Harden AVRDUDE against pre-C99 libraries

[stefanrueger]

Apparently, some Windows 7 systems have C libraries that are not C99 compliant. This PR hardens against these problems.

[mcuee]

@stefanrueger

Looks good except it generates new warnings from MSYS2 mingw compiler.

From github action MSYS2 mingw64 build
https://github.com/avrdudes/avrdude/actions/runs/7437554531/job/20235338846

In file included from D:/a/avrdude/avrdude/src/serbb_win32.c:26:
D:/a/avrdude/avrdude/src/serbb_win32.c: In function 'serbb_open':
D:/a/avrdude/avrdude/src/serbb_win32.c:302:77: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
  302 |         pmsg_debug("ser_open(): opened comm port %s, handle 0x%lx\n", port, (unsigned long) hComPort);
      |                                                                             ^
D:/a/avrdude/avrdude/src/avrdude.h:81:121: note: in definition of macro 'pmsg_debug'
   81 | #define pmsg_debug(...)     avrdude_message2(stderr, __LINE__, __FILE__, __func__, MSG2_PROGNAME|MSG2_FLUSH, MSG_DEBUG, __VA_ARGS__)
      |                                                                                                                         ^~~~~~~~~~~
D:/a/avrdude/avrdude/src/serbb_win32.c: In function 'serbb_close':
D:/a/avrdude/avrdude/src/serbb_win32.c:318:68: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
  318 |         pmsg_debug("ser_close(): closed comm port handle 0x%lx\n", (unsigned long) hComPort);
      |                                                                    ^
D:/a/avrdude/avrdude/src/avrdude.h:81:121: note: in definition of macro 'pmsg_debug'
   81 | #define pmsg_debug(...)     avrdude_message2(stderr, __LINE__, __FILE__, __func__, MSG2_PROGNAME|MSG2_FLUSH, MSG_DEBUG, __VA_ARGS__)
      |  

You do not see such warnings with git main. Please refer to the github action build log with git main.
https://github.com/avrdudes/avrdude/actions/runs/7397687783/job/20125270526

[mcuee]

@stefanrueger

BTW, once you merge this into git main, then the Arduino avrdude-packing script in avrdude repo will run. As of now the script does not run on pull-requests and only upon push to git main.

https://github.com/avrdudes/avrdude/blob/main/.github/workflows/arduino_packing.yml

name: avrdude_packing

env:
  # The name of the project
  PROJECT_NAME: avrdude
  DIST_DIR: dist
  ARTIFACT_NAME: dist

on:
  label:
    types:
      - created
  push:
    branches:
      - main

[mcuee]

Another thing, it seems that you are correct that Windows 7 C runtime is not really compatible with C99. But then I do not understand why MinGW MSYS2 build does not have the issue with Hex file type automatic recognition, since it also uses msvcrt.dll under Windows 7. It is said that Windows 10 comes with the universal C Runtime (UCRT) which is C99.
https://www.reddit.com/r/C_Programming/comments/4osr95/alternative_to_msvcrtdll/

However, our default MSYS2 build environment are mingw32 and mingw64 and not ucrt64.
https://www.msys2.org/docs/environments/

Name	Prefix	Toolchain	Architecture	C Library	C++ Library
MSYS	/usr	gcc	x86_64	cygwin	libstdc++
UCRT64	/ucrt64	gcc	x86_64	ucrt	libstdc++
CLANG64	/clang64	llvm	x86_64	ucrt	libc++
CLANGARM64	/clangarm64	llvm	aarch64	ucrt	libc++
CLANG32	/clang32	llvm	i686	ucrt	libc++
MINGW64	/mingw64	gcc	x86_64	msvcrt	libstdc++
MINGW32	/mingw32	gcc	i686	msvcrt	libstdc++

[stefanrueger]

MinGW MSYS2 build does not have the issue with Hex file type automatic recognition

Maybe one is statically linked and one dynamically. The problem is the scanf() library function at execution.

[mcuee]

@stefanrueger

Now this PR is good to go. Please merge this so that we can confirm whether the :a issue is sorted out or not with this PR.

[mcuee]

However, our default MSYS2 build environment are mingw32 and mingw64 and not ucrt64. https://www.msys2.org/docs/environments/

I have created a new PR to add MSYS2 ucrt64, clang32 and clang64 build.

• Update build.yml to add MSYS2 ucrt64, clang32 and clang64 build #1612

clang compilers sometimes capture more codes issues compared to gcc and MSVC.