arm-elf-gdb (insight) -- issue with finish command (in Thumb mode)

[Michael Anburaj]

Hi, 

I see this weird behavior with arm-elf-gdb -w
(insight) while issuing the “finish” command within a
particular ‘while’ loop compiled in thumb mode. 

Target hardware: ARM7TDMI-S with Redboot in the Flash 
Development platform : Windows/Cgywin 
Compilation flags: -g -O0 
Code is built for Thumb mode & loaded at free RAM
address. 

The source for this test program includes a c file
(Thumb mode) containing the code listed below & a .S
(ARM mode) that has the entry point, which just
initializes the sp & branch to entry_func. 
I load the elf image using “remote target /dev/com1” &
then set breakpoints within entry_func at the
following statements: function call to func1() & the
while(1). 
After the code breaks at the 1st breakpoint, I
step-into the function ‘func1' & then into func4. Then
I issue ‘finish’ commands, 1st finish takes me back to
func1 at the while & the following 3 ‘finish’ commands
execute the while & after the 3rd time the code breaks
at the while(1) in entry_func. Which is because gdb
issues a ‘$c’ <for continue – from the remote-log>
without setting a breakpoint (UNDEF instruction) at
address following ‘bl func1' at entry_func. 

Why?? Idealy the very 1st time I issue the 'finish' at
func1 it should have executed the while loop 3 times &
should have broken at the caller 'entry_func'.

Where as the same code built for ARM mode works
better. 

Thanks, 
-Mike. 


///////////// Code ///////////////// 

volatile int ii; 

void func4() 
{ 
ii = ii+2; 
} 

void func1() 
{ 
int k=0; 

while(k++<3){func4();} 
} 

void func2() 
{ 
ii += 3; 
} 

void func3() 
{ 
ii += 4; 
} 

void entry_func(void) 
{ 
func1(); 

func2(); 

func3(); 

while(1); 

}



                
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