[PATCH] libc function availability checker for a shared library

[Takuya ASADA]

This script list up missing libc function called from a shared library.
Usage:
./scripts/check-libcfunc-avail.sh release apps/memcached/memcached.so

Signed-off-by: Takuya ASADA <sy...@cloudius-systems.com>
---
scripts/check-libcfunc-avail.sh | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
create mode 100755 scripts/check-libcfunc-avail.sh

diff --git a/scripts/check-libcfunc-avail.sh b/scripts/check-libcfunc-avail.sh
new file mode 100755
index 0000000..0a412ee
--- /dev/null
+++ b/scripts/check-libcfunc-avail.sh
@@ -0,0 +1,21 @@
+#!/bin/bash
+
+if [ "$1" == "" -o "$2" == "" ]; then
+ echo "usage: $0 [release | debug] [app.so]"
+ exit 1
+fi
+
+MODE=$1
+APP=$2
+
+FUNCS=`objdump -T $APP | grep GLIBC|sed -e "s/.*GLIBC_[0-9.]* //"`
+for i in $FUNCS; do
+ if [ ! -f build/$MODE/loader.elf ]; then
+ echo "build/$MODE/loader.elf not found"
+ exit 1
+ fi
+ FOUND=`objdump -t build/$MODE/loader.elf | grep -e " $i$" | wc -l`
+ if [ $FOUND == 0 ]; then
+ echo "$i not found"
+ fi
+done
--
1.8.5.3

[Nadav Har'El]

On Sat, Mar 8, 2014 at 5:50 AM, Takuya ASADA <sy...@cloudius-systems.com> wrote:

This script list up missing libc function called from a shared library.
Usage:
./scripts/check-libcfunc-avail.sh release apps/memcached/memcached.so

Signed-off-by: Takuya ASADA <sy...@cloudius-systems.com>
---
 scripts/check-libcfunc-avail.sh | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100755 scripts/check-libcfunc-avail.sh

diff --git a/scripts/check-libcfunc-avail.sh b/scripts/check-libcfunc-avail.sh
new file mode 100755
index 0000000..0a412ee
--- /dev/null
+++ b/scripts/check-libcfunc-avail.sh
@@ -0,0 +1,21 @@
+#!/bin/bash
+
+if [ "$1" == "" -o "$2" == "" ]; then

Arguably, checking [ $# != 2 ] is more elegant ($# is the number of arguments, like argc-1 in C )

+    echo "usage: $0 [release | debug] [app.so]"
+    exit 1
+fi
+
+MODE=$1
+APP=$2
+
+FUNCS=`objdump -T $APP | grep GLIBC|sed -e "s/.*GLIBC_[0-9.]* //"`
+for i in $FUNCS; do
+    if [ ! -f build/$MODE/loader.elf ]; then
+        echo "build/$MODE/loader.elf not found"
+        exit 1
+    fi
+    FOUND=`objdump -t build/$MODE/loader.elf | grep -e " $i$" | wc -l`

You are doing here objdump again and again. I guess on a modern computer this is insignificant and the whole loop will not take much more than a few seconds, but it could have a few milliseconds...

The most efficient way to do this would be to run objdump loader.elf just once, put all the names in it in a hash table (bash has hashtables, or use python if you prefer) and then look for the functions in the hash table.

By the way, unrelated shell notes:
 1.  "grep -q" can be used to see if there's any match - no need for wc.

 2. normal grep, without "-e", already supports "$".

So you could have also did something equally slow to what you did but arguably nicer shell:

if objdump -t build/$MODE/loader.elf | grep -q " $i$"

then

    echo "$i not found"

fi

+    if [ $FOUND == 0 ]; then
+        echo "$i not found"
+    fi
+done

--
1.8.5.3

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Nadav Har'El

n...@cloudius-systems.com

[Takuya ASADA]

This script list up missing libc function called from a shared library.
Usage:
./scripts/check-libcfunc-avail.sh release apps/memcached/memcached.so

Signed-off-by: Takuya ASADA <sy...@cloudius-systems.com>
---

scripts/check-libcfunc-avail.sh | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)

create mode 100755 scripts/check-libcfunc-avail.sh

diff --git a/scripts/check-libcfunc-avail.sh b/scripts/check-libcfunc-avail.sh
new file mode 100755

index 0000000..0bca3aa
--- /dev/null
+++ b/scripts/check-libcfunc-avail.sh
@@ -0,0 +1,25 @@
+#!/bin/bash
+
+if [ $# != 2 ]; then

+ echo "usage: $0 [release | debug] [app.so]"
+ exit 1
+fi
+
+MODE=$1
+APP=$2
+

+if [ ! -f build/$MODE/loader.elf ]; then

+ echo "build/$MODE/loader.elf not found"
+ exit 1
+fi

+DUMPFILE=`mktemp`
+objdump -t build/$MODE/loader.elf > $DUMPFILE

+FUNCS=`objdump -T $APP | grep GLIBC|sed -e "s/.*GLIBC_[0-9.]* //"`
+for i in $FUNCS; do

+ grep -q " $i$" $DUMPFILE
+ FOUND=$?
+ if [ $FOUND != 0 ]; then

+ echo "$i not found"
+ fi
+done

+rm $DUMPFILE
--
1.8.5.3

[Nadav Har'El]

Looks better (could have been more efficient if you didn't read DUMPFILE again and again, but at this point, I don't think anyone cares).

