Build: add compatibility between precompiled libraries and new glibc

On Linux, precompiled libraries may be made with a glibc version that is
incompatible with the system libraries that Blender is built on. To solve
this we add a few -ffast-math symbols that can be missing.

Differential Revision: https://developer.blender.org/D6930

build_files/cmake/Modules/GTestTesting.cmake

@@ -63,6 +63,9 @@ macro(BLENDER_SRC_GTEST_EX)
     if(WITH_OPENMP_STATIC)
       target_link_libraries(${TARGET_NAME} ${OpenMP_LIBRARIES})
     endif()
+    if(UNIX AND NOT APPLE)
+      target_link_libraries(${TARGET_NAME} bf_intern_libc_compat)
+    endif()
 
     get_property(GENERATOR_IS_MULTI_CONFIG GLOBAL PROPERTY GENERATOR_IS_MULTI_CONFIG)
     if(GENERATOR_IS_MULTI_CONFIG)

intern/CMakeLists.txt

@@ -76,3 +76,7 @@ endif()
 if(WITH_QUADRIFLOW)
   add_subdirectory(quadriflow)
 endif()
+
+if(UNIX AND NOT APPLE)
+  add_subdirectory(libc_compat)
+endif()

intern/libc_compat/CMakeLists.txt

@@ -0,0 +1,37 @@
+# ***** BEGIN GPL LICENSE BLOCK *****
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software Foundation,
+# Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#
+# The Original Code is Copyright (C) 2015, Blender Foundation
+# All rights reserved.
+# ***** END GPL LICENSE BLOCK *****
+
+set(INC
+  .
+)
+
+set(INC_SYS
+)
+
+set(SRC
+  libc_compat.c
+)
+
+set(LIB
+)
+
+add_c_flag(-ffast-math)
+
+blender_add_lib(bf_intern_libc_compat "${SRC}" "${INC}" "${INC_SYS}" "${LIB}")

intern/libc_compat/libc_compat.c

@@ -0,0 +1,109 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2020 Blender Foundation.
+ * All rights reserved.
+ */
+
+/* On Linux, precompiled libraries may be made with an glibc version that is
+ * incompatible with the system libraries that Blender is built on. To solve
+ * this we add a few -ffast-math symbols that can be missing. */
+
+#include <math.h>
+
+double __exp_finite(double x);
+double __acos_finite(double x);
+double __asin_finite(double x);
+double __log2_finite(double x);
+double __log10_finite(double x);
+double __log_finite(double x);
+double __pow_finite(double x, double y);
+float __expf_finite(float x);
+float __acosf_finite(float x);
+float __asinf_finite(float x);
+float __log2f_finite(float x);
+float __log10f_finite(float x);
+float __logf_finite(float x);
+float __powf_finite(float x, float y);
+
+double __exp_finite(double x)
+{
+  return exp(x);
+}
+
+double __acos_finite(double x)
+{
+  return acos(x);
+}
+
+double __asin_finite(double x)
+{
+  return asin(x);
+}
+
+double __log2_finite(double x)
+{
+  return log2(x);
+}
+
+double __log10_finite(double x)
+{
+  return log10(x);
+}
+
+double __log_finite(double x)
+{
+  return log(x);
+}
+
+double __pow_finite(double x, double y)
+{
+  return pow(x, y);
+}
+
+float __expf_finite(float x)
+{
+  return expf(x);
+}
+
+float __acosf_finite(float x)
+{
+  return acosf(x);
+}
+
+float __asinf_finite(float x)
+{
+  return asinf(x);
+}
+
+float __log2f_finite(float x)
+{
+  return log2f(x);
+}
+
+float __log10f_finite(float x)
+{
+  return log10f(x);
+}
+
+float __logf_finite(float x)
+{
+  return logf(x);
+}
+
+float __powf_finite(float x, float y)
+{
+  return powf(x, y);
+}

source/blender/blenlib/CMakeLists.txt

@@ -277,6 +277,12 @@ if(WIN32)
   )
 endif()
 
+if(UNIX AND NOT APPLE)
+  list(APPEND LIB
+    bf_intern_libc_compat
+  )
+endif()
+
 # no need to compile object files for inline headers.
 set_source_files_properties(
   intern/math_base_inline.c