[PATCH 1/5] scripts: Add mkstrerror.sh

From: danielfsantos
Date: Tue Sep 17 2013 - 19:08:30 EST


This is a simple bash script that parses our errno*.h files and formats
them into the error_strings.h header that our strerror and strerror_name
functions will use later.

First it looks at $ARCH and examines the errno.h files and figures out
which to use. Then, it parses their error definitions into a
pipe-character delimited table with the fields name, number and
descrption from the comments. Finally, it does some consistency checks
and output them as usable C code.

On my Phenom it takes between 1.2 and 2 seconds to run depending upon
the arch. There are a few arch-specific conditions that the script has
to manage however:
* alpha: EAGAIN is redefined as 35 while EDEADLK is defined as 11
* mips: EDQUOT is 1133, which overlaps the internal error range
(512-529), so I'm just removing it.

This is done in a little case $ARCH statement in parse_errors().

Signed-off-by: Daniel Santos <daniel.santos@xxxxxxxxx>
---
scripts/mkstrerror.sh | 209 ++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 209 insertions(+)
create mode 100755 scripts/mkstrerror.sh

diff --git a/scripts/mkstrerror.sh b/scripts/mkstrerror.sh
new file mode 100755
index 0000000..e7842fc
--- /dev/null
+++ b/scripts/mkstrerror.sh
@@ -0,0 +1,209 @@
+#!/bin/bash
+
+# Generate lib/error_names.h by parsing errno*.h files
+
+typeset -i first=0
+typeset -i last=0
+typeset -i count=0
+
+die() {
+ echo "ERROR: $*" >&2
+ exit 1
+}
+
+parse_errors() {
+ egrep -h '^#define\s+\w+\s+[0-9]+' "$@" | # Extract error definitions
+ case "${ARCH}" in # Apply per-arch fixups
+ alpha) egrep -v 'EAGAIN\s+11';;
+ mips) egrep -v 'EDQUOT\s+1133';;
+ *) cat;;
+ esac |
+ perl -pe '
+ # Replace missing comments with "/* \0 */"
+ s:(\d+)\s*$:$1 /\* \\0 \*/\n:g;
+
+ # Parse into pipe-delimited table
+ s:^#define\s+(\w+)\s+(\w+)\s+/\*\s+(.*?)\s+\*/:$1|$2|$3:g;
+
+ # Since we will be feeding this to printf later, double any
+ # occurrence of %
+ s:%:%%:g;
+ ' |
+ sort '-t|' -nk2 # Sort by error number
+}
+
+tab_align() {
+ typeset -i tabs=$1
+ typeset -i next=0
+ typeset -i i
+ typeset -i len
+ local s
+ shift
+
+ while (($#)); do
+ for (( i = 0; i < next; ++i)); do
+ printf "\t"
+ done
+
+ printf "$1"
+
+ # Get un-escaped string size
+ s=$(printf "$1")
+ (( next = tabs - (${#s} ) / 8 ))
+ shift
+ done
+}
+
+print_errors() {
+ typeset -i next_err=$1
+ typeset -i tabs=$2
+ typeset -i errnum
+ local errname
+ while read; do
+ errnum=${REPLY/*|/}
+ errname=${REPLY/|*/}
+
+ (( next_err <= errnum )) || die "errors out of order :("
+
+ # Fill in any gaps with empty names
+ while (( next_err < errnum )); do
+ printf "\t%s\n" "$(tab_align ${tabs} '"\\0"' "/* ${next_err} */\n")"
+ (( ++next_err ))
+ done
+
+ printf "\t%s\n" "$(tab_align ${tabs} "\"${errname}"'\\0"' "/* ${errnum} */\n")"
+ (( ++next_err ))
+ done
+
+}
+
+count_and_validate() {
+ local names="$1"
+ typeset -i expected_count
+
+ first=$(echo "${names}" | head -1 | awk '{print $3}')
+ last=$(echo "${names}" | tail -1 | awk '{print $3}')
+ count=$(echo "${names}" | wc -l)
+ expected_count=$((last - first + 1))
+
+ if (( count != expected_count )); then
+ echo "ERROR: count = ${count}, expected ${expected_count}"
+ return 1;
+ fi
+ return 0;
+}
+
+find_arch_errno() {
+ for d in $(find arch/${ARCH}/include -name errno.h); do
+ # If it just includes asm-generic/errno.h then skip it
+ if ! grep '#include <asm-generic/errno.h>' $d > /dev/null; then
+ arch_errno="$d"
+ return;
+ fi
+ done
+
+ # Otherwise, no arch-specific errno
+ arch_errno=include/uapi/asm-generic/errno.h
+}
+
+find_arch_errno
+
+base_err_table=$(
+ parse_errors include/uapi/asm-generic/errno-base.h ${arch_errno}
+) || die
+
+internal_err_table=$(
+ parse_errors include/linux/errno.h
+) || die
+
+base_err_names=$(
+ echo "${base_err_table}" |
+ perl -pe 's:(\d+)\|.*:$1:g;'|
+ print_errors 0 4
+) || die
+
+count_and_validate "${base_err_names}" || die
+typeset -i base_err_first=${first}
+typeset -i base_err_last=${last}
+typeset -i base_err_count=${count}
+
+int_err_names=$(
+ echo "${internal_err_table}" |
+ perl -pe 's:(\d+)\|.*:$1:g;'|
+ print_errors 512 4
+) || die
+
+count_and_validate "${int_err_names}" || die
+typeset -i int_err_first=${first}
+typeset -i int_err_last=${last}
+typeset -i int_err_count=${count}
+
+
+cat << asdf
+/* DO NOT EDIT!
+ *
+ * This file is automatically generated by scripts/mkstrerror.sh
+ */
+
+#ifndef _KERNEL_STRERROR_H
+#define _KERNEL_STRERROR_H
+
+#if defined(CONFIG_STRERROR) || defined(CONFIG_STRERROR_NAME)
+
+static const struct error_strings {
+ const unsigned first;
+ const unsigned last;
+ const unsigned count;
+ const char * const desc[2];
+} error_strings[2] = {
+ {
+ .first = ${base_err_first},
+ .last = ${base_err_last},
+ .count = ${base_err_count},
+ .desc = {
+#ifdef CONFIG_STRERROR_NAME
+${base_err_names},
+#else
+ NULL,
+#endif /* CONFIG_STRERROR_NAME */
+
+#ifdef CONFIG_STRERROR
+$(
+ echo "${base_err_table}" |
+ perl -pe 's:.*?(\d+)\|(.*):$2|$1:g;'|
+ print_errors 0 7
+),
+#else
+ NULL,
+#endif /* CONFIG_STRERROR */
+ },
+ }, {
+ .first = ${int_err_first},
+ .last = ${int_err_last},
+ .count = ${int_err_count},
+ .desc = {
+#ifdef CONFIG_STRERROR_NAME
+${int_err_names},
+#else
+ NULL,
+#endif /* CONFIG_STRERROR_NAME */
+
+
+#ifdef CONFIG_STRERROR
+$(
+ echo "${internal_err_table}" |
+ perl -pe 's:.*?(\d+)\|(.*):$2|$1:g;'|
+ print_errors 512 7
+),
+#else
+ NULL,
+#endif /* CONFIG_STRERROR */
+ },
+ }
+};
+
+#endif /* defined(CONFIG_STRERROR) || defined(CONFIG_STRERROR_NAME) */
+
+#endif /* _KERNEL_STRERROR_H */
+asdf
+
--
1.8.1.5

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