The following program seems to me to be valid Fortran 95, because the f95
standard 5.1.1.5 and 7.1.6.2 say a CHARACTER(n) declaration is OK if n is a
scalar integer restricted expression, in which each primary is a constant,
the intrinsic LEN is allowed, and so are pure functions that are not intrinsic,
not internal, not statement functions, do not have dummy procedure arguments,
and are not recursive. But gfortran won't compile it. Evidence:
[EMAIL PROTECTED] test system: ~/Jfh/Test 52 >cat testspec.f90
MODULE halvestring ! Can halfit be in a specification expression?
CONTAINS
PURE FUNCTION halfit(s1) RESULT (s2)
CHARACTER(*),INTENT(IN):: s1
CHARACTER(len(s1)/2) :: s2
s2 = s1
END FUNCTION halfit
END MODULE halvestring
! -----------
PROGRAM testspec
USE halvestring
CHARACTER(*),PARAMETER :: stringa = 'abcdeedcba'
CHARACTER(len(halfit(stringa))) :: stringb
stringb = halfit(stringa)
PRINT "(I4,A)", len(stringb),' "'//stringb//'"' ! 5 "abcde"
END PROGRAM testspec
[EMAIL PROTECTED] test system: ~/Jfh/Test 53 >gfortran -v testspec.f90
Driving: gfortran -v testspec.f90 -lgfortranbegin -lgfortran -lm -shared-libgcc
Using built-in specs.
Target: i386-redhat-linux
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man
--infodir=/usr/share/info --enable-shared --enable-threads=posix
--enable-checking=release --with-system-zlib --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-libgcj-multifile
--enable-languages=c,c++,objc,obj-c++,java,fortran,ada --enable-java-awt=gtk
--disable-dssi --enable-plugin
--with-java-home=/usr/lib/jvm/java-1.4.2-gcj-1.4.2.0/jre --with-cpu=generic
--host=i386-redhat-linux
Thread model: posix
gcc version 4.1.1 20070105 (Red Hat 4.1.1-52)
/usr/libexec/gcc/i386-redhat-linux/4.1.1/f951 testspec.f90 -quiet -dumpbase
testspec.f90 -mtune=generic -auxbase testspec -version -I
/usr/lib/gcc/i386-redhat-linux/4.1.1/finclude -o /tmp/ccUf0R9I.s
GNU F95 version 4.1.1 20070105 (Red Hat 4.1.1-52) (i386-redhat-linux)
compiled by GNU C version 4.1.1 20070105 (Red Hat 4.1.1-52).
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
In file testspec.f90:13
CHARACTER(len(halfit(stringa))) :: stringb
1
Error: 'stringb' at (1) must have constant character length in this context
[EMAIL PROTECTED] test system: ~/Jfh/Test 54 >
--
Summary: Pure function not allowed in specification expression
Product: gcc
Version: 4.1.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: john dot harper at vuw dot ac dot nz
GCC build triplet: ?
GCC host triplet: ?
GCC target triplet: i386-redhat-linux
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32386
