[commit: ghc] ghc-8.2: Fix Windows GCC driver (018ac7f)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : ghc-8.2
Link       : http://ghc.haskell.org/trac/ghc/changeset/018ac7f4b2f7345e28d21fb1f99b44dbc79f6e85/ghc

>---------------------------------------------------------------

commit 018ac7f4b2f7345e28d21fb1f99b44dbc79f6e85
Author: Tamar Christina <tamar at zhox.com>
Date:   Tue Mar 14 13:31:36 2017 -0400

    Fix Windows GCC driver
    
    In Windows 10 Insiders build 15019+ which will probably be released
    mainstream somewhere this year Microsoft seems to have started being
    stricter with API calls.
    
    The call to `FreeConsole` just after `CreateProcess` is making Windows
    treat the process
    as an interactive process. In which case it tries to use the `Desktop
    session` but fails resulting
    in the cryptic error reported.
    
    I don't understand why the call to `FreeConsole` was there and it
    doesn't seem to be needed,
    so removed.
    
    This fixes #13411
    
    Test Plan: ./validate, alternative just do anything with ghc which
    requires compilation.
    
    Reviewers: austin, bgamari, simonmar
    
    Reviewed By: bgamari
    
    Subscribers: rwbarton, thomie, #ghc_windows_task_force
    
    Differential Revision: https://phabricator.haskell.org/D3319
    
    (cherry picked from commit 4b673e804fb8598dac02596f107544c7f2ea263b)


>---------------------------------------------------------------

018ac7f4b2f7345e28d21fb1f99b44dbc79f6e85
 driver/utils/cwrapper.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/driver/utils/cwrapper.c b/driver/utils/cwrapper.c
index 5105924..da6cec4 100644
--- a/driver/utils/cwrapper.c
+++ b/driver/utils/cwrapper.c
@@ -130,11 +130,9 @@ __attribute__((noreturn)) int run (char *exePath,
                        &pi) ) {
         die("Unable to start %s (error code: %lu)\n", exePath, GetLastError());
     }
-    /* Disable handling of console events in the parent by dropping its
-     * connection to the console. This has the (minor) downside of not being
-     * able to subsequently emit any error messages to the console.
-     */
-    FreeConsole();
+
+    /* Synchronize input and wait for target to be ready.  */
+    WaitForInputIdle(pi.hProcess, INFINITE);
 
     switch (WaitForSingleObject(pi.hProcess, INFINITE) ) {
     case WAIT_OBJECT_0: