Add a link-time flag to en/disable the RTS options

If RTS options are disabled then:
* The ghc_rts_opts C code variable is processed as normal
* The GHCRTS environment variable is ignored and, if it is defined, a
  warning is emitted
* The +RTS flag gives an error and terminates the program

3 files changed, 42 insertions, 2 deletions

diff --git a/rts/RtsFlags.c b/rts/RtsFlags.c
index b99995b16d..790bf426c2 100644
--- a/rts/RtsFlags.c
+++ b/rts/RtsFlags.c
@@ -10,6 +10,7 @@
 #include "PosixSource.h"
 #include "Rts.h"
 
+#include "RtsOpts.h"
 #include "RtsUtils.h"
 #include "Profiling.h"
 
@@ -413,7 +414,13 @@ setupRtsFlags(int *argc, char *argv[], int *rts_argc, char *rts_argv[])
 	char *ghc_rts = getenv("GHCRTS");
 
 	if (ghc_rts != NULL) {
-	    splitRtsFlags(ghc_rts, rts_argc, rts_argv);
+            if (rtsOptsEnabled) {
+                splitRtsFlags(ghc_rts, rts_argc, rts_argv);
+            }
+            else {
+                errorBelch("Warning: Ignoring GHCRTS variable");
+                // We don't actually exit, just warn
+            }
 	}
     }
 
@@ -432,7 +439,13 @@ setupRtsFlags(int *argc, char *argv[], int *rts_argc, char *rts_argv[])
 	    break;
 	}
 	else if (strequal("+RTS", argv[arg])) {
-	    mode = RTS;
+            if (rtsOptsEnabled) {
+                mode = RTS;
+            }
+            else {
+                errorBelch("RTS options are disabled");
+                stg_exit(EXIT_FAILURE);
+            }
 	}
 	else if (strequal("-RTS", argv[arg])) {
 	    mode = PGM;
diff --git a/rts/RtsOpts.h b/rts/RtsOpts.h
new file mode 100644
index 0000000000..381ee0e3c5
--- /dev/null
+++ b/rts/RtsOpts.h
@@ -0,0 +1,14 @@
+/* -----------------------------------------------------------------------------
+ *
+ * (c) The GHC Team, 2010
+ *
+ * En/disable RTS options
+ *
+ * ---------------------------------------------------------------------------*/
+
+#ifndef RTSOPTS_H
+#define RTSOPTS_H
+
+extern const rtsBool rtsOptsEnabled;
+
+#endif /* RTSOPTS_H */
diff --git a/rts/hooks/RtsOptsEnabled.c b/rts/hooks/RtsOptsEnabled.c
new file mode 100644
index 0000000000..d7d6cb595f
--- /dev/null
+++ b/rts/hooks/RtsOptsEnabled.c
@@ -0,0 +1,13 @@
+/* -----------------------------------------------------------------------------
+ *
+ * (c) The GHC Team 2010
+ *
+ * En/disable RTS options
+ *
+ * ---------------------------------------------------------------------------*/
+
+#include "Rts.h"
+#include "RtsOpts.h"
+
+const rtsBool rtsOptsEnabled = rtsFalse;
+