ci: Build parallel port code on supported systems

Build parallel port code on supported systems

Unsupported systems are:

  * MSVC compiler (does not support GNU style inline asm)
  * macos operating system (no macos implementations for preprocessor
    macros DO_PPI_READ, DO_PPI_WRITE, ppi_claim, ppi_release)

This means the CI can test

  * native Linux builds (yes, even for arm systems)
  * native Windows builds using mingw

Untested at this time are the BSDs.

Removes the dysfunctional Windows (since Windows XP)  parallel port code,
and has the buildsystems fail Windows builds if parallel port builds are
requested (HAVE_PARPORT or --enable-parport).

#1874 (comment)

.github/workflows/build.yml

@@ -105,6 +105,7 @@ jobs:
           cmake
           -D BUILD_DOC=1
           -D DEBUG_CMAKE=1
+          -D HAVE_PARPORT=1
           -D HAVE_LINUXGPIO=1
           -D HAVE_LINUXSPI=1
           -D CMAKE_BUILD_TYPE=${{env.BUILD_TYPE}}
@@ -169,6 +170,7 @@ jobs:
         run: >-
           cmake
           -D DEBUG_CMAKE=1
+          -D HAVE_PARPORT=1
           -D HAVE_LINUXGPIO=1
           -D HAVE_LINUXSPI=1
           -D CMAKE_BUILD_TYPE=${{env.BUILD_TYPE}}

CMakeLists.txt

@@ -340,6 +340,14 @@ if(BUILD_DOC)
     add_subdirectory(src/doc)
 endif()
 
+if(HAVE_PARPORT)
+  if(WIN32)
+    message(FATAL_ERROR "avrdude does not support parallel port on Windows")
+  elseif(APPLE)
+    message(FATAL_ERROR "avrdude does not support parallel port on Apple systems")
+  endif()
+endif()
+
 # =====================================
 # Configuration
 # =====================================

src/CMakeLists.txt

@@ -223,7 +223,6 @@ add_library(libavrdude
     pindefs.c
     ppi.c
     ppi.h
-    ppiwin.c
     serbb.h
     serbb_posix.c
     serbb_win32.c

src/Makefile.am

@@ -159,7 +159,6 @@ libavrdude_la_SOURCES = \
 	pindefs.c \
 	ppi.c \
 	ppi.h \
-	ppiwin.c \
 	serbb.h \
 	serbb_posix.c \
 	serbb_win32.c \

src/configure.ac

@@ -449,6 +449,17 @@ AC_ARG_ENABLE(
 		esac],
 	[enabled_parport=no])
 
+AS_IF([test "x$enabled_parport" = xyes], [dnl
+  case $target in
+        *-*-mingw32* | *-*-cygwin* | *-*-windows*)
+	  AC_MSG_ERROR([avrdude does not support parallel port on Windows])
+	;;
+        *-*-darwin*)
+	  AC_MSG_ERROR([avrdude does not support parallel port on MacOS])
+	;;
+  esac
+])
+
 AC_ARG_ENABLE(
 	[linuxgpio],
 	AS_HELP_STRING([--enable-linuxgpio],