diff mbox series

[1/2] xen/cppcheck: add a way to exclude files from the scan

Message ID 20230214085635.3170962-2-luca.fancellu@arm.com (mailing list archive)
State Superseded
Headers show
Series xen/misra: create exclusion file list | expand

Commit Message

Luca Fancellu Feb. 14, 2023, 8:56 a.m. UTC
Add a way to exclude files from the scan, in this way we can skip
some findings from the report on those files that Xen doesn't own.

To do that, introduce the exclude-list.json file under docs/misra,
this file will be populated with relative path to the files/folder
to be excluded.
Introduce a new module, exclusion_file_list.py, to deal with the
exclusion list file and use the new module in cppcheck_analysis.py
to take a list of excluded paths to update the suppression list of
cppcheck.
Modified --suppress flag for cppcheck tool to remove
unmatchedSuppression findings for those external file that are
listed but for example not built for the current architecture.

Add documentation for the file.

Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
---
 docs/misra/exclude-list.json                  |  4 +
 docs/misra/exclude-list.rst                   | 44 +++++++++++
 xen/scripts/xen_analysis/cppcheck_analysis.py | 21 ++++-
 .../xen_analysis/exclusion_file_list.py       | 79 +++++++++++++++++++
 4 files changed, 146 insertions(+), 2 deletions(-)
 create mode 100644 docs/misra/exclude-list.json
 create mode 100644 docs/misra/exclude-list.rst
 create mode 100644 xen/scripts/xen_analysis/exclusion_file_list.py

Comments

Jan Beulich Feb. 14, 2023, 9:51 a.m. UTC | #1
On 14.02.2023 09:56, Luca Fancellu wrote:
> Add a way to exclude files from the scan, in this way we can skip
> some findings from the report on those files that Xen doesn't own.
> 
> To do that, introduce the exclude-list.json file under docs/misra,
> this file will be populated with relative path to the files/folder
> to be excluded.
> Introduce a new module, exclusion_file_list.py, to deal with the
> exclusion list file and use the new module in cppcheck_analysis.py
> to take a list of excluded paths to update the suppression list of
> cppcheck.
> Modified --suppress flag for cppcheck tool to remove
> unmatchedSuppression findings for those external file that are
> listed but for example not built for the current architecture.
> 
> Add documentation for the file.
> 
> Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
> ---
>  docs/misra/exclude-list.json                  |  4 +
>  docs/misra/exclude-list.rst                   | 44 +++++++++++
>  xen/scripts/xen_analysis/cppcheck_analysis.py | 21 ++++-
>  .../xen_analysis/exclusion_file_list.py       | 79 +++++++++++++++++++
>  4 files changed, 146 insertions(+), 2 deletions(-)
>  create mode 100644 docs/misra/exclude-list.json
>  create mode 100644 docs/misra/exclude-list.rst
>  create mode 100644 xen/scripts/xen_analysis/exclusion_file_list.py

As I think I have asked for before: Can new files please avoid underscores
in their names, when dashes do quite fine? Or does Python have special
restrictions?

> --- a/xen/scripts/xen_analysis/cppcheck_analysis.py
> +++ b/xen/scripts/xen_analysis/cppcheck_analysis.py
> @@ -1,7 +1,8 @@
>  #!/usr/bin/env python3
>  
>  import os, re, shutil
> -from . import settings, utils, cppcheck_report_utils
> +from . import settings, utils, cppcheck_report_utils, exclusion_file_list
> +from .exclusion_file_list import ExclusionFileListError
>  
>  class GetMakeVarsPhaseError(Exception):
>      pass
> @@ -50,6 +51,22 @@ def __generate_suppression_list(out_file):
>              # header for cppcheck
>              supplist_file.write("*:*generated/compiler-def.h\n")
>  
> +            try:
> +                exclusion_file = \
> +                    "{}/docs/misra/exclude-list.json".format(settings.repo_dir)
> +                exclusion_list = \
> +                    exclusion_file_list.load_exclusion_file_list(exclusion_file)
> +            except ExclusionFileListError as e:
> +                    raise CppcheckDepsPhaseError(
> +                            "Issue with reading file {}: {}"
> +                                .format(exclusion_file, e)
> +                          )

My Python isn't very good, but isn't indentation one level too deep
here?

