Program without program-statement misclassification during parsing

[ivan-pi]

Description

fpm doesn't classify correctly the source type of program units without a program-statement, such as:

print *, "Hello World"
end

or

print *, "Hello World"
end program

which are allowed according to the standard.

Currently, parse_f_source will return FPM_UNIT_SUBPROGRAM (=4)` for these two cases.

Expected Behaviour

The expected source unit type should be FPM_UNIT_PROGRAM (=1).

Version of fpm

0.8.1, alpha

Platform and Architecture

MacOS (Intel)

Additional Information

The culprit is the parsing logic, which relies on detecting the program statement at front:

fpm/src/fpm_source_parsing.f90

Lines 335 to 355 in da6d1bf

	! Detect if contains a program
	! (no modules allowed after program def)
	if (index(file_lines_lower(i)%s,'program ') == 1) then
	temp_string = split_n(file_lines_lower(i)%s,n=2,delims=' ',stat=stat)
	if (stat == 0) then
	if (scan(temp_string,'=(')>0 ) then
	! Ignore:
	! program =*
	! program (i) =*
	cycle
	end if
	end if
	f_source%unit_type = FPM_UNIT_PROGRAM
	cycle
	end if

Instead it should probably rely on the end program statement which is mandatory per the standard. (J3/24-007, 14.1)

[ivan-pi]

I suppose that from the build perspective, a program unit is not very different to an external procedure.

[ivan-pi]

Apparently, @urbanjost already knew about this long time ago:
#820 (comment)

[ivan-pi]

This is a duplicate of #637.