Ticket #5004: linker-partially-striped-objects-fix.dpatch

1 patch for repository http://darcs.haskell.org/ghc-7.0/ghc:

Thu May 12 17:43:59 BST 2011  Duncan Coutts <duncan@well-typed.com>
  * Make the GHCi linker handle partially stripped object files (#5004)
  When you use 'strip --strip-unneeded' on a ELF format .o or .a file, if
  the object file has no global/exported symbols then 'strip' ends up
  removing the symbol table entirely. Previously the GHCi linker assumed
  there would always be exactly one symbol table and exactly one string
  table. In fact, in ELF object files there is no such limitation, instead
  each section points to the other sections it needs, in particular
  relocation sections have a link to the symbol table section they use and
  symbol table sections have a link to the corresponding string table.
  So instead of assuming there will always be a global symbol and string
  table, all we have to do is validate and follow these links. Then, when
  we encounter an empty object file that has no symbols then we handle it
  correctly, because since it's empty we never process any relocations and
  so never have to follow any links to non-existant symbol tables.
  
  Also, in the case where an object is fully stripped, we can now detect
  this more reliably and emit a more helpful error message, e.g:
  
  libHSghc-7.1.20110509.a(DsMeta.o): relocation section #2 has no symbol table
  This object file has probably been fully striped. Such files cannot be linked.

New patches:

[Make the GHCi linker handle partially stripped object files (#5004)
Duncan Coutts <duncan@well-typed.com>**20110512164359
 Ignore-this: ebbc16fdc14124e3235199b24a9e63c8
 When you use 'strip --strip-unneeded' on a ELF format .o or .a file, if
 the object file has no global/exported symbols then 'strip' ends up
 removing the symbol table entirely. Previously the GHCi linker assumed
 there would always be exactly one symbol table and exactly one string
 table. In fact, in ELF object files there is no such limitation, instead
 each section points to the other sections it needs, in particular
 relocation sections have a link to the symbol table section they use and
 symbol table sections have a link to the corresponding string table.
 So instead of assuming there will always be a global symbol and string
 table, all we have to do is validate and follow these links. Then, when
 we encounter an empty object file that has no symbols then we handle it
 correctly, because since it's empty we never process any relocations and
 so never have to follow any links to non-existant symbol tables.
 
 Also, in the case where an object is fully stripped, we can now detect
 this more reliably and emit a more helpful error message, e.g:
 
 libHSghc-7.1.20110509.a(DsMeta.o): relocation section #2 has no symbol table
 This object file has probably been fully striped. Such files cannot be linked.
] {
hunk ./rts/Linker.c 2210
             //  stgFree(oc->image);
             // #endif
             stgFree(oc->fileName);
+            stgFree(oc->archiveMemberName);
             stgFree(oc->symbols);
             stgFree(oc->sections);
             stgFree(oc);
hunk ./rts/Linker.c 3543
  * Generic ELF functions
  */
 
-static char *
-findElfSection ( void* objImage, Elf_Word sh_type )
-{
-   char* ehdrC = (char*)objImage;
-   Elf_Ehdr* ehdr = (Elf_Ehdr*)ehdrC;
-   Elf_Shdr* shdr = (Elf_Shdr*)(ehdrC + ehdr->e_shoff);
-   char* sh_strtab = ehdrC + shdr[ehdr->e_shstrndx].sh_offset;
-   char* ptr = NULL;
-   int i;
-
-   for (i = 0; i < ehdr->e_shnum; i++) {
-      if (shdr[i].sh_type == sh_type
-          /* Ignore the section header's string table. */
-          && i != ehdr->e_shstrndx
-          /* Ignore string tables named .stabstr, as they contain
-             debugging info. */
-          && 0 != memcmp(".stabstr", sh_strtab + shdr[i].sh_name, 8)
-         ) {
-         ptr = ehdrC + shdr[i].sh_offset;
-         break;
-      }
-   }
-   return ptr;
-}
-
 static int
 ocVerifyImage_ELF ( ObjectCode* oc )
 {
hunk ./rts/Linker.c 3550
    Elf_Sym*  stab;
    int i, j, nent, nstrtab, nsymtabs;
    char* sh_strtab;
-   char* strtab;
 
    char*     ehdrC = (char*)(oc->image);
    Elf_Ehdr* ehdr  = (Elf_Ehdr*)ehdrC;
hunk ./rts/Linker.c 3631
                ehdrC + shdr[i].sh_offset,
                       ehdrC + shdr[i].sh_offset + shdr[i].sh_size - 1));
 
-      if (shdr[i].sh_type == SHT_REL) {
-          IF_DEBUG(linker,debugBelch("Rel  " ));
-      } else if (shdr[i].sh_type == SHT_RELA) {
-          IF_DEBUG(linker,debugBelch("RelA " ));
-      } else {
-          IF_DEBUG(linker,debugBelch("     "));
+#define SECTION_INDEX_VALID(ndx) (ndx > SHN_UNDEF && ndx < ehdr->e_shnum)
+
+      switch (shdr[i].sh_type) {
+
+        case SHT_REL:
+        case SHT_RELA:
+          IF_DEBUG(linker,debugBelch( shdr[i].sh_type == SHT_REL ? "Rel  " : "RelA "));
+
+          if (!SECTION_INDEX_VALID(shdr[i].sh_link)) {
+            if (shdr[i].sh_link == SHN_UNDEF)
+              errorBelch("\n%s: relocation section #%d has no symbol table\n"
+                         "This object file has probably been fully striped. "
+                         "Such files cannot be linked.\n",
+                         oc->archiveMemberName ? oc->archiveMemberName : oc->fileName, i);
+            else
+              errorBelch("\n%s: relocation section #%d has an invalid link field (%d)\n",
+                         oc->archiveMemberName ? oc->archiveMemberName : oc->fileName,
+                         i, shdr[i].sh_link);
+            return 0;
+          }
+          if (shdr[shdr[i].sh_link].sh_type != SHT_SYMTAB) {
+            errorBelch("\n%s: relocation section #%d does not link to a symbol table\n",
+                       oc->archiveMemberName ? oc->archiveMemberName : oc->fileName, i);
+            return 0;
+          }
+          if (!SECTION_INDEX_VALID(shdr[i].sh_info)) {
+            errorBelch("\n%s: relocation section #%d has an invalid info field (%d)\n",
+                       oc->archiveMemberName ? oc->archiveMemberName : oc->fileName,
+                       i, shdr[i].sh_info);
+            return 0;
+          }
+
+          break;
+        case SHT_SYMTAB:
+          IF_DEBUG(linker,debugBelch("Sym  "));
+
+          if (!SECTION_INDEX_VALID(shdr[i].sh_link)) {
+            errorBelch("\n%s: symbol table section #%d has an invalid link field (%d)\n",
+                       oc->archiveMemberName ? oc->archiveMemberName : oc->fileName,
+                       i, shdr[i].sh_link);
+            return 0;
+          }
+          if (shdr[shdr[i].sh_link].sh_type != SHT_STRTAB) {
+            errorBelch("\n%s: symbol table section #%d does not link to a string table\n",
+                       oc->archiveMemberName ? oc->archiveMemberName : oc->fileName, i);
+
+            return 0;
+          }
+          break;
+        case SHT_STRTAB: IF_DEBUG(linker,debugBelch("Str  ")); break;
+        default:         IF_DEBUG(linker,debugBelch("     ")); break;
       }
       if (sh_strtab) {
           IF_DEBUG(linker,debugBelch("sname=%s\n", sh_strtab + shdr[i].sh_name ));
hunk ./rts/Linker.c 3688
       }
    }
 
-   IF_DEBUG(linker,debugBelch( "\nString tables" ));
-   strtab = NULL;
+   IF_DEBUG(linker,debugBelch( "\nString tables\n" ));
    nstrtab = 0;
    for (i = 0; i < ehdr->e_shnum; i++) {
       if (shdr[i].sh_type == SHT_STRTAB
hunk ./rts/Linker.c 3698
              debugging info. */
           && 0 != memcmp(".stabstr", sh_strtab + shdr[i].sh_name, 8)
          ) {
-         IF_DEBUG(linker,debugBelch("   section %d is a normal string table", i ));
-         strtab = ehdrC + shdr[i].sh_offset;
+         IF_DEBUG(linker,debugBelch("   section %d is a normal string table\n", i ));
          nstrtab++;
       }
    }
hunk ./rts/Linker.c 3702
-   if (nstrtab != 1) {
-      errorBelch("%s: no string tables, or too many", oc->fileName);
-      return 0;
+   if (nstrtab == 0) {
+      IF_DEBUG(linker,debugBelch("   no normal string tables (potentially, but not necessarily a problem)\n"));
    }
 
    nsymtabs = 0;
hunk ./rts/Linker.c 3707
-   IF_DEBUG(linker,debugBelch( "\nSymbol tables" ));
+   IF_DEBUG(linker,debugBelch( "Symbol tables\n" ));
    for (i = 0; i < ehdr->e_shnum; i++) {
       if (shdr[i].sh_type != SHT_SYMTAB) continue;
       IF_DEBUG(linker,debugBelch( "section %d is a symbol table\n", i ));
hunk ./rts/Linker.c 3749
          }
          IF_DEBUG(linker,debugBelch("  " ));
 
-         IF_DEBUG(linker,debugBelch("name=%s\n", strtab + stab[j].st_name ));
+         IF_DEBUG(linker,debugBelch("name=%s\n",
+                        ehdrC + shdr[shdr[i].sh_link].sh_offset
+                              + stab[j].st_name ));
       }
    }
 
hunk ./rts/Linker.c 3756
    if (nsymtabs == 0) {
-      errorBelch("%s: didn't find any symbol tables", oc->fileName);
-      return 0;
+     // Not having a symbol table is not in principle a problem.
+     // When an object file has no symbols then the 'strip' program
+     // typically will remove the symbol table entirely.
+     IF_DEBUG(linker,debugBelch("   no symbol tables (potentially, but not necessarily a problem)\n"));
    }
 
    return 1;
hunk ./rts/Linker.c 3806
 
    char*     ehdrC    = (char*)(oc->image);
    Elf_Ehdr* ehdr     = (Elf_Ehdr*)ehdrC;
-   char*     strtab   = findElfSection ( ehdrC, SHT_STRTAB );
+   char*     strtab;
    Elf_Shdr* shdr     = (Elf_Shdr*) (ehdrC + ehdr->e_shoff);
 