Jan
Luca Fancellu Feb. 14, 2023, 10:02 a.m. UTC | #2
> On 14 Feb 2023, at 09:51, Jan Beulich <jbeulich@suse.com> wrote:
> 
> On 14.02.2023 09:56, Luca Fancellu wrote:
>> Add a way to exclude files from the scan, in this way we can skip
>> some findings from the report on those files that Xen doesn't own.
>> 
>> To do that, introduce the exclude-list.json file under docs/misra,
>> this file will be populated with relative path to the files/folder
>> to be excluded.
>> Introduce a new module, exclusion_file_list.py, to deal with the
>> exclusion list file and use the new module in cppcheck_analysis.py
>> to take a list of excluded paths to update the suppression list of
>> cppcheck.
>> Modified --suppress flag for cppcheck tool to remove
>> unmatchedSuppression findings for those external file that are
>> listed but for example not built for the current architecture.
>> 
>> Add documentation for the file.
>> 
>> Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
>> ---
>> docs/misra/exclude-list.json                  |  4 +
>> docs/misra/exclude-list.rst                   | 44 +++++++++++
>> xen/scripts/xen_analysis/cppcheck_analysis.py | 21 ++++-
>> .../xen_analysis/exclusion_file_list.py       | 79 +++++++++++++++++++
>> 4 files changed, 146 insertions(+), 2 deletions(-)
>> create mode 100644 docs/misra/exclude-list.json
>> create mode 100644 docs/misra/exclude-list.rst
>> create mode 100644 xen/scripts/xen_analysis/exclusion_file_list.py
> 
> As I think I have asked for before: Can new files please avoid underscores
> in their names, when dashes do quite fine? Or does Python have special
> restrictions?

From the python coding style:

Modules should have short, all-lowercase names. Underscores can be used in
the module name if it improves readability. Python packages should also have
short, all-lowercase names, although the use of underscores is discouraged.

In this case I think it improves readability

> 
>> --- a/xen/scripts/xen_analysis/cppcheck_analysis.py
>> +++ b/xen/scripts/xen_analysis/cppcheck_analysis.py
>> @@ -1,7 +1,8 @@
>> #!/usr/bin/env python3
>> 
>> import os, re, shutil
>> -from . import settings, utils, cppcheck_report_utils
>> +from . import settings, utils, cppcheck_report_utils, exclusion_file_list
>> +from .exclusion_file_list import ExclusionFileListError
>> 
>> class GetMakeVarsPhaseError(Exception):
>>     pass
>> @@ -50,6 +51,22 @@ def __generate_suppression_list(out_file):
>>             # header for cppcheck
>>             supplist_file.write("*:*generated/compiler-def.h\n")
>> 
>> +            try:
>> +                exclusion_file = \
>> +                    "{}/docs/misra/exclude-list.json".format(settings.repo_dir)
>> +                exclusion_list = \
>> +                    exclusion_file_list.load_exclusion_file_list(exclusion_file)
>> +            except ExclusionFileListError as e:
>> +                    raise CppcheckDepsPhaseError(
>> +                            "Issue with reading file {}: {}"
>> +                                .format(exclusion_file, e)
>> +                          )
> 
> My Python isn't very good, but isn't indentation one level too deep
> here?

Good catch, I’ll fix it

> 
> Jan
diff mbox series

Patch

diff --git a/docs/misra/exclude-list.json b/docs/misra/exclude-list.json
new file mode 100644
index 000000000000..1fb0ac67747b
--- /dev/null
+++ b/docs/misra/exclude-list.json
@@ -0,0 +1,4 @@ 
+{
+    "version": "1.0",
+    "content": []
+}
diff --git a/docs/misra/exclude-list.rst b/docs/misra/exclude-list.rst
new file mode 100644
index 000000000000..969539c46beb
--- /dev/null
+++ b/docs/misra/exclude-list.rst
@@ -0,0 +1,44 @@ 
+.. SPDX-License-Identifier: CC-BY-4.0
+
+Exclude file list for xen-analysis script
+=========================================
+
+The code analysis is performed on the Xen codebase for both MISRA checkers and
+static analysis checkers, there are some files however that needs to be removed
+from the findings report because they are not owned by Xen and they must be kept
+in sync with their origin (completely or even partially), hence we can't easily
+fix findings or deviate from them.
+
+For this reason the file docs/misra/exclude-list.json is used to exclude every
+entry listed in that file from the final report.
+Currently only the cppcheck analysis will use this file.
+
+Here is an example of the exclude-list.json file::
+
+|{
+|    "version": "1.0",
+|    "content": [
+|        {
+|            "rel_path": "relative/path/from/xen/file",
+|            "comment": "This file is originated from ..."
+|        },
+|        {
+|            "rel_path": "relative/path/from/xen/folder/*",
+|            "comment": "This folder is a library"
+|        },
+|        {
+|            "rel_path": "relative/path/from/xen/mem*.c",
+|            "comment": "memcpy.c, memory.c and memcmp.c are from the outside"
+|        }
+|    ]
+|}
+
+Here is an explanation of the fields inside an object of the "content" array:
+ - rel_path: it is the relative path from the Xen folder to the file/folder that
+   needs to be excluded from the analysis report, it can contain a wildcard to
+   match more than one file/folder at the time. This field is mandatory.
+ - comment: an optional comment to explain why the file is removed from the
+   analysis.
+
+To ease the review and the modifications of the entries, they shall be listed in
+alphabetical order referring to the rel_path field.
diff --git a/xen/scripts/xen_analysis/cppcheck_analysis.py b/xen/scripts/xen_analysis/cppcheck_analysis.py
index cc1f403d315e..b681dca90836 100644
--- a/xen/scripts/xen_analysis/cppcheck_analysis.py
+++ b/xen/scripts/xen_analysis/cppcheck_analysis.py
@@ -1,7 +1,8 @@ 
 #!/usr/bin/env python3
 
