-dynamic)
(byte-compile-lambda, byte-compile-form, byte-compile-normal-call)
(byte-compile-check-variable, byte-compile-free-vars-warn)
(byte-compile-subr-wrong-args, byte-compile-fset, byte-compile-set-default)
(byte-compile-condition-case, byte-compile-save-excursion)
(byte-compile-defvar, byte-compile-autoload)
(byte-compile-make-variable-buffer-local, byte-compile-define-symbol-prop)
(byte-compile-define-keymap): Replace byte-compile-warn with
byte-compile-warn-x.
(byte-compile-file, compile-defun): Bind symbols-with-pos-enabled to non-nil.
(compile-defun, byte-compile-from-buffer): Use `read-positioning-symbols'
rather than plain `read'.
(byte-compile-toplevel-file-form, byte-compile-form): Dynamically bind
byte-compile--form-stack.
(byte-compile-file-form-autoload, byte-compile-file-form-defvar)
(byte-compile-file-form-make-obsolete, byte-compile-lambda)
(byte-compile-push-constant, byte-compile-cond-jump-table)
(byte-compile-define-keymap, byte-compile-annotate-call-tree):
Strip positions from symbols where they are unwanted.
(byte-compile-file-form-defvar): Strip positions from symbols using
`bare-symbol'.
(byte-compile-file-form-defmumble): New variable bare-name, a version of name
without its position.
(byte-compile-lambda): Similarly, new variable bare-arglist.
(byte-compile-free-vars-warn): New argument arg supplying position information
to byte-compile-warn-x.
(byte-compile-push-constant): Manipulation of symbol positions.
(display-call-tree): Strip positions from symbols.

* lisp/emacs-lisp/cconv.el (cconv-convert, cconv--analyze-use)
(cconv--analyze-function, cconv-analyze-form): Replace use of
byte-compile-warn with byte-compile-warn-x.

* lisp/emacs-lisp/cl-generic.el (cl-defmethod): New variable org-name which
  will supply position information to a new macroexp-warn-and-return.

  * lisp/emacs-lisp/cl-macs.el (cl-macs--strip-s-p-1)
  (cl-macs--strip-symbol-positions): New functions to strip positions from
  symbols in an expression.  These duplicaate similarly named functions in
  bytecomp.el.

  * lisp/emacs-lisp/macroexpand.el (macroexp--warn-wrap): Calls
  byte-compile-warn-x in place of byte-compile-warn.
  (macroexp-warn-and-return): Commented out new position parameter _arg.

* src/.gdbinit: Add in code to handle symbols with position.

* src/alloc.c (XPNTR, set_symbol_name, valid_lisp_object_p, purecopy)
(mark_char_table, mark_object, survives_gc_p, symbol_uses_obj): Use
BARE_SYMBOL_P and XBARE_SYMBOL in place of the former SYMBOLP and XSYMBOL.
(build_symbol_with_pos): New function.
(Fgarbage_collect): Bind Qsymbols_with_pos_enabled to nil around the call to
garbage_collect.

* src/data.c (Ftype_of): Add case for PVEC_SYMBOL_WITH_POS.
(Fbare_symbol_p, Fsymbol_with_pos_p, Fbare_symbol, Fsymbol_with_pos_pos)
(Fposition_symbol): New functions.
(symbols_with_pos_enabled): New boolean variable.

* src/fns.c (internal_equal, hash_lookup): Handle symbols with position.

* src/keyboard.c (recursive_edit_1): Bind Qsymbols_with_pos_enabled and
Qprint_symbols_bare to nil.

