xen/cppcheck: add parameter to skip given MISRA rules

Add parameter to skip the passed MISRA rules during the cppcheck
analysis, the rules are specified as a list of comma separated
rules with the MISRA number notation (e.g. 1.1,1.3,...).

Modify convert_misra_doc.py script to take an extra parameter
giving a list of MISRA rule to be skipped, comma separated.
While there, fix some typos in the help and print functions.

Modify settings.py and cppcheck_analysis.py to have a new
parameter (--cppcheck-skip-rules) used to specify a list of
MISRA rule to be skipped during the cppcheck analysis.

Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>

xen/scripts/xen_analysis/cppcheck_analysis.py

@@ -153,11 +153,15 @@ def generate_cppcheck_deps():
     if settings.cppcheck_misra:
         cppcheck_flags = cppcheck_flags + " --addon=cppcheck-misra.json"
 
+        skip_rules_arg = ""
+        if settings.cppcheck_skip_rules != "":
+            skip_rules_arg = "-s {}".format(settings.cppcheck_skip_rules)
+
         utils.invoke_command(
             "{}/convert_misra_doc.py -i {}/docs/misra/rules.rst"
-            " -o {}/cppcheck-misra.txt -j {}/cppcheck-misra.json"
+            " -o {}/cppcheck-misra.txt -j {}/cppcheck-misra.json {}"
                 .format(settings.tools_dir, settings.repo_dir,
-                        settings.outdir, settings.outdir),
+                        settings.outdir, settings.outdir, skip_rules_arg),
             False, CppcheckDepsPhaseError,
             "An error occured when running:\n{}"
         )

xen/scripts/xen_analysis/settings.py

@@ -24,6 +24,7 @@ cppcheck_binpath = "cppcheck"
 cppcheck_html = False
 cppcheck_htmlreport_binpath = "cppcheck-htmlreport"
 cppcheck_misra = False
+cppcheck_skip_rules = ""
 make_forward_args = ""
 outdir = xen_dir
 
@@ -53,20 +54,22 @@ Cppcheck report creation phase runs only when --run-cppcheck is passed to the
 script.
 
 Options:
-  --build-only          Run only the commands to build Xen with the optional
-                        make arguments passed to the script
-  --clean-only          Run only the commands to clean the analysis artifacts
-  --cppcheck-bin=       Path to the cppcheck binary (Default: {})
-  --cppcheck-html       Produce an additional HTML output report for Cppcheck
-  --cppcheck-html-bin=  Path to the cppcheck-html binary (Default: {})
-  --cppcheck-misra      Activate the Cppcheck MISRA analysis
-  --distclean           Clean analysis artifacts and reports
-  -h, --help            Print this help
-  --no-build            Skip the build Xen phase
-  --no-clean            Don\'t clean the analysis artifacts on exit
-  --run-coverity        Run the analysis for the Coverity tool
-  --run-cppcheck        Run the Cppcheck analysis tool on Xen
-  --run-eclair          Run the analysis for the Eclair tool
+  --build-only            Run only the commands to build Xen with the optional
+                          make arguments passed to the script
+  --clean-only            Run only the commands to clean the analysis artifacts
+  --cppcheck-bin=         Path to the cppcheck binary (Default: {})
+  --cppcheck-html         Produce an additional HTML output report for Cppcheck
+  --cppcheck-html-bin=    Path to the cppcheck-html binary (Default: {})
+  --cppcheck-misra        Activate the Cppcheck MISRA analysis
+  --cppcheck-skip-rules=  List of MISRA rules to be skipped, comma separated.
+                          (e.g. --cppcheck-skip-rules=1.1,20.7,8.4)
+  --distclean             Clean analysis artifacts and reports
+  -h, --help              Print this help
+  --no-build              Skip the build Xen phase
+  --no-clean              Don\'t clean the analysis artifacts on exit
+  --run-coverity          Run the analysis for the Coverity tool
+  --run-cppcheck          Run the Cppcheck analysis tool on Xen
+  --run-eclair            Run the analysis for the Eclair tool
 """
     print(msg.format(sys.argv[0], cppcheck_binpath,
                      cppcheck_htmlreport_binpath))
@@ -78,6 +81,7 @@ def parse_commandline(argv):
     global cppcheck_html
     global cppcheck_htmlreport_binpath
     global cppcheck_misra
+    global cppcheck_skip_rules
     global make_forward_args
     global outdir
     global step_get_make_vars
@@ -115,6 +119,9 @@ def parse_commandline(argv):
             cppcheck_htmlreport_binpath = args_with_content_regex.group(2)
         elif option == "--cppcheck-misra":
             cppcheck_misra = True
+        elif args_with_content_regex and \
+             args_with_content_regex.group(1) == "--cppcheck-skip-rules":
+            cppcheck_skip_rules = args_with_content_regex.group(2)
         elif option == "--distclean":
             target_distclean = True
         elif (option == "--help") or (option == "-h"):

