FreeBASIC 1.09.0 Release

[srvaldez]

found an anomaly with FB-win64 from 2021-8-8 64-bit version, both gen gcc and gen gas64
code reduced to minimum only to show the error

Code: Select all

Dim y As Double

function gs(byval  z as double) as double
	dim as double a, y

	y=y*(z+a)^(z+.5)*exp(-z-a)
	
	return y
end function

y = gs(.5)
Print y '<-- causes the error
sleep

fbc64 -t 2048 -w all -arch native -gen gcc -Wc -O2 -v "foo.bas"
FreeBASIC Compiler - Version 1.09.0 (2021-08-08), built for win64 (64bit)
Copyright (C) 2004-2021 The FreeBASIC development team.
standalone
target: win64, x86-64, 64bit
backend: gcc
compiling: foo.bas -o foo.c (main module)
compiling C: FreeBASIC-1.09.0-win-gcc-9.3\bin\win64\gcc.exe -m64 -march=native -S -nostdlib -nostdinc -Wall -Wno-unused -Wno-main -Werror-implicit-function-declaration -O0 -fno-strict-aliasing -frounding-math -fno-math-errno -fwrapv -fno-exceptions -fno-unwind-tables -fno-asynchronous-unwind-tables -Wno-format -masm=intel "foo.c" -o "foo.asm" -O2
assembling: FreeBASIC-1.09.0-win-gcc-9.3\bin\win64\as.exe --64 --strip-local-absolute "foo.asm" -o "foo.o"
foo.asm: Assembler messages:
foo.asm:62: Error: unsupported syntax for `call'
assembling failed: 'FreeBASIC-1.09.0-win-gcc-9.3\bin\win64\as.exe' terminated with exit code 1
Compilation failed.

if I add -asm att to the compile command then there's no problem
compiles ok in 32-bit

[fxm]

It is the procedure name 'gs' which causes the problem in 64-bit.

Code: Select all

sub gs()
end sub

gs()

Ditto for 'fs', 'cs', .....
(all register names)

[srvaldez]

hello fxm
there's more to the story
the following compiles ok, still same function name

Code: Select all

Dim y As Double

function gs(byval  z as double) as double
	dim as double a, y

	y=exp(-z-a)
	
	return y
end function

y = gs(.5)
Print y
sleep

[SARG]

With gas64 in every case there is a 'call GS' which is not allowed.

edit segment registers : CS, SS, DS, ES, FS and GS

[fxm]

hello fxm
there's more to the story
the following compiles ok, still same function name

Code: Select all

Dim y As Double

function gs(byval  z as double) as double
	dim as double a, y

	y=exp(-z-a)
	
	return y
end function

y = gs(.5)
Print y
sleep

For me, this code also doesn't compile (for 64-bit).

[fxm]

@Jeff, @admins (and other developers)

I would like to add in the documentation a special warning about choosing user procedure identifier names in the global namespace (in addition to the classic alphanumeric rules and the uniqueness of identifier names in the source code).
But this additional restriction only seems to affect the 64-bit compiler with the names of the segment registers (CS, SS, DS, ES, FS and GS).
Is it correct ?

[SARG]

@fxm what I can say
With gcc64 and gas64 unlike with gcc32/gas32 procedure names are not decorated so using ALL register names are forbidden : assembly errors (segment registers), unexpected results or more probably crashes (other registers).

[fxm]

@SARG, thank you.
It also seems useful to caution against using names from other registries, which can cause runtime bugs only.

[dodicat]

You could namespace the forbidden, alias the forbidden or best, don't use the forbidden.
But the 64 bit compiler gives an error at the forbidden (all cases??), so it is not as if you could use the forbidden or get caught out with it as a bug, unless of course you create your program in 32 bits in the first place.
Linux as I remember, is fussy in 32 bits also, but my Linux box is in storage in the attic,(overheating processors, needing taken apart and re greased).

Code: Select all

Dim y As Double


Function fs Alias "b"(Byval  z As Double) As Double
      Dim As Double a, y
      
      y=Exp(-z-a)
      
      Return y
End Function

Sub b
      Print fs(2)
End Sub

y = fs(.5)
Print y
b

Sleep 

[SARG]

call GS --> assembly error so compilation failed

call RDX --> no compilation error but unexpected result or probably a crash

[dodicat]

Thanks SARG.

[paul doe]

@SARG, thank you.
It also seems useful to caution against using names from other registries, which can cause runtime bugs only.

There are also other nasty situations that arise if one uses assembler symbols as procedure names, say:

Code: Select all

sub word()
  ? "Hai!"
end sub

dim as sub() f = @word

f()

So I'd say the warning in the manual is not a bad idea, indeed...

[srvaldez]

if you are not using intel inline asm in your code then you can solve all this by including -asm att in the compile command

There are also other nasty situations that arise if one uses assembler symbols as procedure names, say:

Code: Select all

sub word()
  ? "Hai!"
end sub

dim as sub() f = @word

f()

using -asm att the output is Hai!

[dodicat]

Code: Select all

sub Ԝord()
 ? "Hai!"
end sub

dim as sub() f = @Ԝord


f() 
sleep

Yes, strange result, even with 32 bits

[fxm]

This is part of what I called above the "classic alphanumeric rules" among which the identifier must start with an alphabetic character or with an "_" (see Identifier Rules).