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Variadic print #5829

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b9281c9
Inline println(...) functions
cousteaulecommandant Jan 10, 2017
d6058b9
Inline some print() functions
cousteaulecommandant Jan 10, 2017
ceee9e9
Add print(signed char | short | float) explicitly
cousteaulecommandant Jan 10, 2017
d2f7f1b
Force inlining of inline print[ln] methods
cousteaulecommandant Jan 10, 2017
587eec5
Add support for variadic Serial.print(...)
cousteaulecommandant Jan 10, 2017
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109 changes: 1 addition & 108 deletions hardware/arduino/avr/cores/arduino/Print.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -59,32 +59,7 @@ size_t Print::print(const String &s)
return write(s.c_str(), s.length());
}

size_t Print::print(const char str[])
{
return write(str);
}

size_t Print::print(char c)
{
return write(c);
}

size_t Print::print(unsigned char b, int base)
{
return print((unsigned long) b, base);
}

size_t Print::print(int n, int base)
{
return print((long) n, base);
}

size_t Print::print(unsigned int n, int base)
{
return print((unsigned long) n, base);
}

size_t Print::print(long n, int base)
size_t Print::print(signed long n, int base)
{
if (base == 0) {
return write(n);
Expand All @@ -111,93 +86,11 @@ size_t Print::print(double n, int digits)
return printFloat(n, digits);
}

size_t Print::println(const __FlashStringHelper *ifsh)
{
size_t n = print(ifsh);
n += println();
return n;
}

size_t Print::print(const Printable& x)
{
return x.printTo(*this);
}

size_t Print::println(void)
{
return write("\r\n");
}

size_t Print::println(const String &s)
{
size_t n = print(s);
n += println();
return n;
}

size_t Print::println(const char c[])
{
size_t n = print(c);
n += println();
return n;
}

size_t Print::println(char c)
{
size_t n = print(c);
n += println();
return n;
}

size_t Print::println(unsigned char b, int base)
{
size_t n = print(b, base);
n += println();
return n;
}

size_t Print::println(int num, int base)
{
size_t n = print(num, base);
n += println();
return n;
}

size_t Print::println(unsigned int num, int base)
{
size_t n = print(num, base);
n += println();
return n;
}

size_t Print::println(long num, int base)
{
size_t n = print(num, base);
n += println();
return n;
}

size_t Print::println(unsigned long num, int base)
{
size_t n = print(num, base);
n += println();
return n;
}

size_t Print::println(double num, int digits)
{
size_t n = print(num, digits);
n += println();
return n;
}

size_t Print::println(const Printable& x)
{
size_t n = print(x);
n += println();
return n;
}

// Private Methods /////////////////////////////////////////////////////////////

size_t Print::printNumber(unsigned long n, uint8_t base)
Expand Down
70 changes: 51 additions & 19 deletions hardware/arduino/avr/cores/arduino/Print.h
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Original file line number Diff line number Diff line change
Expand Up @@ -31,6 +31,8 @@
#define OCT 8
#define BIN 2

#define _always_inline __attribute__ ((__always_inline__)) // undefined at end

class Print
{
private:
Expand All @@ -57,28 +59,58 @@ class Print

size_t print(const __FlashStringHelper *);
size_t print(const String &);
size_t print(const char[]);
size_t print(char);
size_t print(unsigned char, int = DEC);
size_t print(int, int = DEC);
size_t print(unsigned int, int = DEC);
size_t print(long, int = DEC);
size_t print( signed long, int = DEC);
size_t print(unsigned long, int = DEC);
size_t print(double, int = 2);
size_t print(const Printable&);

size_t println(const __FlashStringHelper *);
size_t println(const String &s);
size_t println(const char[]);
size_t println(char);
size_t println(unsigned char, int = DEC);
size_t println(int, int = DEC);
size_t println(unsigned int, int = DEC);
size_t println(long, int = DEC);
size_t println(unsigned long, int = DEC);
size_t println(double, int = 2);
size_t println(const Printable&);

_always_inline size_t print(const char str[]) { return write(str); }
_always_inline size_t print(const char c) { return write(c); }
_always_inline size_t print(const Printable &x) { return x.printTo(*this); }

_always_inline size_t print( signed char n, int f = DEC) { return print(( signed long) n, f); }
_always_inline size_t print( signed short n, int f = DEC) { return print(( signed long) n, f); }
_always_inline size_t print( signed int n, int f = DEC) { return print(( signed long) n, f); }
_always_inline size_t print(unsigned char n, int f = DEC) { return print((unsigned long) n, f); }
_always_inline size_t print(unsigned short n, int f = DEC) { return print((unsigned long) n, f); }
_always_inline size_t print(unsigned int n, int f = DEC) { return print((unsigned long) n, f); }
_always_inline size_t print( float n, int f = 2 ) { return print(( double ) n, f); }

size_t println(void);

#if __cplusplus >= 201103L
template<typename ...Ts> _always_inline size_t println(const Ts &...args) { size_t t = print(args...); return t + println(); }
#else
template<typename T> _always_inline size_t println(const T &arg) { size_t t = print(arg); return t + println(); }
template<typename T> _always_inline size_t println(const T &n, int f) { size_t t = print(n, f); return t + println(); }
#endif // __cplusplus >= 201103L


/** Variadic methods **/
#if __cplusplus >= 201103L // requires C++11
// Ensure there are at least two parameters to avoid infinite recursion.
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This deserves a bit more explanation, best to include an example.

