Re: [PATCH 1/4] terminal: use flags for save_term()

[Phillip Wood <phillip.wood123@gmail.com>]

Hi Ramsay

On 04/03/2022 20:40, Ramsay Jones wrote:
> Hi Phillip,
> 
> I have not studied/applied your patches, they are just floating
> past my inbox, so please ignore me if I have misunderstood ...
> 
> On 04/03/2022 13:11, Phillip Wood wrote:
>> From: Phillip Wood <phillip.wood@dunelm.org.uk>
>>
>> The next commit will add another flag in addition to the existing
>> full_duplex so change the function signature to take an unsigned flags
>> argument. Also alter the functions that call save_term() so that they
>> can pass flags down to it.
>>
>> Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
>> ---
>>   compat/terminal.c | 41 +++++++++++++++++++++--------------------
>>   compat/terminal.h |  5 ++++-
>>   2 files changed, 25 insertions(+), 21 deletions(-)
>>
>> diff --git a/compat/terminal.c b/compat/terminal.c
>> index d882dfa06e..bad8e04cd8 100644
>> --- a/compat/terminal.c
>> +++ b/compat/terminal.c
>> @@ -34,7 +34,7 @@ void restore_term(void)
>>   	sigchain_pop_common();
>>   }
>>   
>> -int save_term(int full_duplex)
>> +int save_term(unsigned flags)
>>   {
>>   	if (term_fd < 0)
>>   		term_fd = open("/dev/tty", O_RDWR);
>> @@ -47,11 +47,11 @@ int save_term(int full_duplex)
>>   	return 0;
>>   }
>>   
>> -static int disable_bits(tcflag_t bits)
>> +static int disable_bits(unsigned flags, tcflag_t bits)
> 
> .. you add the 'flags' as the new first parameter ...
> 
>>   {
>>   	struct termios t;
>>   
>> -	if (save_term(0) < 0)
>> +	if (save_term(flags) < 0)
>>   		goto error;
>>   
>>   	t = old_term;
>> @@ -71,14 +71,14 @@ static int disable_bits(tcflag_t bits)
>>   	return -1;
>>   }
>>   
>> -static int disable_echo(void)
>> +static int disable_echo(unsigned flags)
>>   {
>> -	return disable_bits(ECHO);
>> +	return disable_bits(flags, ECHO);
> 
> .. and pass it as first parameter, good, and ...
> 
>>   }
>>   
>> -static int enable_non_canonical(void)
>> +static int enable_non_canonical(unsigned flags)
>>   {
>> -	return disable_bits(ICANON | ECHO);
>> +	return disable_bits(flags, ICANON | ECHO);
> 
> .. here as well, good, and ...
> 
>>   }
>>   
>>   #elif defined(GIT_WINDOWS_NATIVE)
>> @@ -126,15 +126,15 @@ void restore_term(void)
>>   	hconin = hconout = INVALID_HANDLE_VALUE;
>>   }
>>   
>> -int save_term(int full_duplex)
>> +int save_term(unsigned flags)
>>   {
>>   	hconin = CreateFileA("CONIN$", GENERIC_READ | GENERIC_WRITE,
>>   	    FILE_SHARE_READ, NULL, OPEN_EXISTING,
>>   	    FILE_ATTRIBUTE_NORMAL, NULL);
>>   	if (hconin == INVALID_HANDLE_VALUE)
>>   		return -1;
>>   
>> -	if (full_duplex) {
>> +	if (flags & SAVE_TERM_DUPLEX) {
>>   		hconout = CreateFileA("CONOUT$", GENERIC_READ | GENERIC_WRITE,
>>   			FILE_SHARE_WRITE, NULL, OPEN_EXISTING,
>>   			FILE_ATTRIBUTE_NORMAL, NULL);
>> @@ -154,7 +154,7 @@ int save_term(int full_duplex)
>>   	return -1;
>>   }
>>   
>> -static int disable_bits(DWORD bits)
>> +static int disable_bits(unsigned flags, DWORD bits)
> 
> .. Huh? Ah, the DWORD suggests this is in an #ifdef'd windows
> part of the file, OK. ...
> 
>>   {
>>   	if (use_stty) {
>>   		struct child_process cp = CHILD_PROCESS_INIT;
>> @@ -191,7 +191,7 @@ static int disable_bits(DWORD bits)
>>   		use_stty = 0;
>>   	}
>>   
>> -	if (save_term(0) < 0)
>> +	if (save_term(flags) < 0)
>>   		return -1;
>>   
>>   	if (!SetConsoleMode(hconin, cmode_in & ~bits)) {
>> @@ -204,14 +204,15 @@ static int disable_bits(DWORD bits)
>>   	return 0;
>>   }
>>   
>> -static int disable_echo(void)
>> +static int disable_echo(unsigned flags)
>>   {
>> -	return disable_bits(ENABLE_ECHO_INPUT);
>> +	return disable_bits(ENABLE_ECHO_INPUT, flags);
> 
> .. but here, you pass the flags as the second parameter. ;-)

