https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94228
Bug ID: 94228
Summary: Preprocessor inconsistency for macros when invoked
from gfortran
Product: gcc
Version: 9.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: markwayne1969 at gmail dot com
Target Milestone: ---
This report details differing behavior for preprocessor directives containing
variadic macros when processed directly by cpp
$ cpp-9 --version
cpp-9 (Homebrew GCC 9.2.0_3) 9.2.0
Copyright (C) 2019 Free Software Foundation, Inc.
and when invoked from the gfortran compiler
$ gfortran-9 --version
GNU Fortran (Homebrew GCC 9.2.0_3) 9.2.0
Copyright (C) 2019 Free Software Foundation, Inc.
An MWE is included.
1) The source ('test-function-macro.f90'):
! filename: test-function-macro.f90
! v0: Thu Mar 19 11:06:40 2020
program test_function_macro
implicit none
#define F(...) print *, 0,__VA_ARGS__
F('1','2','3')
end program test_function_macro
2) cpp direct processing:
$ cpp-9 test-function-macro.f90
# 1 "test-function-macro.f90"
# 1 "<built-in>"
# 1 "<command-line>"
# 1 "test-function-macro.f90"
! filename: test-function-macro.f90
! v0: Thu Mar 19 11:06:40 2020
program test_function_macro
implicit none
print *, 0,'1','2','3'
end program test_function_macro
3) gfortran invocation:
$ gfortran-9 -cpp test-function-macro.f90
test-function-macro.f90:7:0:
7 | #define F(...) print *, 0,__VA_ARGS__
|
Error: syntax error in macro parameter list
4) Comments
i) the behavior in item 2) is the desired behavior
ii) the behavior in item 3) is undesired
iii) The system is runs mac OS; the behavior is identical whether the above cpp
is used or the system cpp is used:
$ cpp --version
Apple LLVM version 10.0.1 (clang-1001.0.46.4)
Target: x86_64-apple-darwin18.7.0
Thread model: posix
InstalledDir: /Library/Developer/CommandLineTools/usr/bin
