Move _ctype to PROGMEM, update accessors #1
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The _ctype array is included in most sketches automatically, taking up RAM. Move the array to ROM, freeing the 257 bytes it takes, and modify all accessor functions/macros to use pgm_read_byte to access it.
earlephilhower
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| @@ -123,6 +123,7 @@ No supporting OS subroutines are required. | |||
| #include <errno.h> | |||
| #include <stdlib.h> | |||
| #include <reent.h> | |||
| #include "../machine/xtensa/pgmspace.h" | |||
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Why is it necessary to include pgmspace in this file?
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When building newlib -Os the ctype functions evaluate to the macros, and those require pgm_read_byte. This function uses isupper() and isdigit().
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Does that mean that every user of <ctype.h> now has to include this machine-specific header file? How about including the necessary header file from ctype.h?
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Technically, yes, but practically for the Arduino SDK at least, no, because the one in the Arduino SDK is always included beforehand....argh....well, in the main .ino anyway. Extra files do not get the same #include pre-treatment by the IDE/SDK if my quick and dirty test is to be believed. So, one more vote for includeing the pgm_read_byte() stuff somewhere in newlib proper...
edit Actually, a cleaner way, for ctype at least, would be to move it to a 32-bit array from byte arrays (cost: wasted 768b of PROGMEM), and then no pgm_read* required at all for the macros.
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Closing in lieu of #5 . No changes required at all for any ctype-using code, it's handled in sys/ctype.h (a new include). |
This patch is related to esp8266/Arduino#3740 , increasing heap RAM on the ESP8266 by moving library constants into ROM.
The _ctype array is included in most sketches automatically, taking up RAM.
Move the array to ROM, freeing the 257 bytes it takes, and modify all
accessor functions/macros to use pgm_read_byte to access it.