It seems with gcc-4.8.3 -fno-automatic prevents initializers from being applied to automatic variables. The following does not behave as I would expect it to with (linux-x86-64): function f (x) implicit none integer f, x integer a ! should be SAVEd from -fno-automatic a = a + x ! should increment by y every time f = a return endfunction recursive function g (x) implicit none integer g, x integer b ! should be automatic from recursive b = b + x ! should be set to y every time g = b return endfunction implicit none integer f, g ! Should return static value of a; accumulates x print *, f(3) ! -> 3, ok print *, f(4) ! -> 7, ok print *, f(2) ! -> 2, ok ! Should return automatic value of c; equal to y each time print *, g(3) ! -> garbage, expected 3 print *, g(4) ! -> garbage, expected 4 print *, g(2) ! -> garbage, expected 2 end $ gfortran -fno-automatic -finit-local-zero auto_test.f $ ./a.out 3 7 9 32770 32771 32769 $ According to gfortran's manual page, -fno-automatic should "Treat each program unit (except those marked as RECURSIVE) as if the "SAVE" statement were specified for every local variable [...]". As far as I can tell, -finit-local-zero should still initialize automatic variables in RECURSIVE functions.
Created attachment 33418 [details] Patch and testcase I believe this is a simple fix; to actually follow the specification set forth in the man page, don't treat symbols in a RECURSIVE namespace as if they are saved in resolve.c (apply_default_init_local): 2014-08-29 Fritz Reese <Reese-Fritz@zai.com> * resolve.c (apply_default_init_local): Don't treat variables in RECURSIVE units as saved. diff --git a/gcc/fortran/resolve.c b/gcc/fortran/resolve.c index 43eb240..a428633 100644 --- a/gcc/fortran/resolve.c +++ b/gcc/fortran/resolve.c @@ -11104,6 +11104,7 @@ apply_default_init_local (gfc_symbol *sym) result variable, which are also nonstatic. */ if (sym->attr.save || sym->ns->save_all || (gfc_option.flag_max_stack_var_size == 0 && !sym->attr.result + && !sym->ns->proc_name->attr.recursive && (!sym->attr.dimension || !is_non_constant_shape_array (sym)))) { /* Don't clobber an existing initializer! */ diff --git a/gcc/testsuite/gfortran.dg/auto_save_2.f90 b/gcc/testsuite/gfortran. new file mode 100644 index 0000000..0d39d48 --- /dev/null +++ b/gcc/testsuite/gfortran.dg/auto_save_2.f90 @@ -0,0 +1,52 @@ +! { dg-do run } +! { dg-options "-fno-automatic -finit-local-zero" } +! +! Make sure variables are saved with -fno-automatic except in +! functions marked RECURSIVE, and that they are still initialized with +! -finit-local-zero. +! + +function f (x) +implicit none + integer f, x + integer a ! should be SAVEd + a = a + x ! should increment by y every time + f = a + return +endfunction + +recursive function g (x) +implicit none + integer g, x + integer b ! should be automatic + b = b + x ! should be set to y every time + g = b + return +endfunction + +implicit none +integer f, g + +! Should return static value of a; accumulates y +if ( f(3) .ne. 3 ) then + call abort () +endif +if ( f(4) .ne. 7 ) then + call abort () +endif +if ( f(2) .ne. 9 ) then + call abort () +endif + +! Should return automatic value of a; equal to y each time +if ( g(3) .ne. 3 ) then + call abort () +endif +if ( g(4) .ne. 4 ) then + call abort () +endif +if ( g(2) .ne. 2 ) then + call abort () +endif + +end
Author: burnus Date: Sun Aug 31 22:28:30 2014 New Revision: 214771 URL: https://gcc.gnu.org/viewcvs?rev=214771&root=gcc&view=rev Log: 2014-08-31 Fritz Reese <Reese-Fritz@zai.com> PR fortran/62309 * resolve.c (apply_default_init_local): Don't treat variables in RECURSIVE procedures as saved. 2014-08-31 Fritz Reese <Reese-Fritz@zai.com> Tobias Burnus <burnus@net-b.de> PR fortran/62309 * gcc/testsuite/gfortran.dg/auto_save_2.f90: New. Added: trunk/gcc/testsuite/gfortran.dg/auto_save_2.f90 Modified: trunk/gcc/fortran/ChangeLog trunk/gcc/fortran/resolve.c trunk/gcc/testsuite/ChangeLog
FIXED on the trunk (GCC 5, which will be released in spring 2015).