[Bug 3511806] Compiler checks too early

(autoconf still to be run!)

3 files changed, 41 insertions, 9 deletions

diff --git a/unix/configure.in b/unix/configure.in
index a30c2b4..b3df242 100644
--- a/unix/configure.in
+++ b/unix/configure.in
@@ -247,7 +247,9 @@ SC_TIME_HANDLER
 #	lack blkcnt_t.
 #--------------------------------------------------------------------
 
+if test "$ac_cv_cygwin" != "yes"; then
 AC_CHECK_MEMBERS([struct stat.st_blocks, struct stat.st_blksize])
+fi
 AC_CHECK_TYPES([blkcnt_t])
 AC_CHECK_FUNC(fstatfs, , [AC_DEFINE(NO_FSTATFS, 1, [Do we have fstatfs()?])])
 
@@ -381,7 +383,7 @@ AC_CHECK_FUNC(opendir, , [AC_DEFINE(USE_DIRENT2_H, 1, [May we include <dirent2.h
 #--------------------------------------------------------------------
 
 AC_CACHE_CHECK([union wait], tcl_cv_union_wait, [
-    AC_TRY_LINK([#include <sys/types.h> 
+    AC_TRY_LINK([#include <sys/types.h>
 #include <sys/wait.h>], [
 union wait x;
 WIFEXITED(x);		/* Generates compiler error if WIFEXITED
@@ -590,7 +592,7 @@ fi
 
 #--------------------------------------------------------------------
 #	The statements below check for systems where POSIX-style
-#	non-blocking I/O (O_NONBLOCK) doesn't work or is unimplemented. 
+#	non-blocking I/O (O_NONBLOCK) doesn't work or is unimplemented.
 #	On these systems (mostly older ones), use the old BSD-style
 #	FIONBIO approach instead.
 #--------------------------------------------------------------------
@@ -785,12 +787,12 @@ if test "$FRAMEWORK_BUILD" = "1" ; then
     PRIVATE_INCLUDE_DIR="${libdir}/PrivateHeaders"
     HTML_DIR="${libdir}/Resources/Documentation/Reference/Tcl"
     EXTRA_INSTALL="install-private-headers html-tcl"
-    EXTRA_BUILD_HTML='@ln -fs contents.htm "$(HTML_INSTALL_DIR)"/TclTOC.html' 
+    EXTRA_BUILD_HTML='@ln -fs contents.htm "$(HTML_INSTALL_DIR)"/TclTOC.html'
     EXTRA_INSTALL_BINARIES='@echo "Installing Info.plist to $(LIB_INSTALL_DIR)/Resources" && mkdir -p "$(LIB_INSTALL_DIR)/Resources" && $(INSTALL_DATA) Tcl-Info.plist "$(LIB_INSTALL_DIR)/Resources/Info.plist"'
     EXTRA_INSTALL_BINARIES="$EXTRA_INSTALL_BINARIES"' && echo "Installing license.terms to $(LIB_INSTALL_DIR)/Resources" && $(INSTALL_DATA) "$(TOP_DIR)/license.terms" "$(LIB_INSTALL_DIR)/Resources"'
     EXTRA_INSTALL_BINARIES="$EXTRA_INSTALL_BINARIES"' && echo "Finalizing Tcl.framework" && rm -f "$(LIB_INSTALL_DIR)/../Current" && ln -s "$(VERSION)" "$(LIB_INSTALL_DIR)/../Current" && for f in "$(LIB_FILE)" tclConfig.sh Resources Headers PrivateHeaders; do rm -f "$(LIB_INSTALL_DIR)/../../$$f" && ln -s "Versions/Current/$$f" "$(LIB_INSTALL_DIR)/../.."; done && f="$(STUB_LIB_FILE)" && rm -f "$(LIB_INSTALL_DIR)/../../$$f" && ln -s "Versions/$(VERSION)/$$f" "$(LIB_INSTALL_DIR)/../.."'
-    # Don't use AC_DEFINE for the following as the framework version define 
-    # needs to go into the Makefile even when using autoheader, so that we  
+    # Don't use AC_DEFINE for the following as the framework version define
+    # needs to go into the Makefile even when using autoheader, so that we
     # can pick up a potential make override of VERSION. Also, don't put this
     # into CFLAGS as it should not go into tclConfig.sh
     EXTRA_CC_SWITCHES='-DTCL_FRAMEWORK_VERSION=\"$(VERSION)\"'
diff --git a/unix/tcl.m4 b/unix/tcl.m4
index fe9b136..ca77586 100644
--- a/unix/tcl.m4
+++ b/unix/tcl.m4
@@ -1237,7 +1237,7 @@ AC_DEFUN([SC_CONFIG_CFLAGS], [
 	    CC_SEARCH_FLAGS=""
 	    LD_SEARCH_FLAGS=""
 	    ;;
-	CYGWIN_*)
+	CYGWIN_*|MINGW32*)
 	    SHLIB_CFLAGS=""
 	    SHLIB_LD='${CC} -shared'
 	    SHLIB_SUFFIX=".dll"
@@ -1248,6 +1248,19 @@ AC_DEFUN([SC_CONFIG_CFLAGS], [
 	    TCL_NEEDS_EXP_FILE=1
 	    TCL_EXPORT_FILE_SUFFIX='${VERSION}\$\{DBGX\}.dll.a'
 	    TCL_SHLIB_LD_EXTRAS='-Wl,--out-implib,$[@].a'
+	    AC_CACHE_CHECK(for Cygwin version of gcc,
+		ac_cv_cygwin,
+		AC_TRY_COMPILE([
+		#ifdef __CYGWIN__
+		    #error cygwin
+		#endif
+		], [],
+		ac_cv_cygwin=no,
+		ac_cv_cygwin=yes)
+	    )
+	    if test "$ac_cv_cygwin" = "no"; then
+		AC_MSG_ERROR([${CC} is not a cygwin compiler.])
+	    fi
 	    ;;
 	dgux*)
 	    SHLIB_CFLAGS="-K PIC"
@@ -2069,7 +2082,7 @@ dnl # preprocessing tests use only CPPFLAGS.
 	case $system in
 	    AIX-*) ;;
 	    BSD/OS*) ;;
-	    CYGWIN_*) ;;
+	    CYGWIN_*|MINGW32_*) ;;
 	    IRIX*) ;;
 	    NetBSD-*|FreeBSD-*|OpenBSD-*) ;;
 	    Darwin-*) ;;
@@ -2114,6 +2127,25 @@ dnl # preprocessing tests use only CPPFLAGS.
         TCL_LIBS="${DL_LIBS} ${LIBS} ${MATH_LIBS}"])
     AC_SUBST(TCL_LIBS)
 