    ASSERT(symhash != NULL);
hunk ./rts/Linker.c 3811
 
-   if (!strtab) {
-      errorBelch("%s: no strtab", oc->fileName);
-      return 0;
-   }
-
    k = 0;
    for (i = 0; i < ehdr->e_shnum; i++) {
       /* Figure out what kind of section it is.  Logic derived from
hunk ./rts/Linker.c 3843
 
       /* copy stuff into this module's object symbol table */
       stab = (Elf_Sym*) (ehdrC + shdr[i].sh_offset);
+      strtab = ehdrC + shdr[shdr[i].sh_link].sh_offset;
       nent = shdr[i].sh_size / sizeof(Elf_Sym);
 
       oc->n_symbols = nent;
hunk ./rts/Linker.c 3947
    relocations appear to be of this form. */
 static int
 do_Elf_Rel_relocations ( ObjectCode* oc, char* ehdrC,
-                         Elf_Shdr* shdr, int shnum,
-                         Elf_Sym*  stab, char* strtab )
+                         Elf_Shdr* shdr, int shnum )
 {
    int j;
    char *symbol;
hunk ./rts/Linker.c 3953
    Elf_Word* targ;
    Elf_Rel*  rtab = (Elf_Rel*) (ehdrC + shdr[shnum].sh_offset);
+   Elf_Sym*  stab;
+   char*     strtab;
    int         nent = shdr[shnum].sh_size / sizeof(Elf_Rel);
    int target_shndx = shdr[shnum].sh_info;
    int symtab_shndx = shdr[shnum].sh_link;
hunk ./rts/Linker.c 3958
+   int strtab_shndx = shdr[symtab_shndx].sh_link;
 
    stab  = (Elf_Sym*) (ehdrC + shdr[ symtab_shndx ].sh_offset);
hunk ./rts/Linker.c 3961
+   strtab= (char*)    (ehdrC + shdr[ strtab_shndx ].sh_offset);
    targ  = (Elf_Word*)(ehdrC + shdr[ target_shndx ].sh_offset);
hunk ./rts/Linker.c 3963
-   IF_DEBUG(linker,debugBelch( "relocations for section %d using symtab %d\n",
-                          target_shndx, symtab_shndx ));
+   IF_DEBUG(linker,debugBelch( "relocations for section %d using symtab %d and strtab %d\n",
+                          target_shndx, symtab_shndx, strtab_shndx ));
 
    /* Skip sections that we're not interested in. */
    {
hunk ./rts/Linker.c 4050
    sparc-solaris relocations appear to be of this form. */
 static int
 do_Elf_Rela_relocations ( ObjectCode* oc, char* ehdrC,
-                          Elf_Shdr* shdr, int shnum,
-                          Elf_Sym*  stab, char* strtab )
+                          Elf_Shdr* shdr, int shnum )
 {
    int j;
    char *symbol = NULL;
hunk ./rts/Linker.c 4056
    Elf_Addr targ;
    Elf_Rela* rtab = (Elf_Rela*) (ehdrC + shdr[shnum].sh_offset);
+   Elf_Sym*  stab;
+   char*     strtab;
    int         nent = shdr[shnum].sh_size / sizeof(Elf_Rela);
    int target_shndx = shdr[shnum].sh_info;
    int symtab_shndx = shdr[shnum].sh_link;
hunk ./rts/Linker.c 4061
+   int strtab_shndx = shdr[symtab_shndx].sh_link;
 
    stab  = (Elf_Sym*) (ehdrC + shdr[ symtab_shndx ].sh_offset);
hunk ./rts/Linker.c 4064
+   strtab= (char*)    (ehdrC + shdr[ strtab_shndx ].sh_offset);
    targ  = (Elf_Addr) (ehdrC + shdr[ target_shndx ].sh_offset);
    IF_DEBUG(linker,debugBelch( "relocations for section %d using symtab %d\n",
                           target_shndx, symtab_shndx ));
hunk ./rts/Linker.c 4333
 static int
 ocResolve_ELF ( ObjectCode* oc )
 {
-   char *strtab;
    int   shnum, ok;
hunk ./rts/Linker.c 4334
-   Elf_Sym*  stab  = NULL;
    char*     ehdrC = (char*)(oc->image);
    Elf_Ehdr* ehdr  = (Elf_Ehdr*) ehdrC;
    Elf_Shdr* shdr  = (Elf_Shdr*) (ehdrC + ehdr->e_shoff);
hunk ./rts/Linker.c 4338
 
-   /* first find "the" symbol table */
-   stab = (Elf_Sym*) findElfSection ( ehdrC, SHT_SYMTAB );
-
-   /* also go find the string table */
-   strtab = findElfSection ( ehdrC, SHT_STRTAB );
-
-   if (stab == NULL || strtab == NULL) {
-      errorBelch("%s: can't find string or symbol table", oc->fileName);
-      return 0;
-   }
-
    /* Process the relocation sections. */
    for (shnum = 0; shnum < ehdr->e_shnum; shnum++) {
       if (shdr[shnum].sh_type == SHT_REL) {
hunk ./rts/Linker.c 4341
-         ok = do_Elf_Rel_relocations ( oc, ehdrC, shdr,
-                                       shnum, stab, strtab );
+         ok = do_Elf_Rel_relocations ( oc, ehdrC, shdr, shnum );
          if (!ok) return ok;
       }
       else
hunk ./rts/Linker.c 4346
       if (shdr[shnum].sh_type == SHT_RELA) {
-         ok = do_Elf_Rela_relocations ( oc, ehdrC, shdr,
-                                        shnum, stab, strtab );
+         ok = do_Elf_Rela_relocations ( oc, ehdrC, shdr, shnum );
          if (!ok) return ok;
       }
    }
hunk ./rts/Linker.c 4379
 
   if( i == ehdr->e_shnum )
   {
-    errorBelch( "This ELF file contains no symtab" );
-    return 0;
+    // Not having a symbol table is not in principle a problem.
+    // When an object file has no symbols then the 'strip' program
+    // typically will remove the symbol table entirely.
+    IF_DEBUG(linker, debugBelch( "The ELF file %s contains no symtab\n",
+             oc->archiveMemberName ? oc->archiveMemberName : oc->fileName ));
+    return 1;
   }
 
   if( shdr[i].sh_entsize != sizeof( Elf_Sym ) )
}

Context:

[TAG GHC 7.0.3 release
Ian Lynagh <igloo@earth.li>**20110330192940
 Ignore-this: 47c50101fdaf792e63a500337d06dd53
] 
[Set RELEASE back to NO
Ian Lynagh <igloo@earth.li>**20110327114744
 Ignore-this: 7dcded4ef11a6bfb890c65a5c1532e0d
] 
[Set RELEASE back to YES
Ian Lynagh <igloo@earth.li>**20110325170950
 Ignore-this: 1301c9113d6d510a9f263d2e9321cd95
] 
[Add #4914 to release notes
Ian Lynagh <igloo@earth.li>**20110325170935
 Ignore-this: 1679db9aa93280140a4efaaf9135db18
] 
[Fix #4914 (I hope)
Simon Marlow <marlowsd@gmail.com>**20110325161234
 Ignore-this: 86d3f17a6811d78b3dfda18f43d7160d
 
 Here's a bit of erroneous code:
 
 00000c5c <s1ad_info>:
      c5c:       8b 45 08                mov    0x8(%ebp),%eax
      c5f:       d9 46 03                flds   0x3(%esi)
      c62:       dd d9                   fstp   %st(1)
      c64:       d9 55 08                fsts   0x8(%ebp)
      c67:       89 c6                   mov    %eax,%esi
      c69:       c7 45 00 24 0c 00 00    movl   $0xc24,0x0(%ebp)
      c70:       f7 c6 03 00 00 00       test   $0x3,%esi
      c76:       75 ac                   jne    c24 <s1ac_info>
 
 So we should be doing some ffrees before the jne.  The code that
 inserts the ffrees wasn't expecting to do it for a conditional jump,
 because they are usually local, but we have a late optimisation that
 shortcuts jumps-to-jumps, and that can result in a non-local
 conditional jump.
 
 This at least fixes an instance of the bug that I was able to
 reproduce, let's hope there aren't any more.
] 
[Set RELEASE back to NO
Ian Lynagh <igloo@earth.li>**20110325141148
 Ignore-this: 5e0cd56b287234886d1876f0047ce3d3
] 
[Fix OSTYPE test
Ian Lynagh <igloo@earth.li>**20110120000308
 Ignore-this: 8fa5d5c03297cb507a166bd85675145c
] 
[Bump versino to 7.0.3 and set RELEASE to YES
Ian Lynagh <igloo@earth.li>**20110322212641] 
[Add release notes for 7.0.3
Ian Lynagh <igloo@earth.li>**20110322212619] 
[Update ANNOUNCE for 7.0.3
Ian Lynagh <igloo@earth.li>**20110322211020] 
[Change how we compute install paths on cygwin
Ian Lynagh <igloo@earth.li>**20110320012540
 We used to have
     MK_INSTALL_DEST = "$(shell cygpath $1)"
 but this meant we ended up with
     "$(shell cygpath "[...]/html/`basename $$i`")"
 and the $(...) gets evaluated before the makefile rule, so the for loop
 hasn't been run, and so $i isn't defined. So we were taking the basename
 of the empty string, meaning docs weren't being installed in the right
 place.
 
 Now we have
     MK_INSTALL_DEST = $$(cygpath $1)
 so the evaluation happens in the shell, while the for loop is running.
] 
[Add OSTYPE build-system variable, and use it
simonpj@microsoft.com**20110113155023
 Ignore-this: c4a75f0bb27a680924e57ca7075ec116
 
 The use is in install.mk.in, where we need to know when
 we're on Cygwin.
 
