Implement nd_vsnprintf_s and nd_memset if possible

CMakeLists.txt

@@ -2,6 +2,8 @@ cmake_minimum_required(VERSION 3.12)
 
 option(BDD_INCLUDE_TOOL "Include the disasmtool executable" ON)
 option(BDD_INCLUDE_ISAGENERATOR "Include the isagenerator target (if a python interpreter is found)" ON)
+option(BDD_USE_EXTERNAL_VSNPRINTF "Expect nd_vsnprintf_s implementation from the integrator" OFF)
+option(BDD_USE_EXTERNAL_MEMSET "Expect nd_memset implementation from the integrator" OFF)
 
 set(BDD_VER_FILE ${CMAKE_CURRENT_LIST_DIR}/inc/version.h)
 
@@ -87,6 +89,9 @@ set(BDDISASM_INSTALL_INCLUDE_DIR
 
 # -- bddisasm --
 
+include(CheckFunctionExists)
+include(CheckSymbolExists)
+
 add_library(
     bddisasm STATIC
     bddisasm/crt.c
@@ -103,6 +108,26 @@ add_library(
     bddisasm/include/tabledefs.h
     "${BDDISASM_PUBLIC_HEADERS}")
 
+if (NOT BDD_USE_EXTERNAL_VSNPRINTF)
+    check_function_exists(vsnprintf HAS_VSNPRINTF)
+    if (HAS_VSNPRINTF)
+        target_compile_definitions(bddisasm PUBLIC -DBDDISASM_HAS_VSNPRINTF)
+    else ()
+        # See https://cmake.org/Bug/view.php?id=15659
+        check_symbol_exists(vsnprintf stdio.h HAS_VSNPRINTF_SYMBOL)
+        if (HAS_VSNPRINTF_SYMBOL)
+            target_compile_definitions(bddisasm PUBLIC -DBDDISASM_HAS_VSNPRINTF)
+        endif ()
+    endif ()
+endif ()
+
+if (NOT BDD_USE_EXTERNAL_MEMSET)
+    check_function_exists(memset HAS_MEMSET)
+    if (HAS_MEMSET)
+        target_compile_definitions(bddisasm PUBLIC -DBDDISASM_HAS_MEMSET)
+    endif ()
+endif ()
+
 set_target_properties(
     bddisasm
     PROPERTIES POSITION_INDEPENDENT_CODE ON

README.md

@@ -94,6 +94,10 @@ target_link_libraries(decoder-tool PRIVATE bddisasm::bddisasm)
 target_link_libraries(emulator-tool PRIVATE bddisasm::bdshemu)
 ```
 
+### nd_vsnprintf_s and nd_memset
+
+By default, if `vsnprintf` and `memset` functions are available, the `nd_vsnprintf_s` and `nd_memset` functions are implemented directly by `bddisasm`. To signal this, `BDDISASM_HAS_VSNPRINTF` and `BDDISASM_HAS_MEMSET` will be added to the public compile definitions of `bddisasm`. This can be disabled by configuring CMake with `BDD_USE_EXTERNAL_VSNPRINTF=ON` and `BDD_USE_EXTERNAL_MEMSET=ON`.
+
 #### Using as a sub-project
 
 The project can be consumed as a sub-project, either by adding it as a git submodule, or by using [CMake's FetchContent](https://cmake.org/cmake/help/latest/module/FetchContent.html):
@@ -127,6 +131,8 @@ To build the project run `make` in the root of the repository. This will build o
 
 To install the project run `make install`. Depending on the install location you may need to run the command as root.
 
+[nd_vsnprintf_s and nd_memset](#nd_vsnprintf_s-and-nd_memset) will not be defined by `bddisasm`, integrators must provide these functions.
+
 ### Using MSBuild on Windows
 
 In order to build the projects on Windows you need:
@@ -146,6 +152,8 @@ Building any of the projects is done directly from Visual Studio.
 
 The results will be in the bin directory in the root of the repository.
 
+[nd_vsnprintf_s and nd_memset](#nd_vsnprintf_s-and-nd_memset) will not be defined by `bddisasm`, integrators must provide these functions.
+
 ## Decoding instructions
 
 ### Decoding API

bddisasm/crt.c

@@ -4,7 +4,6 @@
  */
 #include "include/nd_crt.h"
 
-
 //
 // nd_strcat_s
 //
@@ -42,3 +41,22 @@ nd_strcat_s(
 
     return dst;
 }
+
+#if !defined(BDDISASM_NO_FORMAT) && defined(BDDISASM_HAS_VSNPRINTF)
+#include <stdio.h>
+
+int nd_vsnprintf_s(char *buffer, size_t sizeOfBuffer, size_t count, const char *format, va_list argptr)
+{
+    UNREFERENCED_PARAMETER(count);
+    return vsnprintf(buffer, sizeOfBuffer, format, argptr);
+}
+#endif // !defined(BDDISASM_NO_FORMAT) && defined(BDDISASM_HAS_VSNPRINTF)
+
+#if !defined(BDDISASM_NO_FORMAT) && defined(BDDISASM_HAS_MEMSET)
+#include <string.h>
+
+void *nd_memset(void *s, int c, size_t n)
+{
+    return memset(s, c, n);
+}
+#endif // !defined(BDDISASM_NO_FORMAT) && defined(BDDISASM_HAS_MEMSET)

disasmtool/disasmtool.c

@@ -62,6 +62,7 @@ char *gSpaces[16] =
 };
 
 
+#if !defined(BDDISASM_HAS_VSNPRINTF)
 //
 // nd_vsnprintf
 //
@@ -75,12 +76,14 @@ int nd_vsnprintf_s(
 {
     return _vsnprintf_s(buffer, sizeOfBuffer, count, format, argptr);
 }
+#endif // !defined(BDDISASM_HAS_VSNPRINTF)
 
+#if !defined(BDDISASM_HAS_MEMSET)
 void* nd_memset(void *s, int c, size_t n)
 {
     return memset(s, c, n);
 }
-
+#endif // !defined(BDDISASM_HAS_MEMSET)
 
 //
 // set_to_string

disasmtool_lix/disasmtool.cpp

@@ -77,19 +77,22 @@ struct options {
 
 extern "C"
 {
+#if !defined(BDDISASM_HAS_VSNPRINTF)
     int nd_vsnprintf_s(char *buffer, size_t sizeOfBuffer, [[maybe_unused]] size_t count, const char *format, va_list argptr)
     {
         return vsnprintf(buffer, sizeOfBuffer, format, argptr);
     }
+#endif // !defined(BDDISASM_HAS_VSNPRINTF)
 
+#if !defined(BDDISASM_HAS_MEMSET)
     void *
     nd_memset(void *s, int c, size_t n)
     {
         return memset(s, c, n);
     }
+#endif // !defined(BDDISASM_HAS_MEMSET)
 }
 
-
 static bool _hexstring_to_bytes(options &opts)
 {
     if (!opts.hex_file.empty()) {