From 4b126db9ca7b0cafa9cf23609f1a062c80ccf789 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <daniel.marjamaki@gmail.com>
Date: Fri, 13 Aug 2021 18:03:37 +0200
Subject: [PATCH] misra: implement rule 22.10

---
 addons/misra.py                | 25 ++++++++++++++++++++++++-
 addons/test/misra/misra-test.c | 11 +++++++++++
 2 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/addons/misra.py b/addons/misra.py
index 6ffb92933..4162e8886 100755
--- a/addons/misra.py
+++ b/addons/misra.py
@@ -1082,7 +1082,7 @@ def generateTable():
     numberOfRules[19] = 2
     numberOfRules[20] = 14
     numberOfRules[21] = 12
-    numberOfRules[22] = 6
+    numberOfRules[22] = 10
 
     # Rules that can be checked with compilers:
     # compiler = ['1.1', '1.2']
@@ -3453,6 +3453,28 @@ class MisraChecker:
                 if fileptr.variable and cppcheckdata.simpleMatch(fileptr.variable.typeStartToken, 'FILE *'):
                     self.reportError(token, 22, 5)
 
+    def misra_22_10(self, cfg):
+        errno_setting_functions = ('ftell', 'fgetpos', 'fsetpos', 'fgetwc', 'fputwc'
+                                   'strtoimax', 'strtoumax', 'strtol', 'strtoul',
+                                   'strtoll', 'strtoull', 'strtof', 'strtod', 'strtold'
+                                   'wcstoimax', 'wcstoumax', 'wcstol', 'wcstoul',
+                                   'wcstoll', 'wcstoull', 'wcstof', 'wcstod', 'wcstold'
+                                   'wcrtomb', 'wcsrtombs', 'mbrtowc')
+
+        last_function_call = None
+        for token in cfg.tokenlist:
+            if token.str == '(' and not simpleMatch(token.link, ') {'):
+                name, args = cppcheckdata.get_function_call_name_args(token.previous)
+                last_function_call = name
+            if token.str == '}':
+                last_function_call = None
+            if token.str == 'errno' and token.astParent and token.astParent.isComparisonOp:
+                if last_function_call is None:
+                    self.reportError(token, 22, 10)
+                if last_function_call not in errno_setting_functions:
+                    self.reportError(token, 22, 10)
+
+
     def get_verify_expected(self):
         """Return the list of expected violations in the verify test"""
         return self.verify_expected
@@ -4022,6 +4044,7 @@ class MisraChecker:
             self.executeCheck(2115, self.misra_21_15, cfg)
             # 22.4 is already covered by Cppcheck writeReadOnlyFile
             self.executeCheck(2205, self.misra_22_5, cfg)
+            self.executeCheck(2210, self.misra_22_10, cfg)
 
     def analyse_ctu_info(self, ctu_info_files):
         all_typedef_info = []
diff --git a/addons/test/misra/misra-test.c b/addons/test/misra/misra-test.c
index 40f78dbcb..496b05587 100644
--- a/addons/test/misra/misra-test.c
+++ b/addons/test/misra/misra-test.c
@@ -1601,6 +1601,7 @@ static int misra_21_1(void) {
 }
 static int _misra_21_1_2(void); // no warning
 #define errno 11 // 21.1
+#undef errno // 20.5
 
 #define __BUILTIN_SOMETHING 123 // 21.2 21.1
 extern void *memcpy ( void *restrict s1, const void *restrict s2, size_t n ); // 21.2 8.14
@@ -1786,3 +1787,13 @@ static void misra_22_5(FILE *f) {
     int y = f->pos; // 22.5
 }
 
+static void misra_22_10(void)
+{
+  errno = 0;
+  f = atof ( "A.12" ); // 21.7
+  if ( 0 == errno ) {} // 22.10
+
+  errno = 0;
+  f = strtod ( "A.12", NULL );
+  if ( 0 == errno ) {}
+}