 This fixes the build on my Windows box, where I have
 both Msys and Cygwin.
] 
[Don't use read_only_relocs on darwin x86-64; fixes #4984
William Knop <william.knop.nospam@gmail.com>**20110309201911
 Ignore-this: 2e2d90673fc6b32d0978cd9ac5b59905
] 
[Don't put includes/rts/Config.h in bindists twice
Ian Lynagh <igloo@earth.li>**20110316190117
 Ignore-this: b2d37c44557a84ae87675e795de209c
] 
[Don't put 2 copies of the RTS libraries in the bindists
Ian Lynagh <igloo@earth.li>**20110316172945] 
[Impredicative polymorphism no longer deprecated.
Edward Z. Yang <ezyang@mit.edu>**20110306215916
 Ignore-this: 49157eaae716879effb99c2638518265
] 
[Consistently use <sect1> etc rather than <section>; fixes #5009
Ian Lynagh <igloo@earth.li>**20110311212958
 It might be nicer to actually go the other way, and make everything
 use <section> instead, but this fixes the incorrect numbering for
 now, and we can look into whether <section> has any disadvantages
 later.
] 
[LLVM: Fix #4995, llvm mangler broken for large compiles
David Terei <davidterei@gmail.com>**20110309215346
 Ignore-this: 4fcef11ad0be0cff26c108bd05db0485
] 
[Write the XCode version test differently
Ian Lynagh <igloo@earth.li>**20110313134913
 Using && causes problems on opensolaris, for an unknown reason.
 http://www.haskell.org/pipermail/cvs-ghc/2011-March/060314.html
] 
[Improve the XCode version detection
Ian Lynagh <igloo@earth.li>**20110307225823
 Amongst other improvements, we now handle 3-component versions
 (like "3.1.4") correctly.
] 
[Turn off split objects on Darwin if XCode < 3.2 (#4013)
Ian Lynagh <igloo@earth.li>**20110225184358
 Ignore-this: 3e894673649fee957df2413ca82b1c99
] 
[Reenable object splitting on Darwin, now #4013 appears to be fixed
Ian Lynagh <igloo@earth.li>**20110219191409
 Ignore-this: e39e46beab8c8f2dc3369d5ec98610f2
] 
[Stop explicitly asking for 10.5 support on OS X; fixes #5011
Ian Lynagh <igloo@earth.li>**20110313140322
 XCode 4 doesn't include the 10.5 SDK, so if we explicitly ask for it
 then linking fails.
] 
[TAG GHC 7.0.2 release
Ian Lynagh <igloo@earth.li>**20110303150235
 Ignore-this: cef1c9db7cc8e3364ff0d50d85d68f99
] 
[Set RELEASE back to NO
Ian Lynagh <igloo@earth.li>**20110303014713
 Ignore-this: 250a5d5cb5e548a90be368fdf8339663
] 
[Set version to 7.0.2 and RELEASE to YES
Ian Lynagh <igloo@earth.li>**20110228160331
 Ignore-this: 837167f8f02752d56ffbb5e6dcb16f6c
] 
[Re-enable SPECIALISE INSTANCE pragmas
simonpj@microsoft.com**20110224174744
 Ignore-this: 7dda31a2d9ffebfd3e8c1b038d767745
 
 This mirror a similar patch in HEAD. Lacking it was responsible
 for signficant performance regressions in numeric operations on
 Rationals.
] 
[libffi: backport incorrect detection of selinux
Sergei Trofimovich <slyfox@community.haskell.org>**20110208212140
 Ignore-this: 31bdddb5683acae2bffa3e97effaefea
 
 This patch unbreaks ghci on GRSEC kernels hardened with
 TPE (Trusted Path Execution) protection.
 
 TPE forbids mmap('rwx') files opened for writes:
     fd = open (a_file_in_tmp, O_RDWR);
     mmap (...,               PROT_READ | PROT_WRITE | PROT_EXEC, fd);
 
 while allows anonymous RWX mappings:
     mmap (...MAP_ANONYMOUS , PROT_READ | PROT_WRITE | PROT_EXEC, -1);
 
 Thanks to klondike for finding it out.
 
 The result of a horrible typo.
 
 (unreleased yet) upstream also has the patch:
 
 http://github.com/atgreen/libffi/commit/eaf444eabc4c78703c0f98ac0197b1619c1b1bef
] 
[Generate the OS X installer from a bindist, rather than from a source tree
Ian Lynagh <igloo@earth.li>**20110223170016] 
[Fix another fundep error (fixes Trac #4969)
simonpj@microsoft.com**20110221153239
 Ignore-this: 9308a7c55346c9eaeaa0818903c8d67b
 
 If I had a pound for every hour Dimitrios and I have spent
 making functional dependencies work right, we'd be rich!
 
 We had stupidly caused a 'wanted' to be rewritten by a 'derived', with
 resulting abject failure.  As well as fixing the bug, this patch
 refactors some more, adds useful assert and comments.
] 
[Use -h rather than -soname; fixes dynlibs on Solaris 10; trac #4973
Ian Lynagh <igloo@earth.li>**20110222152656] 
[Fix #4867 (updated; corrects address calculation)
gwright@antiope.com**20110214150924
 Ignore-this: b68bcf1262f3507e1b9a7459139054bc
 
 This is a corrected fix for ticket #4867, "ghci displays negative floats
 incorrectly".  The previous patch sometimes gave incorrect offset to values
 in the __const section of the __TEXT segment.  The new patch arranges a zero
 fixup for non-external, not-global offset table signed relocations.  This
 is apparently what is required, though documentation on this point is scarce.
 
 With this change Doubles are negated properly, because the sign bit mask
 is loaded from the correct offset.  This was tested both on HEAD and the 7.0
 branch.
 
] 
[Fix Trac #4966
simonpj@microsoft.com**20110217141000
 Ignore-this: d4caaf910dfb86b1e469c5da3fe9cde2
 
 This is just a program that exploits overlapping
 instances in a delicate way. The fix makes GHC
 a bit more friendly towards such programs. 
 
 See Note [Overlap and deriving] in TcSimplify
] 
[Use "on the spot" solving for fundeps
simonpj@microsoft.com**20110217140921
 Ignore-this: 99290ef5538819053af708f5f9464488
 
 When we spot an equality arising from a functional dependency,
 we now use that equality (a "wanted") to rewrite the work-item
 constraint right away.  This avoids two dangers
 
  Danger 1: If we send the original constraint on down the pipeline
            it may react with an instance declaration, and in delicate
           situations (when a Given overlaps with an instance) that
           may produce new insoluble goals: see Trac #4952
 
  Danger 2: If we don't rewrite the constraint, it may re-react
            with the same thing later, and produce the same equality
            again --> termination worries.
 
 To achieve this required some refactoring of FunDeps.lhs (nicer
 now!).  
 
 This patch also contains a couple of unrelated improvements
 
 * A bad bug in TcSMonad.nestImplicTcS whereby the Tcs tyvars
   of an outer implication were not untouchable inside
 
 * Improved logging machinery for the type constraint solver;
   use -ddump-cs-trace (probably with a wider default line width
   -dppr-cols=200 or something)
] 
[makeSolvedByInst is only called on wanteds
simonpj@microsoft.com**20110211173415
 Ignore-this: 36e6201ab59a082e6dc38e56bea99e29
 
 This patch just adds an assert error.
] 
[Make exprIsCheap/exprIsExpandable understand about casts
simonpj@microsoft.com**20110215120228
 Ignore-this: 6d471f931a58896fb41131c513271ace
 
 This bug was causing arity lossage and lint errors
] 
[Add a simple arity analyser
simonpj@microsoft.com**20101221165800
 Ignore-this: d5f3a9f56404d61bb7f374c875b42c49
 
 I've wanted to do this for ages, but never gotten around to
 it.  The main notes are in Note [Arity analysis] in SimplUtils.
 
 The motivating example for arity analysis is this:
 
   f = \x. let g = f (x+1)
           in \y. ...g...
 
 What arity does f have?  Really it should have arity 2, but a naive
 look at the RHS won't see that.  You need a fixpoint analysis which
 says it has arity "infinity" the first time round.
 
 This makes things more robust to the way in which you write code.  For
 example, see Trac #4474 which is fixed by this change.
 
 Not a huge difference, but worth while:
 
         Program           Size    Allocs   Runtime   Elapsed
 --------------------------------------------------------------------------------
             Min          -0.4%     -2.2%    -10.0%    -10.0%
             Max          +2.7%     +0.3%     +7.1%     +6.9%
  Geometric Mean          -0.3%     -0.2%     -2.1%     -2.2%
 
 I don't really believe the runtime numbers, because the machine was
 busy, but the bottom line is that not much changes, and what does
 change reliably (allocation and size) is in the right direction.
] 
[Just moving comments around
simonpj@microsoft.com**20100924155600
 Ignore-this: 96635b8e8c9d88b50d82938568152ef8
] 
[Yet another go at CoreArity
simonpj@microsoft.com**20101027185630
 Ignore-this: 400f04c4c7b6999567410081c672b081
 
 Amazingly, there were still Wrong Things in the arity analysis, 
 exposed by my fiddling with eta expansion.
 
 I simplified the code, clarified the comments, added more examples,
 and tidied it all up.  I hope it's better this time.
] 
[Release note updates
Ian Lynagh <igloo@earth.li>**20110215160114] 
[add missing initialisation of ws->todo_large_objects
Simon Marlow <marlowsd@gmail.com>**20110204093148
 Ignore-this: dc9a28f85aff97e0896d212d7b21ae30
 Found-by: Valgrind.  Thanks Julian!
] 
[Fix small but egregious error: using un-zonked constraints in simplifyRule
simonpj@microsoft.com**20110211173835
 Ignore-this: 238586e420dbbb1be7f6368117cf6280
 
 This resulted in double unifications.  Fix is trivial.
] 
[Fix Trac #4953: local let binders can have IdInfo with free names
simonpj@microsoft.com**20110214140334
 Ignore-this: c8e5dbc6f0270e45d9cf2edee34d0354
 
 Local let binders in IfaceExpr never used to have unfoldings,
 but lately they can (becuase they can have an INLINE pragma).
 We must take account of the variables mentioned in the pragma
 when computing the fingerprint.
] 
[LLVM: Huge improvement to mangler speed.
David Terei <davidterei@gmail.com>**20110213014406
 Ignore-this: 4eeaa572dfe956c990895154bd942bb2
 
 The old llvm mangler was horrible! Very slow
 due to bad design and code. New version is
 linear complexity as it should be and far
 lower coefficients. This fixes trac 4838.
] 
[Defensify naked read in LLVM mangler
Ben Lippmeier <benl@ouroborus.net>**20101210045922
 Ignore-this: 1373f597863851bd03e7a7254558ed04
] 
[Formatting only
Ben Lippmeier <benl@ouroborus.net>**20101210042600
 Ignore-this: 20bbcd95c70b59094d0bb8a63e459103
] 
[New plan: push unsolved wanteds inwards
simonpj@microsoft.com**20110211174058
 Ignore-this: ed40762e260dab75b5e51c696f9965fa
 
 This fixes Trac #4935.  See Note [Preparing inert set for implications].
 Lots of comments, but not a lot of code is changed!
] 
[Fix platform detection in bindists
Ian Lynagh <igloo@earth.li>**20110211184244
 In a bindist, we generate files like the hsc2hs wrapper.
 This means we need to have the right values for the variables like
 CONF_GCC_LINKER_OPTS_STAGE1 which in turn means we need to know what
 platform we're on.
] 
[replace C++ comments with C comments (Solaris' DTrace fails on C++ comments)
Karel Gardas <karel.gardas@centrum.cz>**20110112051829
 Ignore-this: c229292227c7e2b512daf9129cb66aeb
] 
[Use DTrace whenever it's available
Ian Lynagh <igloo@earth.li>**20110210153300
 Ignore-this: 111c72bf20d6eaafd3e488196a89b2c
 Now that we've stopped trying to support 64bit OS X 10.5, the DTrace
 problems there don't matter.
] 
[Enable DTrace on Solaris; based on a patch from Karel Gardas
Ian Lynagh <igloo@earth.li>**20110210155217
 Ignore-this: 93eaf0e06c721c80c175aaee9a113e6
] 
[Fix #4867, ghci displays negative floats incorrectly
gwright@antiope.com**20110209222423
 Ignore-this: 1b3279fa5f6c4849ed6311275b1a466a
 
 This patch fixes the erroneous relocations that caused
 the bug in ticket #4867.  External addresses and global
 offset table entries were relocated correctly, but all other
 relocations were incorrectly calculated.  This caused, for
 example, bad references to constants stored in the __const
 section of the __TEXT segment.
 
