addons/namingng.py: Add checks for include guards.

Include guard naming can be validated against various patterns:
- prefixes/suffixes (_FILE_H, PROJECT_FILE_H, FILE_H_)
- basename/full path (FILE_H, SUB_DIR_INC_FILE_H)
- upper- or lowercase (FILE_H, file_h) or case kept as-is (File_h)
- any combination of the above (project_sub_dir_inc_file_h_)

A regexp can be specified to match header filenames. The default matches any
filename not starting with / and ending with .h, intended to match C header
files while exluding system files.

The check is not limited to naming only; validity and presence of include
guards can also be tested by setting "required":true in the config file.

Enabling this feature requires adding the key "include_guard" to the namingng
config file.

The namingng unit test is extended to test various features of the include
guard check.

addons/namingng.config.json

@@ -2,6 +2,15 @@
     "RE_VARNAME": ["[a-z]*[a-zA-Z0-9_]*\\Z"],
     "RE_PRIVATE_MEMBER_VARIABLE": null,
     "RE_FUNCTIONNAME": ["[a-z0-9A-Z]*\\Z"],
+    "include_guard": {
+        "input": "path",
+        "prefix": "",
+        "suffix": "",
+        "case": "upper",
+        "max_linenr": 5,
+        "RE_HEADERFILE": "[^/].*\\.h\\Z",
+        "required": true
+    },
     "var_prefixes": {"uint32_t": "ui32",
                      "int*": "intp"},
     "function_prefixes": {"uint16_t": "ui16",

addons/namingng.py

@@ -3,6 +3,7 @@
 # cppcheck addon for naming conventions
 # An enhanced version. Configuration is taken from a json file
 # It supports to check for type-based prefixes in function or variable names.
+# Aside from include guard naming, include guard presence can also be tested.
 #
 # Example usage (variable name must start with lowercase, function name must start with uppercase):
 # $ cppcheck --dump path-to-src/
@@ -14,6 +15,14 @@
 #    "RE_VARNAME": "[a-z]*[a-zA-Z0-9_]*\\Z",
 #    "RE_PRIVATE_MEMBER_VARIABLE": null,
 #    "RE_FUNCTIONNAME": "[a-z0-9A-Z]*\\Z",
+#    "include_guard": {
+#        "input": "path",
+#        "prefix": "GUARD_",
+#        "case": "upper",
+#        "max_linenr": 5,
+#        "RE_HEADERFILE": "[^/].*\\.h\\Z",
+#        "required": true
+#    },
 #    "var_prefixes": {"uint32_t": "ui32"},
 #    "function_prefixes": {"uint16_t": "ui16",
 #                          "uint32_t": "ui32"}
@@ -73,10 +82,115 @@ def evalExpr(conf, exp, mockToken, msgType):
         msg = msgType + ' ' + mockToken.str + ' violates naming convention'
         checkFalseRegex(mockToken, exp, msg)
 
