Fortran: Revert to non-multilib-specific ISO_Fortran_binding.h

Commit fef67987cf502fe322e92ddce22eea7ac46b4d75 changed the
libgfortran build process to generate multilib-specific versions of
ISO_Fortran_binding.h from a template, by running gfortran to identify
the values of the Fortran kind constants C_LONG_DOUBLE, C_FLOAT128,
and C_INT128_T.  This caused multiple problems with search paths, both
for build-tree testing and installed-tree use, not all of which have
been fixed.

This patch reverts to a non-multilib-specific .h file that uses GCC's
predefined preprocessor symbols to detect the supported types and map
them to kind values in the same way as the Fortran front end.

2021-09-06  Sandra Loosemore  <sandra@codesourcery.com>

libgfortran/
	* ISO_Fortran_binding-1-tmpl.h: Deleted.
	* ISO_Fortran_binding-2-tmpl.h: Deleted.
	* ISO_Fortran_binding-3-tmpl.h: Deleted.
	* ISO_Fortran_binding.h: New file to replace the above.
	* Makefile.am (gfor_cdir): Remove MULTISUBDIR.
	(ISO_Fortran_binding.h): Simplify to just copy the file.
	* Makefile.in: Regenerated.
	* mk-kinds-h.sh: Revert pieces no longer needed for
	ISO_Fortran_binding.h.

6 files changed, 87 insertions, 86 deletions

diff --git a/libgfortran/ISO_Fortran_binding-2-tmpl.h b/libgfortran/ISO_Fortran_binding-2-tmpl.h
deleted file mode 100644
index ad88f8b..0000000
--- a/libgfortran/ISO_Fortran_binding-2-tmpl.h
+++ /dev/null
@@ -1,42 +0,0 @@
-#include "config.h"
-#include "kinds.inc"
-
-/* Note that -1 is used by CFI_type_other, hence, -2 is used for unavailable kinds.  */
-
-#if GFC_C_INT128_T_KIND == 16
-#define CFI_type_int128_t (CFI_type_Integer + (16 << CFI_type_kind_shift))
-#define CFI_type_int_least128_t (CFI_type_Integer + (16 << CFI_type_kind_shift))
-#define CFI_type_int_fast128_t (CFI_type_Integer + (16 << CFI_type_kind_shift))
-#elif GFC_C_INT128_T_KIND < 0
-#define CFI_type_int128_t -2
-#define CFI_type_int_least128_t -2
-#define CFI_type_int_fast128_t -2
-#else
-#error "Unexpected value for GFC_C_INT128_T_KIND"
-#endif 
-
-#if GFC_C_LONG_DOUBLE_KIND == 16
-#define CFI_type_long_double (CFI_type_Real + (16 << CFI_type_kind_shift))
-#define CFI_type_long_double_Complex (CFI_type_Complex + (16 << CFI_type_kind_shift))
-#elif GFC_C_LONG_DOUBLE_KIND == 10 
-#define CFI_type_long_double (CFI_type_Real + (10 << CFI_type_kind_shift))
-#define CFI_type_long_double_Complex (CFI_type_Complex + (10 << CFI_type_kind_shift))
-#elif GFC_C_LONG_DOUBLE_KIND == 8 
-#define CFI_type_long_double (CFI_type_Real + (8 << CFI_type_kind_shift))
-#define CFI_type_long_double_Complex (CFI_type_Complex + (8 << CFI_type_kind_shift))
-#elif GFC_C_LONG_DOUBLE_KIND < 0 
-#define CFI_type_long_double -2
-#define CFI_type_long_double_Complex -2
-#else
-#error "Unexpected value for GFC_C_LONG_DOUBLE_KIND"
-#endif 
-
-#if GFC_C_FLOAT128_KIND == 16
-#define CFI_type_float128 (CFI_type_Real + (16 << CFI_type_kind_shift))
-#define CFI_type_float128_Complex (CFI_type_Complex + (16 << CFI_type_kind_shift))
-#elif GFC_C_FLOAT128_KIND < 0
-#define CFI_type_float128 -2
-#define CFI_type_float128_Complex -2
-#else
-#error "Unexpected value for GFC_C_FLOAT128_KIND"
-#endif 
diff --git a/libgfortran/ISO_Fortran_binding-3-tmpl.h b/libgfortran/ISO_Fortran_binding-3-tmpl.h
deleted file mode 100644
index aec4288..0000000
--- a/libgfortran/ISO_Fortran_binding-3-tmpl.h
+++ /dev/null
@@ -1,5 +0,0 @@
-#ifdef __cplusplus
-}
-#endif
-
-#endif /* ISO_FORTRAN_BINDING_H */
diff --git a/libgfortran/ISO_Fortran_binding-1-tmpl.h b/libgfortran/ISO_Fortran_binding.h
index b998d6c..5335ea4 100644
--- a/libgfortran/ISO_Fortran_binding-1-tmpl.h
+++ b/libgfortran/ISO_Fortran_binding.h
@@ -32,6 +32,7 @@ extern "C" {
 
