[libgo PATCH 0/1] mksyscalls.awk: make split ERE more portable

[libgo PATCH 0/1] mksyscalls.awk: make split ERE more portable

[Bernhard Reutner-Fischer]

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Hi,

When using busybox' awk to bootstrap, libgo's syscalls are generated
incorrectly.

I'm attaching the split() used by busybox' awk including output before
and after the patch for reference.

Please install / ok to install?

Bernhard Reutner-Fischer (1):
  mksyscalls.awk: make split ERE more portable

 libgo/go/syscall/mksyscall.awk |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

-- 
1.7.10.4

[-- Attachment #2: regexec.c --]
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#include <regex.h>
#include <string.h>
#include <stdio.h>
int main(void) {
	int l, n = 0;
	char *inp = "//sysnb	pipe(p *[2]_C_int) (err error)";
	char *out = __builtin_alloca(strlen(inp)*2+3);
	regex_t re;
	regmatch_t m[1];
	strcpy(out, inp);
#ifndef ERE
# define ERE "[	 (]*"
#endif
	if (regcomp(&re, ERE, REG_EXTENDED) != 0)
		__builtin_abort();
	do {
		l = strcspn(inp, "\n\0");
		if (regexec(&re, inp, 1, m, 0) == 0 && m[0].rm_so <= l) {
			l = m[0].rm_so;
			if (m[0].rm_eo == 0)
				m[0].rm_eo++, l++;
			n++;
		} else {
			m[0].rm_eo = l;
			if (inp[l])
				m[0].rm_eo++;
		}
		memcpy(out, inp, l);
		do {
			out[l] = '\0';
		} while (++l < m[0].rm_eo);
		printf("[%2d] '%s'\n", n, out);
		while (*(out++) != '\0')
			continue;
		inp += m[0].rm_eo;
	} while (*inp);
	regfree(&re);
	return 0;
}

#if 0
+ gcc '-DERE="[ 	(]*"' -o x regexec.c
+ ./x
[ 1] '/'
[ 2] '/'
[ 3] 's'
[ 4] 'y'
[ 5] 's'
[ 6] 'n'
[ 7] 'b'
[ 8] ''
[ 9] 'p'
[10] 'i'
[11] 'p'
[12] 'e'
[13] ''
[14] 'p'
[15] ''
[16] '*'
[17] '['
[18] '2'
[19] ']'
[20] '_'
[21] 'C'
[22] '_'
[23] 'i'
[24] 'n'
[25] 't'
[26] ')'
[27] ''
[28] 'e'
[29] 'r'
[30] 'r'
[31] ''
[32] 'e'
[33] 'r'
[34] 'r'
[35] 'o'
[36] 'r'
[37] ')'
+ gcc '-DERE="[ 	(]"' -o x regexec.c
+ ./x
[ 1] '//sysnb'
[ 2] 'pipe'
[ 3] 'p'
[ 4] '*[2]_C_int)'
[ 5] ''
[ 6] 'err'
[ 6] 'error)'
#endif

[libgo PATCH 1/1] mksyscalls.awk: make split ERE more portable

[Bernhard Reutner-Fischer]

awk's split() ERE was splitting on (essentially) .
Double checked with mawk 1.3.3, GNU Awk 4.0.1, busybox awk
that they still produce identical output.

libgo/ChangeLog (???)

2013-08-01  Bernhard Reutner-Fischer  <aldot@gcc.gnu.org>

	* go/syscall/mksyscall.awk (split): Fix ere argument.

Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>
---
 libgo/go/syscall/mksyscall.awk |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libgo/go/syscall/mksyscall.awk b/libgo/go/syscall/mksyscall.awk
index 74f0e28..829b6fe 100644
--- a/libgo/go/syscall/mksyscall.awk
+++ b/libgo/go/syscall/mksyscall.awk
@@ -53,7 +53,7 @@ BEGIN {
     }
 
     # Sets a[1] = //sysnb, a[2] == function name.
-    split(line, a, "[ 	(]*")
+    split(line, a, "[ 	(]")
     gofnname = a[2]
 
     off = match(line, "\\([^()]*\\)")
@@ -78,7 +78,7 @@ BEGIN {
 	next
     }
 
-    split(line, a, "[ 	(]*")
+    split(line, a, "[ 	(]")
     cfnname = substr(a[1], 3, length(a[1]) - 2)
 
     off = match(line, "\\([^()]*\\)")
-- 
1.7.10.4

Re: [libgo PATCH 0/1] mksyscalls.awk: make split ERE more portable

[Ian Lance Taylor]

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On Thu, Aug 1, 2013 at 5:36 AM, Bernhard Reutner-Fischer
<rep.dot.nop@gmail.com> wrote:
>
> When using busybox' awk to bootstrap, libgo's syscalls are generated
> incorrectly.
>
> I'm attaching the split() used by busybox' awk including output before
> and after the patch for reference.
>
> Please install / ok to install?

I installed a slightly different version, that retains the desired
semantics (skip arbitrary amounts of whitespace).  This should avoid
confusing the busybox awk by matching the null string.  Committed to
mainline and 4.8 branch.

Thanks for reporting the issue.

Ian

[-- Attachment #2: foo.patch --]
[-- Type: application/octet-stream, Size: 572 bytes --]

diff -r 76558b3ff8f3 libgo/go/syscall/mksyscall.awk
--- a/libgo/go/syscall/mksyscall.awk	Fri Aug 02 09:59:39 2013 -0700
+++ b/libgo/go/syscall/mksyscall.awk	Fri Aug 02 15:28:21 2013 -0700
@@ -53,7 +53,7 @@
     }
 
     # Sets a[1] = //sysnb, a[2] == function name.
-    split(line, a, "[ 	(]*")
+    split(line, a, "[ 	(]+")
     gofnname = a[2]
 
     off = match(line, "\\([^()]*\\)")
@@ -78,7 +78,7 @@
 	next
     }
 
-    split(line, a, "[ 	(]*")
+    split(line, a, "[ 	(]+")
     cfnname = substr(a[1], 3, length(a[1]) - 2)
 
     off = match(line, "\\([^()]*\\)")