Re: [GHC] #11777: RTS source code issues

18 May 2016


      #11777: RTS source code issues
-------------------------------------+-------------------------------------
        Reporter:  simonpj           |                Owner:
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Runtime System    |              Version:  7.10.3
      Resolution:                    |             Keywords:  newcomer
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------
Changes (by thomie):

 * keywords:   => newcomer
 * cc: erikd (added)
 * component:  Compiler => Runtime System


@@ -2,1 +2,4 @@
- the C files used in GHC and noticed these issues:
+ the C files used in GHC and noticed these issues [edit: this list now
+ shows only those issues that haven't been fixed yet]:
+
+ * driver/utils/dynwrapper.c:
@@ -4,1 +7,4 @@
- /driver/utils/cwrapper.c : int main(int, char **);
+ int main(int argc, char *argv[]) {
+     void *p;
+     ...
+ }
@@ -6,0 +12,1 @@
+
@@ -9,0 +16,3 @@
+
+
+ * rts/RetainerSet.c:
@@ -10,7 +20,0 @@
- /rts/RetainerProfile.c : static nat sanityCheckHeapClosure(StgClosure *)
- }}}
- `StgInfoTable *info` has the same issue as above
-
- {{{
- /rts/RetainerSet.c
-
@@ -32,0 +35,1 @@
+ * rts/win32/IOManager.c:
@@ -33,14 +37,1 @@
- /rts/sm/MarkWeak.c : void markWeakPtrList (void);
-
-             if (w->header.info == &stg_DEAD_WEAK_info) {
-                 last_w = &(w->link);
-             } else {
-                 last_w = &(w->link);
-             }
- }}}
- Not sure what's going on here. Regardless of the test the two branches do
- the same thing.
- {{{
-
- /rts/win32/IOManager.c : AddIORequest, AddDelayRequest, AddProcRequest
- functions
+ AddIORequest, AddDelayRequest, AddProcRequest functions

New description:

 Tiago Silva <tiagosilva@hush.com> writes: Last night I started looking at
 the C files used in GHC and noticed these issues [edit: this list now
 shows only those issues that haven't been fixed yet]:

 * driver/utils/dynwrapper.c:
 {{{
 int main(int argc, char *argv[]) {
     void *p;
     ...
 }
 }}}

 `void *p` is apparently unused, even if the compiler optimizes it away..
 you should check if something went missing.



 * rts/RetainerSet.c:
 {{{
 #elif defined(RETAINER_SCHEME_CC)
 // Retainer scheme 3: retainer = cost centre
 void
 printRetainerSetShort(FILE *f, RetainerSet *rs, nat max_length)

 {
     char tmp[max_length + 1];
     int size;
     nat j;

 }
 }}}
 Unlike the other functions around it, this function does nothing. Its
 variables are also not unused?

 * rts/win32/IOManager.c:
 {{{
 AddIORequest, AddDelayRequest, AddProcRequest functions
 }}}
 If `(!ioMan || !wItem)` the functions either return 0 or FALSE, but they
 don't free `wItem` before. Is this optimized by the compiler?

--

Comment:

 I removed some issues from the description that have since been fixed.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11777#comment:5>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler

    