Make postgres.bki use the same literal-string syntax as postgresql.conf.

The BKI file's string quoting conventions were previously quite weird,
perhaps as a result of repurposing a function built to scan
single-quoted strings to scan double-quoted ones.  Change to use the
same rules as we use in GUC files, allowing some simplifications in
genbki.pl and initdb.c.

While at it, completely remove the backend's scanstr() function, which
was essentially a duplicate of the string dequoting code in guc-file.l.
Instead export that one (under a less generic name than it had) and let
bootscanner.l use it.  Now we can clarify that scansup.c exists only to
support the main lexer. We could alternatively have removed GUC_scanstr,
but this way seems better since the previous arrangement could mislead
a reader into thinking that scanstr() had something to do with the main
lexer's handling of string literals.  Maybe it did once, but if so it
was a long time ago.

This patch does not bump catversion, since the initially-installed
catalog contents don't change.  Note however that successful initdb
after applying this patch will require up-to-date postgres.bki as well
as postgres and initdb executables.

In passing, remove a bunch of very-long-obsolete #include's in
bootparse.y and bootscanner.l.

John Naylor

Discussion: https://postgr.es/m/CACPNZCtDpd18T0KATTmCggO2GdVC4ow86ypiq5ENff1VnauL8g@mail.gmail.com

1 files changed, 1 insertions, 94 deletions

diff --git a/src/backend/parser/scansup.c b/src/backend/parser/scansup.c
index cac70d5df7a..d07cbafcee7 100644
--- a/src/backend/parser/scansup.c
+++ b/src/backend/parser/scansup.c
@@ -1,8 +1,7 @@
 /*-------------------------------------------------------------------------
  *
  * scansup.c
- *	  support routines for the lex/flex scanner, used by both the normal
- * backend as well as the bootstrap backend
+ *	  scanner support routines used by the core lexer
  *
  * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
@@ -20,98 +19,6 @@
 #include "mb/pg_wchar.h"
 #include "parser/scansup.h"
 
-/* ----------------
- *		scanstr
- *
- * if the string passed in has escaped codes, map the escape codes to actual
- * chars
- *
- * the string returned is palloc'd and should eventually be pfree'd by the
- * caller!
- * ----------------
- */
-
-char *
-scanstr(const char *s)
-{
-	char	   *newStr;
-	int			len,
-				i,
-				j;
-
-	if (s == NULL || s[0] == '\0')
-		return pstrdup("");
-
-	len = strlen(s);
-
-	newStr = palloc(len + 1);	/* string cannot get longer */
-
-	for (i = 0, j = 0; i < len; i++)
-	{
-		if (s[i] == '\'')
-		{
-			/*
-			 * Note: if scanner is working right, unescaped quotes can only
-			 * appear in pairs, so there should be another character.
-			 */
-			i++;
-			/* The bootstrap parser is not as smart, so check here. */
-			Assert(s[i] == '\'');
-			newStr[j] = s[i];
-		}
-		else if (s[i] == '\\')
-		{
-			i++;
-			switch (s[i])
-			{
-				case 'b':
-					newStr[j] = '\b';
-					break;
-				case 'f':
-					newStr[j] = '\f';
-					break;
-				case 'n':
-					newStr[j] = '\n';
-					break;
-				case 'r':
-					newStr[j] = '\r';
-					break;
-				case 't':
-					newStr[j] = '\t';
-					break;
-				case '0':
-				case '1':
-				case '2':
-				case '3':
-				case '4':
-				case '5':
-				case '6':
-				case '7':
-					{
-						int			k;
-						long		octVal = 0;
-
-						for (k = 0;
-							 s[i + k] >= '0' && s[i + k] <= '7' && k < 3;
-							 k++)
-							octVal = (octVal << 3) + (s[i + k] - '0');
-						i += k - 1;
-						newStr[j] = ((char) octVal);
-					}
-					break;
-				default:
-					newStr[j] = s[i];
-					break;
-			}					/* switch */
-		}						/* s[i] == '\\' */
-		else
-			newStr[j] = s[i];
-		j++;
-	}
-	newStr[j] = '\0';
-	return newStr;
-}
-
 
 /*
  * downcase_truncate_identifier() --- do appropriate downcasing and