PROC
The new home for Visual Studio documentation is Visual Studio 2017 Documentation on docs.microsoft.com.
The latest version of this topic can be found at PROC.
Marks start and end of a procedure block called label. The statements in the block can be called with the CALL instruction or INVOKE directive.
Syntax
label PROC [[distance]] [[langtype]] [[visibility]] [[<prologuearg>]]
[[USES reglist]] [[, parameter [[:tag]]]]...
[FRAME [:ehandler-address] ]
statements
label ENDP
Remarks
[FRAME [:ehandler-address] ] is only valid with ml64.exe, and causes MASM to generate a function table entry in .pdata and unwind information in .xdata for a function's structured exception handling unwind behavior.
When the FRAME attribute is used, it must be followed by an .ENDPROLOG directive.
See MASM for x64 (ml64.exe) for more information on using ml64.exe.
Example
; ml64 ex1.asm /link /entry:Example1 /SUBSYSTEM:CONSOLE
_text SEGMENT
Example1 PROC FRAME
push r10
.pushreg r10
push r15
.pushreg r15
push rbx
.pushreg rbx
push rsi
.pushreg rsi
.endprolog
; rest of function ...
ret
Example1 ENDP
_text ENDS
END
The above code will emit the following function table and unwind information:
FileHeader->Machine 34404
Dumping Unwind Information for file ex2.exe
.pdata entry 1 0x00001000 0x00001023
Unwind data: 0x00002000
Unwind version: 1
Unwind Flags: None
Size of prologue: 0x08
Count of codes: 3
Frame register: rbp
Frame offset: 0x0
Unwind codes:
Code offset: 0x08, SET_FPREG, register=rbp, offset=0x00
Code offset: 0x05, ALLOC_SMALL, size=0x10
Code offset: 0x01, PUSH_NONVOL, register=rbp