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allenhuffman
Joined: 17 Jun 2019
Posts: 562
Location: Des Moines, Iowa, USA
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| [Solved] CCS returning a constant string. |
 Posted: Thu Feb 20, 2020 11:59 am |
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In a PIC24 project I worked on a few months ago, I had debugging functions that would print out a text version of a value, such as:
| Code: |
printf ("Command: %d (%s)\r\n", command, GetCommandString(command));
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It worked well.
Another developer here is using a routine to return a string for a mode to display on an LCD, and sometimes it ends up pointing to 0s instead of the hard-coded string constant. I wrote a quick test program, and found mine also seems to point to NULL. I tested using 5.082 and 5.092.
I created a very simple test program, identical in flow to the routines I used earlier that worked. But today, it doesn't work for me (and the other project works, unless he add some lines of code, then it starts returning a pointer to 0s).
| Code: | #include <main.h>
// Prototypes
const char *GetName(int nameValue);
// Functions
void main()
{
printf (__DATE__" "__TIME__"\r\n");
for (int idx = 0; idx < 5; idx++)
{
printf ("%d = '%s'\r\n", idx, GetName(idx));
}
while(TRUE);
}
const char *GetName(int nameValue)
{
printf ("GetName(%d)\r\n", nameValue);
switch (nameValue)
{
case 0:
return "Zero";
case 1:
return "One";
case 2:
return "Two";
default:
return "???";
}
}
// End of main.c |
_________________
Allen C. Huffman, Sub-Etha Software (est. 1990) http://www.subethasoftware.com
Embedded C, Arduino, MSP430, ESP8266/32, BASIC Stamp and PIC24 programmer.
http://www.whywouldyouwanttodothat.com ?
Last edited by allenhuffman on Thu Feb 20, 2020 2:18 pm; edited 1 time in total |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19544
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| Posted: Thu Feb 20, 2020 12:09 pm |
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You need to either be enabling PSV, or using PASS_STRINGS=IN_RAM to
support this. Much more efficient to enable PSV, |
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allenhuffman
Joined: 17 Jun 2019
Posts: 562
Location: Des Moines, Iowa, USA
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| Posted: Thu Feb 20, 2020 12:16 pm |
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| Ttelmah wrote: | You need to either be enabling PSV, or using PASS_STRINGS=IN_RAM to
support this. Much more efficient to enable PSV, |
Ah, that could have been enabled in the project I was doing this in, though we don't use any strings (no I/O).
I just added that in my master header file, but no change. The ptr being returns is correct, however, and matches where the data in flash is located.
_________________
Allen C. Huffman, Sub-Etha Software (est. 1990) http://www.subethasoftware.com
Embedded C, Arduino, MSP430, ESP8266/32, BASIC Stamp and PIC24 programmer.
http://www.whywouldyouwanttodothat.com ? |
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allenhuffman
Joined: 17 Jun 2019
Posts: 562
Location: Des Moines, Iowa, USA
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| Posted: Thu Feb 20, 2020 12:34 pm |
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Changing from constant quotes to const strings works. Oddly.
| Code: | #include <main.h>
// Prototypes
const char *GetName(int nameValue);
// Functions
void main()
{
printf (__DATE__" "__TIME__"\r\n");
for (int idx = 0; idx < 5; idx++)
{
printf ("%d = 0x%x '%s'\r\n", idx, GetName(idx), GetName(idx));
}
while(TRUE);
}
const char *zero = "Zero";
const char *one = "One";
const char *two = "Two";
const char *unknown = "???";
const char *GetName(int nameValue)
{
//printf ("GetName(%d)\r\n", nameValue);
switch (nameValue)
{
case 0:
//return "Zero";
return zero;
case 1:
//return "One";
return one;
case 2:
//return "Two";
return two;
default:
//return "???";
return unknown;
}
}
// End of main.c
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| Quote: | 20-Feb-20 12:33:14
0 = 0x802 'Zero'
1 = 0x808 'One'
2 = 0x80c 'Two'
3 = 0x810 '???'
