Patch LIBCMT.LIB instead of linking separate goldp_libcmt static lib

Two issues with the previous approach prevented 100% reccmp match on the
heap CRT functions and operator new/delete:

1. Linking goldp_libcmt as a separate static lib alongside RTM's LIBCMT.LIB
   left the linker with two definitions of _calloc/_malloc/etc. With certain
   optimization combinations the linker pulled the LIBCMT.LIB version, not
   ours, dropping calloc/malloc/heap_alloc to <30% match.

2. Compiling the SP3 sources with RelWithDebInfo emitted S_GPROC32 PDB entries
   with the C source name (_nh_malloc, one underscore) which shadowed the
   PUBLIC entry's linker-decorated name (__nh_malloc, two underscores).
   LR's binary has no S_GPROC32 for CRT internals, so reccmp displayed the
   PUBLIC name for LR and the GPROC name for ours — name mismatch even when
   bytes were byte-identical (operator new dropped to 83%, delete to 75%).

Fix:

- Compile the SP3 overlay as an OBJECT library so we can grab the raw .obj
  files. Use lib /REMOVE to strip RTM's heap .obj members from a copy of
  LIBCMT.LIB, then lib /OUT to add ours. The patched LIBCMT.LIB contains
  exactly one definition of each heap symbol — ours — and the linker has
  no other choice.

- Suppress MSVC_DEBUG_INFORMATION_FORMAT on goldp_libcmt_objs so its PDB
  contains only PUBLIC symbol entries (matching LR's PDB granularity).

- Use /NODEFAULTLIB:LIBCMT plus an explicit reference to the patched lib
  so the linker pulls our patched version instead of the system default.

Result: _free, _calloc, _malloc, __nh_malloc, __heap_alloc, _realloc,
_expand, _msize, all __sbh_* functions, operator new, and operator delete
are now at 100% reccmp match. The four remaining sub-100% CRT functions
(__dosmaperr, __flsbuf, __NMSG_WRITE, __setmbcp) have layout-dependent
address-literal mismatches and are unrelated to this change.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: foxtacles

