[S] Change in coreboot[main]: genbuild_h: Fix and harden major/minor version parsing

[Nico Huber (Code Review)]

Nico Huber has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/81290?usp=email )

Change subject: genbuild_h: Fix and harden major/minor version parsing
......................................................................

genbuild_h: Fix and harden major/minor version parsing

Our major version is suddenly two digits long to represent the year.
This can't be parsed with the current sed scripts. To make sure that
no unparsed data ends up in our major/minor versions,  we'll run sed
with `-n' and only print the extracted numbers if anything. Also, to
allow us to use the version numbers in C code, we strip leading zeros
(a leading 0 identifies octal numbers, so for instance 08 for August
is not a valid number).

This can result in empty major/minor version strings, so we move the
default `0' to the final variable expansion.

As a bonus, this makes an explicit check if the numbers can be parsed
unnecessary.

Change-Id: Ie39381a8ef4b971556168b6996efeefe6adf2b14
Reported-by: Christoph Zechner 
Signed-off-by: Nico Huber 
---
M util/genbuild_h/genbuild_h.sh
1 file changed, 8 insertions(+), 12 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/90/81290/1

diff --git a/util/genbuild_h/genbuild_h.sh b/util/genbuild_h/genbuild_h.sh
index 2bfcc4c..b381ab2 100755
--- a/util/genbuild_h/genbuild_h.sh
+++ b/util/genbuild_h/genbuild_h.sh
@@ -6,8 +6,8 @@
 GITREV=""
 TIMESOURCE=""
 XGCCPATH="${XGCCPATH:-util/crossgcc/xgcc/bin/}"
-MAJOR_VER="0"
-MINOR_VER="0"
+MAJOR_VER=""
+MINOR_VER=""
 COREBOOT_VERSION_FILE=".coreboot-version"

export LANG=C
@@ -36,19 +36,15 @@
    TIMESOURCE=git
    DATE="$(get_git_head_data %ct)"
    VERSION="$(git describe)"
-	# Only use the `git describe` output if the tag is in the expected <major>.<minor>
-	# format, e.g. 4.18. Forks of coreboot may have other tags in different formats.
-	if echo "${VERSION}" | grep -q "^[0-9].[0-9][0-9]*"; then
-		MAJOR_VER="$(echo "${VERSION}" | sed 's/([0-9]).([0-9][0-9]*).*/\1/')"
-		MINOR_VER="$(echo "${VERSION}" | sed 's/([0-9]).([0-9][0-9]*).*/\2/')"
-	fi
+	MAJOR_VER="$(echo "${VERSION}" | sed -n 's/^0*([0-9]*).0*([0-9]*).*/\1/p')"
+	MINOR_VER="$(echo "${VERSION}" | sed -n 's/^0*([0-9]*).0*([0-9]*).*/\2/p')"
 else
    GITREV=Unknown
    TIMESOURCE="date"
    DATE=$(LANG="" LC_ALL=C TZ=UTC0 date +%s)
    if [ -f "${COREBOOT_VERSION_FILE}" ]; then
-		MAJOR_VER="$(sed 's/([0-9]).([0-9][0-9]*).*/\1/' "${COREBOOT_VERSION_FILE}")"
-		MINOR_VER="$(sed 's/([0-9]).([0-9][0-9]*).*/\2/' "${COREBOOT_VERSION_FILE}")"
+		MAJOR_VER="$(sed -n 's/^0*([0-9]*).0*([0-9]*).*/\1/p' "${COREBOOT_VERSION_FILE}")"
+		MINOR_VER="$(sed -n 's/^0*([0-9]*).0*([0-9]*).*/\2/p' "${COREBOOT_VERSION_FILE}")"
    fi
 fi

@@ -84,8 +80,8 @@
 printf "#define COREBOOT_ORIGIN_GIT_REVISION "%s"\n" "${GITREV}"

printf "#define COREBOOT_EXTRA_VERSION "%s"\n" "${COREBOOT_EXTRA_VERSION}"
-printf "#define COREBOOT_MAJOR_VERSION %s\n" "${MAJOR_VER}"
-printf "#define COREBOOT_MINOR_VERSION %s\n" "${MINOR_VER}"
+printf "#define COREBOOT_MAJOR_VERSION %s\n" "${MAJOR_VER:-0}"
+printf "#define COREBOOT_MINOR_VERSION %s\n" "${MINOR_VER:-0}"
 printf "#define COREBOOT_BUILD "%s"\n" "$(our_date "${DATE}" "+%a %b %d %H:%M:%S %Z %Y")"
 printf "#define COREBOOT_BUILD_YEAR_BCD 0x%s\n" "$(our_date "${DATE}" "+%y")"
 printf "#define COREBOOT_BUILD_MONTH_BCD 0x%s\n" "$(our_date "${DATE}" "+%m")"