 This bug only affected OS X on 64-bit platforms.
 
] 
[Simpify constraints from a TH bracket eagerly
simonpj@microsoft.com**20110209175003
 Ignore-this: b341ea3d235af1b2e617107f238ae1d6
 
 See Trac #4949, where having a TH bracket implication
 was messing things up.  Better to get rid of it right away.
] 
[Fix typo in SpecConstr that made it not work at all
simonpj@microsoft.com**20110203172756
 Ignore-this: b550d5c5b73ed13709ee2938c80a750f
 
 There was a terrible typo in this patch; I wrote "env"
 instead of "env1".
 
    Mon Jan 31 11:35:29 GMT 2011  simonpj@microsoft.com
      * Improve Simplifier and SpecConstr behaviour
 
 Anyway, this fix is essential to make it work properly.
 Thanks to Max for spotting the problem (again).
] 
[avoid adding HPC ticks to arrow constructs (fixes #1333)
Ross Paterson <ross@soi.city.ac.uk>**20110202211425
 Ignore-this: 2938850ebbb53d1bc6bf0399f68dd8e5
] 
[Fix type checker error message
simonpj@microsoft.com**20110201122920
 Ignore-this: 7369cc5f8dae3d81621f580a8ddaf41e
 
 See Trac #4940. We had a message
      The lambda expression `\ x -> x' has one argument one argument,
 repeating the "one argument" part.  Easy fix.
] 
[Fix bug in roughTopNames
simonpj@microsoft.com**20110126171803
 Ignore-this: eca8b144162f1bd94e2ccb433bca1e02
 
 roughTopNames was returning a name that in fact might be
 "looked though" by the rule matcher. Result: a rule
 that should match was being pre-emptively discarded.
 
 See Note [Care with roughTopName].
 
 Fixes a bug noticed by Pedro (Trac #4918).
] 
[Fix Trac #4917: try a bit harder to unify on-the-fly
simonpj@microsoft.com**20110125110112
 Ignore-this: e96e0a19ab8517d4ba648efe91f6b379
 
 This is generally a modest improvement but, more important,
 it fixes a "unify-under-forall" problem.  See Note [Avoid deferring].
 
 There's still a lurking unsatisfactory-ness in that we can't
 defer arbitrary constraints that are trapped under a forall.
] 
[Look through type synonyms when computing orphans
simonpj@microsoft.com**20110126171229
 Ignore-this: 6dfc45dae3a94cdb0022b2d21d6e09f6
 
 I renamed functions tyClsNamesOfTypes to oprhNamesOfType,
 because it's only used in that capacity, and we therefore
 want to look through type synonyms.  Similarly exprOrphNames.
 
 This fixes Trac #4912.
] 
[Improve Simplifier and SpecConstr behaviour
simonpj@microsoft.com**20110131113529
 Ignore-this: e5b96c97cee0950e558ddf15178bb6c9
 
 Trac #4908 identified a case where SpecConstr wasn't "seeing" a
 specialisation it should easily get.  The solution was simple: see
 Note [Add scrutinee to ValueEnv too] in SpecConstr.
 
 Then it turned out that there was an exactly analogous infelicity in
 the mighty Simplifer too; see Note [Add unfolding for scrutinee] in
 Simplify. This fix is good for Simplify even in the absence of the
 SpecConstr change.  (It arose when I moved the binder- swap stuff to
 OccAnall, not realising that it *remains* valuable to record info
 about the scrutinee of a case expression.  The Note says why.
 
 Together these two changes are unconditionally good.  Better
 simplification, better specialisation. Thank you Max.
] 
[Fix dependencies among specialisations for imported Ids
simonpj@microsoft.com**20110126172112
 Ignore-this: 364e09c11affe7bfe8f1b934ea28bbb6
 
 This was a subtle one (Trac #4903).  See
   Note [Glom the bindings if imported functions are specialised]
 in Speclialise.
 
 Fundamentally, a specialised binding for an imported Id was being
 declared non-recursive, whereas in fact it can become recursive
 via a RULE.  Once it's specified non-recurive the OccAnal pass
 treats that as gospel -- and that in turn led to infinite inlining.
 
 Easily fixed by glomming all the specialised bindings in a Rec;
 now the OccAnal will sort them out correctly.
] 
[Fix Trac #4874: specialisation of INLINABLE things
simonpj@microsoft.com**20110114163227
 Ignore-this: b90543117ebddaf3bbeeaf0af0c18699
 
 Johan discovered that when INLINABLE things are specialised
 bad things can happen. This patch implements a hack -- but
 it's a simple hack and it solves the problem.
 
 See Note [Inline specialisations]. 
 
 The hack part is that really INLINABLE should not cause *any* loss
 optimisation, and it does; see Note [Don't w/w INLINABLE things] in
 WorkWrap.
] 
[Fix an egregious strictness analyser bug (Trac #4924)
simonpj@microsoft.com**20110128080748
 Ignore-this: 3bf533c3d30b45a8e78b1fec3d9634f
 
 The "virgin" flag was being threaded rather than treated
 like an environment.  As a result, the second and subsequent
 recursive definitions in a module were not getting a
 correctly-initialised fixpoint loop, causing much worse
 strictness analysis results.  Indeed the symptoms in
 Trac #4924 were quite bizarre.
 
 Anyway, it's easily fixed.  Merge to stable branch.
] 
[tweak newArray# documentation again
Simon Marlow <marlowsd@gmail.com>**20110119140633
 Ignore-this: ceee33428dbad7e0f5eabfa0a2590466
] 
[Fix documentation bug: newArray# accepts word count, not byte count.
Edward Z. Yang <ezyang@mit.edu>**20110118221834
 Ignore-this: 8daab134bf72a740b89d273fb4e983d5
] 
[Fix validate on OS X 64
Ian Lynagh <igloo@earth.li>**20110124183618] 
[Whitespace-only in rts/Linker.c
Ian Lynagh <igloo@earth.li>**20101217234124] 
[Fix Windows build: move rtsTimerSignal to the POSIX-only section
Simon Marlow <marlowsd@gmail.com>**20101210090045
 Ignore-this: aa1844b70b9f1a44447787c4bbe10d44
] 
[Export the value of the signal used by scheduler (#4504)
Dmitry Astapov <dastapov@gmail.com>**20101208183755
 Ignore-this: 427bf8c2469283fc7a6f759440d07d87
] 
[Add some casts to fix warnings; patch from Greg Wright
Ian Lynagh <igloo@earth.li>**20101217223811] 
[Keep separate linker flags, for when we want to link with gcc or ld
Ian Lynagh <igloo@earth.li>**20110124233121] 
[Track change in isInlinePragma
simonpj@microsoft.com**20101105131545
 Ignore-this: 256f4940744d84086c0f1c99a9ab8778
 
 In TcBinds we want to use isAnyInlinePragma, to get
 both INLINE and INLINABLE.  I don't know why this isn't
 leading to failures for others!  The (bogus) error I got, 
 triggered by this bug was:
 
   libraries\haskeline\System\Console\Haskeline\Key.hs:23:1:
     You cannot SPECIALISE `M.findWithDefault'
       because its definition has no INLINE/INLINABLE pragma
] 
[In configure, test that GHC generates code for the correct platform (#4819)
Simon Marlow <marlowsd@gmail.com>**20110107163541
 Ignore-this: 29541d3896f9c9bcf791510edae70254
 Patch supplied by the bug reporter, tidied up by me.
 
 $ ./configure --with-ghc=$HOME/fp/bin/i386-unknown-linux/ghc --build=x86_64-unknown-linux
 checking for gfind... no
 checking for find... /usr/bin/find
 checking for sort... /usr/bin/sort
 checking for GHC version date... inferred 7.1.20110107
 checking version of ghc... 7.0.1
 checking build system type... x86_64-unknown-linux-gnu
 checking host system type... x86_64-unknown-linux-gnu
 checking target system type... x86_64-unknown-linux-gnu
 Host platform inferred as: i386-unknown-linux
 Target platform inferred as: i386-unknown-linux
 This GHC (/home/simonmar/fp/bin/i386-unknown-linux/ghc) does not generate code for the build platform
    GHC target platform    : i386-unknown-linux
    Desired build platform : x86_64-unknown-linux
] 
[Produce an error message, not a crash, for HsOpApp with non-var operator
simonpj@microsoft.com**20110112170719
 Ignore-this: df0f6f2e3318f9c33a714609019b0262
 
 Fixes Trac #4877.
] 
[Fix longstanding bug in C-- inlining for functions calls.
Edward Z. Yang <ezyang@mit.edu>**20110113130654
 Ignore-this: 79001003b1f3cc5005207ccfed980c21
] 
[Fix a buglet in postInlineUnconditionally
simonpj@microsoft.com**20110114162927
 Ignore-this: 7a7b8610ef863907843d4ae36a8a1a3c
 
 Under obscure circumstances (actually only shown up when fixing something
 else) it was possible for a variable binding to be discarded although
 it was still used.  See Note [Top level and postInlineUnconditionally]
] 
[Some infrastruture for lambda-lifting
simonpj@microsoft.com**20101116173500
 Ignore-this: bb0b7db06898b9fa731602107febbf7
 
 This stuff should have no effect but it sets things
 up so that we can try floating out lambdas of n value
 arguments.
 
