Compile warning caused by Python3.12 header from -Wdeclaration-after-statement

[yskelg]

In Makefile, We use C11.

• 4c9117d
  But because C89 based compiler warning flag -Wdeclaration-after-statement, latest compiler (gcc version 14.1.1 20240522, clang version 18.1.6) told me that some warning.
• 1e2a3f3

COMMON_CFLAGS := -std=gnu11 -D_GNU_SOURCE $(CFLAGS) $(CPPFLAGS)
COMMON_CFLAGS += -iquote $(srcdir) -iquote $(objdir) -iquote $(srcdir)/arch/$(ARCH)
COMMON_CFLAGS += -W -Wall -Wno-unused-parameter -Wno-missing-field-initializers
COMMON_CFLAGS += -Wdeclaration-after-statement -Wstrict-prototypes

Here is the build log.

In file included from /usr/include/python3.12/Python.h:44,
                 from /home/paran/uftrace/utils/script-python.h:20,
                 from /home/paran/uftrace/utils/script.h:13,
                 from /home/paran/uftrace/utils/script-luajit.c:9:
/usr/include/python3.12/object.h: In function ‘Py_SIZE’:
/usr/include/python3.12/object.h:233:5: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  233 |     PyVarObject *var_ob = _PyVarObject_CAST(ob);
      |     ^~~~~~~~~~~
In file included from /usr/include/python3.12/Python.h:53:
/usr/include/python3.12/cpython/longintrepr.h: In function ‘_PyLong_CompactValue’:
/usr/include/python3.12/cpython/longintrepr.h:121:5: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  121 |     Py_ssize_t sign = 1 - (op->long_value.lv_tag & _PyLong_SIGN_MASK);
      |     ^~~~~~~~~~
  CC       utils/script-python.o
In file included from /usr/include/python3.12/Python.h:44,
                 from /home/paran/uftrace/utils/script-python.h:20,
                 from /home/paran/uftrace/utils/script-python.c:15:
/usr/include/python3.12/object.h: In function ‘Py_SIZE’:
/usr/include/python3.12/object.h:233:5: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  233 |     PyVarObject *var_ob = _PyVarObject_CAST(ob);
      |     ^~~~~~~~~~~
In file included from /usr/include/python3.12/Python.h:53:
/usr/include/python3.12/cpython/longintrepr.h: In function ‘_PyLong_CompactValue’:
/usr/include/python3.12/cpython/longintrepr.h:121:5: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  121 |     Py_ssize_t sign = 1 - (op->long_value.lv_tag & _PyLong_SIGN_MASK);
      |     ^~~~~~~~~~

[namhyung]

It's a matter of coding style and I feel it's better to have declarations before statements. Maybe I need to reconsider later but let's fix the external codes like python (or luajit) with pragma push/pop:

https://gcc.gnu.org/onlinedocs/gcc/Diagnostic-Pragmas.html

[namhyung]

In file included from /usr/include/python3.12/Python.h:44,
from /home/paran/uftrace/utils/script-python.h:20,
from /home/paran/uftrace/utils/script.h:13,
from /home/paran/uftrace/utils/script-luajit.c:9:

Also, it seems we include python headers for the luajit script. This is not needed and I think we should remove the language specific headers from the utils/script.h file.