Generate and install hb-features.h

This header has defines for all the optional
dependendencies that come with their own Harfbuzz
headers, so you can do:

  #include <hb-features.h>
  #ifdef HB_HAS_DIRECTWRITE
  #include <hb-directwrite.h>
  #endif

src/Makefile.am

@@ -47,6 +47,9 @@ HBLIBS   += $(GLIB_LIBS)
 HBDEPS   += $(GLIB_DEPS)
 HBSOURCES += $(HB_GLIB_sources)
 HBHEADERS += $(HB_GLIB_headers)
+HB_HAS_GLIB_DEF = define HB_HAS_GLIB 1
+else
+HB_HAS_GLIB_DEF = undef HB_HAS_GLIB
 endif
 
 if HAVE_FREETYPE
@@ -55,6 +58,9 @@ HBLIBS   += $(FREETYPE_LIBS)
 HBDEPS   += $(FREETYPE_DEPS)
 HBSOURCES += $(HB_FT_sources)
 HBHEADERS += $(HB_FT_headers)
+HB_HAS_FREETYPE_DEF = define HB_HAS_FREETYPE 1
+else
+HB_HAS_FREETYPE_DEF = undef HB_HAS_FREETYPE
 endif
 
 if HAVE_GRAPHITE2
@@ -63,6 +69,9 @@ HBLIBS   += $(GRAPHITE2_LIBS)
 HBDEPS   += $(GRAPHITE2_DEPS)
 HBSOURCES += $(HB_GRAPHITE2_sources)
 HBHEADERS += $(HB_GRAPHITE2_headers)
+HB_HAS_GRAPHITE_DEF = define HB_HAS_GRAPHITE 1
+else
+HB_HAS_GRAPHITE_DEF = undef HB_HAS_GRAPHITE
 endif
 
 if HAVE_UNISCRIBE
@@ -70,6 +79,9 @@ HBCFLAGS += $(UNISCRIBE_CFLAGS)
 HBNONPCLIBS += $(UNISCRIBE_LIBS)
 HBSOURCES += $(HB_UNISCRIBE_sources)
 HBHEADERS += $(HB_UNISCRIBE_headers)
+HB_HAS_UNISCRIBE_DEF = define HB_HAS_UNISCRIBE 1
+else
+HB_HAS_UNISCRIBE_DEF = undef HB_HAS_UNISCRIBE
 endif
 
 if HAVE_DIRECTWRITE
@@ -77,6 +89,9 @@ HBCFLAGS += $(DIRECTWRITE_CXXFLAGS)
 HBNONPCLIBS += $(DIRECTWRITE_LIBS)
 HBSOURCES += $(HB_DIRECTWRITE_sources)
 HBHEADERS += $(HB_DIRECTWRITE_headers)
+HB_HAS_DIRECTWRITE_DEF = define HB_HAS_DIRECTWRITE 1
+else
+HB_HAS_DIRECTWRITE_DEF = undef HB_HAS_DIRECTWRITE
 endif
 
 if HAVE_GDI
@@ -84,6 +99,9 @@ HBCFLAGS += $(GDI_CXXFLAGS)
 HBNONPCLIBS += $(GDI_LIBS)
 HBSOURCES += $(HB_GDI_sources)
 HBHEADERS += $(HB_GDI_headers)
+HB_HAS_GDI_DEF = define HB_HAS_GDI 1
+else
+HB_HAS_GDI_DEF = undef HB_HAS_GDI
 endif
 
 if HAVE_CORETEXT
@@ -91,6 +109,9 @@ HBCFLAGS += $(CORETEXT_CFLAGS)
 HBNONPCLIBS += $(CORETEXT_LIBS)
 HBSOURCES += $(HB_CORETEXT_sources)
 HBHEADERS += $(HB_CORETEXT_headers)
+HB_HAS_CORETEXT_DEF = define HB_HAS_CORETEXT 1
+else
+HB_HAS_CORETEXT_DEF = undef HB_HAS_CORETEXT
 endif
 
