[Support] Fix handle and memory leak for processes that are not waited for

Execute's Data parameter is now optional, so we won't allocate memory
for it on Windows and we'll close the process handle.

The Unix code should probably do something similar to avoid accumulation
of zombie children that haven't been waited on.

Tested on Linux and Windows.

llvm-svn: 183906

1 files changed, 18 insertions, 28 deletions

diff --git a/llvm/lib/Support/Windows/Program.inc b/llvm/lib/Support/Windows/Program.inc
index 0e8bbc80..90a5cdb 100644
--- a/llvm/lib/Support/Windows/Program.inc
+++ b/llvm/lib/Support/Windows/Program.inc
@@ -170,20 +170,13 @@ static unsigned int ArgLenWithQuotes(const char *Str) {
 
 }
 
-static bool Execute(void *&Data,
+static bool Execute(void **Data,
                     const Path& path,
                     const char** args,
                     const char** envp,
                     const Path** redirects,
                     unsigned memoryLimit,
                     std::string* ErrMsg) {
-  if (Data) {
-    Win32ProcessInfo* wpi = reinterpret_cast<Win32ProcessInfo*>(Data);
-    CloseHandle(wpi->hProcess);
-    delete wpi;
-    Data = 0;
-  }
-
   if (!path.canExecute()) {
     if (ErrMsg)
       *ErrMsg = "program not executable";
@@ -321,10 +314,12 @@ static bool Execute(void *&Data,
                path.str() + "'");
     return false;
   }
-  Win32ProcessInfo* wpi = new Win32ProcessInfo;
-  wpi->hProcess = pi.hProcess;
-  wpi->dwProcessId = pi.dwProcessId;
-  Data = wpi;
+  if (Data) {
+    Win32ProcessInfo* wpi = new Win32ProcessInfo;
+    wpi->hProcess = pi.hProcess;
+    wpi->dwProcessId = pi.dwProcessId;
+    *Data = wpi;
+  }
 
   // Make sure these get closed no matter what.
   ScopedCommonHandle hThread(pi.hThread);
@@ -354,21 +349,17 @@ static bool Execute(void *&Data,
     }
   }
 
+  // Don't leak the handle if the caller doesn't want it.
+  if (!Data)
+    CloseHandle(pi.hProcess);
+
   return true;
 }
 
-static int WaitAux(void *&Data, const Path &path,
-                   unsigned secondsToWait,
-                   std::string* ErrMsg) {
-  if (Data == 0) {
-    MakeErrMsg(ErrMsg, "Process not started!");
-    return -1;
-  }
-
-  Win32ProcessInfo* wpi = reinterpret_cast<Win32ProcessInfo*>(Data);
-  HANDLE hProcess = wpi->hProcess;
-
+static int WaitAux(Win32ProcessInfo *wpi, const Path &path,
+                   unsigned secondsToWait, std::string *ErrMsg) {
   // Wait for the process to terminate.
+  HANDLE hProcess = wpi->hProcess;
   DWORD millisecondsToWait = INFINITE;
   if (secondsToWait > 0)
     millisecondsToWait = secondsToWait * 1000;
@@ -407,12 +398,11 @@ static int WaitAux(void *&Data, const Path &path,
   return 1;
 }
 
-static int Wait(void *&Data, const Path &path,
-                unsigned secondsToWait,
-                std::string* ErrMsg) {
-  int Ret = WaitAux(Data, path, secondsToWait, ErrMsg);
+static int Wait(void *&Data, const Path &path, unsigned secondsToWait,
+                std::string *ErrMsg) {
+  Win32ProcessInfo *wpi = reinterpret_cast<Win32ProcessInfo *>(Data);
+  int Ret = WaitAux(wpi, path, secondsToWait, ErrMsg);
 
-  Win32ProcessInfo* wpi = reinterpret_cast<Win32ProcessInfo*>(Data);
   CloseHandle(wpi->hProcess);
   delete wpi;
   Data = 0;