 #include <stddef.h>  /* Standard ptrdiff_t tand size_t. */
 #include <stdint.h>  /* Integer types. */
+#include <float.h>  /* Macros for floating-point type characteristics.  */
 
 /* Constants, defined as macros. */
 #define CFI_VERSION 1
@@ -198,3 +199,79 @@ extern int CFI_setpointer (CFI_cdesc_t *, CFI_cdesc_t *, const CFI_index_t []);
 #define CFI_type_double (CFI_type_Real + (sizeof (double) << CFI_type_kind_shift))
 #define CFI_type_float_Complex (CFI_type_Complex + (sizeof (float) << CFI_type_kind_shift))
 #define CFI_type_double_Complex (CFI_type_Complex + (sizeof (double) << CFI_type_kind_shift))
+
+/* If GCC supports int128_t on this target, it predefines
+   __SIZEOF_INT128__ to 16.  */
+#if defined(__SIZEOF_INT128__)
+#if (__SIZEOF_INT128__ == 16)
+#define CFI_type_int128_t (CFI_type_Integer + (16 << CFI_type_kind_shift))
+#define CFI_type_int_least128_t (CFI_type_Integer + (16 << CFI_type_kind_shift))
+#define CFI_type_int_fast128_t (CFI_type_Integer + (16 << CFI_type_kind_shift))
+#else
+#error "Can't determine kind of int128_t"
+#endif
+#else
+#define CFI_type_int128_t -2
+#define CFI_type_int_least128_t -2
+#define CFI_type_int_fast128_t -2
+#endif
+
+/* The situation with long double support is more complicated; we need to
+   examine the type in more detail to figure out its kind.  */
+
+/* Long double is the same kind as double.  */
+#if (LDBL_MANT_DIG == DBL_MANT_DIG \
+     && LDBL_MIN_EXP == DBL_MIN_EXP \
+     && LDBL_MAX_EXP == DBL_MAX_EXP)
+#define CFI_type_long_double CFI_type_double
+#define CFI_type_long_double_Complex CFI_type_double_Complex
+
+/* This is the 80-bit encoding on x86; Fortran assigns it kind 10.  */
+#elif (LDBL_MANT_DIG == 64 \
+       && LDBL_MIN_EXP == -16381 \
+       && LDBL_MAX_EXP == 16384)
+#define CFI_type_long_double (CFI_type_Real + (10 << CFI_type_kind_shift))
+#define CFI_type_long_double_Complex (CFI_type_Complex + (10 << CFI_type_kind_shift))
+
+/* This is the IEEE 128-bit encoding, same as float128.  */
+#elif (LDBL_MANT_DIG == 113 \
+       && LDBL_MIN_EXP == -16381 \
+       && LDBL_MAX_EXP == 16384)
+#define CFI_type_long_double (CFI_type_Real + (16 << CFI_type_kind_shift))
+#define CFI_type_long_double_Complex (CFI_type_Complex + (16 << CFI_type_kind_shift))
+
+/* This is the IBM128 encoding used on PowerPC; also assigned kind 16.  */
+#elif (LDBL_MANT_DIG == 106 \
+       && LDBL_MIN_EXP == -968 \
+       && LDBL_MAX_EXP == 1024)
+#define CFI_type_long_double (CFI_type_Real + (16 << CFI_type_kind_shift))
+#define CFI_type_long_double_Complex (CFI_type_Complex + (16 << CFI_type_kind_shift))
+#define CFI_no_float128 1
+
+/* It's a bug if we get here.  If you've got a target that has some other
+   long double encoding, you need add something here for Fortran to
+   recognize it.  */
+#else
+#error "Can't determine kind of long double"
+#endif
+
+/* Similarly for __float128.  This always refers to the IEEE encoding
+   and not some other 128-bit representation, so if we already used
+   kind 16 for a non-IEEE representation, this one must be unsupported
+   in Fortran even if it's available in C.  */
+#if (!defined (CFI_no_float128) \
+     && defined(__FLT128_MANT_DIG__) && __FLT128_MANT_DIG__ == 113  \
+     && defined(__FLT128_MIN_EXP__) && __FLT128_MIN_EXP__ == -16381 \
+     && defined(__FLT128_MAX_EXP__) && __FLT128_MAX_EXP__ == 16384)
+#define CFI_type_float128 (CFI_type_Real + (16 << CFI_type_kind_shift))
+#define CFI_type_float128_Complex (CFI_type_Complex + (16 << CFI_type_kind_shift))
+#else
+#define CFI_type_float128 -2
+#define CFI_type_float128_Complex -2
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* ISO_FORTRAN_BINDING_H */
diff --git a/libgfortran/Makefile.am b/libgfortran/Makefile.am
index 6fc4b46..366198b 100644
--- a/libgfortran/Makefile.am
+++ b/libgfortran/Makefile.am
@@ -31,7 +31,7 @@ version_dep =
 endif
 