+def check_include_guard_name(conf_ig,cfg,directive):
+    parts = directive.str.split()
+    if len(parts) != 2:
+        msg = 'syntax error'
+        reportNamingError(directive,msg,'syntax')
+        return None
+    guard_name = parts[1]
+
+    filename = directive.file
+    if conf_ig.get('input','path') == 'basename':
+        filename = os.path.basename(filename)
+    use_case = conf_ig.get('case','upper')
+    if use_case == 'upper':
+        filename = filename.upper()
+    elif use_case == 'lower':
+        filename = filename.lower()
+    elif use_case == 'keep':
+        pass # keep filename case as-is
+    else:
+        print("invalid config value for 'case': '%s'"%use_case,file=sys.stderr)
+        sys.exit(1)
+
+    barename = re.sub('[^A-Za-z0-9]','_',filename).strip('_')
+    expect_guard_name = conf_ig.get('prefix','') + barename + conf_ig.get('suffix','')
+    if expect_guard_name != guard_name:
+        msg = 'include guard naming violation; %s != %s'%(guard_name,expect_guard_name)
+        reportNamingError(directive,msg,'includeGuardName')
+
+    return guard_name
+
+def check_include_guard(conf_ig,cfg,unguarded_include_files):
+    # Scan for '#ifndef FILE_H' as the first directive, in the first N lines.
+    # Then test whether the next directive #defines the found name.
+    # Various tests are done:
+    # - check include guards for their naming and consistency
+    # - test whether include guards are in place
+    max_linenr = conf_ig.get('max_linenr', 5)
+
+    def report(directive,msg,errorId):
+        reportNamingError(directive,msg,errorId)
+
+    def report_pending_ifndef(directive):
+        report(directive,'include guard #ifndef is not followed by #define','includeGuardIncomplete')
+
+    last_fn = None
+    pending_ifndef = None
+    phase = 0
+    for directive in cfg.directives:
+        if last_fn != directive.file:
+            if pending_ifndef:
+                report_pending_ifndef(pending_ifndef)
+                pending_ifndef = None
+            last_fn = directive.file
+            phase = 0
+        if phase == -1:
+            # ignore (the remainder of) this file
+            continue
+        if not re.match(include_guard_header_re,directive.file):
+            phase = -1
+            continue
+
+        if directive.linenr > max_linenr:
+            if phase == 0 and conf_ig.get('required',1):
+                report(directive,'include guard not found before line %d'%max_linenr,'includeGuardMissing')
+                pass
+            phase = -1
+            continue
+
+        if phase == 0:
+            # looking for '#ifndef FILE_H'
+            if not directive.str.startswith('#ifndef'):
+                if conf_ig.get('required',1):
+                    report(directive,'first preprocessor directive should be include guard #ifndef','includeGuardMissing')
+                phase = -1
+                continue
+            guard_name = check_include_guard_name(conf_ig,cfg,directive)
+            if guard_name == None:
+                phase = -1
+                continue
+            pending_ifndef = directive
+            phase = 1
+        elif phase == 1:
+            pending_ifndef = None
+            # looking for '#define FILE_H'
+            if not directive.str.startswith('#define'):
+                report(directive,'second preprocessor directive should be include guard #define','includeGuardIncomplete')
+                phase = -1
+                continue
+            parts = directive.str.split()
+            if len(parts) == 1:
+                report(directive,'syntax error','syntax')
+                phase = -1
+                continue
+            if guard_name != parts[1]:
+                report(directive,'include guard does not guard; %s != %s'%(guard_name,parts[1]),'includeGuardAwayFromDuty',severity='warning')
+
+            unguarded_include_files.remove(directive.file)
+
+            phase = -1
+    if pending_ifndef:
+        report_pending_ifndef(pending_ifndef)
 
 def process(dumpfiles, configfile, debugprint=False):
     conf = loadConfig(configfile)
 
+    if "include_guard" in conf and conf["include_guard"]:
+        global include_guard_header_re
+        include_guard_header_re = conf["include_guard"].get('RE_HEADERFILE',"[^/].*\\.h\\Z")
+
     for afile in dumpfiles:
         if not afile[-5:] == '.dump':
             continue
@@ -105,6 +219,11 @@ def process(dumpfiles, configfile, debugprint=False):
                     for exp in conf["RE_NAMESPACE"]:
                         evalExpr(conf["RE_NAMESPACE"], exp, mockToken, msgType)
 
+        unguarded_include_files = []
+        if "include_guard" in conf and conf["include_guard"]:
+            if conf["include_guard"].get('required',1):
+                unguarded_include_files = [fn for fn in data.files if re.match(include_guard_header_re,fn)]
+
         for cfg in data.configurations:
             if not args.cli:
                 print('Checking %s, config %s...' % (afile, cfg.name))
@@ -203,6 +322,14 @@ def process(dumpfiles, configfile, debugprint=False):
                         for exp in conf["RE_CLASS_NAME"]:
                             evalExpr(conf["RE_CLASS_NAME"], exp, mockToken, msgType)
 
