PerformanceAnalyzer: Fix tracepoints script

Fixed issues seen running the tracepoint script in Arch Linux:
* Use /lib/ rather than /lib for the call to find to work with cases
  where /lib is a symlink.
* When finding <name>_ret entries in match_tracepoints, search for
  <name>_ret__return if the initial check failed. Newer versions of perf
  seem to decorate the name with __return when the function name is
  followed by %return.
* Handle arrays output from the call to awk in match_tracepoints. This
  can happen when multiple functions are added with the tracepoint, and
  breaks when checking for "bad" probes when a loop isn't used to add
  individual checks for each entry.

Fixes: QTCREATORBUG-25651
Change-Id: Ie528b4d80f9ece8f23d27a84356c74577219ed45
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>

src/plugins/perfprofiler/tracepoints.sh

@@ -49,8 +49,20 @@ match_tracepoints() {
 
     BASE="perfprofiler_${MACHINE}_${NAME}"
     RETURN=`perf probe -l "${BASE}_ret" | awk '{print $3}'`
+    if [ -z "$RETURN" ]; then
+        RETURN=`perf probe -l "${BASE}_ret__return" | awk '{print $3}'`
+    fi
+
+    CHECK=
+    for RET in $RETURN; do
+        if [ -n "$CHECK" ]; then
+            CHECK="$CHECK && "
+        fi
+        CHECK="$CHECK\$3 != \"$RET\""
+    done
+
     ENTRY=`echo ${RETURN} | awk '{sub(/%return/, ""); print $1}'`
-    BAD=`perf probe -l "${BASE}*" | awk '{ if ($3 != "'$RETURN'" && $3 != "'$ENTRY'") { print $1 } }'`
+    BAD=`perf probe -l "${BASE}*" | awk '{ if ('"$CHECK"' && $3 != "'$ENTRY'") { print $1 } }'`
     for PROBE in $BAD; do
         perf probe -d $PROBE
     done
@@ -121,7 +133,7 @@ set_tracepoint() {
 }
 
 HOST_MACHINE=`uname -m`
-find /lib -name libc.so.6 | while read LIBC; do
+find /lib/ -name libc.so.6 | while read LIBC; do
     echo $LIBC | awk -F '/' '{print $(NF-1)}' | while IFS='-' read MACHINE KERNEL SYSTEM; do
         if [ "$MACHINE" = "lib" ]; then MACHINE=$HOST_MACHINE; fi
         >&2 echo "</pre><h3>Removing old trace points for $MACHINE</h3><pre>"