fdo#82430: gcc-wrappers: don't stop if REAL_CXX_FLAGS is empty

Hopefully should fix MSVC 2010 build...

Change-Id: I3dc71acfa58cdf65dfc6d731d9ebb77fd18f7fac

solenv/gcc-wrappers/g++.cxx

@@ -13,7 +13,7 @@ int main(int argc, char *argv[]) {
     vector<string> rawargs(argv + 1, argv + argc);
 
     string command=getexe("REAL_CXX");
-    string flags=getexe("REAL_CXX_FLAGS");
+    string flags=getexe("REAL_CXX_FLAGS", true);
 
     string args=flags.empty() ? string() : flags + " ";
     args += processccargs(rawargs);

solenv/gcc-wrappers/gcc.cxx

@@ -13,7 +13,7 @@ int main(int argc, char *argv[]) {
     vector<string> rawargs(argv + 1, argv + argc);
 
     string command=getexe("REAL_CC");
-    string flags=getexe("REAL_CC_FLAGS");
+    string flags=getexe("REAL_CC_FLAGS", true);
 
     string args=flags.empty() ? string() : flags + " ";
     args += processccargs(rawargs);

solenv/gcc-wrappers/wrapper.cxx

@@ -15,11 +15,14 @@
 
 #define BUFLEN 2048
 
-string getexe(string exename) {
+string getexe(string exename, bool maybeempty) {
     char* cmdbuf;
     size_t cmdlen;
     _dupenv_s(&cmdbuf,&cmdlen,exename.c_str());
     if(!cmdbuf) {
+        if (maybeempty) {
+            return string();
+        }
         cout << "Error " << exename << " not defined. Did you forget to source the environment?" << endl;
         exit(1);
     }

solenv/gcc-wrappers/wrapper.hxx

@@ -16,7 +16,7 @@
 
 using namespace std;
 
-string getexe(string exename);
+string getexe(string exename, bool maybeempty = false);
 
 void setupccenv();