 
@@ -147,7 +168,7 @@ pkgconfigdir = $(libdir)/pkgconfig
 pkgconfig_DATA = harfbuzz.pc
 cmakedir = $(libdir)/cmake/harfbuzz
 cmake_DATA = harfbuzz-config.cmake
-EXTRA_DIST += hb-version.h.in harfbuzz.pc.in harfbuzz-config.cmake.in
+EXTRA_DIST += hb-version.h.in hb-features.h.in harfbuzz.pc.in harfbuzz-config.cmake.in
 
 lib_LTLIBRARIES += libharfbuzz-subset.la
 libharfbuzz_subset_la_LINK = $(chosen_linker) $(libharfbuzz_subset_la_LDFLAGS)
@@ -178,6 +199,7 @@ HBCFLAGS += $(ICU_CFLAGS)
 HBLIBS += $(ICU_LIBS)
 HBSOURCES += $(HB_ICU_sources)
 HBHEADERS += $(HB_ICU_headers)
+HB_HAS_ICU_DEF = define HB_HAS_ICU 1
 else
 lib_LTLIBRARIES += libharfbuzz-icu.la
 libharfbuzz_icu_la_SOURCES = $(HB_ICU_sources)
@@ -187,6 +209,7 @@ libharfbuzz_icu_la_LIBADD = $(ICU_LIBS) libharfbuzz.la
 EXTRA_libharfbuzz_icu_la_DEPENDENCIES = $(harfbuzz_icu_def_dependency)
 pkginclude_HEADERS += $(HB_ICU_headers)
 pkgconfig_DATA += harfbuzz-icu.pc
+HB_HAS_ICU_DEF = undef HB_HAS_ICU
 endif
 endif
 EXTRA_DIST += harfbuzz-icu.pc.in
@@ -226,6 +249,23 @@ EXTRA_DIST += \
 	$(NULL)
 
 
+BUILT_SOURCES += \
+	hb-features.h
+
+hb-features.h: hb-features.h.in $(top_srcdir)/configure.ac
+	$(AM_V_GEN) $(SED) \
+		-e 's/mesondefine HB_HAS_FREETYPE/$(HB_HAS_FREETYPE_DEF)/' \
+		-e 's/mesondefine HB_HAS_GDI/$(HB_HAS_GDI_DEF)/' \
+		-e 's/#mesondefine HB_HAS_GDI/$(HB_HAS_GDI_DEF)/' \
+		-e 's/#mesondefine HB_HAS_GRAPHITE/$(HB_HAS_GRAPHITE_DEF)/' \
+		-e 's/#mesondefine HB_HAS_GLIB/$(HB_HAS_GLIB_DEF)/' \
+		-e 's/#mesondefine HB_HAS_UNISCRIBE/$(HB_HAS_UNISCRIBE_DEF)/' \
+		-e 's/#mesondefine HB_HAS_DIRECTWRITE/$(HB_HAS_DIRECTWRITE_DEF)/' \
+		-e 's/#mesondefine HB_HAS_CORETEXT/$(HB_HAS_CORETEXT_DEF)/' \
+		-e 's/#mesondefine HB_HAS_ICU/$(HB_HAS_ICU_DEF)/' \
+		"$<" > "$@" || ($(RM) "$@"; false)
+
+
 %.pc: %.pc.in $(top_builddir)/config.status
 	$(AM_V_GEN) \
 	$(SED)	-e 's@%prefix%@$(prefix)@g' \

