diff --git a/include/clspv/Compiler.h b/include/clspv/Compiler.h
index 13594a02b..72c0cc930 100644
--- a/include/clspv/Compiler.h
+++ b/include/clspv/Compiler.h
@@ -21,9 +21,9 @@
 #include <string>
 #include <vector>
 #else
+#include <stddef.h>
 #include <stdint.h>
 #include <stdlib.h>
-#include <stddef.h>
 #endif
 
 #ifdef __cplusplus
@@ -67,14 +67,6 @@ typedef enum ClspvError {
 #define EXPORT __attribute__((visibility("default")))
 #endif
 
-#ifndef clspv_restrict
-
-/** Optional restrict qualifier for given C API with C++ implementation where
- * restrict is not the thing. */
-#define clspv_restrict
-
-#endif
-
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -90,27 +82,23 @@ extern "C" {
 // |options|            - String of options to pass to Clspv compiler.
 // |output_binary|      - Handle to compiler output/result.
 // |output_binary_size| - Size of compiler output/result (in bytes).
-// |output_log|         - Handle to compiler build log,
-// 			  will assume log is not needed if param is NULL.
-// 			  its value will be NULL when no build log is empty.
+// |output_log|         - Handle to compiler build log. `output_log` can be NULL
+//                        in which case no log will be generated.
 EXPORT ClspvError clspvCompileFromSourcesString(
-    const size_t program_count, const size_t *clspv_restrict program_sizes,
-    const char *const clspv_restrict *clspv_restrict programs,
-    const char *clspv_restrict options,
-    char *clspv_restrict *clspv_restrict output_binary,
-    size_t *clspv_restrict output_binary_size,
-    char *clspv_restrict *clspv_restrict output_log_opt);
+    const size_t program_count, const size_t *program_sizes,
+    const char **programs, const char *options, char **output_binary,
+    size_t *output_binary_size, char **output_log);
 
 // Frees the output memory from clspvCompileFromSourcesString
 //
 // |output_binary|      - Handle to spv
 // |output_log|         - Handle to compiler build log
-static inline void clspvFreeOutputBuildObjs(char *clspv_restrict output_binary,
-                                            char *clspv_restrict output_log) {
-  if (output_binary)
-    free(output_binary);
-  if (output_log)
-    free(output_log);
+static inline void clspvFreeOutputBuildObjs(char *output_binary,
+                                            char *output_log) {
+  free(output_binary);
+  output_binary = NULL;
+  free(output_log);
+  output_log = NULL;
 }
 
 #ifdef __cplusplus
diff --git a/lib/Compiler.cpp b/lib/Compiler.cpp
index 2a050b7a5..dd33762c6 100644
--- a/lib/Compiler.cpp
+++ b/lib/Compiler.cpp
@@ -245,7 +245,7 @@ clang::TargetInfo *PrepareTargetInfo(CompilerInstance &instance) {
           enabled) {
         instance.getPreprocessorOpts().addMacroDef(str);
       }
-      if (feat == clspv::FeatureMacro::__opencl_c_int64 && !enabled) {
+      if (feat == clspv::FeatureMacro::__opencl_c_int64 && !enabled){
         instance.getPreprocessorOpts().addMacroUndef(str);
       }
     }
@@ -712,7 +712,7 @@ int RunPassPipeline(llvm::Module &M, llvm::raw_svector_ostream *binaryStream) {
     pm.addPass(clspv::SimplifyPointerBitcastPass());
     pm.addPass(clspv::ReplacePointerBitcastPass());
     pm.addPass(llvm::createModuleToFunctionPassAdaptor(llvm::DCEPass()));
-
+  
     pm.addPass(clspv::UndoTranslateSamplerFoldPass());
 
     if (clspv::Option::ModuleConstantsInStorageBuffer()) {
@@ -1206,6 +1206,7 @@ int CompilePrograms(const std::vector<std::string> &programs,
         ProgramToModule(context, "source", program, output_log, &error));
     if (error != 0)
       return error;
+
   }
   assert(modules.size() > 0 && modules.back() != nullptr);
 
@@ -1351,7 +1352,7 @@ int CompileFromSourceString(const std::string &program,
 // C API
 ClspvError clspvCompileFromSourcesString(
     const size_t program_count, const size_t *program_sizes,
-    const char *const *programs, const char *options, char **output_binary,
+    const char **programs, const char *options, char **output_binary,
     size_t *output_binary_size, char **output_log) {
   if (programs == nullptr || program_count == 0 || output_binary == nullptr ||
       output_binary_size == nullptr) {
@@ -1377,14 +1378,18 @@ ClspvError clspvCompileFromSourcesString(
   err =
       clspv::CompileFromSourcesString(vPrograms, sOptions, &binary, &buildLog);
 
-  if (!buildLog.empty()) {
-    // Alloc and copy backing mem for build log
-    *output_log = static_cast<char *>(std::malloc(buildLog.size() + 1));
-    if (*output_log == NULL) {
-      return CLSPV_OUT_OF_HOST_MEM;
+  if (output_log != NULL) {
+    if (!buildLog.empty()) {
+      // Alloc and copy backing mem for build log
+      *output_log = static_cast<char *>(std::malloc(buildLog.size() + 1));
+      if (*output_log == NULL) {
+        return CLSPV_OUT_OF_HOST_MEM;
+      }
+      std::memcpy(static_cast<void *>(*output_log), buildLog.c_str(),
+                  buildLog.size() + 1);
+    } else {
+      *(output_log) = static_cast<char *>(NULL);
     }
-    std::memcpy(static_cast<void *>(*output_log), buildLog.c_str(),
-                buildLog.size() + 1);
   }
 
   if (err != 0) {
@@ -1393,6 +1398,12 @@ ClspvError clspvCompileFromSourcesString(
 
   // Alloc and copy backing mem for spv output
   size_t spv_bytes = binary.size() * sizeof(uint32_t);
+  if (spv_bytes == 0) {
+    /** Early return: when allocation is not needed. */
+    *output_binary = static_cast<char *>(NULL);
+    return CLSPV_SUCCESS;
+  }
+
   *output_binary = static_cast<char *>(std::malloc(spv_bytes));
   if (*output_binary == NULL) {
     return CLSPV_OUT_OF_HOST_MEM;