Bug#1096662: fteqcc: ftbfs with GCC-15

[Matthias Klose]

Package: src:fteqcc
Version: 3343+svn3400-6
Severity: important
Tags: sid forky
User: debian-gcc at lists.debian.org
Usertags: ftbfs-gcc-15

[This bug is NOT targeted to the upcoming trixie release]

Please keep this issue open in the bug tracker for the package it
was filed for.  If a fix in another package is required, please
file a bug for the other package (or clone), and add a block in this
package. Please keep the issue open until the package can be built in
a follow-up test rebuild.

The package fails to build in a test rebuild on at least amd64 with
gcc-15/g++-15, but succeeds to build with gcc-14/g++-14. The
severity of this report will be raised before the forky release.

The full build log can be found at:
http://qa-logs.debian.net/2025/02/16/amd64exp/fteqcc_3343+svn3400-6_unstable_gccexp.log.gz
The last lines of the build log are at the end of this report.

To build with GCC 15, either set CC=gcc-15 CXX=g++-15 explicitly,
or install the gcc, g++, gfortran, ... packages from experimental.

  apt-get -t=experimental install g++ 

GCC 15 now defaults to the C23/C++23 standards, exposing many FTBFS.
Other Common build failures are new warnings resulting in build failures
with -Werror turned on, or new/dropped symbols in Debian symbols files.
For other C/C++ related build failures see the porting guide at
http://gcc.gnu.org/gcc-15/porting_to.html

[...]
      |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      |                 (                                           )
qccmain.c: In function ‘QCC_BspModels’:
qccmain.c:295:17: warning: ignoring return value of ‘system’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
  295 |                 system (cmd);
      |                 ^~~~~~~~~~~~
make[3]: *** [<builtin>: qcctui.o] Error 1
make[3]: *** [Makefile:59: qcd_main.o] Error 1
qcc_pr_lex.c: In function ‘ParsePrecompilerIf’:
qcc_pr_lex.c:209:15: warning: unused variable ‘start’ [-Wunused-variable]
  209 |         char *start = pr_file_p;
      |               ^~~~~
qcc_pr_lex.c: In function ‘QCC_PR_Precompiler’:
qcc_pr_lex.c:803:20: warning: unused variable ‘currentsourcefile’ [-Wunused-variable]
  803 |         extern int currentsourcefile;
      |                    ^~~~~~~~~~~~~~~~~
make[3]: *** [Makefile:41: qccmain.o] Error 1
make[3]: *** [Makefile:53: comprout.o] Error 1
qcc_pr_comp.c: In function ‘QCC_PR_GenerateFunctionCall’:
qcc_pr_comp.c:2806:13: warning: variable ‘np’ set but not used [-Wunused-but-set-variable]
 2806 |         int np;
      |             ^~
qcc_pr_comp.c:2805:13: warning: variable ‘extraparms’ set but not used [-Wunused-but-set-variable]
 2805 |         int extraparms=false;
      |             ^~~~~~~~~~
qcc_pr_comp.c: In function ‘QCC_PR_ParseFunctionCall’:
qcc_pr_comp.c:3020:13: warning: variable ‘callconvention’ set but not used [-Wunused-but-set-variable]
 3020 |         int callconvention;
      |             ^~~~~~~~~~~~~~
qcc_pr_comp.c:3018:13: warning: unused variable ‘laststatement’ [-Wunused-variable]
 3018 |         int laststatement = numstatements;
      |             ^~~~~~~~~~~~~
make[3]: *** [Makefile:50: qcc_pr_lex.o] Error 1
qcc_pr_comp.c: In function ‘QCC_PR_Expression’:
qcc_pr_comp.c:5028:33: warning: variable ‘type_b’ set but not used [-Wunused-but-set-variable]
 5028 |         etype_t         type_a, type_b, type_c;
      |                                 ^~~~~~
qcc_pr_comp.c: In function ‘QCC_PR_ParseState’:
qcc_pr_comp.c:6394:14: warning: variable ‘f’ set but not used [-Wunused-but-set-variable]
 6394 |         char f;
      |              ^
qcc_pr_comp.c: In function ‘QCC_PR_DummyFieldDef’:
qcc_pr_comp.c:8194:25: warning: value computed is not used [-Wunused-value]
 8194 |                         *fieldofs++;
      |                         ^~~~~~~~~~~
qcc_pr_comp.c: In function ‘QCC_PR_ExpandUnionToFields’:
qcc_pr_comp.c:8288:53: warning: pointer targets in passing argument 5 of ‘QCC_PR_DummyFieldDef’ differ in signedness [-Wpointer-sign]
 8288 |         QCC_PR_DummyFieldDef(pass, "", pr_scope, 1, fields, true);
      |                                                     ^~~~~~
      |                                                     |
      |                                                     int *
qcc_pr_comp.c:8151:110: note: expected ‘unsigned int *’ but argument is of type ‘int *’
 8151 | QCC_def_t *QCC_PR_DummyFieldDef(QCC_type_t *type, char *name, QCC_def_t *scope, int arraysize, unsigned int *fieldofs, pbool saved)
      |                                                                                                ~~~~~~~~~~~~~~^~~~~~~~
qcc_pr_comp.c: In function ‘QCC_PR_ParseDefs’:
qcc_pr_comp.c:9044:9: note: ‘#pragma message: this is experimental’
 9044 | #pragma message("this is experimental")
      |         ^~~~~~~
qcc_pr_comp.c:9491:96: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
 9491 |                                                         if (Hash_GetKey(&floatconstdefstable, *(int*)&pr_immediate._float))
      |                                                                                                ^~~~~~~~~~~~~~~~~~~~~~~~~~
make[3]: *** [Makefile:47: qcc_pr_comp.o] Error 1
make[3]: Leaving directory '/build/reproducible-path/fteqcc-3343+svn3400'
make[2]: *** [Makefile:38: qcc] Error 2
make[2]: Leaving directory '/build/reproducible-path/fteqcc-3343+svn3400'
dh_auto_build: error: make -j8 "INSTALL=install --strip-program=true" "CFLAGS=-g -O2 -Werror=implicit-function-declaration -ffile-prefix-map=/build/reproducible-path/fteqcc-3343+svn3400=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -fcf-protection -Wdate-time -D_FORTIFY_SOURCE=2" BASE_CFLAGS\+=-Wl,-z,relro returned exit code 2
make[1]: *** [debian/rules:10: override_dh_auto_build] Error 25
make[1]: Leaving directory '/build/reproducible-path/fteqcc-3343+svn3400'
make: *** [debian/rules:7: binary] Error 2
dpkg-buildpackage: error: debian/rules binary subprocess returned exit status 2