Some minor shell style suggestions below.

On Sun, Mar 9, 2014 at 10:33 AM, Takuya ASADA <sy...@cloudius-systems.com> wrote:

This script list up missing libc function called from a shared library.
Usage:
./scripts/check-libcfunc-avail.sh release apps/memcached/memcached.so

Signed-off-by: Takuya ASADA <sy...@cloudius-systems.com>
---

 scripts/check-libcfunc-avail.sh | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

 create mode 100755 scripts/check-libcfunc-avail.sh

diff --git a/scripts/check-libcfunc-avail.sh b/scripts/check-libcfunc-avail.sh
new file mode 100755

index 0000000..0bca3aa
--- /dev/null
+++ b/scripts/check-libcfunc-avail.sh
@@ -0,0 +1,25 @@
+#!/bin/bash
+
+if [ $# != 2 ]; then

+    echo "usage: $0 [release | debug] [app.so]"

It is customary to print error messages to the standard error. Also, it is Unix tradition when printing the "Usage" to put in brackets *optional* arguments,  while here in fact the argument is not optional (see also http://pubs.opengroup.org/onlinepubs/009696899/basedefs/xbd_chap12.html). So I would prefer this:

    echo "Usage: $0 release|debug <app.so> " >&2

(the >&2 redirects the output to fd 2, which is the standard error).

+if [ ! -f build/$MODE/loader.elf ]; then

+    echo "build/$MODE/loader.elf not found"
+    exit 1
+fi

+DUMPFILE=`mktemp`

Please clean up the temporary file if the script is interrupted:

trap "rm $DUMPFILE" 1 2 3 15

(this runs that code if the shell is killed with SIGHUP, SIGINT, SIGQUIT or SIGTERM). 

+objdump -t build/$MODE/loader.elf > $DUMPFILE

+FUNCS=`objdump -T $APP | grep GLIBC|sed -e "s/.*GLIBC_[0-9.]* //"`
+for i in $FUNCS; do

+    grep -q " $i$" $DUMPFILE
+    FOUND=$?

+    if [ $FOUND != 0 ]; then

You can replace the above three lines by the simpler

    if grep -q " $i$" $DUMPFILE

    then

(if normally checks the exit code of the command - no need to save this exit code in a variable and then run test ("[") on it).

 

+        echo "$i not found"
+    fi
+done

+rm $DUMPFILE

--
1.8.5.3

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[Nadav Har'El]

On Tue, Mar 11, 2014 at 8:45 AM, Nadav Har'El <n...@cloudius-systems.com> wrote:

trap "rm $DUMPFILE" 1 2 3 15

Sorry, this should have been

 trap "rm -f $DUMPFILE; exit" 1 2 3 15

Otherwise, if we don't exit, the shell will continue after the signal instead of exiting like it should.

[Takuya ASADA]

This script list up missing libc function called from a shared library.
Usage:
./scripts/check-libcfunc-avail.sh release apps/memcached/memcached.so

Signed-off-by: Takuya ASADA <sy...@cloudius-systems.com>
---
scripts/check-libcfunc-avail.sh | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
create mode 100755 scripts/check-libcfunc-avail.sh

diff --git a/scripts/check-libcfunc-avail.sh b/scripts/check-libcfunc-avail.sh
new file mode 100755
index 0000000..0bca3aa
--- /dev/null
+++ b/scripts/check-libcfunc-avail.sh
@@ -0,0 +1,25 @@
+#!/bin/bash
+
+if [ $# != 2 ]; then
+ echo "usage: $0 [release | debug] [app.so]"

+ exit 1
+fi
+
+MODE=$1
+APP=$2
+

+if [ ! -f build/$MODE/loader.elf ]; then
+ echo "build/$MODE/loader.elf not found"
+ exit 1
+fi
+DUMPFILE=`mktemp`

+objdump -t build/$MODE/loader.elf > $DUMPFILE
+FUNCS=`objdump -T $APP | grep GLIBC|sed -e "s/.*GLIBC_[0-9.]* //"`
+for i in $FUNCS; do
+ grep -q " $i$" $DUMPFILE
+ FOUND=$?
+ if [ $FOUND != 0 ]; then

[Asias He]

Ping.

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Asias

[Commit Bot]

From: Takuya ASADA <sy...@cloudius-systems.com>

libc function availability checker for a shared library

This script list up missing libc function called from a shared library.
Usage:
./scripts/check-libcfunc-avail.sh release apps/memcached/memcached.so

Signed-off-by: Takuya ASADA <sy...@cloudius-systems.com>

Signed-off-by: Pekka Enberg <pen...@cloudius-systems.com>

---
diff --git a/scripts/check-libcfunc-avail.sh
b/scripts/check-libcfunc-avail.sh
--- a/scripts/check-libcfunc-avail.sh