// e.g. `StringSumHelper s; print(s)` may be treated as `print(s, ...)`
// with `...` being the empty list, thus calling `print(s)` again.
// (This is because print(StringSumHelper) isn't explicitly defined.)
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I don't agree with this - with one parameter, won't this simply fall back on print(), which you could define privately as a no-op?

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I recall that this was tried too, but that triggered other corner cases (that I can't recall right now). With care, it can be made to work though (I have some local changes on top of this PR that do so, as well as add some formatting support, but I can't get around to finishing them...).

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with one parameter, won't this simply fall back on print(), which you could define privately as a no-op?

It will fall back on print(s) followed by print(). The latter could indeed be implemented as a no-op, but the former will be expanded to print(s) followed by print() again, entering an infinite loop (at compile time).
I don't remember the exact situation that caused this (I think it was something about passing a StringSumHelper but I cannot come up with an example right now); only that infinite recursion happened.

template<typename T, typename T2, typename ...Ts>
_always_inline size_t print(const T &arg, const T2 &arg2, const Ts &...args) {
size_t t = print(arg);
return t + print(arg2, args...);
}
// Some methods take an extra int parameter. If so, use these templates.
// In a future, it would be nice to make the base/precision a special type.
template<typename ...Ts> _always_inline size_t print( signed char n, int f, const Ts &...args) { size_t t = print(n, f); return t + print(args...); }
template<typename ...Ts> _always_inline size_t print( signed short n, int f, const Ts &...args) { size_t t = print(n, f); return t + print(args...); }
template<typename ...Ts> _always_inline size_t print( signed int n, int f, const Ts &...args) { size_t t = print(n, f); return t + print(args...); }
template<typename ...Ts> _always_inline size_t print( signed long n, int f, const Ts &...args) { size_t t = print(n, f); return t + print(args...); }
template<typename ...Ts> _always_inline size_t print(unsigned char n, int f, const Ts &...args) { size_t t = print(n, f); return t + print(args...); }
template<typename ...Ts> _always_inline size_t print(unsigned short n, int f, const Ts &...args) { size_t t = print(n, f); return t + print(args...); }
template<typename ...Ts> _always_inline size_t print(unsigned int n, int f, const Ts &...args) { size_t t = print(n, f); return t + print(args...); }
template<typename ...Ts> _always_inline size_t print(unsigned long n, int f, const Ts &...args) { size_t t = print(n, f); return t + print(args...); }
template<typename ...Ts> _always_inline size_t print( float n, int f, const Ts &...args) { size_t t = print(n, f); return t + print(args...); }
template<typename ...Ts> _always_inline size_t print( double n, int f, const Ts &...args) { size_t t = print(n, f); return t + print(args...); }
#endif // __cplusplus >= 201103L
};

#undef _always_inline

#endif
109 changes: 1 addition & 108 deletions hardware/arduino/sam/cores/arduino/Print.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -51,32 +51,7 @@ size_t Print::print(const String &s)
return write(s.c_str(), s.length());
}

size_t Print::print(const char str[])
{
return write(str);
}

size_t Print::print(char c)
{
return write(c);
}

size_t Print::print(unsigned char b, int base)
{
return print((unsigned long) b, base);
}

size_t Print::print(int n, int base)
{
return print((long) n, base);
}

size_t Print::print(unsigned int n, int base)
{
return print((unsigned long) n, base);
}

size_t Print::print(long n, int base)
size_t Print::print(signed long n, int base)
{
if (base == 0) {
return write(n);
Expand All @@ -103,93 +78,11 @@ size_t Print::print(double n, int digits)
return printFloat(n, digits);
}

size_t Print::println(const __FlashStringHelper *ifsh)
{
size_t n = print(ifsh);
n += println();
return n;
}

size_t Print::print(const Printable& x)
{
return x.printTo(*this);
}

size_t Print::println(void)
{
return write("\r\n");
}

size_t Print::println(const String &s)
{
size_t n = print(s);
n += println();
return n;
}

size_t Print::println(const char c[])
{
size_t n = print(c);
n += println();
return n;
}

size_t Print::println(char c)
{
size_t n = print(c);
n += println();
return n;
}

size_t Print::println(unsigned char b, int base)
{
size_t n = print(b, base);
n += println();
return n;
}

size_t Print::println(int num, int base)
{
size_t n = print(num, base);
n += println();
return n;
}

size_t Print::println(unsigned int num, int base)
{
size_t n = print(num, base);
n += println();
return n;
}

size_t Print::println(long num, int base)
{
size_t n = print(num, base);
n += println();
return n;
}

size_t Print::println(unsigned long num, int base)
{
size_t n = print(num, base);
n += println();
return n;
}

size_t Print::println(double num, int digits)
{
size_t n = print(num, digits);
n += println();
return n;
}

size_t Print::println(const Printable& x)
{
size_t n = print(x);
n += println();
return n;
}

// Private Methods /////////////////////////////////////////////////////////////

size_t Print::printNumber(unsigned long n, uint8_t base)
Expand Down
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