Adds MethodCompiler::insertTrace() for JIT code trace injection

Issue: #17 Issue: #92
0x7CFE · Jul 17, 2016 · c9af814 · c9af814
1 parent 5263fe0
commit c9af814
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Showing 3 changed files with 27 additions and 0 deletions.
diff --git a/include/Core.ll b/include/Core.ll
@@ -350,6 +350,8 @@ declare %TObject* @callPrimitive(i8 %opcode, %TObjectArray* %args, i1* %primitiv
     %TContext*      ; targetContext
 }
 
+declare i32 @printf(i8* noalias nocapture, ...)
+
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;;;;;;;;;;;;;;;; exception API ;;;;;;;;;;;;;;;;;;;;;;;
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

diff --git a/include/jit.h b/include/jit.h
@@ -398,6 +398,9 @@ class MethodCompiler {
 
     TStackObject allocateStackObject(llvm::IRBuilder<>& builder, uint32_t baseSize, uint32_t fieldsCount);
 
+    void insertTrace(TJITContext& jit, const char* message);
+    void insertTrace(TJITContext& jit, const char* message, llvm::Value* value);
+
     MethodCompiler(
         JITRuntime& runtime,
         llvm::Module* JITModule,

diff --git a/src/MethodCompiler.cpp b/src/MethodCompiler.cpp
@@ -56,6 +56,28 @@ std::string to_string(const T& x) {
     return ss.str();
 }
 
+static Constant* createStringConstant(Module& M, char const* str, Twine const& name) {
+    LLVMContext& ctx = getGlobalContext();
+    Constant* strConstant = ConstantDataArray::getString(ctx, str);
+    GlobalVariable* GVStr =
+    new GlobalVariable(M, strConstant->getType(), true,
+                       GlobalValue::InternalLinkage, strConstant, name);
+    Constant* zero = Constant::getNullValue(IntegerType::getInt32Ty(ctx));
+    Constant* indices[] = {zero, zero};
+    Constant* strVal = ConstantExpr::getGetElementPtr(GVStr, indices, true);
+    return strVal;
+}
+
+void MethodCompiler::insertTrace(MethodCompiler::TJITContext& jit, const char* message) {
+    Value* const print = m_JITModule->getFunction("printf");
+    jit.builder->CreateCall(print, createStringConstant(*m_JITModule, message, "str."));
+}
+
+void MethodCompiler::insertTrace(MethodCompiler::TJITContext& jit, const char* message, llvm::Value* value) {
+    Value* const print = m_JITModule->getFunction("printf");
+    jit.builder->CreateCall2(print, createStringConstant(*m_JITModule, message, "str."), value);
+}
+
 MethodCompiler::MethodCompiler(
     JITRuntime& runtime,
     llvm::Module* JITModule,