A step towards getting libclang tests working on Windows

[yaron.keren]

Summary

One of the problems libclang tests has running under Windows is memory malloced in libclang.dll being but freed in the test executable, possibly by a different memory manager. This patch exposes a new export function, clang_free(), used to free this malloced memory with the same libclang.dll memory manager that malloced the memory.

[doug.gregor]

It would be fantastic to get these tests running on Windows (and make libclang more usable on Windows in general).

tools/clang/include/clang-c/BuildSystem.h

92

Let's make this more general: make it take a "void *", and be used for anything that the library allocates from the normal heap that must later be freed.

[rnk]

tools/clang/include/clang-c/BuildSystem.h

92

out_buffer_ptr doesn't make sense as a parameter name; it is not an out param. Probably 'buffer' or something is fine.

[yaron.keren]

Changed type, name of input argument of clang_free and its description.

[rnk]

lgtm

[yaron.keren]

Committed revision 241789.

Phabricator does not let me close this for some reason so I abandon it to close.

tools/clang/include/clang-c/BuildSystem.h

 clang_VirtualFileOverlay_setCaseSensitivity(CXVirtualFileOverlay,
                       int caseSensitive);
 
 /**
  * \brief Write out the \c CXVirtualFileOverlay object to a char buffer.
  *
  * \param options is reserved, always pass 0.
  * \param out_buffer_ptr pointer to receive the buffer pointer, which should be
- * disposed using \c free().
+ * disposed using \c clang_free().
  * \param out_buffer_size pointer to receive the buffer size.
  * \returns 0 for success, non-zero to indicate an error.
  */
 CINDEX_LINKAGE enum CXErrorCode
 clang_VirtualFileOverlay_writeToBuffer(CXVirtualFileOverlay, unsigned options,
                                        char **out_buffer_ptr,
                                        unsigned *out_buffer_size);
 
 /**
+ * \brief free memory allocated by libclang, such as the buffer returned by
+ * \c CXVirtualFileOverlay() or \c clang_ModuleMapDescriptor_writeToBuffer().
+ *
+ * \param buffer memory pointer to free.
+ */
+CINDEX_LINKAGE void clang_free(void *buffer);
+
+/**
  * \brief Dispose a \c CXVirtualFileOverlay object.
  */
 CINDEX_LINKAGE void clang_VirtualFileOverlay_dispose(CXVirtualFileOverlay);
 
 /**
  * \brief Object encapsulating information about a module.map file.
  */
 typedef struct CXModuleMapDescriptorImpl *CXModuleMapDescriptor;

 clang_ModuleMapDescriptor_setUmbrellaHeader(CXModuleMapDescriptor,
                                             const char *name);
 
 /**
  * \brief Write out the \c CXModuleMapDescriptor object to a char buffer.
  *
  * \param options is reserved, always pass 0.
  * \param out_buffer_ptr pointer to receive the buffer pointer, which should be
- * disposed using \c free().
+ * disposed using \c clang_free().
  * \param out_buffer_size pointer to receive the buffer size.
  * \returns 0 for success, non-zero to indicate an error.
  */
 CINDEX_LINKAGE enum CXErrorCode
 clang_ModuleMapDescriptor_writeToBuffer(CXModuleMapDescriptor, unsigned options,
                                        char **out_buffer_ptr,
                                        unsigned *out_buffer_size);
 

tools/clang/tools/libclang/BuildSystem.cpp

 
   StringRef Data = OS.str();
   *out_buffer_ptr = (char*)malloc(Data.size());
   *out_buffer_size = Data.size();
   memcpy(*out_buffer_ptr, Data.data(), Data.size());
   return CXError_Success;
 }
 
+void clang_free(void *buffer) {
+  free(buffer);
+}
+
 void clang_VirtualFileOverlay_dispose(CXVirtualFileOverlay VFO) {
   delete unwrap(VFO);
 }
 
 
 struct CXModuleMapDescriptorImpl {
   std::string ModuleName;
   std::string UmbrellaHeader;

tools/clang/tools/libclang/libclang.exports

 clang_equalRanges
 clang_equalTypes
 clang_executeOnThread
 clang_findIncludesInFile
 clang_findIncludesInFileWithBlock
 clang_findReferencesInFile
 clang_findReferencesInFileWithBlock
 clang_formatDiagnostic
+clang_free
 clang_getArgType
 clang_getArrayElementType
 clang_getArraySize
 clang_getBuildSessionTimestamp
 clang_getCString
 clang_getCXTUResourceUsage
 clang_getCXXAccessSpecifier
 clang_getCanonicalCursor

tools/clang/unittests/libclang/LibclangTest.cpp

 
   ~TestVFO() {
     if (Contents) {
       char *BufPtr;
       unsigned BufSize;
       clang_VirtualFileOverlay_writeToBuffer(VFO, 0, &BufPtr, &BufSize);
       std::string BufStr(BufPtr, BufSize);
       EXPECT_STREQ(Contents, BufStr.c_str());
-      free(BufPtr);
+      clang_free(BufPtr);
     }
     clang_VirtualFileOverlay_dispose(VFO);
   }
 };
 }
 
 TEST(libclang, VirtualFileOverlay_Basic) {
   const char *contents =

   clang_ModuleMapDescriptor_setFrameworkModuleName(MMD, "TestFrame");
   clang_ModuleMapDescriptor_setUmbrellaHeader(MMD, "TestFrame.h");
 
   char *BufPtr;
   unsigned BufSize;
   clang_ModuleMapDescriptor_writeToBuffer(MMD, 0, &BufPtr, &BufSize);
   std::string BufStr(BufPtr, BufSize);
   EXPECT_STREQ(Contents, BufStr.c_str());
-  free(BufPtr);
+  clang_free(BufPtr);
   clang_ModuleMapDescriptor_dispose(MMD);
 }
 
 class LibclangReparseTest : public ::testing::Test {
   std::set<std::string> Files;
 public:
   std::string TestDir;
   CXIndex Index;