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[Notes]
C Compiler Package for RL78 Family
Outline
When using the C compiler package for RL family CC-RL, note the following points:
1. Point for caution when the -misra2012 option is specified. (CCRL#023)
Note: The number following the note is an identifying number for the precautionary note.
1. Point for caution when the -misra2012 option is specified. (CCRL#023)
1.1 Applicable Products
CC-RL V1.03.00 to V1.07.00 [Professional edition] (Rule 16.1 and 16.4)
CC-RL V1.06.00 to V1.07.00 [Professional edition] (Rule 15.6, 15.7, and 16.2)
1.2 Details
When checking source code against MISRA-C:2012 rules by specifying -misra2012 option, the compiler may output
a message for a code which does not violate the rules and may not output a message for a code which violates the rules.
MISRA-C is a set of software development guidelines whose purpose is to maintain the safety, portability and
reliability of embedded systems programmed in the C language.
1.3 Conditions
An error occurs when the following rules are specified.
⚫ Rule 15.6
No message is output for a code which violates the rule if the -lang=c99 option is specified.
⚫ Rule 15.7
No message is output for a code which violates the rule if the -lang=c99 option is specified.
⚫ Rule 16.1
No message is output for a code that violates the rule if all of the following conditions are met:
(1) “{“ is written immediately after a switch statement (controlling expression).
(2) Both a case clause and a default clause are written in the switch statement (1).
(3) Each case clause and default clause in (2) ends with a break statement or a compound statement
(Note1)
(block) which includes a break statement at the end.
(4) At least one of the case clauses or default clauses in (3) meets all the conditions below.
(4-1) A compound statement (block) which is neither a selection statement (if or switch) nor a repeat
statement (while, do-while, or for) is written at the end.
(4-2) A statement is written before the compound statement (block) in (4-1).
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⚫ Rule 16.2
No message is output for a code that violates the rule if all of the following conditions are met.
(1) The -lang=c99 option is specified.
(2) A case or default label is written immediately after switch (controlling expression) without “{”.
⚫ Rule 16.4
A message may be output for a code that does not violate the rule if either of the following conditions is met:
(1) -lang=c is specified and a compound statement (block) is written in the function definition.
(2) -lang=c99 is specified, and a compound statement (block), selection statement (if or switch), or repeat
statement (while, do-while, or for) is written in the function definition.
This includes a case where a selection statement or repeat statement is written without “{ }”.
Note: A compound statement refers to a statement enclosed with “{ }”. An if statement enclosed with “{ }” is also a
compound statement.
1.4 Example
The example of an error is shown below. Characters in red are the parts corresponding to the conditions.
[C source code] (rule 16.1)
Although the C source code above violates rule 16.1 of MISRA C: 2012, no message is output.
Lines 3 and 12: Condition (1) is met because “{” is written immediately after switch (controlling expression).
Lines 4 and 10: Condition (2) is met because both a case clause and a default clause are written.
Lines 8 and 11: Condition (3) is met because the case clause and default clause end with a break statement.
Lines 6 and 9: Condition (4-1) is met because the case clause ends with a compound statement (block).
Line 5: Condition (4-2) is met because a statement is written before a compound statement (block).
1:
2:
3:
4:
5:
6:
7:
8:
9:
10:
11:
12:
13:
int x;
void func(void) {
switch(x) { // Condition (1)
case 1: // Condition (2)
++x; // Condition (4-2)
{ // Condition (4-1)
--x;
break; // Condition (3)
} // Condition (4-1)
default: // Condition (2)
break; // Condition (3)
} // Condition (1)
}
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[C source code] (rule 16.2)
The C source code above violates rule 16.2 of MISRA C:2012. Although a message is output when -lang=c is specified,
no message is output when -lang=c99 is specified.
Lines 3 and 4: Condition (2) is met because a case label is written without “{” immediately after switch (controlling
expression).
1.5 Workaround
There is no workaround for this problem.
1.6 Schedule for Fixing the Problem
This problem is fixed in CC-RL V1.08.00. (Scheduled to be released on January 21.)
1:
2:
3:
4:
5:
6:
int x;
void func(void) {
switch(x) // Condition (2)
case 1: // Condition (2)
break;
}
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Revision History
Rev.
Date
Page
Summary
1.00
Jan. 16, 2019
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First edition issued
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