 The new (secret) flag is -ffloatt-lam-args=n.
 
 This is *not* working yet, but it's got tangled up with
 other stuff I want to commit, and it does no harm.
] 
[Refactoring of the way that inlinings and rules are activated
simonpj@microsoft.com**20101116173719
 Ignore-this: d195c39a646e1fac3804fb044644d226
 
 Principally, the SimplifierMode now carries several (currently
 four) flags in *all* phases, not just the "Gentle" phase.
 This makes things simpler and more uniform.
 
 As usual I did more refactoring than I had intended.
 
 This stuff should go into 7.0.2 in due course, once
 we've checked it solves the DPH performance problems.
] 
[Two signficant changes to the simplifier
simonpj@microsoft.com**20101027193729
 Ignore-this: 9b35e8ad975ba1cebbba28028f1c7f43
 
 1. Do eta-expansion at let-bindings, not lambdas.
    I have wanted to do this for a long time.
    See Note [Eta-expanding at let bindings] in SimplUtils
 
 2. Simplify the rather subtle way in which InlineRules (the
    template captured by an INLINE pragma) was simplified.
    Now, these templates are always simplified in "gentle"
    mode only, and only INLINE things inline inside them.
 
    See Note Note [Gentle mode], Note [Inlining in gentle mode]
    and Note [RULEs enabled in SimplGently] in SimplUtils
] 
[Can't use DeriveFunctor in 7.0, as we need to be able to build with 6.10
Ian Lynagh <igloo@earth.li>**20110121151201
 Ignore-this: 5bdffaf4e23bf333bf5ca2d2872a026a
] 
[Resolve conflicts
Ian Lynagh <igloo@earth.li>**20110121150119
 Ignore-this: b26de1a8fcd756bd233225f79724c032
] 
[Resolve conflict
Ian Lynagh <igloo@earth.li>**20110121144437
 Ignore-this: 57893f741650c80c758f8d69ac192ed8
] 
[Major refactoring of the type inference engine
simonpj@microsoft.com**20110112145604
 Ignore-this: 6a7fc90c9b798e89505606726cc8090e
 
 This patch embodies many, many changes to the contraint solver, which
 make it simpler, more robust, and more beautiful.  But it has taken
 me ages to get right. The forcing issue was some obscure programs
 involving recursive dictionaries, but these eventually led to a
 massive refactoring sweep.
 
 Main changes are:
  * No more "frozen errors" in the monad.  Instead "insoluble
    constraints" are now part of the WantedConstraints type.
 
  * The WantedConstraint type is a product of bags, instead of (as
    before) a bag of sums.  This eliminates a good deal of tagging and
    untagging.
 
  * This same WantedConstraints data type is used
      - As the way that constraints are gathered
      - As a field of an implication constraint
      - As both argument and result of solveWanted
      - As the argument to reportUnsolved
 
  * We do not generate any evidence for Derived constraints. They are
    purely there to allow "impovement" by unifying unification
    variables.
 
  * In consequence, nothing is ever *rewritten* by a Derived
    constraint.  This removes, by construction, all the horrible
    potential recursive-dictionary loops that were making us tear our
    hair out.  No more isGoodRecEv search either. Hurrah!
 
  * We add the superclass Derived constraints during canonicalisation,
    after checking for duplicates.  So fewer superclass constraints
    are generated than before.
 
  * Skolem tc-tyvars no longer carry SkolemInfo.  Instead, the
    SkolemInfo lives in the GivenLoc of the Implication, where it
    can be tidied, zonked, and substituted nicely.  This alone is
    a major improvement.
 
  * Tidying is improved, so that we tend to get t1, t2, t3, rather
    than t1, t11, t111, etc
 
    Moreover, unification variables are always printed with a digit
    (thus a0, a1, etc), so that plain 'a' is available for a skolem
    arising from a type signature etc. In this way,
      (a) We quietly say which variables are unification variables,
          for those who know and care
      (b) Types tend to get printed as the user expects.  If he writes
              f :: a -> a
              f = ...blah...
          then types involving 'a' get printed with 'a', rather than
          some tidied variant.
 
  * There are significant improvements in error messages, notably
    in the "Cannot deduce X from Y" messages.
] 
[A little refactoring (remove redundant argument passed to isGoodRecEv)
simonpj@microsoft.com**20101202123110
 Ignore-this: e517c5c12109a230f08dafb4d1e386df
] 
[Doing the smart canonicalization only if we are not simplifying a Rule LHS.
dimitris@microsoft.com**20101210132221
 Also, same thing now applies for adding superclasses.
 
] 
[Fix recursive superclasses (again).  Fixes Trac #4809.
simonpj@microsoft.com**20101213171511
 Ignore-this: b91651397918fd8f0183812f9a070073
 
 This patch finally deals with the super-delicate question of
 superclases in possibly-recursive dictionaries.  The key idea
 is the DFun Superclass Invariant (see TcInstDcls):
 
      In the body of a DFun, every superclass argument to the
      returned dictionary is
        either   * one of the arguments of the DFun,
        or       * constant, bound at top level
 
 To establish the invariant, we add new "silent" superclass
 argument(s) to each dfun, so that the dfun does not do superclass
 selection internally.  There's a bit of hoo-ha to make sure that
 we don't print those silent arguments in error messages; a knock
 on effect was a change in interface-file format.
 
 A second change is that instead of the complex and fragile
 "self dictionary binding" in TcInstDcls and TcClassDcl,
 using the same mechanism for existential pattern bindings.
 See Note [Subtle interaction of recursion and overlap] in TcInstDcls
 and Note [Binding when looking up instances] in InstEnv.
 
 Main notes are here:
 
   * Note [Silent Superclass Arguments] in TcInstDcls,
     including the DFun Superclass Invariant
 
 Main code changes are:
 
   * The code for MkId.mkDictFunId and mkDictFunTy
 
   * DFunUnfoldings get a little more complicated;
     their arguments are a new type DFunArg (in CoreSyn)
 
   * No "self" argument in tcInstanceMethod
   * No special tcSimplifySuperClasss
   * No "dependents" argument to EvDFunApp
 
 IMPORTANT
    It turns out that it's quite tricky to generate the right
    DFunUnfolding for a specialised dfun, when you use SPECIALISE
    INSTANCE.  For now I've just commented it out (in DsBinds) but
    that'll lose some optimisation, and I need to get back to
    this.
] 
[Comments and layout
simonpj@microsoft.com**20101015131924
 Ignore-this: 126fbdb629a08c1380c7a1f5cd967d97
] 
[Occurrence analyser takes account of the phase when handing RULES
simonpj@microsoft.com**20101116173312
 Ignore-this: 50558fb8ec8fe1d0d50db46a7153b077
 
 See Note [Finding rule RHS free vars]
 
 This should make Roman happy.
] 
[Comments and formatting only
benl@ouroborus.net**20100914062903
 Ignore-this: b0fc25f0952cafd56cc25353936327d4
] 
[Fix up TcInstDcls
simonpj@microsoft.com**20101203180758
 Ignore-this: 9311aeb4ee67c799704afec90b5982d0
 
 I really don't know how this module got left out of my last
 patch, namely
   Thu Dec  2 12:35:47 GMT 2010  simonpj@microsoft.com
   * Re-jig simplifySuperClass (again)
 
 I suggest you don't pull either the patch above, or this
 one, unless you really have to.  I'm not fully confident
 that it works properly yet.  Ran out of time. Sigh.
] 
[Moved canonicalisation inside solveInteract
dimitris@microsoft.com**20101209141215
 
 Moreover canonicalisation now is "clever", i.e. it never canonicalizes a class 
 constraint if it can already discharge it from some other inert or previously
 encountered constraints. See Note [Avoiding the superclass explosion]
 
] 
[Fix Trac #3731: more superclass subtlety (sigh)
simonpj@microsoft.com**20101214180344
 Ignore-this: f4168e59f3164303ba7be022ba19c37b
 
 I will add more comments, but I want to commit this tonight,
 so the overnight builds get it.
] 
[Re-jig simplifySuperClass (again)
simonpj@microsoft.com**20101202123547
 Ignore-this: fe4062b8988258f6748ebd8fbd6515b5
 
 This fixes the current loop in T3731, and will fix other
 reported loops.  The loops show up when we are generating
 evidence for superclasses in an instance declaration.
 
 The trick is to make the "self" dictionary simplifySuperClass
 depend *explicitly* on the superclass we are currently trying
 to build.  See Note [Dependencies in self dictionaries] in TcSimplify.
 
 That in turn means that EvDFunApp needs a dependency-list, used
 when chasing dependencies in isGoodRecEv.
] 
[Do dependency analysis when kind-checking type declarations
simonpj@microsoft.com**20110110110351
 Ignore-this: 17a8dee32694d3e1835cf7bb02d3abb5
 
 This patch fixes Trac #4875.  The main point is to do dependency
 analysis on type and class declarations, and kind-check them in
 dependency order, so as to improve error messages.
 
 This patch means that a few programs that would typecheck before won't
 typecheck any more; but before we were (naughtily) going beyond
 Haskell 98 without any language-extension flags, and Trac #4875
 convinces me that doing so is a Bad Idea.
 
 Here's an example that won't typecheck any more
        data T a b = MkT (a b)
        type F k = T k Maybe
 
 If you look at T on its own you'd default 'a' to kind *->*;
 and then kind-checking would fail on F.
 