xen/tools/convert_misra_doc.py

@@ -4,12 +4,14 @@
 This script is converting the misra documentation RST file into a text file
 that can be used as text-rules for cppcheck.
 Usage:
-    convert_misr_doc.py -i INPUT [-o OUTPUT] [-j JSON]
+    convert_misra_doc.py -i INPUT [-o OUTPUT] [-j JSON] [-s RULES,[...,RULES]]
 
     INPUT  - RST file containing the list of misra rules.
     OUTPUT - file to store the text output to be used by cppcheck.
              If not specified, the result will be printed to stdout.
     JSON   - cppcheck json file to be created (optional).
+    RULES  - list of rules to skip during the analysis, comma separated
+             (e.g. 1.1,1.2,1.3,...)
 """
 
 import sys, getopt, re
@@ -47,21 +49,25 @@ def main(argv):
     outfile = ''
     outstr = sys.stdout
     jsonfile = ''
+    force_skip = ''
 
     try:
-        opts, args = getopt.getopt(argv,"hi:o:j:",["input=","output=","json="])
+        opts, args = getopt.getopt(argv,"hi:o:j:s:",
+                                   ["input=","output=","json=","skip="])
     except getopt.GetoptError:
-        print('convert-misra.py -i <input> [-o <output>] [-j <json>')
+        print('convert-misra.py -i <input> [-o <output>] [-j <json>] [-s <rules>]')
         sys.exit(2)
     for opt, arg in opts:
         if opt == '-h':
-            print('convert-misra.py -i <input> [-o <output>] [-j <json>')
+            print('convert-misra.py -i <input> [-o <output>] [-j <json>] [-s <rules>]')
             print('  If output is not specified, print to stdout')
             sys.exit(1)
         elif opt in ("-i", "--input"):
             infile = arg
         elif opt in ("-o", "--output"):
             outfile = arg
+        elif opt in ("-s", "--skip"):
+            force_skip = arg
         elif opt in ("-j", "--json"):
             jsonfile = arg
 
@@ -169,14 +175,18 @@ def main(argv):
 
     skip_list = []
 
+    # Add rules to be skipped anyway
+    for r in force_skip.split(','):
+        skip_list.append(r)
+
     # Search for missing rules and add a dummy text with the rule number
     for i in misra_c2012_rules:
         for j in list(range(1,misra_c2012_rules[i]+1)):
-            if str(i) + '.' + str(j) not in rule_list:
-                outstr.write('Rule ' + str(i) + '.' + str(j) + '\n')
-                outstr.write('No description for rule ' + str(i) + '.' + str(j)
-                             + '\n')
-                skip_list.append(str(i) + '.' + str(j))
+            rule_str = str(i) + '.' + str(j)
+            if (rule_str not in rule_list) and (rule_str not in skip_list):
+                outstr.write('Rule ' + rule_str + '\n')
+                outstr.write('No description for rule ' + rule_str + '\n')
+                skip_list.append(rule_str)
 
     # Make cppcheck happy by starting the appendix
     outstr.write('Appendix B\n')