https://gcc.gnu.org/g:381fc8ed0f1530d0c30d5dbb6119b370fd91ba68
commit r16-6142-g381fc8ed0f1530d0c30d5dbb6119b370fd91ba68 Author: Jerry DeLisle <[email protected]> Date: Sun Dec 14 13:23:36 2025 -0800 Fortran: Fix bad read involving extra input text. The problem here involved DTIO mixed with non-DTIO variables in list formatted reads. The previous fix to PR105361 broke the test case here by mis-handling the end of file conditions. It was found that the code could be significantly reduced as well. PR libfortran/122936 libgfortran/ChangeLog: * io/list_read.c (finish_list_read): Remove the use of hit_eof and free_line. Simplify the logic. Add comments to clarify. gcc/testsuite/ChangeLog: * gfortran.dg/pr122936.f90: New test. Diff: --- gcc/testsuite/gfortran.dg/pr122936.f90 | 43 ++++++++++++++++++++++++++++++++++ libgfortran/io/list_read.c | 27 ++++++++++++++------- 2 files changed, 61 insertions(+), 9 deletions(-) diff --git a/gcc/testsuite/gfortran.dg/pr122936.f90 b/gcc/testsuite/gfortran.dg/pr122936.f90 new file mode 100644 index 000000000000..88fa2cb050b3 --- /dev/null +++ b/gcc/testsuite/gfortran.dg/pr122936.f90 @@ -0,0 +1,43 @@ +! { dg-do run } +! PR122936, derived from the original provided by the reporter. +! Before the patch this gave a runtime error. +module test_io + TYPE :: MYTYPE + REAL :: value + END TYPE + INTERFACE read(formatted) + MODULE PROCEDURE read_formatted + END INTERFACE + PUBLIC :: read(formatted) +contains + ! Formatted Input + SUBROUTINE read_formatted(dtv, unit, iotype, v_list, iostat, iomsg) + CLASS(MYTYPE), INTENT(INOUT) :: dtv + INTEGER, INTENT(IN) :: unit + CHARACTER(*), INTENT(IN) :: iotype + INTEGER, INTENT(IN) :: v_list(:) + INTEGER, INTENT(OUT) :: iostat + CHARACTER(*), INTENT(INOUT) :: iomsg + + REAL :: tmp + + READ(unit, FMT = *, IOSTAT=iostat, IOMSG=iomsg) tmp + IF (iostat == 0) dtv%value = tmp + END SUBROUTINE read_formatted + +end module + +PROGRAM MAIN + USE test_io + INTEGER, PARAMETER :: NIN = 15 + TYPE(MYTYPE) :: V11, V12, V13 + INTEGER :: V21, V22, V23 + OPEN(NIN, status='scratch') + WRITE(NIN,*) " 2.5 9 1.5, AValue for V1" + WRITE(NIN,*) " 15 2.4 17, BValue for V2" + REWIND(NIN) + READ(NIN, FMT = *) V11, V23, V12 + READ(NIN, FMT = *) V21, V13, V22 + CLOSE(NIN) +END PROGRAM MAIN + diff --git a/libgfortran/io/list_read.c b/libgfortran/io/list_read.c index 7c22f61e5a70..c20900841e38 100644 --- a/libgfortran/io/list_read.c +++ b/libgfortran/io/list_read.c @@ -2554,6 +2554,7 @@ finish_list_read (st_parameter_dt *dtp) return; } + /* Only perform the following cleanup on external files or the stdin file. */ if (!is_internal_unit (dtp)) { int c; @@ -2561,23 +2562,31 @@ finish_list_read (st_parameter_dt *dtp) /* Set the next_char and push_char worker functions. */ set_workers (dtp); - if (likely (dtp->u.p.child_saved_iostat == LIBERROR_OK) - && ((dtp->common.flags & IOPARM_DT_HAS_UDTIO) == 0)) + /* Make sure there were no errors from a DTIO child read. */ + if (likely (dtp->u.p.child_saved_iostat == LIBERROR_OK)) { + /* Peek ahead to see where we are in the parent read. */ c = next_char (dtp); - if (c == EOF) + unget_char (dtp, c); + + /* If the last read used DTIO, handle end conditions differently. */ + if ((dtp->common.flags & IOPARM_DT_HAS_UDTIO) != 0) { - free_line (dtp); - hit_eof (dtp); - return; + if ((c == EOF) || (c == ' ')) + return; + } + else + { + if (c == EOF) + { + hit_eof (dtp); + return; + } } if (c != '\n') eat_line (dtp); } } - - free_line (dtp); - } /* NAMELIST INPUT