+            # Check include guard naming
+            if "include_guard" in conf and conf["include_guard"]:
+                check_include_guard(conf["include_guard"],cfg,unguarded_include_files)
+
+        for fn in unguarded_include_files:
+            mockToken = DataStruct(fn,0,os.path.basename(fn))
+            reportNamingError(mockToken,'Missing include guard','includeGuardMissing')
+
 if __name__ == "__main__":
     parser = cppcheckdata.ArgumentParser()
     parser.add_argument("--debugprint", action="store_true", default=False,

test/cli/test-other.py

@@ -346,13 +346,28 @@ def test_addon_namingng(tmpdir):
     "RE_VARNAME": ["[a-z][a-z0-9_]*[a-z0-9]\\Z"],
     "RE_GLOBAL_VARNAME": ["[a-z][a-z0-9_]*[a-z0-9]\\Z"],
     "RE_FUNCTIONNAME": ["[a-z][a-z0-9_]*[a-z0-9]\\Z"],
+    "include_guard": {
+        "input": "basename",
+        "prefix": "_",
+        "suffix": "",
+        "case": "upper",
+        "max_linenr": 5,
+        "RE_HEADERFILE": ".*\\.h\\Z",
+        "required": true
+    },
     "var_prefixes": {"uint32_t": "ui32"},
     "function_prefixes": {"uint16_t": "ui16",
                           "uint32_t": "ui32"},
     "skip_one_char_variables": false
 }
                 """.replace('\\','\\\\'))
 
+    test_unguarded_include_file_basename = 'test_unguarded.h'
+    test_unguarded_include_file = os.path.join(tmpdir, test_unguarded_include_file_basename)
+    with open(test_unguarded_include_file, 'wt') as f:
+        f.write("""
+void InvalidFunctionUnguarded();
+""")
 
     test_include_file_basename = '_test.h'
     test_include_file = os.path.join(tmpdir, test_include_file_basename)
@@ -364,8 +379,10 @@ def test_addon_namingng(tmpdir):
 void InvalidFunction();
 extern int _invalid_extern_global;
 
+#include "{}"
+
 #endif
-""")
+""".format(test_unguarded_include_file))
 
     test_file_basename = 'test_.c'
     test_file = os.path.join(tmpdir, test_file_basename)
@@ -403,11 +420,18 @@ def test_addon_namingng(tmpdir):
     lines = [line for line in stderr.splitlines() if line.strip() != '^' and line != '']
     expect = [
         '{}:0:0: style: File name {} violates naming convention [namingng-namingConvention]'.format(test_include_file,test_include_file_basename),
+        '{}:2:0: style: include guard naming violation; TEST_H != _TEST_H [namingng-includeGuardName]'.format(test_include_file),
+        '#ifndef TEST_H',
         '{}:5:0: style: Function InvalidFunction violates naming convention [namingng-namingConvention]'.format(test_include_file),
         'void InvalidFunction();',
         '{}:6:0: style: Public member variable _invalid_extern_global violates naming convention [namingng-namingConvention]'.format(test_include_file),
         'extern int _invalid_extern_global;',
 
+        '{}:0:0: style: File name {} violates naming convention [namingng-namingConvention]'.format(test_unguarded_include_file,test_unguarded_include_file_basename),
+        '{}:0:0: style: Missing include guard [namingng-includeGuardMissing]'.format(test_unguarded_include_file),
+        '{}:2:0: style: Function InvalidFunctionUnguarded violates naming convention [namingng-namingConvention]'.format(test_unguarded_include_file),
+        'void InvalidFunctionUnguarded();',
+
         '{}:0:0: style: File name {} violates naming convention [namingng-namingConvention]'.format(test_file,test_file_basename),
         '{}:7:0: style: Variable _invalid_arg violates naming convention [namingng-namingConvention]'.format(test_file),
         'void valid_function2(int _invalid_arg);',