bugprone-suspicious-missing-comma¶
String literals placed side-by-side are concatenated at translation phase 6 (after the preprocessor). This feature is used to represent long string literal on multiple lines.
For instance, the following declarations are equivalent:
const char* A[] = "This is a test";
const char* B[] = "This" " is a " "test";
A common mistake done by programmers is to forget a comma between two string literals in an array initializer list.
const char* Test[] = {
"line 1",
"line 2" // Missing comma!
"line 3",
"line 4",
"line 5"
};
The array contains the string “line 2line3” at offset 1 (i.e. Test[1]). Clang won’t generate warnings at compile time.
This check may warn incorrectly on cases like:
const char* SupportedFormat[] = {
"Error %s",
"Code " PRIu64, // May warn here.
"Warning %s",
};
Options¶
- SizeThreshold¶
An unsigned integer specifying the minimum size of a string literal to be considered by the check. Default is
5U
.
- RatioThreshold¶
A string specifying the maximum threshold ratio [0, 1.0] of suspicious string literals to be considered. Default is
".2"
.
- MaxConcatenatedTokens¶
An unsigned integer specifying the maximum number of concatenated tokens. Default is
5U
.