added file_remove(path) as wrapper for unlink(path)

Added file_remove, the obvious wrapper around the OS-specific unlink.
This will be replaced by std::filesystem::remove once we have C++17.

Author: Daniel Kroening

src/goto-cc/hybrid_binary.cpp

@@ -11,6 +11,7 @@ Author: Michael Tautschnig, 2018
 
 #include "hybrid_binary.h"
 
+#include <util/file_util.h>
 #include <util/run.h>
 #include <util/suffix.h>
 
@@ -64,8 +65,8 @@ int hybrid_binary(
   }
 
   // delete the goto binary
-  int remove_result = remove(goto_binary_file.c_str());
-  if(remove_result != 0)
+  bool remove_result = file_remove(goto_binary_file);
+  if(!remove_result)
   {
     message.error() << "Remove failed: " << std::strerror(errno)
                     << messaget::eom;
@@ -124,8 +125,8 @@ int hybrid_binary(
   }
 
   // delete the goto binary
-  int remove_result = remove(goto_binary_file.c_str());
-  if(remove_result != 0)
+  bool remove_result = file_remove(goto_binary_file);
+  if(!remove_result)
   {
     message.error() << "Remove failed: " << std::strerror(errno)
                     << messaget::eom;

src/util/file_util.cpp

@@ -212,3 +212,12 @@ bool file_exists(const std::string &path)
   return access(path.c_str(), F_OK) == 0;
 #endif
 }
+
+bool file_remove(const std::string &path)
+{
+#ifdef _WIN32
+  return _wunlink(utf8_to_utf16_native_endian(path).c_str()) == 0;
+#else
+  return unlink(path.c_str()) == 0;
+#endif
+}

src/util/file_util.h

@@ -37,4 +37,9 @@ bool create_directory(const std::string &path);
 /// \return true iff the file exists
 bool file_exists(const std::string &path);
 
+// Delete a file with given path
+/// C++17 will allow us to use std::filesystem::remove
+/// \return true if the file was deleted, false if it did not exist
+bool file_remove(const std::string &path);
+
 #endif // CPROVER_UTIL_FILE_UTIL_H

src/util/tempfile.cpp

@@ -34,6 +34,7 @@ Author: Daniel Kroening
 #include <cstring>
 
 #include "exception_utils.h"
+#include "file_util.h"
 
 #if defined(__linux__) || \
     defined(__FreeBSD_kernel__) || \
@@ -143,5 +144,5 @@ std::string get_temporary_file(
 temporary_filet::~temporary_filet()
 {
   if(!name.empty())
-    std::remove(name.c_str());
+    file_remove(name);
 }