Fix FileSpec::GetPath to return null-terminated strings

Summary:
Before this fix the FileSpec::GetPath() returned string which might be without '\0' at the end.
It could have happened if the size of buffer for path was less than actual path.

Test case:
```
FileSpec test("/path/to/file", false);
char buf[]="!!!!!!";
test.GetPath(buf, 3);
```

Before fix:
```
   233          FileSpec test("/path/to/file", false);
   234          char buf[]="!!!!!!";
   235          test.GetPath(buf, 3);
   236
-> 237          if (core_file)
   238          {
   239              if (!core_file.Exists())
   240              {
(lldb) print buf
(char [7]) $0 = "/pa!!!"
```

After fix:
```
   233          FileSpec test("/path/to/file", false);
   234          char buf[]="!!!!!!";
   235          test.GetPath(buf, 3);
   236
-> 237          if (core_file)
   238          {
   239              if (!core_file.Exists())
   240              {
(lldb) print buf
(char [7]) $0 = "/p"
```

Reviewers: zturner, abidh, clayborg

Reviewed By: abidh, clayborg

Subscribers: tberghammer, vharron, lldb-commits, clayborg, zturner, abidh

Differential Revision: http://reviews.llvm.org/D7553

llvm-svn: 230787

4 files changed, 39 insertions, 44 deletions

diff --git a/lldb/source/Host/common/FileSpec.cpp b/lldb/source/Host/common/FileSpec.cpp
index 553764e560d..a968dd93b61 100644
--- a/lldb/source/Host/common/FileSpec.cpp
+++ b/lldb/source/Host/common/FileSpec.cpp
@@ -793,10 +793,8 @@ FileSpec::GetPath(char *path, size_t path_max_len, bool denormalize) const
         return 0;
 
     std::string result = GetPath(denormalize);
-
-    size_t result_length = std::min(path_max_len-1, result.length());
-    ::strncpy(path, result.c_str(), result_length + 1);
-    return result_length;
+    ::snprintf(path, path_max_len, "%s", result.c_str());
+    return std::min(path_max_len-1, result.length());
 }
 
 std::string
diff --git a/lldb/source/Host/common/SocketAddress.cpp b/lldb/source/Host/common/SocketAddress.cpp
index b6a7a08bb3a..3ab6cfeec4a 100644
--- a/lldb/source/Host/common/SocketAddress.cpp
+++ b/lldb/source/Host/common/SocketAddress.cpp
@@ -48,8 +48,7 @@ const char* inet_ntop(int af, const void * src,
                 const char* formatted = inet_ntoa(*static_cast<const in_addr*>(src));
                 if (formatted && strlen(formatted) < size)
                 {
-                    strncpy(dst, formatted, size);
-                    return dst;
+                    return ::strcpy(dst, formatted);
                 }
             }
             return nullptr;
@@ -64,8 +63,7 @@ const char* inet_ntop(int af, const void * src,
                                           );
                 if (full_size < static_cast<int>(size))
                 {
-                    strncpy(dst,tmp,size);
-                    return dst;
+                    return ::strcpy(dst, tmp);
                 }
                 return nullptr;
             }
diff --git a/lldb/source/Host/macosx/HostInfoMacOSX.mm b/lldb/source/Host/macosx/HostInfoMacOSX.mm
index a22674e63aa..edaff083373 100644
--- a/lldb/source/Host/macosx/HostInfoMacOSX.mm
+++ b/lldb/source/Host/macosx/HostInfoMacOSX.mm
@@ -134,22 +134,23 @@ HostInfoMacOSX::ComputeSupportExeDirectory(FileSpec &file_spec)
     FileSpec lldb_file_spec;
     if (!GetLLDBPath(lldb::ePathTypeLLDBShlibDir, lldb_file_spec))
         return false;
-    char raw_path[PATH_MAX];
-    lldb_file_spec.GetPath(raw_path, sizeof(raw_path));
 
-    char *framework_pos = ::strstr(raw_path, "LLDB.framework");
-    if (framework_pos)
+    std::string raw_path = lldb_file_spec.GetPath();
+
+    size_t framework_pos = raw_path.find("LLDB.framework");
+    if (framework_pos != std::string::npos)
     {
         framework_pos += strlen("LLDB.framework");
 #if defined(__arm__) || defined(__arm64__) || defined(__aarch64__)
         // Shallow bundle
-        *framework_pos = '\0';
+        raw_path.resize(framework_pos);
 #else
         // Normal bundle
-        ::strncpy(framework_pos, "/Resources", PATH_MAX - (framework_pos - raw_path));
+        raw_path.resize(framework_pos);
+        raw_path.append("/Resources");
 #endif
     }
-    file_spec.GetDirectory().SetCString(raw_path);
+    file_spec.GetDirectory().SetString(llvm::StringRef(raw_path.c_str(), raw_path.size()));
     return (bool)file_spec.GetDirectory();
 }
 
@@ -160,16 +161,16 @@ HostInfoMacOSX::ComputeHeaderDirectory(FileSpec &file_spec)
     if (!HostInfo::GetLLDBPath(lldb::ePathTypeLLDBShlibDir, lldb_file_spec))
         return false;
 
-    char raw_path[PATH_MAX];
-    lldb_file_spec.GetPath(raw_path, sizeof(raw_path));
+    std::string raw_path = lldb_file_spec.GetPath();
 
