Moved include asmjit to CompiledExpression.cpp

Currently, this allows avoiding an exploding number of warnings
originating from amsjit header files to be shown when compiling.

In general, it better decouples asmjit from lepton. Later on
we might allow one to switch asmjit on/off with an environment variable
if desired.

src/lepton/CompiledExpression.cpp

@@ -64,6 +64,9 @@
 #include "CompiledExpression.h"
 #include "Operation.h"
 #include "ParsedExpression.h"
+#ifdef __PLUMED_HAS_ASMJIT
+    #include "asmjit/asmjit.h"
+#endif
 #include <utility>
 
 namespace PLMD {
@@ -73,6 +76,19 @@ using namespace std;
     using namespace asmjit;
 #endif
 
+AsmJitRuntimePtr::AsmJitRuntimePtr()
+#ifdef __PLUMED_HAS_ASMJIT
+  : ptr(new asmjit::JitRuntime)
+#endif
+{}
+
+AsmJitRuntimePtr::~AsmJitRuntimePtr()
+{
+#ifdef __PLUMED_HAS_ASMJIT
+  delete static_cast<asmjit::JitRuntime*>(ptr);
+#endif
+}
+
 CompiledExpression::CompiledExpression() : jitCode(NULL) {
 }
 
@@ -225,8 +241,11 @@ static double evaluateOperation(Operation* op, double* args) {
     return op->evaluate(args, *dummyVariables);
 }
 
+static void generateSingleArgCall(X86Compiler& c, X86Xmm& dest, X86Xmm& arg, double (*function)(double));
+
 void CompiledExpression::generateJitCode() {
     CodeHolder code;
+    auto & runtime(*static_cast<asmjit::JitRuntime*>(runtimeptr.get()));
     code.init(runtime.getCodeInfo());
     X86Assembler a(&code);
     X86Compiler c(&code);
@@ -431,7 +450,7 @@ void CompiledExpression::generateJitCode() {
     jitCode = (void*) func0;
 }
 
-void CompiledExpression::generateSingleArgCall(X86Compiler& c, X86Xmm& dest, X86Xmm& arg, double (*function)(double)) {
+void generateSingleArgCall(X86Compiler& c, X86Xmm& dest, X86Xmm& arg, double (*function)(double)) {
     X86Gp fn = c.newIntPtr();
     c.mov(fn, imm_ptr((void*) function));
     CCFuncCall* call = c.call(fn, FuncSignature1<double, double>(CallConv::kIdHost));

src/lepton/CompiledExpression.h

@@ -71,13 +71,31 @@
 #include <string>
 #include <utility>
 #include <vector>
-#ifdef __PLUMED_HAS_ASMJIT
-    #include "asmjit/asmjit.h"
-#endif
 
 namespace PLMD {
 namespace lepton {
 
+// Utility class.
+// Implement an unique pointer to asmjit::JitRuntime.
+// Needed to decouple asmjit header file from this one.
+class AsmJitRuntimePtr {
+/// if ASMJIT is not defined, just set the pointer to null
+  void* ptr=nullptr;
+public:
+/// constructor
+  AsmJitRuntimePtr();
+/// destructor
+  ~AsmJitRuntimePtr();
+/// deleted copy constructor
+  AsmJitRuntimePtr(const AsmJitRuntimePtr&) = delete;
+/// deleted assignment
+  AsmJitRuntimePtr & operator=(const AsmJitRuntimePtr&) = delete;
+/// get the pointer
+  void* get() {
+    return ptr;
+  }
+};
+
 class Operation;
 class ParsedExpression;
 
@@ -133,12 +151,9 @@ private:
     mutable std::vector<double> argValues;
     std::map<std::string, double> dummyVariables;
     void* jitCode;
-#ifdef __PLUMED_HAS_ASMJIT
     void generateJitCode();
-    void generateSingleArgCall(asmjit::X86Compiler& c, asmjit::X86Xmm& dest, asmjit::X86Xmm& arg, double (*function)(double));
     std::vector<double> constants;
-    asmjit::JitRuntime runtime;
-#endif
+    AsmJitRuntimePtr runtimeptr;
 };
 
 } // namespace lepton