Adjust section placement and relocation logic for Mach-O

1. Place each section on a separate page to ensure required
alignment (wastes lots ot space, needs to be improved).
2. Unwire relocation logic from macho sections (the most fiddly part
is adjusting internal relocations).

Other todos:
0. Add a test for section alignment.
1. Investigate 32bit relocations!
2. Fix memory leak in ZEROPAGE section allocation.
3. Fix creating redundant jump islands for GOT.
4. Investigate more compact section placement.

6 files changed, 95 insertions, 0 deletions

diff --git a/testsuite/tests/rts/linker/Makefile b/testsuite/tests/rts/linker/Makefile
new file mode 100644
index 0000000000..c5d80faa3f
--- /dev/null
+++ b/testsuite/tests/rts/linker/Makefile
@@ -0,0 +1,8 @@
+TOP=../../..
+include $(TOP)/mk/boilerplate.mk
+include $(TOP)/mk/test.mk
+
+unsigned_reloc_macho_64:
+	as -o unsigned_reloc_macho_64.o unsigned_reloc_macho_64.s
+	'$(TEST_HC)' $(TEST_HC_OPTS_NO_RTSOPTS) -v0 --make -no-rtsopts-suggestions -no-hs-main -o runner -debug runner.c
+	./runner unsigned_reloc_macho_64.o getAnswer
diff --git a/testsuite/tests/rts/linker/all.T b/testsuite/tests/rts/linker/all.T
new file mode 100644
index 0000000000..d1b3c22b27
--- /dev/null
+++ b/testsuite/tests/rts/linker/all.T
@@ -0,0 +1,9 @@
+# -*-: mode: python -*-
+
+test('unsigned_reloc_macho_64',
+     [
+         extra_files(['runner.c', 'unsigned_reloc_macho_64.s']),
+         unless(opsys('darwin'), skip),
+         unless(arch('x86_64'), skip)
+     ],
+     run_command, ['$MAKE -s --no-print-directory unsigned_reloc_macho_64'])
diff --git a/testsuite/tests/rts/linker/runner b/testsuite/tests/rts/linker/runner
new file mode 100755
index 0000000000..7771d4ab57
--- /dev/null
+++ b/testsuite/tests/rts/linker/runner
diff --git a/testsuite/tests/rts/linker/runner.c b/testsuite/tests/rts/linker/runner.c
new file mode 100644
index 0000000000..7c34ac284a
--- /dev/null
+++ b/testsuite/tests/rts/linker/runner.c
@@ -0,0 +1,65 @@
+#include <Rts.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+
+#define MAX_SYMNAME 256
+
+typedef long (*fun_t)(void);
+
+int main(int argc, char *argv[])
+{
+    fun_t f;
+    int ok;
+    char * objpath;
+
+    hs_init(&argc, &argv);
+
+    initLinker();
+
+    if (argc < 3) {
+            errorBelch("usage: runner <objpath> <symname>");
+            exit(1);
+    }
+    objpath = argv[1];
+
+#ifdef darwin_HOST_OS
+    char symname[MAX_SYMNAME + 1];
+    symname[0] = '_';
+    strncpy(&symname[1], argv[2], MAX_SYMNAME);
+#else
+    char * symname = argv[2];
+#endif
+
+    printf("Linking: path = %s, symname = %s\n", objpath, symname);
+
+    ok = loadObj(objpath);
+    if (!ok) {
+            errorBelch("loadObj(%s) failed", objpath);
+            exit(1);
+    }
+
+    ok = resolveObjs();
+    if (!ok) {
+            errorBelch("resolveObjs failed");
+            exit(1);
+    }
+
+    f = lookupSymbol(symname);
+    if (!f) {
+            errorBelch("lookupSymbol failed");
+            exit(1);
+    }
+
+    printf("%ld\n", f());
+
+    ok = unloadObj(objpath);
+    if (!ok) {
+            errorBelch("unloadObj(%s) failed", objpath);
+            exit(1);
+    }
+
+    return 0;
+}
+
diff --git a/testsuite/tests/rts/linker/unsigned_reloc_macho_64.s b/testsuite/tests/rts/linker/unsigned_reloc_macho_64.s
new file mode 100644
index 0000000000..733c9863bd
--- /dev/null
+++ b/testsuite/tests/rts/linker/unsigned_reloc_macho_64.s
@@ -0,0 +1,11 @@
+        .text
+        .globl _getAnswer
+
+_getAnswer:
+        mov     L2(%rip), %rdx
+        movq    (%rdx), %rax
+        ret
+
+        .data
+L1:     .quad 42
+L2:     .quad L1
diff --git a/testsuite/tests/rts/linker/unsigned_reloc_macho_64.stdout b/testsuite/tests/rts/linker/unsigned_reloc_macho_64.stdout
new file mode 100644
index 0000000000..8251451f5f
--- /dev/null
+++ b/testsuite/tests/rts/linker/unsigned_reloc_macho_64.stdout
@@ -0,0 +1,2 @@
+Linking: path = unsigned_reloc_macho_64.o, symname = _getAnswer
+42
\ No newline at end of file