https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64517
Bug ID: 64517
Summary: Inconsistent behavior when mixing -E and -M
Product: gcc
Version: 4.9.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: thfanning at gmail dot com
According to documentation, "Passing -M to the driver implies -E". However an
explicit `-E` produces different behavior.
touch test.F90
gfortran -M test.F90
produces:
test.o: test.F90
However,
gfortran -E -M test.F90
produces
# 1 "test.F90"
# 1 "<built-in>"
# 1 "<command-line>"
# 1 "test.F90"
test.o: test.F90
As a result, preprocessor output is mixed with dependency output. A kludge is
to add `-o /dev/null`, but that is ugly.
The description for `-E` states: "The output is in the form of preprocessed
source code, which is sent to the standard output." But shouldn't `-M` change
*what* is sent to stdout?
