core: add compile time format check to format_string_std

Had to rewrite the thing, because gcc's warnings don't work
with templatized var-args. Since there is no string-format.cpp
and I didn't want to inline it, moved it to format.cpp.

String formatting is distributed around at least four
headers: membuffer.h, subsurface-string.h, format.h
and format-string.h. This really should be unified!

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
This commit is contained in:
Berthold Stoeger 2024-03-13 09:41:11 +01:00 committed by bstoeger
parent a123589efb
commit 322c3b55e6
8 changed files with 27 additions and 14 deletions

View file

@ -10,6 +10,7 @@
#include "qthelper.h"
#include "git-access.h"
#include "errorhelper.h"
#include "core/format.h"
#include "core/subsurface-string.h"
#include "core/membuffer.h"
#include "core/settings/qPrefCloudStorage.h"

View file

@ -417,3 +417,21 @@ std::string casprintf_loc(const char *cformat, ...)
va_end(ap);
return std::string(utf8.constData(), utf8.size());
}
std::string __printf(1, 2) format_string_std(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
size_t stringsize = vsnprintf(NULL, 0, fmt, ap);
va_end(ap);
if (stringsize == 0)
return std::string();
std::string res;
res.resize(stringsize); // Pointless clearing, oh my.
// This overwrites the terminal null-byte of std::string.
// That's probably "undefined behavior". Oh my.
va_start(ap, fmt);
vsnprintf(res.data(), stringsize + 1, fmt, ap);
va_end(ap);
return res;
}

View file

@ -25,6 +25,9 @@ __printf(2, 0) int vasprintf_loc(char **dst, const char *cformat, va_list ap);
#ifdef __cplusplus
}
__printf(1, 2) std::string format_string_std(const char *fmt, ...);
#endif
#endif

View file

@ -19,6 +19,7 @@
#include "sample.h"
#include "subsurface-float.h"
#include "subsurface-string.h"
#include "format.h"
#include "device.h"
#include "dive.h"
#include "errorhelper.h"

View file

@ -23,6 +23,7 @@
#include "errorhelper.h"
#include "sample.h"
#include "subsurface-string.h"
#include "format.h"
#include "trip.h"
#include "device.h"
#include "git-access.h"

View file

@ -26,6 +26,7 @@
#include "divesite.h"
#include "errorhelper.h"
#include "parse.h"
#include "format.h"
#include "subsurface-float.h"
#include "subsurface-string.h"
#include "subsurface-time.h"

View file

@ -62,19 +62,6 @@ extern double strtod_flags(const char *str, const char **ptr, unsigned int flags
}
#include <string>
template <class... Args>
std::string format_string_std(const char *fmt, Args&&... args)
{
size_t stringsize = snprintf(NULL, 0, fmt, std::forward<Args>(args)...);
if (stringsize == 0)
return std::string();
std::string res;
res.resize(stringsize); // Pointless clearing, oh my.
// This overwrites the terminal null-byte of std::string.
// That's probably "undefined behavior". Oh my.
snprintf(res.data(), stringsize + 1, fmt, std::forward<Args>(args)...);
return res;
}
// Sadly, starts_with only with C++20!
inline bool starts_with(const std::string &s, const char *s2)
@ -83,4 +70,5 @@ inline bool starts_with(const std::string &s, const char *s2)
}
#endif
#endif // SUBSURFACE_STRING_H

View file

@ -15,7 +15,7 @@
#include "errorhelper.h"
#include "file.h"
#include "save-html.h"
#include "subsurface-string.h"
#include "format.h"
#include "worldmap-save.h"
#include "worldmap-options.h"
#include "gettext.h"