VarSetCapacity to BufferAlloc Topic is solved

[F4Jonatas]

Sometimes I can't pass VarSetCapacity to BufferAlloc, when it is a string.
Here is a small example.

Code: Select all

msgbox( fileversioninfo( a_ahkpath, "FileDescription" ))

; Original version: https://autohotkey.com/board/topic/59496-filegetversioninfo-aw/
fileversioninfo( file :="", fileinfo :="" ) {
	local char := ( a_isunicode ? "W" : "A" )
	local fsize := dllcall( "Version\GetFileVersionInfoSize" char, "str", file, "uint", 0 )

	if not fsize
		return -1

	local trans
	local infoptr := 0
	local translation := 0
	local infoptr := 0
	local fvi := bufferalloc( fsize, 0 )
	varsetcapacity( trans, ( a_isunicode ? 16 : 8 ))

	dllcall( "Version\GetFileVersionInfo" char, "str", file, "int", 0, "uint", fsize, "uint", fvi.ptr )

	if not dllcall( "Version\VerQueryValue" char, "uint", fvi.ptr, "str", "\VarFileInfo\Translation", "uint*", translation, "uint", 0 )
		return -2

	if not dllcall( "msvcrt\swprintf", "str", trans, "str", "%08X", "uint", numget( translation +0 ), "cdecl int" )
		return -3

	local subblock := "\StringFileInfo\" substr( trans, -4 ) substr( trans, 1, 4 ) "\" fileinfo
	if not dllcall( "Version\VerQueryValue" char, "uint", fvi.ptr, "str", subblock, "uint*", infoptr, "uint", 0 )
		return -4

	local info := (
		a_isunicode
		? strget( infoptr, dllcall( "kernel32\lstrlen" char, "uint", infoptr ))
		: dllcall( "Kernel32\MulDiv", "uint", infoptr, "int", 1, "int", 1, "str" )
	)


	return info
}

[lmstearn]

Hey @F4Jonatas, no BufferAlloc in v1, did you want the v2 thread?
Just a couple of things- using swprintf with a possible ANSII string argument is suspect and VerQueryValue is writing to an address of translation so you'll want something like &translation. The folks in v2 will be more reliable than this, though.

[swagfag]

Sometimes I can't pass VarSetCapacity to BufferAlloc, when it is a string.

there isnt a VarSetCapacity() in v2(anymore), so ur "sometimes being unable to pass it to BufferAlloc(), when it is a string" is a sentence that makes literally no sense at all.

---

Code: Select all

	local char := ( a_isunicode ? "W" : "A" )

having this is redundant. v2 is Unicode only

---

ur dllcall types are probably also all incorrect(UInt defined instead of Ptr). half the dllcalls are probably also redundant(since the v1 script is so old), just use ahk's Format()

[F4Jonatas]

Perfect! I forgot that v2 is only Unicode and format function.
So I managed to eliminate some unnecessary things.

Code: Select all

msgbox( fileversioninfo( a_ahkpath, "FileDescription" ))

; Original version: https://autohotkey.com/board/topic/59496-filegetversioninfo-aw/
fileversioninfo( file :="", fileinfo :="" ) {
	local fsize := dllcall( "Version\GetFileVersionInfoSizeW", "str", file, "uint", 0 )

	if not fsize
		return -1

	local translation := 0
	local fvi := bufferalloc( fsize, 0 )

	dllcall( "Version\GetFileVersionInfoW", "str", file, "int", 0, "uint", fsize, "uint", fvi.ptr )

	if not dllcall( "Version\VerQueryValueW", "uint", fvi.ptr, "str", "\VarFileInfo\Translation", "uintp", translation, "uint", 0 )
		return -2

	if not numget( translation )
		return -3


	local infoptr := 0
	local trans := format( "0{:X}", numget( translation ))
	local subblock := "\StringFileInfo\" substr( trans, -4 ) substr( trans, 1, 4 ) "\" fileinfo
	if not dllcall( "Version\VerQueryValueW", "uint", fvi.ptr, "str", subblock, "uintp", infoptr, "uint", 0 )
		return -4

	local info := strget( infoptr, dllcall( "kernel32\lstrlenW", "uint", infoptr ))
	return info
}