 gfor_c_HEADERS = ISO_Fortran_binding.h
-gfor_cdir = $(libdir)/gcc/$(target_alias)/$(gcc_version)$(MULTISUBDIR)/include
+gfor_cdir = $(libdir)/gcc/$(target_alias)/$(gcc_version)/include
 
 LTLDFLAGS = $(shell $(SHELL) $(top_srcdir)/../libtool-ldflags $(LDFLAGS)) \
 	    $(lt_host_flags)
@@ -1079,15 +1079,9 @@ fpu-target.inc: fpu-target.h $(srcdir)/libgfortran.h
 # Place ISO_Fortran_binding.h also under include/ in the build directory such
 # that it can be used for in-built-tree testsuite runs without interference of
 # other files in the build dir - like intrinsic .mod files or other .h files.
-ISO_Fortran_binding.h: $(srcdir)/ISO_Fortran_binding-1-tmpl.h \
-		       $(srcdir)/ISO_Fortran_binding-2-tmpl.h \
-		       $(srcdir)/ISO_Fortran_binding-3-tmpl.h \
-		       kinds.inc
+ISO_Fortran_binding.h: $(srcdir)/ISO_Fortran_binding.h
 	-rm -f $@
-	cp $(srcdir)/ISO_Fortran_binding-1-tmpl.h $@
-	$(COMPILE) -E -dD $(srcdir)/ISO_Fortran_binding-2-tmpl.h \
-	| grep '^#define CFI_type' >> $@
-	cat $(srcdir)/ISO_Fortran_binding-3-tmpl.h >> $@
+	cp $(srcdir)/ISO_Fortran_binding.h $@
 	$(MKDIR_P) include
 	-rm -f include/ISO_Fortran_binding.h
 	cp $@ include/ISO_Fortran_binding.h
diff --git a/libgfortran/Makefile.in b/libgfortran/Makefile.in
index 6fc9baf..a3cb6f4 100644
--- a/libgfortran/Makefile.in
+++ b/libgfortran/Makefile.in
@@ -725,7 +725,7 @@ gcc_version := $(shell @get_gcc_base_ver@ $(top_srcdir)/../gcc/BASE-VER)
 @LIBGFOR_USE_SYMVER_GNU_TRUE@@LIBGFOR_USE_SYMVER_TRUE@version_dep = $(srcdir)/gfortran.map
 @LIBGFOR_USE_SYMVER_SUN_TRUE@@LIBGFOR_USE_SYMVER_TRUE@version_dep = gfortran.map-sun
 gfor_c_HEADERS = ISO_Fortran_binding.h
-gfor_cdir = $(libdir)/gcc/$(target_alias)/$(gcc_version)$(MULTISUBDIR)/include
+gfor_cdir = $(libdir)/gcc/$(target_alias)/$(gcc_version)/include
 LTLDFLAGS = $(shell $(SHELL) $(top_srcdir)/../libtool-ldflags $(LDFLAGS)) \
 	    $(lt_host_flags)
 
