Expose low-level memory (libsass heap) allocator

Author: mgreter

docs/api-context.md

@@ -88,7 +88,7 @@ char* source_map_file;
 char* source_map_root;
 ```
 ```C
-// Custom functions that can be called from sccs code
+// Custom functions that can be called from Sass code
 Sass_C_Function_List c_functions;
 ```
 ```C
@@ -168,12 +168,12 @@ struct Sass_Compiler* sass_make_data_compiler (struct Sass_Data_Context* data_ct
 
 // Execute the different compilation steps individually
 // Usefull if you only want to query the included files
-int sass_compiler_parse(struct Sass_Compiler* compiler);
-int sass_compiler_execute(struct Sass_Compiler* compiler);
+int sass_compiler_parse (struct Sass_Compiler* compiler);
+int sass_compiler_execute (struct Sass_Compiler* compiler);
 
 // Release all memory allocated with the compiler
 // This does _not_ include any contexts or options
-void sass_delete_compiler(struct Sass_Compiler* compiler);
+void sass_delete_compiler (struct Sass_Compiler* compiler);
 
 // Release all memory allocated and also ourself
 void sass_delete_file_context (struct Sass_File_Context* ctx);

include/sass/base.h

@@ -62,6 +62,13 @@ enum Sass_Output_Style {
   SASS_STYLE_TO_SASS
 };
 
+// to allocate buffer to be filled
+void* sass_alloc_memory(size_t size);
+// to allocate a buffer from existing string
+char* sass_copy_c_string(const char* str);
+// to free overtaken memory when done
+void sass_free_memory(void* ptr);
+
 // Some convenient string helper function
 ADDAPI char* ADDCALL sass_string_quote (const char* str, const char quote_mark);
 ADDAPI char* ADDCALL sass_string_unquote (const char* str);

src/sass.cpp

@@ -11,6 +11,30 @@
 extern "C" {
   using namespace Sass;
 
+  // Allocate libsass heap memory
+  // Don't forget string termination!
+  void* ADDCALL sass_alloc_memory(size_t size)
+  {
+    void* ptr = malloc(size);
+    if (ptr == NULL)
+      out_of_memory();
+    return ptr;
+  }
+
+  char* ADDCALL sass_copy_c_string(const char* str)
+  {
+    size_t len = strlen(str) + 1;
+    char* cpy = (char*) sass_alloc_memory(len);
+    std::memcpy(cpy, str, len);
+    return cpy;
+  }
+
+  // Deallocate libsass heap memory
+  void ADDCALL sass_free_memory(void* ptr)
+  {
+    if (ptr) free (ptr);
+  }
+
   // caller must free the returned memory
   char* ADDCALL sass_string_quote (const char *str, const char quote_mark)
   {

src/util.cpp

@@ -12,11 +12,6 @@
 
 namespace Sass {
 
-  #define out_of_memory() do {            \
-      std::cerr << "Out of memory.\n";    \
-      exit(EXIT_FAILURE);                 \
-    } while (0)
-
   double round(double val, size_t precision)
   {
     // https://github.com/sass/sass/commit/4e3e1d5684cc29073a507578fc977434ff488c93

src/util.hpp

@@ -12,6 +12,11 @@
 
 namespace Sass {
 
+  #define out_of_memory() do {            \
+      std::cerr << "Out of memory.\n";    \
+      exit(EXIT_FAILURE);                 \
+    } while (0)
+
   double round(double val, size_t precision = 0);
   char* sass_strdup(const char* str);
   double sass_atof(const char* str);