Prefer signed to unsigned integers

This patch contains more fixes to prefer signed to unsigned
integer types, as modern tools like 'gcc -fsanitize=undefined'
can check for signed integer overflow but not unsigned overflow.
* NEWS: Document the API change.
* boostrap.conf (gnulib_modules): Add intprops.
* data/skeletons/glr.c: Include stddef.h and stdint.h,
since this skeleton can assume C99 or later.
(YYSIZEMAX): Now signed, and the minimum of SIZE_MAX and PTRDIFF_MAX.
(yybool) [!__cplusplus]: Now signed (which is how bool behaves).
(YYTRANSLATE): Avoid use of unsigned, and make the macro
safe even for values greater than UINT_MAX.
(yytnamerr, struct yyGLRState, struct yyGLRStateSet, struct yyGLRStack)
(yyaddDeferredAction, yyinitStateSet, yyinitGLRStack)
(yyexpandGLRStack, yymarkStackDeleted, yyremoveDeletes)
(yyglrShift, yyglrShiftDefer, yy_reduce_print, yydoAction)
(yyglrReduce, yysplitStack, yyreportTree, yycompressStack)
(yyprocessOneStack, yyreportSyntaxError, yyrecoverSyntaxError)
(yyparse, yy_yypstack, yypstack, yypdumpstack):
* tests/input.at (Torturing the Scanner):
Prefer ptrdiff_t to size_t.
* data/skeletons/c++.m4 (b4_yytranslate_define):
* src/AnnotationList.c (AnnotationList__computePredecessorAnnotations):
* src/AnnotationList.h (AnnotationIndex):
* src/InadequacyList.h (InadequacyListNodeCount):
* src/closure.c (closure_new):
* src/complain.c (error_message, complains, complain_indent)
(complain_args, duplicate_directive, duplicate_rule_directive):
* src/gram.c (nritems, ritem_print, grammar_dump):
* src/ielr.c (ielr_compute_ritem_sees_lookahead_set)
(ielr_item_has_lookahead, ielr_compute_annotation_lists)
(ielr_compute_lookaheads):
* src/location.c (columns, boundary_print, location_print):
* src/muscle-tab.c (muscle_percent_define_insert)
(muscle_percent_define_check_values):
* src/output.c (prepare_rules, prepare_actions):
* src/parse-gram.y (id, handle_require):
* src/reader.c (record_merge_function_type, packgram):
* src/reduce.c (nuseless_productions, nuseless_nonterminals)
(inaccessable_symbols):
* src/relation.c (relation_print):
* src/scan-code.l (variant, variant_table_size, variant_count)
(variant_add, get_at_spec, show_sub_message, show_sub_messages)
(parse_ref):
* src/scan-gram.l (<SC_ESCAPED_STRING,SC_ESCAPED_CHARACTER>)
(scan_integer, convert_ucn_to_byte, handle_syncline):
* src/scan-skel.l (at_complain):
* src/symtab.c (complain_symbol_redeclared)
(complain_semantic_type_redeclared, complain_class_redeclared)
(symbol_class_set, complain_user_token_number_redeclared):
* src/tables.c (conflict_tos, conflrow, conflict_table)
(conflict_list, save_row, pack_vector):
* tests/local.at (AT_YYLEX_DEFINE(c)):
Prefer signed to unsigned integer.
* data/skeletons/lalr1.cc (yy_lac_check_):
* tests/actions.at (_AT_CHECK_PRINTER_AND_DESTRUCTOR):
* tests/local.at (AT_YYLEX_DEFINE(c)):
Omit now-unnecessary casts.
* data/skeletons/location.cc (b4_location_define):
* doc/bison.texi (Mfcalc Lexer, C++ position, C++ location):
Prefer int to unsigned for line and column numbers.
Change example to abort explicitly on memory exhaustion,
and fix an off-by-one bug that led to undefined behavior.
* data/skeletons/stack.hh (stack::operator[]):
Also allow ptrdiff_t indexes.
(stack::pop, slice::slice, slice::operator[]):
Index arg is now ptrdiff_t, not int.
(stack::ssize): New method.
(slice::range_): Now ptrdiff_t, not int.
* data/skeletons/yacc.c (b4_state_num_type): Remove.
All uses replaced by b4_int_type.
(YY_CONVERT_INT_BEGIN, YY_CONVERT_INT_END): New macros.
(yylac, yyparse): Use them around conversions that -Wconversion
would give false alarms about. 	Omit unnecessary casts.
(yy_stack_print): Use int rather than unsigned, and omit
a cast that doesn’t seem to be needed here any more.
* examples/c++/variant.yy (yylex):
* examples/c++/variant-11.yy (yylex):
Omit no-longer-needed conversions to unsigned.
* src/InadequacyList.c (InadequacyList__new_conflict):
Don’t assume *node_count is unsigned.
* src/output.c (muscle_insert_unsigned_table):
Remove; no longer used.

doc/bison.texi

@@ -2662,7 +2662,7 @@ found, a pointer to that symbol is returned; otherwise zero is returned.
 