-    char *framework_pos = ::strstr(raw_path, "LLDB.framework");
-    if (framework_pos)
+    size_t framework_pos = raw_path.find("LLDB.framework");
+    if (framework_pos != std::string::npos)
     {
         framework_pos += strlen("LLDB.framework");
-        ::strncpy(framework_pos, "/Headers", PATH_MAX - (framework_pos - raw_path));
+        raw_path.resize(framework_pos);
+        raw_path.append("/Headers");
     }
-    file_spec.GetDirectory().SetCString(raw_path);
+    file_spec.GetDirectory().SetString(llvm::StringRef(raw_path.c_str(), raw_path.size()));
     return true;
 }
 
@@ -181,14 +182,14 @@ HostInfoMacOSX::ComputePythonDirectory(FileSpec &file_spec)
     if (!GetLLDBPath(lldb::ePathTypeLLDBShlibDir, lldb_file_spec))
         return false;
 
-    char raw_path[PATH_MAX];
-    lldb_file_spec.GetPath(raw_path, sizeof(raw_path));
+    std::string raw_path = lldb_file_spec.GetPath();
 
-    char *framework_pos = ::strstr(raw_path, "LLDB.framework");
-    if (framework_pos)
+    size_t framework_pos = raw_path.find("LLDB.framework");
+    if (framework_pos != std::string::npos)
     {
         framework_pos += strlen("LLDB.framework");
-        ::strncpy(framework_pos, "/Resources/Python", PATH_MAX - (framework_pos - raw_path));
+        raw_path.resize(framework_pos);
+        raw_path.append("/Resources/Python");
     }
     else
     {
@@ -198,9 +199,9 @@ HostInfoMacOSX::ComputePythonDirectory(FileSpec &file_spec)
         os.flush();
 
         // We may get our string truncated. Should we protect this with an assert?
-        ::strncat(raw_path, python_version_dir.c_str(), sizeof(raw_path) - strlen(raw_path) - 1);
+        raw_path.append(python_version_dir.c_str());
     }
-    file_spec.GetDirectory().SetCString(raw_path);
+    file_spec.GetDirectory().SetString(llvm::StringRef(raw_path.c_str(), raw_path.size()));
     return true;
 #else
     return false;
@@ -214,16 +215,16 @@ HostInfoMacOSX::ComputeClangDirectory(FileSpec &file_spec)
     if (!GetLLDBPath (lldb::ePathTypeLLDBShlibDir, lldb_file_spec))
         return false;
     
-    char raw_path[PATH_MAX];
-    lldb_file_spec.GetPath (raw_path, sizeof (raw_path));
+    std::string raw_path = lldb_file_spec.GetPath();
     
-    char *framework_pos = ::strstr (raw_path, "LLDB.framework");
-    if (framework_pos)
+    size_t framework_pos = raw_path.find("LLDB.framework");
+    if (framework_pos != std::string::npos)
     {
         framework_pos += strlen("LLDB.framework");
-        ::strncpy (framework_pos, "/Resources/Clang", PATH_MAX - (framework_pos - raw_path));
+        raw_path.resize(framework_pos);
+        raw_path.append("/Resources/Clang");
     }
-    file_spec.SetFile (raw_path, true);
+    file_spec.SetFile (raw_path.c_str(), true);
     return true;
 }
 
@@ -233,16 +234,17 @@ HostInfoMacOSX::ComputeSystemPluginsDirectory(FileSpec &file_spec)
     FileSpec lldb_file_spec;
     if (!GetLLDBPath(lldb::ePathTypeLLDBShlibDir, lldb_file_spec))
         return false;
-    char raw_path[PATH_MAX];
-    lldb_file_spec.GetPath(raw_path, sizeof(raw_path));
 
-    char *framework_pos = ::strstr(raw_path, "LLDB.framework");
-    if (!framework_pos)
+    std::string raw_path = lldb_file_spec.GetPath();
+
+    size_t framework_pos = raw_path.find("LLDB.framework");
+    if (framework_pos == std::string::npos)
         return false;
 
     framework_pos += strlen("LLDB.framework");
-    ::strncpy(framework_pos, "/Resources/PlugIns", PATH_MAX - (framework_pos - raw_path));
-    file_spec.GetDirectory().SetCString(raw_path);
+    raw_path.resize(framework_pos);
+    raw_path.append("/Resources/PlugIns");
+    file_spec.GetDirectory().SetString(llvm::StringRef(raw_path.c_str(), raw_path.size()));
     return true;
 }
 
diff --git a/lldb/source/Host/posix/HostInfoPosix.cpp b/lldb/source/Host/posix/HostInfoPosix.cpp
index 018d423ee9d..debff52d8c1 100644
--- a/lldb/source/Host/posix/HostInfoPosix.cpp
+++ b/lldb/source/Host/posix/HostInfoPosix.cpp
@@ -153,11 +153,8 @@ HostInfoPosix::ComputeSupportExeDirectory(FileSpec &file_spec)
     char *lib_pos = ::strstr(raw_path, "/lib");
     if (lib_pos != nullptr)
     {
-        // First terminate the raw path at the start of lib.
-        *lib_pos = '\0';
-
         // Now write in bin in place of lib.
-        ::strncpy(lib_pos, "/bin", PATH_MAX - (lib_pos - raw_path));
+        ::snprintf(lib_pos, PATH_MAX - (lib_pos - raw_path), "/bin");
 
         if (log)
             log->Printf("Host::%s() derived the bin path as: %s", __FUNCTION__, raw_path);