 But GHC currently accepts this program beause it looks at
 the *occurrences* of T.
] 
[Update the generics docs; pointed out by Christian Maeder
Ian Lynagh <igloo@earth.li>**20110117214632] 
[Reinstate the OS X flags in the LDFLAGS etc variables
Ian Lynagh <igloo@earth.li>**20110117200540
 Ignore-this: 9261baa1843100f65b02fb91c1a0d225
 I expect this will fix:
 http://www.haskell.org/pipermail/cvs-ghc/2011-January/059098.html
] 
[It's not clear if LDFLAGS flags will be given to gcc or ld,
Ian Lynagh <igloo@earth.li>**20110116151230
 Ignore-this: a6a2d0b1f550c922c32f6f252e4e3285
 and they accept different flags, so for now do nothing
] 
[Fix libffi build rules
Ian Lynagh <igloo@earth.li>**20110115202104
 Ignore-this: 57e1763d2079301b0165be7deba29c85
 Fixes a rare race when both libHSffi.a and libHSffi_p.a were being built
 at the same time:
 
 "cp" libffi/dist-install/build/libffi.a libffi/dist-install/build/libHSffi.a
 "cp" libffi/dist-install/build/libffi.a libffi/dist-install/build/libHSffi.a
 "cp" libffi/dist-install/build/libffi.so libffi/dist-install/build/libHSffi-ghc7.1.20110115.so
 cp: cannot create regular file `libffi/dist-install/build/libHSffi.a': File exists
] 
[Turn off dtrace unless you override USE_DTRACE
Ian Lynagh <igloo@earth.li>**20110116180306
 Ignore-this: beafc2002091fa7f0e66666004c870a5
 There are problems with dtrace on 64bit 10.5. For now at least, we
 just turn dtrace off unless you override USE_DTRACE
] 
[throwTo: report the why_blocked value in the barf()
Simon Marlow <marlowsd@gmail.com>**20101203094840
 Ignore-this: 3b167c581be1c51dfe3586cc6359e1d0
] 
[Fix Trac #4870: get the inlining for an imported INLINABLE Id
simonpj@microsoft.com**20110105002712
 Ignore-this: 60c0192eb48590c2e6868d15ba8f84ce
 
 We need the unfolding even for a *recursive* function (indeed
 that's the point) and I was using the wrong function to get it
 (idUnfolding rather than realIdUnfolding).
] 
[Fix installation on cygwin
Ian Lynagh <igloo@earth.li>**20110111194838
 Ignore-this: fe923d0619da3bd3a34968106c92fdab
] 
[Rejig the includes/ installation rules
Ian Lynagh <igloo@earth.li>**20110109181158
 They're a little nicer now, and a regression in the cygwin build is
 fixed (the $i in the destination wasn't surviving being passed through
 cygpath).
] 
[MERGED: releaseCapabilityAndQueueWorker: task->stopped should be false (#4850)
Ian Lynagh <igloo@earth.li>**20110109005801] 
[boundTaskExiting: don't set task->stopped unless this is the last call (#4850)
Simon Marlow <marlowsd@gmail.com>**20101221115807
 Ignore-this: 7e1b990aa08b3ea9cdaa9385d8e41e48
 The bug in this case was that we had a worker thread making a foreign
 call which invoked a callback (in this case it was performGC, I
 think).  When the callback ended, boundTaskExiting() was setting
 task->stopped, but the Task is now per-OS-thread, so it is shared by
 the worker that made the original foreign call.  When the foreign call
 returned, because task->stopped was set, the worker was not placed on
 the queue of spare workers.  Somehow the worker woke up again, and
 found the spare_workers queue empty, which lead to a crash.
 
 Two bugs here: task->stopped should not have been set by
 boundTaskExiting (this broke when I split the Task and InCall structs,
 in 6.12.2), and releaseCapabilityAndQueueWorker() should not be
 testing task->stopped anyway, because it should only ever be called
 when task->stopped is false (this is now an assertion).
] 
[Add utils/ghc-cabal/Makefile
Ian Lynagh <igloo@earth.li>**20110108144049] 
[Make DESTDIR an absolute path when installing; fixes #4883
Ian Lynagh <igloo@earth.li>**20110108171635] 
[Improve error message when importing data constructors (ticket #4058).
Michal Terepeta <michal.terepeta@gmail.com>**20101127211338
 Ignore-this: 3289a08f0391dd90dfef2e0403a04ccd
] 
[Remove redundant import
Ian Lynagh <igloo@earth.li>**20110108130047
 Ignore-this: 1c7fdec77b48319c845c9593b5fb94af
] 
[catch SIGTSTP and save/restore terminal settings (#4460)
Simon Marlow <marlowsd@gmail.com>**20110107124042
 Ignore-this: 38f7f27bf75178899f466404c048241d
 As far as I can tell, it is the responsibility of the program to save
 and restore its own terminal settings across a suspend/foreground, the
 shell doesn't do it (which seems odd).  So I've added a signal handler
 for SIGTSTP to the RTS which will save and restore the terminal
 settings iff we modified them with hSetBuffering or hSetEcho (we
 already restore them at exit time in these cases).
] 
[Improve error message of :set in ghci (ticket #4190).
Michal Terepeta <michal.terepeta@gmail.com>**20101130211505
 Ignore-this: ccc8a0816a900ba8c4a966285a465b23
] 
[Improve printing for -ddump-deriv
simonpj@microsoft.com**20101215121955
 Ignore-this: 3181c948c4c2471bd99b32c5ee487a1e
] 
[do not compile part of shared lib RTS with -fno-PIC on Solaris
Karel Gardas <karel.gardas@centrum.cz>**20101217085133
 Ignore-this: 8c8dbb45cac0578a58a3557f1e03c66
] 
[provide shared libraries support on i386-unknown-solaris2 platform
Karel Gardas <karel.gardas@centrum.cz>**20101217084617
 Ignore-this: b6079c6a39a71200a1ee863573e40828
] 
[fix CPP detection of Solaris in NCG
Karel Gardas <karel.gardas@centrum.cz>**20101217084510
 Ignore-this: 9d1ce59d469294eab1f0cbc697e48d69
] 
[Fix a bug in functorLikeTraverse, which was giving wrong answer for tuples
simonpj@microsoft.com**20101215123725
 Ignore-this: 560220e92429b5b1a6197a62f94a4ff2
 
 This bug led to Trac #4816, which is hereby fixed
] 
[Allow enumerations to have phantom arguments.
simonpj@microsoft.com**20101215121817
 Ignore-this: 32ef8cb869e6e38c2e43b3ae87b1b9a8
 
 The bytecode generator was being too eager.
 Fixes Trac #4528, or rather, a near variant.
] 
[Tighten up what it means to be an "enumeration data constructor"
simonpj@microsoft.com**20101215121927
 Ignore-this: 459b3f9f7994a13094ed87b0768b33a8
 
 See Note [Enumeration types] in TyCon, and comments in Trac #4528
] 
[add 'make re2' for rebuilding stage2 (similarly re1 and re3)
Simon Marlow <marlowsd@gmail.com>**20101221100254
 Ignore-this: 5c0afe3810b66a5b6e53a3a0fe933945
] 
[add comment to remind people to update driver/gcc/gcc.c
Simon Marlow <marlowsd@gmail.com>**20110106152402
 Ignore-this: c07d7ac11eb9221ef821f78aab1807cb
] 
[update paths now that we upgraded gcc to 4.5.0
Simon Marlow <marlowsd@gmail.com>**20110106133729
 Ignore-this: f8f9bcad984fdd472e0ae958b66bea9d
] 
[Create ~/.ghc/ if it doesn't already exist; fixes trac #4522
Ian Lynagh <igloo@earth.li>**20101218184925] 
[Pass --hoogle to haddock; fixes trac #4521
Ian Lynagh <igloo@earth.li>**20101219125243] 
[use Win32 CreateProcess() rather than mingw spawnv() (#4531)
Simon Marlow <marlowsd@gmail.com>**20110106133834
 Ignore-this: 4c0947853549dad034622c044391af6c
] 
[Fix mkUserGuidePart program name on Windows
Ian Lynagh <igloo@earth.li>**20110106143707] 
[On Cygwin, use a Cygwin-style path for /bin/install's destination
Ian Lynagh <igloo@earth.li>**20110106223030
 
 cygwin's /bin/install doesn't set file modes correctly if the
 destination path is a C: style path:
 
 $ /bin/install -c -m 644 foo /cygdrive/c/cygwin/home/ian/foo2
 $ /bin/install -c -m 644 foo c:/cygwin/home/ian/foo3
 $ ls -l foo*
 -rw-r--r-- 1 ian None 0 2011-01-06 18:28 foo
 -rw-r--r-- 1 ian None 0 2011-01-06 18:29 foo2
 -rwxrwxrwx 1 ian None 0 2011-01-06 18:29 foo3
 
 This causes problems for bindisttest/checkBinaries.sh which then
 thinks that e.g. the userguide HTML files are binaries.
 
 We therefore use a /cygdrive path if we are on cygwin
] 
[Fix #4829 (build does not respect --with-gcc option)
gwright@antiope.com**20101221133233
 Ignore-this: 37918feb82f911c2beb75915b6e8b97b
 
 This patch fixes what seems to be the last problem with the --with-gcc
 option.  On OS X, we need to pass the path to gcc to dtrace as the
 preprocessor.  (Internally, dtrace on OS X sets the default preprocessor
 to /usr/bin/gcc.)  ATM, dtrace is only supported on OS X, so we don't
 need any conditionalization.  If dtrace is ported to other platforms,
 we might need to change this. However, usage on other platforms will
 probably be similar to OS X, since many of Apple's changes are to
 use the gnu toolchain instead of the Sun toolchain.
   
] 
[comments on SRC_HC_OPTS (#4829)
Simon Marlow <marlowsd@gmail.com>**20101214101340
 Ignore-this: e2bdec00f07b68e82837e77a4faf6514
] 
[fix #3910
Simon Marlow <marlowsd@gmail.com>**20101216114452
 Ignore-this: 410e95e188344a523520e192a3fb58ea
] 
[refactor and tidy up the section on RTS options
Simon Marlow <marlowsd@gmail.com>**20101216123151
 Ignore-this: 9cdafd687351d8a3ff879b64347f85d3
] 
[Related to #4826: Some minor tweaks to the wording of the User Guide, section 4.16
Orphi <MathematicalOrchid@hotmail.com>**20101209170440
 Ignore-this: c3d942d58594be7d4c2eb4dc3a22f19
] 
[FIX #4826 partial: Add -rtsopts and -with-rtsopts to User Guide section 4.11.6
Orphi <MathematicalOrchid@hotmail.com>**20101209165152
 Ignore-this: 2fc1c0abbb783695773ab0f9c013bbaa
] 
[FIX #4826 partially: Change -f to -? in User Guide section F4.16
Orphi <MathematicalOrchid@hotmail.com>**20101209144148
 Ignore-this: 73410b350e80c8943ae722dec8dea44b
] 
[Fix error compiling AsmCodeGen.lhs for PPC Mac (unused makeFar addr)
naur@post11.tele.dk**20101219213555
 Ignore-this: ab25d5f2e2ebe163547d5babaf4b1dbf
] 
[Fix error compiling AsmCodeGen.lhs for PPC Mac (rtsPackageId)
naur@post11.tele.dk**20101219212530
 Ignore-this: 946f6d3e0d3c3ddf2dc07b85e1f82d85
] 
[Add gcc and ld flags to --info output
Ian Lynagh <igloo@earth.li>**20101220173520] 
[Updated ANNOUNCE
Ian Lynagh <igloo@earth.li>**20101220162525
 Ignore-this: 9cde75aea69b8c945a1cbee488bd8ee4
] 
[Fix checkBinaries on OS X
Ian Lynagh <igloo@earth.li>**20101216201121] 
[Use "-perm -u+x" rather than "-executable" to find executables
Ian Lynagh <igloo@earth.li>**20101216145235
 On Windows, -executable is matching the html docs.
] 
[Remove a debugging print
Ian Lynagh <igloo@earth.li>**20101216011459] 
[Add release notes for 7.0.2
Ian Lynagh <igloo@earth.li>**20101215165746
 Ignore-this: 686eeb9b0b301444a2ab0ed81e9d1d76
] 
[Wibble to InstEnv.instanceHead
simonpj@microsoft.com**20101214082939
 Ignore-this: 851db517f8638a0aeb7ad461298f7e9f
 
