[config] Add HB_LEAN

Part of https://github.com/harfbuzz/harfbuzz/issues/1652

src/hb-config.hh

@@ -36,9 +36,14 @@
 
 
 #ifdef HB_TINY
+#define HB_LEAN
 #define HB_MINI
+#endif
+
+#ifdef HB_LEAN
 #define HB_NO_BITMAP
 #define HB_NO_CFF
+#define HB_NO_MATH
 #endif
 
 #ifdef HB_MINI

src/hb-ot-math.cc

@@ -58,6 +58,10 @@
 hb_bool_t
 hb_ot_math_has_data (hb_face_t *face)
 {
+#ifdef HB_NO_MATH
+  return false;
+#endif
+
   return face->table.MATH->has_data ();
 }
 
@@ -80,6 +84,10 @@ hb_position_t
 hb_ot_math_get_constant (hb_font_t *font,
 			 hb_ot_math_constant_t constant)
 {
+#ifdef HB_NO_MATH
+  return 0;
+#endif
+
   return font->face->table.MATH->get_constant(constant, font);
 }
 
@@ -96,6 +104,10 @@ hb_position_t
 hb_ot_math_get_glyph_italics_correction (hb_font_t *font,
 					 hb_codepoint_t glyph)
 {
+#ifdef HB_NO_MATH
+  return 0;
+#endif
+
   return font->face->table.MATH->get_glyph_info().get_italics_correction (glyph, font);
 }
 
@@ -112,6 +124,10 @@ hb_position_t
 hb_ot_math_get_glyph_top_accent_attachment (hb_font_t *font,
 					    hb_codepoint_t glyph)
 {
+#ifdef HB_NO_MATH
+  return 0;
+#endif
+
   return font->face->table.MATH->get_glyph_info().get_top_accent_attachment (glyph, font);
 }
 
@@ -128,6 +144,10 @@ hb_bool_t
 hb_ot_math_is_glyph_extended_shape (hb_face_t *face,
 				    hb_codepoint_t glyph)
 {
+#ifdef HB_NO_MATH
+  return false;
+#endif
+
   return face->table.MATH->get_glyph_info().is_extended_shape (glyph);
 }
 
@@ -154,6 +174,10 @@ hb_ot_math_get_glyph_kerning (hb_font_t *font,
 			      hb_ot_math_kern_t kern,
 			      hb_position_t correction_height)
 {
+#ifdef HB_NO_MATH
+  return 0;
+#endif
+
   return font->face->table.MATH->get_glyph_info().get_kerning (glyph,
 							       kern,
 							       correction_height,
@@ -187,6 +211,12 @@ hb_ot_math_get_glyph_variants (hb_font_t *font,
 			       unsigned int *variants_count, /* IN/OUT */
 			       hb_ot_math_glyph_variant_t *variants /* OUT */)
 {
+#ifdef HB_NO_MATH
+  if (variants_count)
+    *variants_count = 0;
+  return 0;
+#endif
+
   return font->face->table.MATH->get_variants().get_glyph_variants (glyph, direction, font,
 								    start_offset,
 								    variants_count,
@@ -211,6 +241,10 @@ hb_position_t
 hb_ot_math_get_min_connector_overlap (hb_font_t *font,
 				      hb_direction_t direction)
 {
+#ifdef HB_NO_MATH
+  return 0;
+#endif
+
   return font->face->table.MATH->get_variants().get_min_connector_overlap (direction, font);
 }
 
@@ -243,6 +277,12 @@ hb_ot_math_get_glyph_assembly (hb_font_t *font,
 			       hb_ot_math_glyph_part_t *parts, /* OUT */
 			       hb_position_t *italics_correction /* OUT */)
 {
+#ifdef HB_NO_MATH
+  if (parts_count)
+    *parts_count = 0;
+  return 0;
+#endif
+
   return font->face->table.MATH->get_variants().get_glyph_parts (glyph,
 								 direction,
 								 font,