Oh dear that's embarrassing, thanks for your careful review.

Are patches 3 & 4 OK for non-stop platforms?

Best Wishes

Phillip

>>   }
>>   
>> -static int enable_non_canonical(void)
>> +static int enable_non_canonical(unsigned flags)
>>   {
>> -	return disable_bits(ENABLE_ECHO_INPUT | ENABLE_LINE_INPUT | ENABLE_PROCESSED_INPUT);
>> +	return disable_bits(ENABLE_ECHO_INPUT | ENABLE_LINE_INPUT | ENABLE_PROCESSED_INPUT,
>> +			    flags);
> 
> .. ditto here.
> 
> ATB,
> Ramsay Jones
> 
> 
>>   }
>>   
>>   /*
>> @@ -267,7 +268,7 @@ char *git_terminal_prompt(const char *prompt, int echo)
>>   		return NULL;
>>   	}
>>   
>> -	if (!echo && disable_echo()) {
>> +	if (!echo && disable_echo(0)) {
>>   		fclose(input_fh);
>>   		fclose(output_fh);
>>   		return NULL;
>> @@ -361,7 +362,7 @@ int read_key_without_echo(struct strbuf *buf)
>>   	static int warning_displayed;
>>   	int ch;
>>   
>> -	if (warning_displayed || enable_non_canonical() < 0) {
>> +	if (warning_displayed || enable_non_canonical(0) < 0) {
>>   		if (!warning_displayed) {
>>   			warning("reading single keystrokes not supported on "
>>   				"this platform; reading line instead");
>> @@ -413,10 +414,10 @@ int read_key_without_echo(struct strbuf *buf)
>>   
>>   #else
>>   
>> -int save_term(int full_duplex)
>> +int save_term(unsigned flags)
>>   {
>> -	/* full_duplex == 1, but no support available */
>> -	return -full_duplex;
>> +	/* no duplex support available */
>> +	return -!!(flags & SAVE_TERM_DUPLEX);
>>   }
>>   
>>   void restore_term(void)
>> diff --git a/compat/terminal.h b/compat/terminal.h
>> index 0fb9fa147c..f24b91390d 100644
>> --- a/compat/terminal.h
>> +++ b/compat/terminal.h
>> @@ -1,14 +1,17 @@
>>   #ifndef COMPAT_TERMINAL_H
>>   #define COMPAT_TERMINAL_H
>>   
>> +/* Save input and output settings */
>> +#define SAVE_TERM_DUPLEX (1u << 0)
>> +
>>   /*
>>    * Save the terminal attributes so they can be restored later by a
>>    * call to restore_term(). Note that every successful call to
>>    * save_term() must be matched by a call to restore_term() even if the
>>    * attributes have not been changed. Returns 0 on success, -1 on
>>    * failure.
>>    */
>> -int save_term(int full_duplex);
>> +int save_term(unsigned flags);
>>   /* Restore the terminal attributes that were saved with save_term() */
>>   void restore_term(void);
>>