 Fixes an accidental glitch in T1835
] 
[MERGED: Fix recursive superclasses (again).  Fixes Trac #4809.
Ian Lynagh <igloo@earth.li>**20101214180026
 simonpj@microsoft.com**20101213171511
  Ignore-this: b91651397918fd8f0183812f9a070073
 
  This patch finally deals with the super-delicate question of
  superclases in possibly-recursive dictionaries.  The key idea
  is the DFun Superclass Invariant (see TcInstDcls):
 
       In the body of a DFun, every superclass argument to the
       returned dictionary is
         either   * one of the arguments of the DFun,
         or       * constant, bound at top level
 
  To establish the invariant, we add new "silent" superclass
  argument(s) to each dfun, so that the dfun does not do superclass
  selection internally.  There's a bit of hoo-ha to make sure that
  we don't print those silent arguments in error messages; a knock
  on effect was a change in interface-file format.
 
  A second change is that instead of the complex and fragile
  "self dictionary binding" in TcInstDcls and TcClassDcl,
  using the same mechanism for existential pattern bindings.
  See Note [Subtle interaction of recursion and overlap] in TcInstDcls
  and Note [Binding when looking up instances] in InstEnv.
 
  Main notes are here:
 
    * Note [Silent Superclass Arguments] in TcInstDcls,
      including the DFun Superclass Invariant
 
  Main code changes are:
 
    * The code for MkId.mkDictFunId and mkDictFunTy
 
    * DFunUnfoldings get a little more complicated;
      their arguments are a new type DFunArg (in CoreSyn)
 
    * No "self" argument in tcInstanceMethod
    * No special tcSimplifySuperClasss
    * No "dependents" argument to EvDFunApp
 
  IMPORTANT
     It turns out that it's quite tricky to generate the right
     DFunUnfolding for a specialised dfun, when you use SPECIALISE
     INSTANCE.  For now I've just commented it out (in DsBinds) but
     that'll lose some optimisation, and I need to get back to
     this.
] 
[Add libstdc++-4.5.0-1-mingw32-dll-6.tar.lzma to mingw tarballs
Ian Lynagh <igloo@earth.li>**20101213223153] 
[GHCi linker: Assume non-Haskell libraries are dynamic libs
Ian Lynagh <igloo@earth.li>**20101213124930
 Ignore-this: aa153a8f6e309c7b3dae7e46bb7a9583
 This works around a segfault we get when trying to load libiconv.a on
 some platforms.
] 
[Make the case-to-let transformation a little less eager
simonpj@microsoft.com**20101208172251
 Ignore-this: 55eaa1b5753af31aeb32ec792cb6b662
 
 See Note [Case elimination: lifted case].
 Thanks to Roman for identifying this case.
] 
[Fix Trac #4534: renamer bug
simonpj@microsoft.com**20101210084530
 Ignore-this: 8163bfa3a56344cfe89ad17c62e9655d
   
 The renamer wasn't attaching the right used-variables to a
 TransformStmt constructor.
 
 The real modification is in RnExpr; the rest is just
 pretty-printing and white space.
] 
[Only reset the event log if logging is turned on (addendum to #4512)
Simon Marlow <marlowsd@gmail.com>**20101210093951
 Ignore-this: c9f85f0de2b11a37337672fba59aecc6
] 
[allocate enough room for the longer filename (addendum to #4512)
Simon Marlow <marlowsd@gmail.com>**20101210093906
 Ignore-this: 270dc0219d98f1e0f9e006102ade7087
] 
[warning fix: don't redefine BLOCKS_PER_MBLOCK
Simon Marlow <marlowsd@gmail.com>**20101210094002
 Ignore-this: cadba57f1c38f5e2af1de37d0a79c7ee
] 
[Add a test that all programs in the bindist were built with the right GHC
Ian Lynagh <igloo@earth.li>**20101210161218
 They should use the GHC from the build tree, not the bootstrapping compiler.
] 
[Add --version support to ghc-cabal
Ian Lynagh <igloo@earth.li>**20101212213600
 Ignore-this: ef696dcb1b96a23765f9f18e75a56f5
] 
[Don't link the GHC RTS into our C-only programs
Ian Lynagh <igloo@earth.li>**20101210185402
 Ignore-this: 56f620f7eb16a03e7497a161bc48458e
] 
[Build a copy of ghc-cabal with the in-tree compiler, for the bindist
Ian Lynagh <igloo@earth.li>**20101210181123] 
[fix warnings
Simon Marlow <marlowsd@gmail.com>**20101209115844
 Ignore-this: ffff37feb2abbfc5bd12940c7007c208
] 
[:unset settings support
Boris Lykah <lykahb@gmail.com>**20101123190132
 Ignore-this: 5e97c99238f5d2394592858c34c004d
 Added support for settings [args, prog, prompt, editor and stop].
 Now :unset supports the same set of options as :set.
] 
[Use liftIO rather than io
Ian Lynagh <igloo@earth.li>**20101103212216] 
[Fixes for #4512: EventLog.c - provides ability to terminate event logging, Schedule.c - uses them in forkProcess.
Dmitry Astapov <dastapov@gmail.com>**20101203133950
 Ignore-this: 2da7f215d6c22708a18291a416ba8881
] 
[fix ticket number (#4505)
Simon Marlow <marlowsd@gmail.com>**20101209120404
 Ignore-this: 5769c5ce2a8d69d62d977a9ae138ec23
] 
[Catch too-large allocations and emit an error message (#4505)
Simon Marlow <marlowsd@gmail.com>**20101209114005
 Ignore-this: c9013ab63dd0bd62ea045060528550c6
 
 This is a temporary measure until we fix the bug properly (which is
 somewhat tricky, and we think might be easier in the new code
 generator).
 
 For now we get:
 
 ghc-stage2: sorry! (unimplemented feature or known bug)
   (GHC version 7.1 for i386-unknown-linux):
         Trying to allocate more than 1040384 bytes.
 
 See: http://hackage.haskell.org/trac/ghc/ticket/4550
 Suggestion: read data from a file instead of having large static data
 structures in the code.
] 
[Tweak the "sorry" message a bit
Simon Marlow <marlowsd@gmail.com>**20101208163212
 Ignore-this: aa1ce5bc3c27111548204b740572efbe
 
 -              "sorry! (this is work in progress)\n"
 +              "sorry! (unimplemented feature or known bug)\n"
] 
[Cleanup comments and formatting only
benl@ouroborus.net**20101029065837
 Ignore-this: 393131d43ae57e4c1e7ac0dce734c452
] 
[Fix Windows memory freeing: add a check for fb == NULL; fixes trac #4506
Ian Lynagh <igloo@earth.li>**20101208152349
 Also added a few comments, and a load of code got indented 1 level deeper.
] 
[Make CPPFLAGS variables, as well as CFLAGS and LDFLAGS
Ian Lynagh <igloo@earth.li>**20101207010033
 Ignore-this: 2fc1ca1422aae1988d0fe1d29a8485d9
 This fixes the "does unsetenv return void" test in the unix package on
 OS X, if I tell it to make 10.4-compatible binaries. The test uses
 CPPFLAGS but not CFLAGS, so it thought it returned int (as it was
 in 10.5-mode), but the C compiler (using CFLAGS, so in 10.4 mode)
 thought it returned void.
 
 I also added CONF_LD_OPTS_STAGE$3 to the list of things in LDFLAGS,
 which looks like an accidental ommission.
] 
[Tweak the cleaning of inplace/; fixes trac #4320
Ian Lynagh <igloo@earth.li>**20101205212048] 
[Add a configure message
Ian Lynagh <igloo@earth.li>**20101206215201] 
[Tweak a configure test
Ian Lynagh <igloo@earth.li>**20101123170621] 
[Link even programs containing no Haskell modules with GHC
Ian Lynagh <igloo@earth.li>**20101206203329
 I don't remember why we made it use gcc instead, but going back to
 using ghc doesn't seem to break anything, and should fix the build
 on OS X 10.6.
] 
[Correct the stage that the includes/ tools are built in
Ian Lynagh <igloo@earth.li>**20101206203125] 
[Close .ghci files after reading them; fixes trac #4487
Ian Lynagh <igloo@earth.li>**20101205205301] 
[Fix a nasty bug in RULE matching: Trac #4814
simonpj@microsoft.com**20101202102618
 Ignore-this: ba058ad46a02bd2faf3a14de93fd19c6
 
 See Note [Matching lets], which explains it all in detail.
 It took me a day to think of a nice way to fix the bug,
 but I think the result is quite respectable. Subtle, though.
] 
[Fix a recomp bug: make classes/datatypes depend directly on DFuns (#4469)
Simon Marlow <marlowsd@gmail.com>**20101202122349
 Ignore-this: 61c765583bb1d97caa88cf9b4f45b87c
 And remove the old mechanism of recording dfun uses separately,
 because it didn't work.
 