* src/lisp.h (lisp_h_PSEUDOVECTORP): New macro.
(lisp_h_BASE_EQ): New name for the former lisp_h_EQ.
(lisp_h_EQ): Extended to handle symbols with position.
(lisp_h_NILP): Now uses BASE_EQ rather than EQ.
(lisp_h_SYMBOL_WITH_POS_P, lisp_h_BARE_SYMBOL_P): New macros.
(lisp_h_SYMBOLP): Redefined to handle symbols with position.
(BARE_SYMBOL_P, BASE_EQ): New macros.
(SYMBOLP (macro)): Removed.
(SYMBOLP (function), XSYMBOL, make_lisp_symbol, builtin_lisp_symbol)
(c_symbol_p): Moved to later in file.
(struct Lisp_Symbol_With_Pos): New data type.
(pvec_type): PVEC_SYMBOL_WITH_POS: New type code.
(PSEUDOVECTORP): Redefined to use the lisp_h_PSEUDOVECTORP.
(BARE_SYMBOL_P, SYMBOL_WITH_POS_P, SYMBOLP, XSYMBOL_WITH_POS, XBARE_SYMBOL)
(XSYMBOL, make_lisp_symbol, builtin_lisp_symbol, c_symbol_p, CHECK_SYMBOL)
(BASE_EQ): New functions, or functions moved from earlier in the file.
(SYMBOL_WITH_POS_SYM, SYMBOL_WITH_POS_POS): New INLINE functions.

* src/lread.c (read0, read1, read_list, read_vector, read_internal_start)
(list2): Add a new bool parameter locate_syms.
(Fread_positioning_symbols): New function.
(Fread_from_string, read_internal_start, read0, read1, read_list): Pass around
suitable values for locate_syms.
(read1): Build symbols with position when locate_syms is true.

* src/print.c (print_vectorlike): Add handling for PVEC_SYMBOL_WITH_POS.
(print_object): Replace EQ with BASE_EQ.
(print_symbols_bare): New boolean variable.

1 files changed, 32 insertions, 1 deletions

diff --git a/src/print.c b/src/print.c
index adadb289de0..eb0fe591b85 100644
--- a/src/print.c
+++ b/src/print.c
@@ -1416,6 +1416,30 @@ print_vectorlike (Lisp_Object obj, Lisp_Object printcharfun, bool escapeflag,
       printchar ('>', printcharfun);
       break;
 
+    case PVEC_SYMBOL_WITH_POS:
+      {
+        struct Lisp_Symbol_With_Pos *sp = XSYMBOL_WITH_POS (obj);
+        if (print_symbols_bare)
+          print_object (sp->sym, printcharfun, escapeflag);
+        else
+          {
+            print_c_string ("#<symbol ", printcharfun);
+            if (BARE_SYMBOL_P (sp->sym))
+              print_object (sp->sym, printcharfun, escapeflag);
+            else
+              print_c_string ("NOT A SYMBOL!!", printcharfun);
+            if (FIXNUMP (sp->pos))
+              {
+                print_c_string (" at ", printcharfun);
+                print_object (sp->pos, printcharfun, escapeflag);
+              }
+            else
+              print_c_string (" NOT A POSITION!!", printcharfun);
+            printchar ('>', printcharfun);
+          }
+      }
+      break;
+
     case PVEC_OVERLAY:
       print_c_string ("#<overlay ", printcharfun);
       if (! XMARKER (OVERLAY_START (obj))->buffer)
@@ -1921,7 +1945,7 @@ print_object (Lisp_Object obj, Lisp_Object printcharfun, bool escapeflag)
 	error ("Apparently circular structure being printed");
 
       for (i = 0; i < print_depth; i++)
-	if (EQ (obj, being_printed[i]))
+	if (BASE_EQ (obj, being_printed[i]))
 	  {
 	    int len = sprintf (buf, "#%d", i);
 	    strout (buf, len, len, printcharfun);
@@ -2425,6 +2449,13 @@ priorities.  Values other than nil or t are also treated as
 `default'.  */);
   Vprint_charset_text_property = Qdefault;
 
+  DEFVAR_BOOL ("print-symbols-bare", print_symbols_bare,
+               doc: /* A flag to control printing of symbols with position.
+If the value is nil, print these objects complete with position.
+Otherwise print just the bare symbol.  */);
+  print_symbols_bare = false;
+  DEFSYM (Qprint_symbols_bare, "print-symbols-bare");
+
   /* prin1_to_string_buffer initialized in init_buffer_once in buffer.c */
   staticpro (&Vprin1_to_string_buffer);