 @comment file: mfcalc.y: 3
 @example
-#include <stdlib.h> /* malloc. */
+#include <stdlib.h> /* malloc, abort. */
 #include <string.h> /* strlen. */
 
 @group
@@ -2670,7 +2670,11 @@ symrec *
 putsym (char const *name, int sym_type)
 @{
   symrec *res = (symrec *) malloc (sizeof (symrec));
+  if (!res)
+    abort ();
   res->name = strdup (name);
+  if (!res->name)
+    abort ();
   res->type = sym_type;
   res->value.var = 0; /* Set value to 0 even if fun. */
   res->next = sym_table;
@@ -2712,6 +2716,8 @@ operators in @code{yylex}.
 @comment file: mfcalc.y: 3
 @example
 #include <ctype.h>
+#include <stddef.h>
+#include <stdint.h>
 
 @group
 int
@@ -2748,23 +2754,25 @@ Bison generated a definition of @code{YYSTYPE} with a member named
   /* Char starts an identifier => read the name. */
   if (isalpha (c))
     @{
-      /* Initially make the buffer long enough
-         for a 40-character symbol name. */
-      static size_t length = 40;
+      static ptrdiff_t bufsize = 0;
       static char *symbuf = 0;
 @end group
-      if (!symbuf)
-        symbuf = malloc (length + 1);
-
-      int i = 0;
+      ptrdiff_t i = 0;
       do
 @group
         @{
           /* If buffer is full, make it bigger. */
-          if (i == length)
+          if (bufsize <= i)
             @{
-              length *= 2;
-              symbuf = realloc (symbuf, length + 1);
+              ptrdiff_t maxsize
+                = (PTRDIFF_MAX < SIZE_MAX
+                   ? PTRDIFF_MAX : SIZE_MAX);
+              if ((maxsize - 40) / 2 < bufsize)
+                abort ();
+              bufsize = 2 * bufsize + 40;
+              symbuf = realloc (symbuf, bufsize);
+              if (!symbuf)
+                abort ();
             @}
           /* Add this character to the buffer. */
           symbuf[i++] = c;
@@ -11476,13 +11484,13 @@ classes will not be generated, and the user defined type will be used.
 @node C++ position
 @subsubsection C++ @code{position}
 
-@deftypeop {Constructor} {position} {} position (std::string* @var{file} = nullptr, unsigned @var{line} = 1, unsigned @var{col} = 1)
+@deftypeop {Constructor} {position} {} position (std::string* @var{file} = nullptr, int @var{line} = 1, int @var{col} = 1)
 Create a @code{position} denoting a given point.  Note that @code{file} is
 not reclaimed when the @code{position} is destroyed: memory managed must be
 handled elsewhere.
 @end deftypeop
 
-@deftypemethod {position} {void} initialize (std::string* @var{file} = nullptr, unsigned @var{line} = 1, unsigned @var{col} = 1)
+@deftypemethod {position} {void} initialize (std::string* @var{file} = nullptr, int @var{line} = 1, int @var{col} = 1)
 Reset the position to the given values.
 @end deftypemethod
 
@@ -11493,7 +11501,7 @@ change it to @samp{@var{type}*} using @samp{%define filename_type
 "@var{type}"}.
 @end deftypeivar
 
-@deftypeivar {position} {unsigned} line
+@deftypeivar {position} {int} line
 The line, starting at 1.
 @end deftypeivar
 
@@ -11502,7 +11510,7 @@ If @var{height} is not null, advance by @var{height} lines, resetting the
 column number.  The resulting line number cannot be less than 1.
 @end deftypemethod
 
-@deftypeivar {position} {unsigned} column
+@deftypeivar {position} {int} column
 The column, starting at 1.
 @end deftypeivar
 
@@ -11537,11 +11545,11 @@ Create a @code{Location} from the endpoints of the range.
 @end deftypeop
 
 @deftypeop {Constructor} {location} {} location (const position& @var{pos} = position())
-@deftypeopx {Constructor} {location} {} location (std::string* @var{file}, unsigned @var{line}, unsigned @var{col})
+@deftypeopx {Constructor} {location} {} location (std::string* @var{file}, int @var{line}, int @var{col})
 Create a @code{Location} denoting an empty range located at a given point.
 @end deftypeop
 
-@deftypemethod {location} {void} initialize (std::string* @var{file} = nullptr, unsigned @var{line} = 1, unsigned @var{col} = 1)
+@deftypemethod {location} {void} initialize (std::string* @var{file} = nullptr, int @var{line} = 1, int @var{col} = 1)
 Reset the location to an empty range at the given values.
 @end deftypemethod