gcc options and mingw: move a gcc options detection from a makefile to the configure

+ define XCC and XAR if mingw32 defined
    + use XCC and XAR in lib/Makefile if defined
    Try "./configure --enable-mingw32; make". This must work

Makefile

@@ -8,19 +8,7 @@ VPATH = $(top_srcdir)
 
 CPPFLAGS += -I$(TOP) # for config.h
 
-ifeq (-$(findstring gcc,$(CC))-,-gcc-)
-ifeq (-$(findstring $(GCC_MAJOR),01)-,--)
-CFLAGS+=-fno-strict-aliasing
-ifeq (-$(findstring $(GCC_MAJOR),23)-,--)
-CFLAGS+=-Wno-pointer-sign -Wno-sign-compare
-ifeq (-$(GCC_MAJOR)-$(findstring $(GCC_MINOR),56789)-,-4--)
-CFLAGS+=-D_FORTIFY_SOURCE=0
-else
-CFLAGS+=-Wno-unused-result
-endif
-endif
-endif
-else # not GCC
+ifneq (-$(findstring gcc,$(CC))-,-gcc-)
 ifeq (-$(findstring clang,$(CC))-,-clang-)
 # make clang accept gnuisms in libtcc1.c
 CFLAGS+=-fheinous-gnu-extensions

configure

@@ -373,8 +373,16 @@ else
 fi
 
 # a final configuration tuning
-W_PRESENT="$($cc -v --help 2>&1 | grep deprecated-declarations)"
-if test -n "$W_PRESENT"; then  cc="$cc -Wno-deprecated-declarations"; fi
+W_OPTIONS="deprecated-declarations strict-aliasing pointer-sign sign-compare unused-result uninitialized"
+for i in $W_OPTIONS; do
+    O_PRESENT="$($cc -v --help 2>&1 | grep -- -W$i)"
+    if test -n "$O_PRESENT"; then  CFLAGS="$CFLAGS -Wno-$i"; fi
+done
+F_OPTIONS="strict-aliasing"
+for i in $F_OPTIONS; do
+    O_PRESENT="$($cc -v --help 2>&1 | grep -- -f$i)"
+    if test -n "$O_PRESENT"; then  CFLAGS="$CFLAGS -fno-$i"; fi
+done
 if test -z "$tcc_lddir" -a "$cpu" = "x86-64"; then tcc_lddir="lib64"; fi
 
 echo "Binary  directory   $bindir"
@@ -420,6 +428,12 @@ LDFLAGS=$LDFLAGS
 LIBSUF=$LIBSUF
 EXESUF=$EXESUF
 EOF
+if test "$mingw32" = "yes"; then
+cat >>config.mak <<EOF
+XCC=$cc
+XAR=$ar
+EOF
+fi
 
 print_inc() {
   if test -n "$2"; then

lib/Makefile

@@ -60,15 +60,15 @@ CFLAGS := $(filter-out -fstack-protector-strong,$(CFLAGS))
 ifeq "$(TARGET)" "i386-win"
  OBJ = $(addprefix $(DIR)/,$(WIN32_O))
  TGT = -DTCC_TARGET_I386 -DTCC_TARGET_PE
- XCC = $(TCC) -B$(top_srcdir)/win32 -I$(top_srcdir)/include
- XAR = $(DIR)/tiny_libmaker$(EXESUF)
+ XCC ?= $(TCC) -B$(top_srcdir)/win32 -I$(top_srcdir)/include
+ XAR ?= $(DIR)/tiny_libmaker$(EXESUF)
  PICFLAGS =
 else
 ifeq "$(TARGET)" "x86_64-win"
  OBJ = $(addprefix $(DIR)/,$(WIN64_O))
  TGT = -DTCC_TARGET_X86_64 -DTCC_TARGET_PE
  XCC = $(TCC) -B$(top_srcdir)/win32 -I$(top_srcdir)/include
- XAR = $(DIR)/tiny_libmaker$(EXESUF)
+ XAR ?= $(DIR)/tiny_libmaker$(EXESUF)
  PICFLAGS =
 else
 ifeq "$(TARGET)" "i386"