 This wiki page describes recompilation avoidance and fingerprinting.
 I'll update it to describe the new method and what went wrong with the
 old method:
 
 http://hackage.haskell.org/trac/ghc/wiki/Commentary/Compiler/RecompilationAvoidance
] 
[removeThreadFromQueue: stub out the link field before returning (#4813)
Simon Marlow <marlowsd@gmail.com>**20101202160838
 Ignore-this: 653ae17bc1120d7f4130da94665002a1
] 
[handle ThreadMigrating in throwTo() (#4811)
Simon Marlow <marlowsd@gmail.com>**20101203094818
 Ignore-this: 8ef8cb7fd3b50a27f83c29968131d461
 If a throwTo targets a thread that has just been created with
 forkOnIO, then it is possible the exception strikes while the thread
 is still in the process of migrating.  throwTo() didn't handle this
 case, but it's fairly straightforward.
] 
[Tell gcc to support back to OS X 10.5
Ian Lynagh <igloo@earth.li>**20101203201558
 Ignore-this: f02d70e5b9cce50137981c6cb2b62a18
] 
[Remove the no-ghci-lib warning in ghc-pkg
Ian Lynagh <igloo@earth.li>**20101127235805
 GHCi libs are no longer necessary, as we can use the .a or .so versions
 instead.
] 
[rts/Linker.c (loadArchive):
pho@cielonegro.org**20101130142700
 Ignore-this: bc84f9369ce5c2d289440701b7a3a2ab
 
 This routine should be aware of Mach-O misalignment of malloc'ed memory regions.
] 
[Add GNU-variant support to the .a parser, and other improvements/tidyups
Ian Lynagh <igloo@earth.li>**20101127223945] 
[Re-indent only
Ian Lynagh <igloo@earth.li>**20101127191646] 
[Improve linker debugging for archive files
Ian Lynagh <igloo@earth.li>**20101127190907] 
[Always enable the archive-loading code
Ian Lynagh <igloo@earth.li>**20101127173000
 If the GHCi .o lib doesn't exist, load the .a instead
] 
[FIX #1845 (unconditional relative branch out of range)
pho@cielonegro.org**20101130143014
 Ignore-this: df234bd8ad937104c455656fe3c33732
 
 Don't use mmap on powerpc-apple-darwin as mmap doesn't support
 reallocating but we need to allocate jump islands just after each
 object images. Otherwise relative branches to jump islands can fail
 due to 24-bits displacement overflow.
] 
[rts/Linker.c (machoGetMisalignment):
pho@cielonegro.org**20101130123355
 Ignore-this: 75425600049efd587e9873578e26392f
 
 Use fseek(3) instead of rewind(3) to move the file position indicator back to the initial position. Otherwise we can't use this function in loadArchive().
] 
[rts/Linker.c (ocFlushInstructionCache):
pho@cielonegro.org**20101130121425
 Ignore-this: 1e2c207e4b1d17387617ec5d645204b7
 
 I found this function causes a segfault when ocAllocateSymbolExtras() has allocated a separate memory region for jump islands.
] 
[fix ref to utils/ext-core, which moved to Hackage (extcore package)
Simon Marlow <marlowsd@gmail.com>**20101201092147
 Ignore-this: 272a7daaa335ef60bcc645db70b4d68b
] 
[fix floating-point/FFI section: fenv is C99, not POSIX
Simon Marlow <marlowsd@gmail.com>**20101201092119
 Ignore-this: ce8b3edd428e4f77691dd739b5b4ae73
] 
[Document the behaviour of fenv.h functions with GHC (#4391)
Simon Marlow <marlowsd@gmail.com>**20101126125336
 Ignore-this: bc4eab49428d567505a28add6fed90f1
] 
[Substitution should just substitute, not optimise
simonpj@microsoft.com**20101125172356
 Ignore-this: 657628d9b6796ceb5f915c43d56e4a06
 
 This was causing Trac #4524, by optimising
      (e |> co)  to   e
 on the LHS of a rule.  Result, the template variable
 'co' wasn't bound any more.
 
 Now that substition doesn't optimise, it seems sensible to call
 simpleOptExpr rather than substExpr when substituting in the
 RHS of rules.  Not a big deal either way.
] 
[Allow the old [$foo| ... |] syntax for quasi-quotes
simonpj@microsoft.com**20101112083052
 Ignore-this: 868e0e07fc6bbc9772bcba54e8ca79d
 
 This is just a backward-compatibility thing, to be removed
 eventually.
] 
[For bindists, build ghc-pwd with stage 1
Ian Lynagh <igloo@earth.li>**20101121183520
 Ignore-this: a3b5c8b78c81ec1b6d5fbf23da346ff5
 rather then the bootstrapping compiler. This fixes problems where the
 bootstrapping compiler dynamically links against libraries not on the
 target machine.
] 
[Makefile tweak
Ian Lynagh <igloo@earth.li>**20101121183342
 Ignore-this: cd55a2819c1a5fd36da1bc7a75d2ded1
] 
[Fix a makefile include ordering sanity check
Ian Lynagh <igloo@earth.li>**20101121174916
 Ignore-this: d0bdd41c4b618944d04ecb4f54fdd0f1
] 
[Tweak the bindist configure.ac.in
Ian Lynagh <igloo@earth.li>**20101120173735] 
[configure.ac tweaks
Ian Lynagh <igloo@earth.li>**20101120170245] 
[When testing the bindist, tell it where gcc is
Ian Lynagh <igloo@earth.li>**20101120155920
 The location isn't baked into the bindist, as it may differ from
 machine to machine.
] 
[Add -fwarn-lazy-unlifted-bindings to the list of flags
simonpj@microsoft.com**20101116172211
 Ignore-this: 4f150f347bb74027adacb64545f6b757
] 
[Improve documentation for -fwarn-incomplete-patterns
simonpj@microsoft.com**20101116171527
 Ignore-this: d8386202cc322207436db0c5b185dab
] 
[Eventlog: Put correct size for startup event
scpmw@leeds.ac.uk**20101105151655
 Ignore-this: 8b6eb4fa2137c8dfe50c5917e3a609a7
] 
[Omit bogus test for -XDeriveFunctor
simonpj@microsoft.com**20101118090028
 Ignore-this: a534243011809ebbb788b910961601c5
 
 It was duplicated in the case of 'deriving( Functor )'
 and wrong for 'deriving( Foldable )'
] 
[Move the superclass generation to the canonicaliser
simonpj@microsoft.com**20101118120533
 Ignore-this: 5e0e525402a240b709f2b8104c1682b2
 
 Doing superclass generation in the canonicaliser (rather than
 TcInteract) uses less code, and is generally more efficient.
 
 See Note [Adding superclasses] in TcCanonical.
 
 Fixes Trac #4497.
] 
[Improve error message on advice from a user
simonpj@microsoft.com**20101118085306
 Ignore-this: bd4f3858ff24e602e985288f27d536f3
 
 See Trac #4499
] 
[Buglet in tcIface, now that nested binders can have pragmas
simonpj@microsoft.com**20101027184235
 Ignore-this: de2db50370c35b8ae92ec2574d806b33
 
 This fix ties the knot for recursive groups properly
] 
[Fix initialisation of strictness in the demand analyser
simonpj@microsoft.com**20101026081757
 Ignore-this: d89b117caa95b51b6c24584ac03bedf6
 
 Previously, the demand analyser assumed that every binder 
 starts off with no strictness info.  But now that we are
 preserving strictness on nesting bindings in interface files,
 that assumption is no longer correct, because an inlined function
 might have a nested binding with strictness set.
 
 So we need to know when we are in the initial sweep, so that we can
 set the strictness to 'bottom'. 
 
 See Note [Initialising strictness]
] 
[Fix the generation of in-scope variables for IfaceLint check
simonpj@microsoft.com**20101118090057
 Ignore-this: bbcdba61ddf89d07fe69ca99c2017e3f
] 
[Serialise nested unfoldings across module boundaries
simonpj@microsoft.com**20101025152817
 Ignore-this: 1520586f152501d4acb084ebf9cd3136
 
 As Roman reported in #4428, nested let-bindings weren't
 being recorded with their unfoldings.  Needless to say,
 fixing this had more knock-on effects than I expected.
] 
[Nicer error message for #3782
benl@ouroborus.net**20101029063320
 Ignore-this: fc746cad57410123a29f37f61f13dd3c
 It now says:
 
 ghc-stage2: sorry! (this is work in progress)
   (GHC version 7.1.20101028 for i386-apple-darwin):
        Vectorise.Builtins.indexBuiltin
     
     DPH builtin function 'sumTyCon' of size '11' is not yet implemented.
     This function does not appear in your source program, but it is needed
     to compile your code in the backend. This is a known, current limitation
     of DPH. If you want it to to work you should send mail to cvs-ghc@haskell.org
     and ask what you can do to help (it might involve some GHC hacking).
 
 
 I added 'pprSorry' that behaves like 'pprPanic' except it say sorry! instead 
 of panic!, and doesn't ask the user to report a bug. 
] 
[Build system tweak: Inline DQ now it's the same on all platforms
Ian Lynagh <igloo@earth.li>**20101114134636] 
[Update to docbook 4.5; fixes trac #4447
Ian Lynagh <igloo@earth.li>**20101114155023] 
[Fix -fwarn-missing-import-lists (fix Trac #4489)
simonpj@microsoft.com**20101115232142
 Ignore-this: 656b3a76540a488a7111ba7c9ec8ebc4
] 
[Ensure that instance overlap errors are report properly
simonpj@microsoft.com**20101115142805
 Ignore-this: 2fca29a95bdc69a4c783cbcc663a10f7
 
 This (annoyingly) requires us to re-flatten the class predicate.
 See Note [Flattening in error message generation]
] 
[Fix Trac #4501: a transposition error in DynFlags
simonpj@microsoft.com**20101117100832
 Ignore-this: b81eca419581a7cec773556514915814
 
 Push to STABLE
] 
[Fix Trac #4498: bang-pattern bindings are monomorphic
simonpj@microsoft.com**20101117101058
 Ignore-this: 2a739aeca590b4dd1907078ba80133ff
 
 This patch forces bang patterns to be monomorphic,
 and documents this fact.
] 
[Ensure that unification variables alloc'd during solving are untouchable
simonpj@microsoft.com**20101115121540
 Ignore-this: 4cdb38180488e605489ce5d018998089
 
 This fixes Trac #4494.  See Note [Extra TcsTv untouchables] in TcSimplify.
] 
[Document SPECIALISE for imported functions
simonpj@microsoft.com**20101117111559
 Ignore-this: 5c9e83d15b85fe5a8639321e00e5dcaa
 
 This is a really useful new facility, but I'd forgotten to document it.
 Pls merge to 7.0 branch
] 
[Add a build system dependency; fixes #4357
Ian Lynagh <igloo@earth.li>**20101114140311] 
[Set RELEASE to NO
Ian Lynagh <igloo@earth.li>**20101117141621] 
[TAG GHC 7.0.1 release
Ian Lynagh <igloo@earth.li>**20101117140118
 Ignore-this: ac737bfbb99523a6e0aa7f7a32727de9
] 
Patch bundle hash:
cdb3939dfd7d1a449349979c9d469e1ef887e4cb