Make os::snprintf "nodiscard" and adjust final callsites

Author: dholmes-ora

src/hotspot/os/bsd/os_bsd.cpp

@@ -2156,7 +2156,7 @@ void os::set_native_thread_name(const char *name) {
   if (name != nullptr) {
     // Add a "Java: " prefix to the name
     char buf[MAXTHREADNAMESIZE];
-    snprintf(buf, sizeof(buf), "Java: %s", name);
+    (void) os::snprintf(buf, sizeof(buf), "Java: %s", name);
     pthread_setname_np(buf);
   }
 #endif

src/hotspot/os/linux/os_linux.cpp

@@ -4797,7 +4797,7 @@ uint os::processor_id() {
 void os::set_native_thread_name(const char *name) {
   if (Linux::_pthread_setname_np) {
     char buf [16]; // according to glibc manpage, 16 chars incl. '/0'
-    snprintf(buf, sizeof(buf), "%s", name);
+    (void) os::snprintf(buf, sizeof(buf), "%s", name);
     buf[sizeof(buf) - 1] = '\0';
     const int rc = Linux::_pthread_setname_np(pthread_self(), buf);
     // ERANGE should not happen; all other errors should just be ignored.
@@ -5395,7 +5395,7 @@ bool os::pd_dll_unload(void* libhandle, char* ebuf, int ebuflen) {
       error_report = "dlerror returned no error description";
     }
     if (ebuf != nullptr && ebuflen > 0) {
-      snprintf(ebuf, ebuflen - 1, "%s", error_report);
+      os::snprintf_checked(ebuf, ebuflen - 1, "%s", error_report);
     }
   }
 

src/hotspot/share/oops/generateOopMap.cpp

@@ -2153,7 +2153,7 @@ void GenerateOopMap::error_work(const char *format, va_list ap) {
   (void) os::vsnprintf(msg_buffer, sizeof(msg_buffer), format, ap);
   // Append method name
   char msg_buffer2[512];
-  os::snprintf(msg_buffer2, sizeof(msg_buffer2), "%s in method %s", msg_buffer, method()->name()->as_C_string());
+  (void) os::snprintf(msg_buffer2, sizeof(msg_buffer2), "%s in method %s", msg_buffer, method()->name()->as_C_string());
   Thread* current = Thread::current();
   if (current->can_call_java()) {
     _exception = Exceptions::new_exception(JavaThread::cast(current),

src/hotspot/share/runtime/os.hpp

@@ -800,7 +800,7 @@ class os: AllStatic {
   // an encoding error or any other kind of usage error).
   [[nodiscard]] static int vsnprintf(char* buf, size_t len, const char* fmt, va_list args) ATTRIBUTE_PRINTF(3, 0);
   // Delegates to vsnprintf.
-  static int snprintf(char* buf, size_t len, const char* fmt, ...) ATTRIBUTE_PRINTF(3, 4);
+  [[nodiscard]] static int snprintf(char* buf, size_t len, const char* fmt, ...) ATTRIBUTE_PRINTF(3, 4);
 
   // Delegates to snprintf and asserts that the output was not truncated.
   static void snprintf_checked(char* buf, size_t len, const char* fmt, ...) ATTRIBUTE_PRINTF(3, 4);

test/hotspot/gtest/gtestMain.cpp

@@ -256,7 +256,7 @@ static void runUnitTestsInner(int argc, char** argv) {
 #ifdef __APPLE__
   size_t len = strlen(java_home) + strlen("/lib/jli/libjli.dylib") + 1;
   char* path = new char[len];
-  snprintf(path, len, "%s/lib/jli/libjli.dylib", java_home);
+  os::snprintf_checked(path, len, "%s/lib/jli/libjli.dylib", java_home);
   dlopen(path, RTLD_NOW | RTLD_GLOBAL);
 #endif // __APPLE__
 

test/hotspot/gtest/runtime/test_os_windows.cpp

@@ -376,7 +376,7 @@ static void record_path(char const* name, char const* len_name, wchar_t* path) {
 
   if (convert_to_cstring(buf, JVM_MAXPATHLEN, path)) {
     ::testing::Test::RecordProperty(name, buf);
-    os::snprintf(buf, JVM_MAXPATHLEN, "%d", (int) wcslen(path));
+    os::snprintf_checked(buf, JVM_MAXPATHLEN, "%d", (int) wcslen(path));
     ::testing::Test::RecordProperty(len_name, buf);
   }
 }