Blackberry mkspecs: Refine compiler options

stack-protector-strong gives performance benefits over
stack-protector-all and is still checking more than -stack-protector,
so seems to be a good middle way and we want to use it when it is
there.

The -shared option for the compiler (not the linker) prevents a
RIM internal version of qcc from forcing -fPIE, and should not harm
in general when set.

In addition, add a method "compilerSupportsFlag" for Windows as is
present in the Unix configure script.

Original-patch-by: Greg Bentz

(cherry picked from commit 80f6d7862c0e2e41768620d5bd81b0e1d5e3f61f)

Change-Id: I5867fc03dde1ef6e2fbf3747bdb9aaf15518eb6a
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>

2 files changed, 38 insertions, 0 deletions

diff --git a/tools/configure/configureapp.cpp b/tools/configure/configureapp.cpp
index be28762..21131b6 100644
--- a/tools/configure/configureapp.cpp
+++ b/tools/configure/configureapp.cpp
@@ -1724,6 +1724,7 @@ void Configure::applySpecSpecifics()
         dictionary[ "FONT_CONFIG" ]         = "yes";
         dictionary[ "FONT_CONFIG" ]         = "yes";
         dictionary[ "FREETYPE" ]            = "system";
+        dictionary[ "STACK_PROTECTOR_STRONG" ] = "auto";
     }
 }
 
@@ -2401,6 +2402,11 @@ bool Configure::checkAvailability(const QString &part)
         }
     } else if (part == "DIRECTWRITE") {
         available = findFile("dwrite.h") && findFile("d2d1.h") && findFile("dwrite.lib");
+    } else if (part == "STACK_PROTECTOR_STRONG") {
+        QStringList compilerAndArgs;
+        compilerAndArgs += "qcc";
+        compilerAndArgs += "-fstack-protector-strong";
+        available = dictionary[ "XQMAKESPEC" ].contains("blackberry") && compilerSupportsFlag(compilerAndArgs);
     }
 
     return available;
@@ -2504,6 +2510,10 @@ void Configure::autoDetection()
     if (dictionary["INCREDIBUILD_XGE"] == "auto")
         dictionary["INCREDIBUILD_XGE"] = checkAvailability("INCREDIBUILD_XGE") ? "yes" : "no";
 
+    // Detection of -fstack-protector-strong support
+    if (dictionary["STACK_PROTECTOR_STRONG"] == "auto")
+        dictionary["STACK_PROTECTOR_STRONG"] = checkAvailability("STACK_PROTECTOR_STRONG") ? "yes" : "no";
+
     // Mark all unknown "auto" to the default value..
     for (QMap<QString,QString>::iterator i = dictionary.begin(); i != dictionary.end(); ++i) {
         if (i.value() == "auto")
@@ -2979,6 +2989,9 @@ void Configure::generateOutputVars()
 
     // We currently have no switch for QtSvg, so add it unconditionally.
     qtConfig += "svg";
+    if (dictionary["STACK_PROTECTOR_STRONG"] == "yes")
+        qtConfig += "stack-protector-strong";
+
     // We currently have no switch for QtConcurrent, so add it unconditionally.
     qtConfig += "concurrent";
 
@@ -4426,6 +4439,29 @@ void Configure::saveCmdLine()
 }
 #endif // !EVAL
 
+bool Configure::compilerSupportsFlag(const QStringList &compilerAndArgs)
+{
+    QFile file("conftest.cpp");
+    if (!file.open(QIODevice::WriteOnly | QIODevice::Text)) {
+        cout << "could not open temp file for writing" << endl;
+        return false;
+    }
+    if (!file.write("int main() { return 0; }\r\n")) {
+        cout << "could not write to temp file" << endl;
+        return false;
+    }
+    file.close();
+    // compilerAndArgs contains compiler because there is no way to query it
+    QStringList command = compilerAndArgs;
+    command += "-o";
+    command += "conftest-out.o";
+    command += "conftest.cpp";
+    int code = Environment::execute(command, QStringList(), QStringList());
+    file.remove();
+    QFile::remove("conftest-out.o");
+    return code == 0;
+}
+
 bool Configure::isDone()
 {
     return !dictionary["DONE"].isEmpty();
diff --git a/tools/configure/configureapp.h b/tools/configure/configureapp.h
index ee34b0d..d3f4ca1 100644
--- a/tools/configure/configureapp.h
+++ b/tools/configure/configureapp.h
@@ -161,6 +161,8 @@ private:
     void saveCmdLine();
 #endif
 
+    bool compilerSupportsFlag(const QStringList &compilerAndArgs);
+
     void desc(const char *description, int startingAt = 0, int wrapIndent = 0);
     void desc(const char *option, const char *description, bool skipIndent = false, char fillChar = '.');
     void desc(const char *mark_option, const char *mark, const char *option, const char *description, char fillChar = '.');