Applied patch for several build issues:

+ add empty constructors to make Bullet compile using clang. 
Thanks to Stillmoon for the report and patch, See http://bulletphysics.org/Bullet/phpBB3/viewtopic.php?f=9&t=5730
+ bullet-2.77/Demos/OpenCLClothDemo/cloth.h:103: error: ‘sprintf’ was not declared in this scope
Thanks to pprkut for the report in Issue 435
+ cmake build fails on Unix systems when using BUILD_SHARED_LIBS. Added pthreads to BulletMultiThreaded
Thanks to pprkut for the report in Issue 434

Demos/OpenCLClothDemo/cloth.h

@@ -20,7 +20,7 @@ subject to the following restrictions:
 #include <string>
 #include <cstring>
 #include "LinearMath/btScalar.h"
-
+#include <stdio.h> //sprintf
 
 struct vertex_struct 
 {

src/BulletMultiThreaded/CMakeLists.txt

@@ -73,9 +73,14 @@ SUBDIRS(GpuSoftBodySolvers)
 
 
 IF (BUILD_SHARED_LIBS)
+	IF (UNIX)
+		TARGET_LINK_LIBRARIES(BulletMultiThreaded BulletDynamics BulletCollision pthread)
+	ELSE()
 		TARGET_LINK_LIBRARIES(BulletMultiThreaded BulletDynamics BulletCollision)
+	ENDIF()
 ENDIF (BUILD_SHARED_LIBS)
 
+
 IF (INSTALL_LIBS)
 	IF (NOT INTERNAL_CREATE_DISTRIBUTABLE_MSVC_PROJECTFILES)
 		#INSTALL of other files requires CMake 2.6

src/BulletSoftBody/btSoftBody.h

@@ -183,12 +183,14 @@ public:
 		btScalar				m_kAST;			// Area/Angular stiffness coefficient [0,1]
 		btScalar				m_kVST;			// Volume stiffness coefficient [0,1]
 		int						m_flags;		// Flags
+		Material() : Element() {}
 	};
 
 	/* Feature		*/ 
 	struct	Feature : Element
 	{
 		Material*				m_material;		// Material
+		Feature() : Element() {}
 	};
 	/* Node			*/ 
 	struct	Node : Feature
@@ -202,6 +204,7 @@ public:
 		btScalar				m_area;			// Area
 		btDbvtNode*				m_leaf;			// Leaf data
 		int						m_battach:1;	// Attached
+		Node() : Feature() {}
 	};
 	/* Link			*/ 
 	struct	Link : Feature
@@ -213,6 +216,7 @@ public:
 		btScalar				m_c1;			// rl^2
 		btScalar				m_c2;			// |gradient|^2/c0
 		btVector3				m_c3;			// gradient
+		Link() : Feature() {}
 	};
 	/* Face			*/ 
 	struct	Face : Feature
@@ -221,6 +225,7 @@ public:
 		btVector3				m_normal;		// Normal
 		btScalar				m_ra;			// Rest area
 		btDbvtNode*				m_leaf;			// Leaf data
+		Face() : Feature() {}
 	};
 	/* Tetra		*/ 
 	struct	Tetra : Feature
@@ -231,6 +236,7 @@ public:
 		btVector3				m_c0[4];		// gradients
 		btScalar				m_c1;			// (4*kVST)/(im0+im1+im2+im3)
 		btScalar				m_c2;			// m_c1/sum(|g0..3|^2)
+		Tetra() : Feature() {}
 	};
 	/* RContact		*/ 
 	struct	RContact
@@ -272,6 +278,7 @@ public:
 		int						m_rank;			// Rank
 		Node*					m_nodes[4];		// Nodes
 		btScalar				m_coords[4];	// Coordinates
+		Note() : Element() {}
 	};	
 	/* Pose			*/ 
 	struct	Pose