Add a string_view version of startswith
Commit Message
Makes sure that the string is longer than prefix, so that strncmp will
do the right thing even if the string is not null-terminated.
For use in my string_view conversion patch:
https://sourceware.org/ml/gdb-patches/2019-10/msg00030.html
gdb/ChangeLog:
2019-10-01 Christian Biesinger <cbiesinger@google.com>
* gdbsupport/common-utils.h (startswith): Add an overloaded version
that takes gdb::string_view arguments.
---
gdb/gdbsupport/common-utils.h | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
Comments
On 10/1/19 7:44 PM, Christian Biesinger via gdb-patches wrote:
> diff --git a/gdb/gdbsupport/common-utils.h b/gdb/gdbsupport/common-utils.h
> index a5312cb0c4..c21c5e9603 100644
> --- a/gdb/gdbsupport/common-utils.h
> +++ b/gdb/gdbsupport/common-utils.h
> @@ -23,6 +23,7 @@
> #include <string>
> #include <vector>
>
> +#include "gdb_string_view.h"
> #include "poison.h"
>
> /* If possible, define FUNCTION_NAME, a macro containing the name of
> @@ -113,12 +114,22 @@ extern char *safe_strerror (int);
> /* Return non-zero if the start of STRING matches PATTERN, zero
> otherwise. */
non-zero -> true
zero -> false
>
> -static inline int
> +static inline bool
> startswith (const char *string, const char *pattern)
> {
> return strncmp (string, pattern, strlen (pattern)) == 0;
> }
>
> +/* Version of startswith that takes string_view arguments. See comment
> + above. */
> +
> +static inline bool
> +startswith (gdb::string_view string, gdb::string_view pattern)
> +{
> + return string.length() >= pattern.length () &&
> + strncmp (string.data (), pattern.data (), pattern.length ()) == 0;
&& goes on next line. And then you need to wrap the multiline expression
with (), so that emacs auto-tab-indents the && under "string". Like this:
return (string.length() >= pattern.length ()
&& strncmp (string.data (), pattern.data (), pattern.length ()) == 0);
Otherwise OK.
Thanks,
Pedro Alves
@@ -23,6 +23,7 @@
#include <string>
#include <vector>
+#include "gdb_string_view.h"
#include "poison.h"
/* If possible, define FUNCTION_NAME, a macro containing the name of
@@ -113,12 +114,22 @@ extern char *safe_strerror (int);
/* Return non-zero if the start of STRING matches PATTERN, zero
otherwise. */
-static inline int
+static inline bool
startswith (const char *string, const char *pattern)
{
return strncmp (string, pattern, strlen (pattern)) == 0;
}
+/* Version of startswith that takes string_view arguments. See comment
+ above. */
+
+static inline bool
+startswith (gdb::string_view string, gdb::string_view pattern)
+{
+ return string.length() >= pattern.length () &&
+ strncmp (string.data (), pattern.data (), pattern.length ()) == 0;
+}
+
ULONGEST strtoulst (const char *num, const char **trailer, int base);
/* Skip leading whitespace characters in INP, returning an updated