src/hb-features.h.in

@@ -0,0 +1,96 @@
+/*
+ * Copyright © 2022 Red Hat, Inc.
+ *
+ *  This is part of HarfBuzz, a text shaping library.
+ *
+ * Permission is hereby granted, without written agreement and without
+ * license or royalty fees, to use, copy, modify, and distribute this
+ * software and its documentation for any purpose, provided that the
+ * above copyright notice and the following two paragraphs appear in
+ * all copies of this software.
+ *
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
+ * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+ * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
+ * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
+ * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ */
+
+#if !defined(HB_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
+#error "Include <hb.h> instead."
+#endif
+
+#ifndef HB_FEATURES_H
+#define HB_FEATURES_H
+
+#include "hb-common.h"
+
+HB_BEGIN_DECLS
+
+
+/**
+ * HB_HAS_FREETYPE:
+ *
+ * Defined if Harfbuzz has been built with Freetype support.
+ */
+#mesondefine HB_HAS_FREETYPE
+
+/**
+ * HB_HAS_GDI:
+ *
+ * Defined if Harfbuzz has been built with GDI support.
+ */
+#mesondefine HB_HAS_GDI
+
+/**
+ * HB_HAS_GRAPHITE:
+ *
+ * Defined if Harfbuzz has been built with Graphite support.
+ */
+#mesondefine HB_HAS_GRAPHITE
+
+/**
+ * HB_HAS_GLIB:
+ *
+ * Defined if Harfbuzz has been built with GLib support.
+ */
+#mesondefine HB_HAS_GLIB
+
+/**
+ * HB_HAS_UNISCRIBE:
+ *
+ * Defined if Harfbuzz has been built with Uniscribe support.
+ */
+#mesondefine HB_HAS_UNISCRIBE
+
+/**
+ * HB_HAS_DIRECTWRITE:
+ *
+ * Defined if Harfbuzz has been built with DirectWrite support.
+ */
+#mesondefine HB_HAS_DIRECTWRITE
+
+/**
+ * HB_HAS_CORETEXT:
+ *
+ * Defined if Harfbuzz has been built with CoreText support.
+ */
+#mesondefine HB_HAS_CORETEXT
+
+/**
+ * HB_HAS_ICU:
+ *
+ * Defined if Harfbuzz has been built with ICU support.
+ */
+#mesondefine HB_HAS_ICU
+
+
+HB_END_DECLS
+
+#endif /* HB_FEATURES_H */

src/meson.build

@@ -414,33 +414,40 @@ harfbuzz_deps = [thread_dep, m_dep] + harfbuzz_extra_deps
 
 libharfbuzz_link_language = 'c'
 
+hb_features = configuration_data()
+
 if conf.get('HAVE_FREETYPE', 0) == 1
   hb_sources += hb_ft_sources
   hb_headers += hb_ft_headers
   harfbuzz_deps += [freetype_dep]
+  hb_features.set('HB_HAS_FREETYPE', 1)
 endif
 
 if conf.get('HAVE_GDI', 0) == 1
   hb_sources += hb_gdi_sources
   hb_headers += hb_gdi_headers
   harfbuzz_deps += gdi_uniscribe_deps
+  hb_features.set('HB_HAS_GDI', 1)
 endif
 
 if conf.get('HAVE_GRAPHITE2', 0) == 1
   hb_sources += hb_graphite2_sources
   hb_headers += hb_graphite2_headers
   harfbuzz_deps += [graphite2_dep, graphite_dep]
+  hb_features.set('HB_HAS_GRAPHITE', 1)
 endif
 
 if conf.get('HAVE_GLIB', 0) == 1
   hb_sources += hb_glib_sources
   hb_headers += hb_glib_headers
   harfbuzz_deps += [glib_dep]
+  hb_features.set('HB_HAS_GLIB', 1)
 endif
 
 if conf.get('HAVE_UNISCRIBE', 0) == 1
   hb_sources += hb_uniscribe_sources
   hb_headers += hb_uniscribe_headers
+  hb_features.set('HB_HAS_UNISCRIBE', 1)
 endif
 
 if conf.get('HAVE_DIRECTWRITE', 0) == 1
@@ -448,12 +455,14 @@ if conf.get('HAVE_DIRECTWRITE', 0) == 1
   hb_headers += hb_directwrite_headers
   # hb-directwrite needs a C++ linker
   libharfbuzz_link_language = 'cpp'
+  hb_features.set('HB_HAS_DIRECTWRITE', 1)
 endif
 
 if conf.get('HAVE_CORETEXT', 0) == 1
   hb_sources += hb_coretext_sources
   hb_headers += hb_coretext_headers
   harfbuzz_deps += coretext_deps
+  hb_features.set('HB_HAS_CORETEXT', 1)
 endif
 
 have_icu = conf.get('HAVE_ICU', 0) == 1
@@ -463,8 +472,17 @@ if have_icu and have_icu_builtin
   hb_sources += hb_icu_sources
   hb_headers += hb_icu_headers
   harfbuzz_deps += [icu_dep]
+  hb_features.set('HB_HAS_ICU', 1)
 endif
 
+hb_features_h = configure_file(input: 'hb-features.h.in',
+                               output: 'hb-features.h',
+                               configuration: hb_features,
+                               install: true,
+                               install_dir: get_option('includedir') / meson.project_name())
+
+# Base and default-included sources and headers
+
 # harfbuzz
 gen_def = find_program('gen-def.py')