Create virtual codec APIs so chrome/fuzzers can link separately

The one step to make an actual concrete class is conditionalized
in fpdfview and is unconditional in the fuzzer.

Also replace the clumsy C-style callbacks with a delegate
interface as long as we are making new interfaces.

Change-Id: I733a437483ce5e0c34211cfbbda05105336f55b5
Reviewed-on: https://pdfium-review.googlesource.com/2887
Commit-Queue: Tom Sepez <tsepez@chromium.org>
Commit-Queue: dsinclair <dsinclair@chromium.org>
Reviewed-by: dsinclair <dsinclair@chromium.org>

1 files changed, 9 insertions, 5 deletions

diff --git a/core/fxcodec/codec/ccodec_bmpmodule.cpp b/core/fxcodec/codec/ccodec_bmpmodule.cpp
index c6ebd2d939..9d64199501 100644
--- a/core/fxcodec/codec/ccodec_bmpmodule.cpp
+++ b/core/fxcodec/codec/ccodec_bmpmodule.cpp
@@ -14,7 +14,6 @@
 struct FXBMP_Context {
   bmp_decompress_struct_p bmp_ptr;
   void* parent_ptr;
-  void* child_ptr;
 
   void* (*m_AllocFunc)(unsigned int);
   void (*m_FreeFunc)(void*);
@@ -37,16 +36,22 @@ static void bmp_read_scanline(bmp_decompress_struct_p bmp_ptr,
                               uint8_t* row_buf) {
   FXBMP_Context* p = (FXBMP_Context*)bmp_ptr->context_ptr;
   CCodec_BmpModule* pModule = (CCodec_BmpModule*)p->parent_ptr;
-  pModule->ReadScanlineCallback(p->child_ptr, row_num, row_buf);
+  pModule->GetDelegate()->BmpReadScanline(row_num, row_buf);
 }
 static bool bmp_get_data_position(bmp_decompress_struct_p bmp_ptr,
                                   uint32_t rcd_pos) {
   FXBMP_Context* p = (FXBMP_Context*)bmp_ptr->context_ptr;
   CCodec_BmpModule* pModule = (CCodec_BmpModule*)p->parent_ptr;
-  return pModule->InputImagePositionBufCallback(p->child_ptr, rcd_pos);
+  return pModule->GetDelegate()->BmpInputImagePositionBuf(rcd_pos);
 }
 
-FXBMP_Context* CCodec_BmpModule::Start(void* pModule) {
+CCodec_BmpModule::CCodec_BmpModule() {
+  memset(m_szLastError, 0, sizeof(m_szLastError));
+}
+
+CCodec_BmpModule::~CCodec_BmpModule() {}
+
+FXBMP_Context* CCodec_BmpModule::Start() {
   FXBMP_Context* p = FX_Alloc(FXBMP_Context, 1);
   if (!p)
     return nullptr;
@@ -59,7 +64,6 @@ FXBMP_Context* CCodec_BmpModule::Start(void* pModule) {
   p->m_FreeFunc = bmp_free_func;
   p->bmp_ptr = nullptr;
   p->parent_ptr = (void*)this;
-  p->child_ptr = pModule;
   p->bmp_ptr = bmp_create_decompress();
   if (!p->bmp_ptr) {
     FX_Free(p);