+	# See if the compiler supports casting to a union type.
+	# This is used to stop gcc from printing a compiler
+	# warning when initializing a union member.
+
+	AC_CACHE_CHECK(for cast to union support,
+	    tcl_cv_cast_to_union,
+	    AC_TRY_COMPILE([],
+	    [
+		  union foo { int i; double d; };
+		  union foo f = (union foo) (int) 0;
+	    ],
+	    tcl_cv_cast_to_union=yes,
+	    tcl_cv_cast_to_union=no)
+	)
+	if test "$tcl_cv_cast_to_union" = "yes"; then
+	    AC_DEFINE(HAVE_CAST_TO_UNION, 1,
+		    [Defined when compiler supports casting to union type.])
+	fi
+
     # FIXME: This subst was left in only because the TCL_DL_LIBS
     # entry in tclConfig.sh uses it. It is not clear why someone
     # would use TCL_DL_LIBS instead of TCL_LIBS.
diff --git a/unix/tclUnixPort.h b/unix/tclUnixPort.h
index fef748b..82fc8bb 100644
--- a/unix/tclUnixPort.h
+++ b/unix/tclUnixPort.h
@@ -76,8 +76,6 @@ typedef off_t		Tcl_SeekOffset;
 #ifdef __CYGWIN__
 MODULE_SCOPE int TclOSstat(const char *name, Tcl_StatBuf *statBuf);
 MODULE_SCOPE int TclOSlstat(const char *name, Tcl_StatBuf *statBuf);
-#undef HAVE_STRUCT_STAT_ST_BLOCKS
-#undef HAVE_STRUCT_STAT_ST_BLKSIZE
 #elif defined(HAVE_STRUCT_STAT64)
 #   define TclOSstat		stat64
 #   define TclOSlstat		lstat64