[commit: ghc] master: Allow iOS to load archives through the linker (d5e0b4b)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/d5e0b4bd4a8623169e59a6de6d4d9f84ea94aa22/ghc

>---------------------------------------------------------------

commit d5e0b4bd4a8623169e59a6de6d4d9f84ea94aa22
Author: Moritz Angermann <moritz.angermann at gmail.com>
Date:   Fri Mar 3 15:50:01 2017 -0500

    Allow iOS to load archives through the linker
    
    This basically just adds ios where darwin already was, and is just one
    of the pieces for the rts linker support for ios (aarch64-macho)
    
    ---
    
    The following diagram and legend tries to explain the dependencies a
    bit:
    ```
      .- This
      v
    D3255 <- D3252 <- D3251 <- D3239
      ^
      '- D3238
    ```
    
    - In D3238 we started allowing preloading object code with mmap
      in iOS, where we can't have r+w+x.
    - In D3239 we introduced a richer extension of the object code
      data type to make working with mach-o files easier.
    - In D3240 we set the stage to allow loading archives (.a) on iOS
    - In D3251 we added init and deinit functions to populate and
      depopulate the enriched object code data structure for mach-o
      files.
    - In D3252 we refactored most of the MachO.c file to use the
      new types and data structure.
    - in D3255 we finally introduce the aarch64-mach-o linker.
    
    Reviewers: bgamari, austin, erikd, simonmar
    
    Reviewed By: bgamari
    
    Subscribers: thomie, ryantrinkle
    
    Differential Revision: https://phabricator.haskell.org/D3240


>---------------------------------------------------------------

d5e0b4bd4a8623169e59a6de6d4d9f84ea94aa22
 rts/linker/LoadArchive.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/rts/linker/LoadArchive.c b/rts/linker/LoadArchive.c
index 62922a7..f9997cf 100644
--- a/rts/linker/LoadArchive.c
+++ b/rts/linker/LoadArchive.c
@@ -13,7 +13,7 @@
 /* Platform specific headers */
 #if defined(OBJFORMAT_PEi386)
 #  include "linker/PEi386.h"
-#elif defined(darwin_HOST_OS)
+#elif defined(darwin_HOST_OS) || defined(ios_HOST_OS)
 #  include "linker/MachO.h"
 #  include <regex.h>
 #  include <mach/machine.h>
@@ -29,7 +29,7 @@
 
 #define DEBUG_LOG(...) IF_DEBUG(linker, debugBelch("loadArchive: " __VA_ARGS__))
 
-#if defined(darwin_HOST_OS)
+#if defined(darwin_HOST_OS) || defined(ios_HOST_OS)
 /* Read 4 bytes and convert to host byte order */
 static uint32_t read4Bytes(const char buf[static 4])
 {
@@ -51,6 +51,9 @@ static StgBool loadFatArchive(char tmp[static 20], FILE* f, pathchar* path)
 #elif defined(powerpc64_HOST_ARCH)
     const uint32_t mycputype = CPU_TYPE_POWERPC64;
     const uint32_t mycpusubtype = CPU_SUBTYPE_POWERPC_ALL;
+#elif defined(aarch64_HOST_ARCH)
+    const uint32_t mycputype = CPU_TYPE_ARM64;
+    const uint32_t mycpusubtype = CPU_SUBTYPE_ARM64_ALL;
 #else
 #error Unknown Darwin architecture
 #endif
@@ -149,7 +152,7 @@ static StgBool checkFatArchive(char magic[static 20], FILE* f, pathchar* path)
 {
     StgBool success;
     success = false;
-#ifdef darwin_HOST_OS
+#if defined(darwin_HOST_OS) || defined(ios_HOST_OS)
     /* Not a standard archive, look for a fat archive magic number: */
     if (read4Bytes(magic) == FAT_MAGIC)
         success = loadFatArchive(magic, f, path);
@@ -341,7 +344,7 @@ static HsInt loadArchive_ (pathchar *path)
             }
         }
 
-#if defined(darwin_HOST_OS)
+#if defined(darwin_HOST_OS) || defined(ios_HOST_OS)
         if (strncmp(fileName, "!<arch>\n", 8) == 0) {
             DEBUG_LOG("found the start of another archive, breaking\n");
             break;
@@ -500,7 +503,7 @@ static HsInt loadArchive_ (pathchar *path)
             //       cannot currently allocate blocks large enough.
             image = allocateImageAndTrampolines(path, fileName, f, memberSize,
                                                 isThin);
-#elif defined(darwin_HOST_OS)
+#elif defined(darwin_HOST_OS) || defined(ios_HOST_OS)
             if (RTS_LINKER_USE_MMAP)
                 image = mmapForLinker(memberSize, MAP_ANONYMOUS, -1, 0);
             else {