4 = 0x810 '???'
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_________________
Allen C. Huffman, Sub-Etha Software (est. 1990) http://www.subethasoftware.com
Embedded C, Arduino, MSP430, ESP8266/32, BASIC Stamp and PIC24 programmer.
http://www.whywouldyouwanttodothat.com ? |
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allenhuffman
Joined: 17 Jun 2019
Posts: 562
Location: Des Moines, Iowa, USA
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| Posted: Thu Feb 20, 2020 2:15 pm |
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CCS replied.
That makes the 'return "string"' work. Cool. That must have been in the pre-exiting project that I was working with.
| Quote: | CONST=READ_ONLY
Uses the ANSI keyword CONST definition, making CONST variables read only, rather than located in program memory.
CONST=ROM
Uses the CCS compiler traditional keyword CONST definition, making CONST variables located in program memory.
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_________________
Allen C. Huffman, Sub-Etha Software (est. 1990) http://www.subethasoftware.com
Embedded C, Arduino, MSP430, ESP8266/32, BASIC Stamp and PIC24 programmer.
http://www.whywouldyouwanttodothat.com ? |
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allenhuffman
Joined: 17 Jun 2019
Posts: 562
Location: Des Moines, Iowa, USA
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temtronic
Joined: 01 Jul 2010
Posts: 9244
Location: Greensville,Ontario
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| Posted: Thu Feb 20, 2020 4:05 pm |
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keep going back in versions until it works again.....
I copy/change/compile/test....
If I don't like it, I go back....
pgmv1,pgmv2,......pgmv999
I know it's a lot of HD space, but there's lots available.
Once the project is done,I then delete all but last 3-5 versions. Well I should but really HD space is unlimited, right ? |
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allenhuffman
Joined: 17 Jun 2019
Posts: 562
Location: Des Moines, Iowa, USA
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| Posted: Thu Feb 20, 2020 4:19 pm |
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| temtronic wrote: | | keep going back in versions until it works again..... |
Yeah, the history in the CCS editor is a nice bonus.
_________________
Allen C. Huffman, Sub-Etha Software (est. 1990) http://www.subethasoftware.com
Embedded C, Arduino, MSP430, ESP8266/32, BASIC Stamp and PIC24 programmer.
http://www.whywouldyouwanttodothat.com ? |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19544
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| Posted: Fri Feb 21, 2020 2:24 am |
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Is the current failure with 5.092?.
This seems to have an 'oddity' if you do a lot of changes, that it then
stops working. Creates different output from what it gives after a clean
'launch'. I've noted it and reported this to CCS.
Could explain why you are seeing it working 'sometimes'....
Might be tempted to suggest you try re-installing the compiler. I have
(very occasionally) seen odd issues that seem to come down to a corrupted
installation. Have just tried you code with every combination I could think
of (PSV, PASS_STRINGS, const= etc.), and all worked correctly.... |
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allenhuffman
Joined: 17 Jun 2019
Posts: 562
Location: Des Moines, Iowa, USA
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| Posted: Fri Feb 21, 2020 10:06 am |
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| Ttelmah wrote: | Is the current failure with 5.092?.
This seems to have an 'oddity' if you do a lot of changes, that it then
stops working. Creates different output from what it gives after a clean
'launch'. I've noted it and reported this to CCS.
Could explain why you are seeing it working 'sometimes'.... |
I am so glad we aren't the only ones! :-) I am in the habit of closing all windows and shutting down CCS, then double-clicking the next project file to make that one open. It seems to write files from the old project into the new one if I select it other ways. I may do a quick remove/clean install today, though I'm on my temporary Windows 7 machine again while the DELL laptop is back in the shop.
_________________
Allen C. Huffman, Sub-Etha Software (est. 1990) http://www.subethasoftware.com
Embedded C, Arduino, MSP430, ESP8266/32, BASIC Stamp and PIC24 programmer.
http://www.whywouldyouwanttodothat.com ? |
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