 import os, re, shutil
-from . import settings, utils, cppcheck_report_utils
+from . import settings, utils, cppcheck_report_utils, exclusion_file_list
+from .exclusion_file_list import ExclusionFileListError
 
 class GetMakeVarsPhaseError(Exception):
     pass
@@ -50,6 +51,22 @@  def __generate_suppression_list(out_file):
             # header for cppcheck
             supplist_file.write("*:*generated/compiler-def.h\n")
 
+            try:
+                exclusion_file = \
+                    "{}/docs/misra/exclude-list.json".format(settings.repo_dir)
+                exclusion_list = \
+                    exclusion_file_list.load_exclusion_file_list(exclusion_file)
+            except ExclusionFileListError as e:
+                    raise CppcheckDepsPhaseError(
+                            "Issue with reading file {}: {}"
+                                .format(exclusion_file, e)
+                          )
+
+            # Append excluded files to the suppression list, using * as error id
+            # to suppress every findings on that file
+            for path in exclusion_list:
+                supplist_file.write("*:{}\n".format(path))
+
             for entry in headers:
                 filename = entry["file"]
                 try:
@@ -128,7 +145,7 @@  def generate_cppcheck_deps():
  --relative-paths={}
  --inline-suppr
  --suppressions-list={}/suppression-list.txt
- --suppress='unmatchedSuppression:*generated/compiler-def.h'
+ --suppress='unmatchedSuppression:*'
  --include={}/include/xen/config.h
  -DCPPCHECK
 """.format(settings.outdir, CPPCHECK_BUILD_DIR, settings.xen_dir,
diff --git a/xen/scripts/xen_analysis/exclusion_file_list.py b/xen/scripts/xen_analysis/exclusion_file_list.py
new file mode 100644
index 000000000000..4a47a90f5944
--- /dev/null
+++ b/xen/scripts/xen_analysis/exclusion_file_list.py
@@ -0,0 +1,79 @@ 
+#!/usr/bin/env python3
+
+import os, glob, json
+from . import settings
+
+class ExclusionFileListError(Exception):
+    pass
+
+
+def __cppcheck_path_exclude_syntax(path):
+    # Prepending * to the relative path to match every path where the Xen
+    # codebase could be
+    path = "*" + path
+
+    # Check if the path is to a folder without the wildcard at the end
+    if not (path.endswith(".c") or path.endswith(".h") or path.endswith("*")):
+        # The path is to a folder, if it doesn't have the final /, add it
+        if not path.endswith("/"):
+            path = path + "/"
+        # Since the path is a folder, add a wildcard to the end so that
+        # cppcheck will remove every issue related with this path
+        path = path + "*"
+
+    return path
+
+
+# Reads the exclusion file list and returns a list of relative path to be
+# excluded.
+def load_exclusion_file_list(input_file):
+    ret = []
+    try:
+        with open(input_file, "rt") as handle:
+            content = json.load(handle)
+            entries = content['content']
+    except json.JSONDecodeError as e:
+        raise ExclusionFileListError(
+                "JSON decoding error in file {}: {}".format(input_file, e)
+        )
+    except KeyError:
+        raise ExclusionFileListError(
+            "Malformed JSON file: content field not found!"
+        )
+    except Exception as e:
+        raise ExclusionFileListError(
+                "Can't open file {}: {}".format(input_file, e)
+        )
+
+    for entry in entries:
+        try:
+            path = entry['rel_path']
+        except KeyError:
+            raise ExclusionFileListError(
+                "Malformed JSON entry: rel_path field not found!"
+            )
+        abs_path = settings.xen_dir + "/" + path
+        check_path = [abs_path]
+
+        # If the path contains wildcards, solve them
+        if '*' in abs_path:
+            check_path = glob.glob(abs_path)
+
+        # Check that the path exists
+        for filepath_object in check_path:
+            if not os.path.exists(filepath_object):
+                raise ExclusionFileListError(
+                    "Malformed path: {} refers to {} that does not exists"
+                    .format(path, filepath_object)
+                )
+
+        if settings.analysis_tool == "cppcheck":
+            path = __cppcheck_path_exclude_syntax(path)
+        else:
+            raise ExclusionFileListError(
+                "Unimplemented for {}!".format(settings.analysis_tool)
+            )
+
+        ret.append(path)
+
+    return ret