Add script to parse klp-build's ce.out.txt log and generate a runscri…

…pt from it

klp-build is a series of scripts to generate kernel livepatches. It
supports running clang-extract as a backend for extracting code from
the kernel.  However, when things break inside clang-extract we must
extract the interesting running commands from its logs and cd into
the build dir.  This script facilitates that by generating a .sh
script which can be used to run clang-extract easily.

Signed-off-by: Giuliano Belinassi <gbelinassi@suse.de>

contrib/extract-ce-cmdline.sh

@@ -0,0 +1,134 @@
+#!/bin/sh
+#
+# This project is licensed under the Apache License v2.0 with LLVM Exceptions.
+# See https://llvm.org/LICENSE.txt for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+#
+# \file
+# Script to extract clang-extract command-line from klp-build ce log files.
+#
+
+# Name of the script.
+PROGNAME=`basename "$0"`
+
+# The input file
+INPUT_FILE=''
+
+# The output file
+OUTPUT_FILE=''
+
+# With GDB call?
+WITH_GDB=0
+
+print_help_message()
+{
+  echo "Setup script to extract clang-extract command line from klp-build CE log"
+  echo ""
+  echo "Usage: $PROGNAME ce.out.txt <switches>"
+  echo "where <switches>"
+  echo "  -o=OUTPUT_FILE            Output to write. Empty or '-' will print to stdout."
+  echo "  --with-gdb                clang-extract will be called within gdb."
+  echo ""
+}
+
+# Parse the arguments given to script.
+parse_program_argv()
+{
+  # Parse arguments provided by user.
+  for i in "$@"; do
+    case $i in
+      -o=*)
+        OUTPUT_FILE="${i#*=}"
+        shift
+        ;;
+      --with-gdb)
+        WITH_GDB=1
+        shift
+        ;;
+      -*|--*)
+        echo "Unknown option $i"
+        echo ""
+        print_help_message
+        shift
+        exit 1
+        ;;
+      *)
+        INPUT_FILE=${i}
+        shift
+        ;;
+    esac
+  done
+
+  # Bails out if no input file was given
+  if [ "x$INPUT_FILE" == "x" ]; then
+    echo "Error: no input file.\n"
+    print_help_message
+    exit 1
+  fi
+
+  # Set output to /dev/stdout if no output file was given, or if '-o -'
+  # was passed.
+  if [ "x$OUTPUT_FILE" == "x" -o "$OUTPUT_FILE" == "-" ]; then
+    OUTPUT_FILE="/dev/stdout"
+  fi
+}
+
+generate_script()
+{
+  # Get the pwd where clang-extract was run.
+  local string_pwd=$(sed -nr 's/Executing ce on (.*)/\1/p' $INPUT_FILE)
+  local found_ce=0
+
+  echo '#!/bin/bash'       >  $OUTPUT_FILE
+  echo "set -e"            >> $OUTPUT_FILE
+  echo "pushd $string_pwd" >> $OUTPUT_FILE
+  while IFS= read -r line; do
+    # If we did not reach the error state, then we are parsing clang-extract
+    # options.
+
+    if [ $found_ce -eq 0 ]; then
+      # Find the begining of the clang-extract commands.
+      echo "$line" | grep 'clang-extract$' > /dev/null
+      if [ $? -eq 0 ]; then
+        found_ce=1
+        if [ $WITH_GDB -eq 1 ]; then
+          echo 'gdb -args ' $line '\' >> $OUTPUT_FILE
+        else
+          echo $line '\' >> $OUTPUT_FILE
+        fi
+      fi
+    else
+      # Find the end of the clang-extract command lines.
+      echo "$line" | grep -E '.*warning:.*|.*error:.*|.*note:.*|^In file included*' > /dev/null
+      if [ $? -eq 0 ]; then
+        break
+      fi
+
+      echo $line '\' >> $OUTPUT_FILE
+    fi
+  done < $INPUT_FILE
+
+  # Newline to ignore the fact that the last command ends with a '\'
+  echo '' >> $OUTPUT_FILE
+
+  # Pop the directory to go back where this script was called.
+  echo 'popd' >> $OUTPUT_FILE
+
+  # Newline to comply with POSIX text files.
+  echo '' >> $OUTPUT_FILE
+  # Set file as executable
+  if [ "$OUTPUT_FILE" != "/dev/null" ]; then
+    chmod +x $OUTPUT_FILE
+  fi
+}
+
+# Parse the input file
+
+# Script entry point.
+main()
+{
+  parse_program_argv $*
+  generate_script
+}
+
+main $*