@@ -7045,15 +7045,9 @@ fpu-target.inc: fpu-target.h $(srcdir)/libgfortran.h
 # Place ISO_Fortran_binding.h also under include/ in the build directory such
 # that it can be used for in-built-tree testsuite runs without interference of
 # other files in the build dir - like intrinsic .mod files or other .h files.
-ISO_Fortran_binding.h: $(srcdir)/ISO_Fortran_binding-1-tmpl.h \
-		       $(srcdir)/ISO_Fortran_binding-2-tmpl.h \
-		       $(srcdir)/ISO_Fortran_binding-3-tmpl.h \
-		       kinds.inc
+ISO_Fortran_binding.h: $(srcdir)/ISO_Fortran_binding.h
 	-rm -f $@
-	cp $(srcdir)/ISO_Fortran_binding-1-tmpl.h $@
-	$(COMPILE) -E -dD $(srcdir)/ISO_Fortran_binding-2-tmpl.h \
-	| grep '^#define CFI_type' >> $@
-	cat $(srcdir)/ISO_Fortran_binding-3-tmpl.h >> $@
+	cp $(srcdir)/ISO_Fortran_binding.h $@
 	$(MKDIR_P) include
 	-rm -f include/ISO_Fortran_binding.h
 	cp $@ include/ISO_Fortran_binding.h
diff --git a/libgfortran/mk-kinds-h.sh b/libgfortran/mk-kinds-h.sh
index f4244f0..2496190 100755
--- a/libgfortran/mk-kinds-h.sh
+++ b/libgfortran/mk-kinds-h.sh
@@ -35,8 +35,8 @@ for k in $possible_integer_kinds; do
     echo "typedef ${prefix}int${s}_t GFC_INTEGER_${k};"
     echo "typedef ${prefix}uint${s}_t GFC_UINTEGER_${k};"
     echo "typedef GFC_INTEGER_${k} GFC_LOGICAL_${k};"
-    echo "#define HAVE_GFC_LOGICAL_${k} 1"
-    echo "#define HAVE_GFC_INTEGER_${k} 1"
+    echo "#define HAVE_GFC_LOGICAL_${k}"
+    echo "#define HAVE_GFC_INTEGER_${k}"
     echo ""
   fi
   rm -f tmp$$.*
@@ -98,8 +98,8 @@ for k in $possible_real_kinds; do
     # Output the information we've gathered
     echo "typedef ${ctype} GFC_REAL_${k};"
     echo "typedef ${cplxtype} GFC_COMPLEX_${k};"
-    echo "#define HAVE_GFC_REAL_${k} 1"
-    echo "#define HAVE_GFC_COMPLEX_${k} 1"
+    echo "#define HAVE_GFC_REAL_${k}"
+    echo "#define HAVE_GFC_COMPLEX_${k}"
     echo "#define GFC_REAL_${k}_HUGE ${huge}${suffix}"
     echo "#define GFC_REAL_${k}_LITERAL_SUFFIX ${suffix}"
     if [ "x$suffix" = "x" ]; then
@@ -114,23 +114,6 @@ for k in $possible_real_kinds; do
   rm -f tmp$$.*
 done
 
-# For ISO_Fortran_binding.h
-for k in "C_LONG_DOUBLE" "C_FLOAT128" "C_INT128_T"; do
-  fname="tmp$$.val"
-  echo "use iso_c_binding, only: $k; end" > tmp$$.f90
-  if $compile -S -fdump-parse-tree tmp$$.f90 > "$fname"; then
-    kind=`grep "value:" "$fname" |grep value: | sed -e 's/.*value: *//'`
-    if [ "x$kind" = "x" ]; then
-      echo "ERROR: Failed to extract kind for $k" 1>&2
-      exit 1
-    fi
-    echo "#define GFC_${k}_KIND ${kind}"
-  else
-    echo "ERROR: Failed to extract kind for $k" 1>&2
-    exit 1
-  fi
-  rm -f tmp$$.*
-done
 
 # After this, we include a header that can override some of the
 # autodetected settings.