fix: make sure that postject-api.h compiles without warnings (#54)

* fix: make sure that postject-api.h compiles without warnings

Fixes the following error I came across while integrating Postject in
Node.js:
```console
../deps/postject/src/dist/postject-api.h:30:13: error: unused function 'postject_options_init' [-Werror,-Wunused-function]
static void postject_options_init(struct postject_options* options) {
            ^
1 error generated.
```

Refs: nodejs/node#45038
Signed-off-by: Darshan Sen <raisinten@gmail.com>

* fix: resolve another compiler warning

```console
In file included from /root/project/test/test.c:4:
/root/project/test/../dist/postject-api.h: In function 'postject_find_resource':
/root/project/test/../dist/postject-api.h:96:9: error: unused variable 'ptr' [-Werror=unused-variable]
   96 |   void* ptr = NULL;
      |         ^~~
cc1: all warnings being treated as errors
```

Refs: https://app.circleci.com/pipelines/github/postmanlabs/postject/180/workflows/d0eb47c0-5482-4c85-9c63-aa854ddb0221/jobs/1398?invite=true#step-110-678
Signed-off-by: Darshan Sen <raisinten@gmail.com>

* fix: use -Wall -WX on Windows

Signed-off-by: Darshan Sen <raisinten@gmail.com>

* chore: use -W4 instead of -Wall

-Wall produces too many warnings.

Refs: https://app.circleci.com/pipelines/github/postmanlabs/postject/185/workflows/48b0f126-8000-41d9-b39e-cb8b9e4bc9d6/jobs/1441?invite=true#step-107-693
Signed-off-by: Darshan Sen <raisinten@gmail.com>

* fix: another compilation warning on Windows

```console
C:\Users\circleci\project\test\../dist/postject-api.h(153,5): error C2220: the following warning is treated as an error [C:\Users\circleci\project\build\test\c_test.vcxproj]
C:\Users\circleci\project\test\../dist/postject-api.h(153,5): warning C4996: 'strcpy': This function or variable may be unsafe. Consider using strcpy_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details. [C:\Users\circleci\project\build\test\c_test.vcxproj]
C:\Users\circleci\project\test\test.c(13,5): warning C4996: 'strncpy': This function or variable may be unsafe. Consider using strncpy_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details. [C:\Users\circleci\project\build\test\c_test.vcxproj]
```

Refs: https://app.circleci.com/pipelines/github/postmanlabs/postject/186/workflows/f1389b9f-c958-4a24-9d6e-28af856ff776/jobs/1455?invite=true#step-107-694
Signed-off-by: Darshan Sen <raisinten@gmail.com>

* fix: compiler warning on Windows

```console
C:\Users\circleci\project\test\test.c(13,5): error C2220: the following warning is treated as an error [C:\Users\circleci\project\build\test\c_test.vcxproj]
C:\Users\circleci\project\test\test.c(13,5): warning C4996: 'strncpy': This function or variable may be unsafe. Consider using strncpy_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details. [C:\Users\circleci\project\build\test\c_test.vcxproj]
```

Refs: https://app.circleci.com/pipelines/github/postmanlabs/postject/187/workflows/8bcdcb96-646d-4008-93bf-294e92469b3d/jobs/1464?invite=true#step-107-694
Signed-off-by: Darshan Sen <raisinten@gmail.com>

* fix: use -EHsc for test.cpp

```console
C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30133\include\ostream(743,1): error C2220: the following warning is treated as an error [C:\Users\circleci\project\build\test\cpp_test.vcxproj]
C:\Users\circleci\project\test\test.cpp(13): message : see reference to function template instantiation 'std::basic_ostream<char,std::char_traits<char>> &std::operator <<<std::char_traits<char>>(std::basic_ostream<char,std::char_traits<char>> &,const char *)' being compiled [C:\Users\circleci\project\build\test\cpp_test.vcxproj]
C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30133\include\ostream(743,1): warning C4530: C++ exception handler used, but unwind semantics are not enabled. Specify /EHsc [C:\Users\circleci\project\build\test\cpp_test.vcxproj]
```

Refs: https://app.circleci.com/pipelines/github/postmanlabs/postject/188/workflows/9107adc5-61a3-41ad-bd60-dd3eb0996765/jobs/1470?invite=true#step-107-696
Signed-off-by: Darshan Sen <raisinten@gmail.com>

* fix: use / instead of - for Windows compiler options

Signed-off-by: Darshan Sen <raisinten@gmail.com>

* chore: use target_compile_options instead of set

Signed-off-by: Darshan Sen <raisinten@gmail.com>

Signed-off-by: Darshan Sen <raisinten@gmail.com>

postject-api.h

@@ -27,7 +27,7 @@ struct postject_options {
   const char* pe_resource_name;
 };
 
-static void postject_options_init(struct postject_options* options) {
+inline void postject_options_init(struct postject_options* options) {
   options->elf_section_name = NULL;
   options->macho_framework_name = NULL;
   options->macho_section_name = NULL;
@@ -93,7 +93,6 @@ static const void* postject_find_resource(
 
   return ptr;
 #elif defined(__linux__)
-  void* ptr = NULL;
 
   if (options != NULL && options->elf_section_name != NULL) {
     name = options->elf_section_name;
@@ -151,7 +150,7 @@ static const void* postject_find_resource(
     if (resource_name == NULL) {
       return NULL;
     }
-    strcpy(resource_name, name);
+    strcpy_s(resource_name, strlen(name) + 1, name);
     CharUpperA(resource_name);  // Uppercases inplace
   }
 

test/CMakeLists.txt

@@ -5,3 +5,11 @@ project(postject-tests)
 
 add_executable(c_test test.c)
 add_executable(cpp_test test.cpp)
+
+if(WIN32)
+  target_compile_options(c_test PRIVATE /W4 /WX)
+  target_compile_options(cpp_test PRIVATE /W4 /WX /EHsc)
+else()
+  target_compile_options(c_test PRIVATE -Wall -Werror)
+  target_compile_options(cpp_test PRIVATE -Wall -Werror)
+endif()

test/test.c

@@ -10,7 +10,11 @@ int main() {
   if (ptr && size > 0) {
     char* str = (char*)malloc(size + 1);
     memset(str, 0, size + 1);
+#if defined(_WIN32)
+    strncpy_s(str, size + 1, ptr, size);
+#else
     strncpy(str, ptr, size);
+#endif
     printf("%s\n", str);
   } else {
     printf("Hello world\n");