Code that
uses c-ctype wants only ASCII letters, and departing from this would
likely break things.
How would that match occur? c_isalpha() was/is using a "switch"
statement for EBCDIC.
Oh, sorry, I was assuming that the substitution was being proposed for all the
functions; but it's being proposed only for c_isascii, c_iscntrl, c_isgraph,
c_isprint, and c_ispunct. These functions are so rarely used that it probably
doesn't matter that much what we do....
If the user builds in one locale and runs in another, they're going to
have bigger problems (e.g. garbled program messages). As far as I've
seen, this is considered "out of bounds" in z/OS usage.
Excellent; that simplifies things.
A different code page at run time, I think, is not feasible. But
international users will at least want a different code page at
compile time.
A simple program could generate tables for all the isxxxxx() functions
(see below) at compile time. Would you be inclined to do it that way?
I think we can do it without that kind of compile-time hassle, if we can assume
that the compile-time locale is the same as the run-time. I installed the
attached patch, which makes that assumption, and which I hope does the right thing.
From a5ce2c8c0b604a86fd575c6f80384e3189703546 Mon Sep 17 00:00:00 2001
From: Paul Eggert <egg...@cs.ucla.edu>
Date: Tue, 22 Sep 2015 18:59:28 -0700
Subject: [PATCH] c-ctype: support EBCDIC-style c_isascii
* lib/c-ctype.c (C_TYPE_EBCDIC): Move to top level.
(c_isascii, c_iscntrl): Assume EBCDIC code page 1047 for control
characters, if EBCDIC.
---
lib/c-ctype.c | 93 +++++++++++++++++++++++++++++++++++++++++------------------
1 file changed, 65 insertions(+), 28 deletions(-)
diff --git a/lib/c-ctype.c b/lib/c-ctype.c
index 558c4af..a3913a1 100644
--- a/lib/c-ctype.c
+++ b/lib/c-ctype.c
@@ -37,6 +37,17 @@ enum { C_CTYPE_CONSECUTIVE_LOWERCASE = false };
enum { C_CTYPE_CONSECUTIVE_UPPERCASE = false };
#endif
+enum
+ {
+ /* True if this appears to be a host using EBCDIC. */
+ C_CTYPE_EBCDIC = (' ' == '\x40' && '0' == '\xf0'
+ && 'A' == '\xc1' && 'J' == '\xd1' && 'S' == '\xe2'
+ && 'a' == '\x81' && 'j' == '\x91' && 's' == '\xa2')
+ };
+
+/* The implementation currently supports ASCII and EBCDIC. */
+verify (C_CTYPE_ASCII || C_CTYPE_EBCDIC);
+
/* Convert an int, which may be promoted from either an unsigned or a
signed char, to the corresponding char. */
@@ -54,7 +65,45 @@ to_char (int c)
bool
c_isascii (int c)
{
- return (c >= 0x00 && c <= 0x7f);
+ if (C_CTYPE_ASCII)
+ return 0 <= c && c <= 0x7f;
+
+ /* Use EBCDIC code page 1047's assignments for ASCII control chars;
+ assume all EBCDIC code pages agree about these assignments. */
+ switch (to_char (c))
+ {
+ case '\x00': case '\x01': case '\x02': case '\x03': case '\x05':
+ case '\x0b': case '\x0c': case '\x0d': case '\x0e': case '\x0f':
+ case '\x10': case '\x11': case '\x12': case '\x13': case '\x15':
+ case '\x16': case '\x18': case '\x19': case '\x1c': case '\x1d':
+ case '\x1e': case '\x1f': case '\x26': case '\x27': case '\x2d':
+ case '\x2e': case '\x2f': case '\x32': case '\x37': case '\x3c':
+ case '\x3d': case '\x3f': case '\xff':
+ case '\xff' < 0 ? 0xff : -1:
+
+ case ' ': case '!': case '"': case '#': case '$': case '%':
+ case '&': case '\'': case '(': case ')': case '*': case '+':
+ case ',': case '-': case '.': case '/':
+ case '0': case '1': case '2': case '3': case '4': case '5':
+ case '6': case '7': case '8': case '9':
+ case ':': case ';': case '<': case '=': case '>': case '?':
+ case '@':
+ case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
+ case 'G': case 'H': case 'I': case 'J': case 'K': case 'L':
+ case 'M': case 'N': case 'O': case 'P': case 'Q': case 'R':
+ case 'S': case 'T': case 'U': case 'V': case 'W': case 'X':
+ case 'Y': case 'Z':
+ case '[': case '\\': case ']': case '^': case '_': case '`':
+ case 'a': case 'b': case 'c': case 'd': case 'e': case 'f':
+ case 'g': case 'h': case 'i': case 'j': case 'k': case 'l':
+ case 'm': case 'n': case 'o': case 'p': case 'q': case 'r':
+ case 's': case 't': case 'u': case 'v': case 'w': case 'x':
+ case 'y': case 'z':
+ case '{': case '|': case '}': case '~':
+ return true;
+ default:
+ return false;
+ }
}
bool
@@ -131,36 +180,24 @@ c_isblank (int c)
bool
c_iscntrl (int c)
{
- enum { C_CTYPE_EBCDIC = (' ' == '\x40' && '0' == '\xf0'
- && 'A' == '\xc1' && 'J' == '\xd1' && 'S' == '\xe2'
- && 'a' == '\x81' && 'j' == '\x91' && 's' == '\xa2')
};
if (C_CTYPE_ASCII)
return (0 <= c && c < ' ') || c == 0x7f;
- else
+
+ /* Use EBCDIC code page 1047's assignments for ASCII control chars;
+ assume all EBCDIC code pages agree about these assignments. */
+ switch (c)
{
- /* Return true if C corresponds to an ASCII control character.
- Assume EBCDIC code page 1047, and verify that the compiler
- agrees with this. */
- verify (C_CTYPE_ASCII
- || (C_CTYPE_EBCDIC
- && '!' == '\x5a' && '#' == '\x7b' && '$' == '\x5b'
- && '@' == '\x7c' && '[' == '\xad' && '\\' == '\xe0'
- && ']' == '\xbd' && '^' == '\x5f' && '_' == '\x6d'
- && '`' == '\x79'));
- switch (c)
- {
- case '\x00': case '\x01': case '\x02': case '\x03': case '\x05':
- case '\x0b': case '\x0c': case '\x0d': case '\x0e': case '\x0f':
- case '\x10': case '\x11': case '\x12': case '\x13': case '\x15':
- case '\x16': case '\x18': case '\x19': case '\x1c': case '\x1d':
- case '\x1e': case '\x1f': case '\x26': case '\x27': case '\x2d':
- case '\x2e': case '\x2f': case '\x32': case '\x37': case '\x3c':
- case '\x3d': case '\x3f': case '\xff':
- case '\xff' < 0 ? 0xff : -1:
- return true;
- default:
- return false;
- }
+ case '\x00': case '\x01': case '\x02': case '\x03': case '\x05':
+ case '\x0b': case '\x0c': case '\x0d': case '\x0e': case '\x0f':
+ case '\x10': case '\x11': case '\x12': case '\x13': case '\x15':
+ case '\x16': case '\x18': case '\x19': case '\x1c': case '\x1d':
+ case '\x1e': case '\x1f': case '\x26': case '\x27': case '\x2d':
+ case '\x2e': case '\x2f': case '\x32': case '\x37': case '\x3c':
+ case '\x3d': case '\x3f': case '\xff':
+ case '\xff' < 0 ? 0xff : -1:
+ return true;
+ default:
+ return false;
}
}
--
2.1.0