CMakeLists.txt

@@ -566,7 +566,9 @@ if(MSVC_FOR_DECOMP)
   enable_language(C)
   set(MSVC_CRT_SRC_PATH "" CACHE PATH "Path of MSVC6 CRT/SRC")
   if(MSVC_CRT_SRC_PATH)
-    add_library(goldp_libcmt STATIC
+    # Compile our SP3 heap overlay as an OBJECT library so we can patch the
+    # resulting .obj files into a copy of RTM's LIBCMT.LIB.
+    add_library(goldp_libcmt_objs OBJECT
       "${MSVC_CRT_SRC_PATH}/free.c"
       "${MSVC_CRT_SRC_PATH}/calloc.c"
       "${MSVC_CRT_SRC_PATH}/malloc.c"
@@ -580,13 +582,51 @@ if(MSVC_FOR_DECOMP)
       "${MSVC_CRT_SRC_PATH}/new.cpp"
       "${MSVC_CRT_SRC_PATH}/delete.cpp"
     )
-    target_include_directories(goldp_libcmt PRIVATE "${MSVC_CRT_SRC_PATH}")
-    target_compile_definitions(goldp_libcmt PRIVATE WIN32_LEAN_AND_MEAN NOSERVICE)
-    target_compile_definitions(goldp_libcmt PRIVATE _MBCS _MB_MAP_DIRECT)
-    target_compile_definitions(goldp_libcmt PRIVATE _CRTBLD)
-    target_compile_definitions(goldp_libcmt PRIVATE WINHEAP)
-    target_compile_options(goldp_libcmt PRIVATE /O1 /Zp8 /GFy /GB /Gi- /Zl)
-    set_property(TARGET goldp_libcmt PROPERTY MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>")
-    target_link_libraries(goldp PRIVATE goldp_libcmt)
+    target_include_directories(goldp_libcmt_objs PRIVATE "${MSVC_CRT_SRC_PATH}")
+    target_compile_definitions(goldp_libcmt_objs PRIVATE WIN32_LEAN_AND_MEAN NOSERVICE)
+    target_compile_definitions(goldp_libcmt_objs PRIVATE _MBCS _MB_MAP_DIRECT)
+    target_compile_definitions(goldp_libcmt_objs PRIVATE _CRTBLD)
+    target_compile_definitions(goldp_libcmt_objs PRIVATE WINHEAP)
+    target_compile_options(goldp_libcmt_objs PRIVATE /O1 /Zp8 /GFy /GB /Gi- /Zl)
+    set_property(TARGET goldp_libcmt_objs PROPERTY MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>")
+    # Suppress source-level debug info so the PDB doesn't emit S_GPROC32 entries with C-source
+    # names for CRT internals — this would shadow PUBLIC symbol names and break reccmp's symbol
+    # resolution for call targets that LR's PDB only knows by linker-decorated name.
+    set_property(TARGET goldp_libcmt_objs PROPERTY MSVC_DEBUG_INFORMATION_FORMAT "")
+
+    # Locate the RTM LIBCMT.LIB picked up from the LIB env var
+    find_library(RTM_LIBCMT_LIB NAMES LIBCMT REQUIRED NO_CACHE)
+    message(STATUS "RTM LIBCMT.LIB: ${RTM_LIBCMT_LIB}")
+
+    # Build a patched LIBCMT.LIB: copy RTM's lib, strip heap .obj members, add ours.
+    set(PATCHED_LIBCMT "${CMAKE_BINARY_DIR}/LIBCMT.LIB")
+    add_custom_command(
+      OUTPUT "${PATCHED_LIBCMT}"
+      DEPENDS goldp_libcmt_objs "${RTM_LIBCMT_LIB}"
+      COMMAND ${CMAKE_COMMAND} -E copy "${RTM_LIBCMT_LIB}" "${PATCHED_LIBCMT}"
+      COMMAND lib /nologo /REMOVE:build\\intel\\mt_obj\\free.obj     "${PATCHED_LIBCMT}"
+      COMMAND lib /nologo /REMOVE:build\\intel\\mt_obj\\calloc.obj   "${PATCHED_LIBCMT}"
+      COMMAND lib /nologo /REMOVE:build\\intel\\mt_obj\\malloc.obj   "${PATCHED_LIBCMT}"
+      COMMAND lib /nologo /REMOVE:build\\intel\\mt_obj\\realloc.obj  "${PATCHED_LIBCMT}"
+      COMMAND lib /nologo /REMOVE:build\\intel\\mt_obj\\expand.obj   "${PATCHED_LIBCMT}"
+      COMMAND lib /nologo /REMOVE:build\\intel\\mt_obj\\msize.obj    "${PATCHED_LIBCMT}"
+      COMMAND lib /nologo /REMOVE:build\\intel\\mt_obj\\sbheap.obj   "${PATCHED_LIBCMT}"
+      COMMAND lib /nologo /REMOVE:build\\intel\\mt_obj\\heapinit.obj "${PATCHED_LIBCMT}"
+      COMMAND lib /nologo /REMOVE:build\\intel\\mt_obj\\heapchk.obj  "${PATCHED_LIBCMT}"
+      COMMAND lib /nologo /REMOVE:build\\intel\\mt_obj\\heapmin.obj  "${PATCHED_LIBCMT}"
+      COMMAND lib /nologo /REMOVE:build\\intel\\mt_obj\\new.obj      "${PATCHED_LIBCMT}"
+      COMMAND lib /nologo /REMOVE:build\\intel\\mt_obj\\delete.obj   "${PATCHED_LIBCMT}"
+      COMMAND lib /nologo "${PATCHED_LIBCMT}" $<TARGET_OBJECTS:goldp_libcmt_objs>
+      COMMAND_EXPAND_LISTS
+      VERBATIM
+    )
+    add_custom_target(goldp_libcmt_target DEPENDS "${PATCHED_LIBCMT}")
+    add_dependencies(goldp goldp_libcmt_target)
+
+    # Tell the linker to use our patched LIBCMT instead of RTM's
+    target_link_options(goldp PRIVATE
+      "/NODEFAULTLIB:LIBCMT"
+      "${PATCHED_LIBCMT}"
+    )
   endif()
 endif()