Replace hooks by callbacks in RtsConfig (#8785)

Summary:
Hooks rely on static linking semantics, and are broken by -Bsymbolic
which we need when using dynamic linking.

Test Plan: Built it

Reviewers: austin, hvr, tibbe

Differential Revision: https://phabricator.haskell.org/D8

3 files changed, 33 insertions, 27 deletions

diff --git a/includes/Rts.h b/includes/Rts.h
index 77eeb31f3a..190200aa34 100644
--- a/includes/Rts.h
+++ b/includes/Rts.h
@@ -220,7 +220,6 @@ INLINE_HEADER Time fsecondsToTime (double t)
 
 /* Other RTS external APIs */
 #include "rts/Parallel.h"
-#include "rts/Hooks.h"
 #include "rts/Signals.h"
 #include "rts/BlockSignals.h"
 #include "rts/Hpc.h"
diff --git a/includes/RtsAPI.h b/includes/RtsAPI.h
index 0ba16714e9..853a3a5b30 100644
--- a/includes/RtsAPI.h
+++ b/includes/RtsAPI.h
@@ -60,9 +60,42 @@ typedef enum {
 // reason for using a struct is extensibility: we can add more
 // fields to this later without breaking existing client code.
 typedef struct {
+
+    // Whether to interpret +RTS options on the command line
     RtsOptsEnabledEnum rts_opts_enabled;
+
+    // additional RTS options
     const char *rts_opts;
+
+    // True if GHC was not passed -no-hs-main
     HsBool rts_hs_main;
+
+    // Called before processing command-line flags, so that default
+    // settings for RtsFlags can be provided.
+    void (* defaultsHook) (void);
+
+    // Called just before exiting
+    void (* onExitHook) (void);
+
+    // Called on a stack overflow, before exiting
+    void (* stackOverflowHook) (W_ stack_size);
+
+    // Called on heap overflow, before exiting
+    void (* outOfHeapHook) (W_ request_size, W_ heap_size);
+
+    // Called when malloc() fails, before exiting
+    void (* mallocFailHook) (W_ request_size /* in bytes */, char *msg);
+
+    // Called for every GC
+    void (* gcDoneHook) (unsigned int gen,
+                         W_ allocated_bytes, /* since last GC */
+                         W_ live_bytes,
+                         W_ copied_bytes,
+                         W_ max_copied_per_thread_bytes,
+                         W_ total_bytes,
+                         W_ slop_bytes,
+                         W_ sync_elapsed_ns, W_ elapsed_ns, W_ cpu_ns);
+
 } RtsConfig;
 
 // Clients should start with defaultRtsConfig and then customise it.
diff --git a/includes/rts/Hooks.h b/includes/rts/Hooks.h
deleted file mode 100644
index bf69673d70..0000000000
--- a/includes/rts/Hooks.h
+++ /dev/null
@@ -1,26 +0,0 @@
-/* -----------------------------------------------------------------------------
- *
- * (c) The GHC Team, 1998-2009
- *
- * User-overridable RTS hooks.
- *
- * Do not #include this file directly: #include "Rts.h" instead.
- *
- * To understand the structure of the RTS headers, see the wiki:
- *   http://ghc.haskell.org/trac/ghc/wiki/Commentary/SourceTree/Includes
- *
- * ---------------------------------------------------------------------------*/
-
-#ifndef RTS_HOOKS_H
-#define RTS_HOOKS_H
-
-extern char *ghc_rts_opts;
-
-extern void OnExitHook (void);
-extern int  NoRunnableThreadsHook (void);
-extern void StackOverflowHook (W_ stack_size);
-extern void OutOfHeapHook (W_ request_size, W_ heap_size);
-extern void MallocFailHook (W_ request_size /* in bytes */, char *msg);
-extern void defaultsHook (void);
-
-#endif /* RTS_HOOKS_H */