rust support - Native bstrings (#160)

Backport changes from pelikan to twitter/ccommon#186

Implement proper allocation/free for BString objects

* All allocation of BStrings should happen from libc malloc() that way
  we don't mistakenly free something allocated from rust's allocator.

* Drop should call libc's free() with the pointer, doing the correct
  thing.

* This philosophy allows us to pass bstring pointers back and forth and
  not have to track which heap they're allocated on

* Provide an implementation of a zero-cost reference object, much like
  String -> &str, we have BString -> &BStr.

.gitignore

@@ -42,3 +42,5 @@ tags
 # cscope
 cscope.*
 lcov
+
+CMAKE_BINARY_DIR

CMakeLists.txt

@@ -52,8 +52,8 @@ option(HAVE_ASSERT_PANIC "assert_panic disabled by default" OFF)
 option(HAVE_LOGGING "logging enabled by default" ON)
 option(HAVE_STATS "stats enabled by default" ON)
 option(HAVE_DEBUG_MM "debugging oriented memory management disabled by default" OFF)
-option(HAVE_RUST "build rust components" OFF)
 option(COVERAGE "code coverage" OFF)
+option(HAVE_RUST "rust bindings not built by default" OFF)
 
 if(BUILD_AND_INSTALL_CHECK)
     # (simms) What follows is a crime against build systems as we run the build/install
@@ -123,6 +123,10 @@ set(CFLAGS_LIST
 string(REPLACE "" "" CFLAGS ${CFLAGS_LIST})
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS}  ${CFLAGS}")
 
+if(CMAKE_COMPILER_IS_GNUCC)
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wl,--no-as-needed -ldl -pthread -fPIC")
+endif()
+
 if (COVERAGE)
     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -g -O0 -Wall -W -fprofile-arcs -ftest-coverage")
 endif(COVERAGE)
@@ -147,8 +151,10 @@ find_package(Threads)
 if(HAVE_RUST)
     enable_language(Rust)
     include(CMakeCargo)
+    add_subdirectory(rust)
 endif()
 
+
 # where to find include files
 include_directories(${include_directories}
     "${PROJECT_BINARY_DIR}"

include/cc_bstring.h

@@ -56,6 +56,9 @@ rstatus_i bstring_duplicate(struct bstring *dst, const struct bstring *src);
 rstatus_i bstring_copy(struct bstring *dst, const char *src, uint32_t srclen);
 int bstring_compare(const struct bstring *s1, const struct bstring *s2);
 
+struct bstring *bstring_alloc(uint32_t size);
+void bstring_free(struct bstring **bstring);
+
 /* TODO(yao): is this endian thing really useful? */
 /* efficient implementation of string comparion of short strings */
 #define str2cmp(m, c0, c1)                                                     \

rust/CMakeLists.txt

@@ -0,0 +1,5 @@
+file(WRITE CMAKE_BINARY_DIR "${CMAKE_BINARY_DIR}\n")
+
+if(HAVE_RUST)
+    add_subdirectory(ccommon_rs)
+endif()