On 6/7/26 11:44 AM, Harald Anlauf wrote:
Hi Jerry,
the Fortran parts are trivially OK, so someone else knowing libcpp
should approve it.
Thanks,
Harald
Thanks Harald, I completely agree. I will work on figuring out who that should
be.
Jerry
Am 05.06.26 um 9:47 PM schrieb Jerry D:
See attached patch. This one was a surprise and a subtle problem.
See the explanation in the commit message. Since this touches on libcpp I am
not sure who else should review this.
Regression tested on x86_64.
OK for mainline and backport to 16 later.
Regards,
Jerry
---
The traditional-mode CPP stringification operator escaped double-quote
characters in macro argument tokens with a backslash (e.g.
CPP_STRINGIFY(key .eq. "x") expanded to "key .eq. \"x\""). This is
correct for C but not valid Fortran: Fortran represents an embedded
double-quote with a doubled quote (""), not a backslash-quote (\").
The backslash-escaped output was rejected by the Fortran scanner with a
spurious syntax error.
Fix: add a new flag fortran_string_escaping to struct cpp_options. When
set, traditional.cc emits a doubled quote instead of a backslash-quote when
escaping a double-quote character inside a stringified argument, and
suppresses the extra backslash before a literal backslash in that context.
Set the flag in gfc_cpp_post_options, which configures the CPP reader for
Fortran.
PR fortran/125533
Assisted by: Claude Sonnet 4.6
gcc/fortran/ChangeLog:
* cpp.cc (gfc_cpp_post_options): Set fortran_string_escaping in
cpp_options so traditional-mode stringification uses doubled-quote
escaping instead of backslash-quote.
gcc/testsuite/ChangeLog:
* gfortran.dg/cpp_stringify_quote_1.F90: New test.
libcpp/ChangeLog:
* include/cpplib.h (cpp_options): Add fortran_string_escaping flag.
* traditional.cc (replace_args_and_push): When
fortran_string_escaping is set, escape double-quote with a doubled
quote rather than a backslash; suppress the extra backslash before a
backslash inside a quoted argument.
---
