CHAPTER 21. STRUCTURES CHAPTER 21. STRUCTURES
Hexadecimal number decimal number field name
0x00000025 37 tm_sec
0x0000000a 10 tm_min
0x00000012 18 tm_hour
0x00000002 2 tm_mday
0x00000005 5 tm_mon
0x00000072 114 tm_year
0x00000001 1 tm_wday
0x00000098 152 tm_yday
0x00000001 1 tm_isdst
Just like SYSTEMTIME (21.1 on page 328), there are also other fields available that are not used, like tm_wday, tm_yday,
tm_isdst.
21.3.2 ARM.
Optimizing Keil 6/2013 (Thumb mode)
Same example:
Listing 21.9: Optimizing Keil 6/2013 (Thumb mode)var_38 = -0x38
var_34 = -0x34
var_30 = -0x30
var_2C = -0x2C
var_28 = -0x28
var_24 = -0x24
timer = -0xC
PUSH {LR}
MOVS R0, #0 ; timer
SUB SP, SP, #0x34
BL time
STR R0, [SP,#0x38+timer]
MOV R1, SP ; tp
ADD R0, SP, #0x38+timer ; timer
BL localtime_r
LDR R1, =0x76C
LDR R0, [SP,#0x38+var_24]
ADDS R1, R0, R1
ADR R0, aYearD ; "Year: %d\n"
BL __2printf
LDR R1, [SP,#0x38+var_28]
ADR R0, aMonthD ; "Month: %d\n"
BL __2printf
LDR R1, [SP,#0x38+var_2C]
ADR R0, aDayD ; "Day: %d\n"
BL __2printf
LDR R1, [SP,#0x38+var_30]
ADR R0, aHourD ; "Hour: %d\n"
BL __2printf
LDR R1, [SP,#0x38+var_34]
ADR R0, aMinutesD ; "Minutes: %d\n"
BL __2printf
LDR R1, [SP,#0x38+var_38]
ADR R0, aSecondsD ; "Seconds: %d\n"
BL __2printf
ADD SP, SP, #0x34
POP {PC}Optimizing Xcode 4.6.3 (LLVM) (Thumb-2 mode)
IDA“knows” thetmstructure (becauseIDA“knows” the types of the arguments of library functions likelocaltime_r()),
so it shows here structure elements accesses and their names.