Merge pull request #3486 from MartinNowak/MachO_CDATA

Use constant data sections for MachO
dlang · Apr 24, 2014 · 0f9ff61 · 0f9ff61
2 parents 6de3bd5 + a48547e
commit 0f9ff61
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Showing 3 changed files with 19 additions and 42 deletions.
diff --git a/src/backend/elfobj.c b/src/backend/elfobj.c
@@ -634,23 +634,11 @@ symbol *Obj::sym_cdata(tym_t ty,char *p,int len)
 
 int Obj::data_readonly(char *p, int len, int *pseg)
 {
-    int oldoff;
-    /*if (OPT_IS_SET(OPTfwritable_strings))
-    {
-        oldoff = Doffset;
-        SegData[DATA]->SDbuf->reserve(len);
-        SegData[DATA]->SDbuf->writen(p,len);
-        Doffset += len;
-        *pseg = DATA;
-    }
-    else*/
-    {
-        oldoff = CDoffset;
-        SegData[CDATA]->SDbuf->reserve(len);
-        SegData[CDATA]->SDbuf->writen(p,len);
-        CDoffset += len;
-        *pseg = CDATA;
-    }
+    int oldoff = CDoffset;
+    SegData[CDATA]->SDbuf->reserve(len);
+    SegData[CDATA]->SDbuf->writen(p,len);
+    CDoffset += len;
+    *pseg = CDATA;
     return oldoff;
 }
 

diff --git a/src/backend/machobj.c b/src/backend/machobj.c
@@ -162,6 +162,12 @@ static IDXSTR extdef;
 
 int seg_data::isCode()
 {
+    // The codegen assumes that code->data references are indirect,
+    // but when CDATA is treated as code reftoident will emit a direct
+    // relocation.
+    if (this == SegData[CDATA])
+        return false;
+
     if (I64)
     {
         //printf("SDshtidx = %d, x%x\n", SDshtidx, SecHdrTab64[SDshtidx].flags);
@@ -384,23 +390,11 @@ symbol * Obj::sym_cdata(tym_t ty,char *p,int len)
 
 int Obj::data_readonly(char *p, int len, int *pseg)
 {
-    int oldoff;
-    if (I64)
-    {
-        oldoff = Doffset;
-        SegData[DATA]->SDbuf->reserve(len);
-        SegData[DATA]->SDbuf->writen(p,len);
-        Doffset += len;
-        *pseg = DATA;
-    }
-    else
-    {
-        oldoff = CDoffset;
-        SegData[CDATA]->SDbuf->reserve(len);
-        SegData[CDATA]->SDbuf->writen(p,len);
-        CDoffset += len;
-        *pseg = CDATA;
-    }
+    int oldoff = CDoffset;
+    SegData[CDATA]->SDbuf->reserve(len);
+    SegData[CDATA]->SDbuf->writen(p,len);
+    CDoffset += len;
+    *pseg = CDATA;
     return oldoff;
 }
 
@@ -482,9 +476,10 @@ Obj *Obj::init(Outbuffer *objbuf, const char *filename, const char *csegname)
     seg_count = 0;
     int align = I64 ? 4 : 2;            // align to 16 bytes for floating point
     MachObj::getsegment("__text",  "__TEXT", 2, S_REGULAR | S_ATTR_PURE_INSTRUCTIONS | S_ATTR_SOME_INSTRUCTIONS);
-    MachObj::getsegment("__data",  "__DATA", align, S_REGULAR);         // DATA
+    MachObj::getsegment("__data",  "__DATA", align, S_REGULAR);     // DATA
     MachObj::getsegment("__const", "__TEXT", 2, S_REGULAR);         // CDATA
     MachObj::getsegment("__bss",   "__DATA", 4, S_ZEROFILL);        // UDATA
+    MachObj::getsegment("__const", "__DATA", align, S_REGULAR);     // CDATAREL
 
     if (config.fulltypes)
         dwarf_initfile(filename);

diff --git a/src/backend/out.c b/src/backend/out.c
@@ -514,7 +514,7 @@ void outcommon(symbol *s,targ_size_t n)
 void out_readonly(symbol *s)
 {
     // The default is DATA
-#if ELFOBJ
+#if ELFOBJ || MACHOBJ
     /* Cannot have pointers in CDATA when compiling PIC code, because
      * they require dynamic relocations of the read-only segment.
      * Instead use the .data.rel.ro section. See Bugzilla 11171.
@@ -524,12 +524,6 @@ void out_readonly(symbol *s)
     else
         s->Sseg = CDATA;
 #endif
-#if MACHOBJ
-    /* Because of PIC and CDATA being in the _TEXT segment;
-     * cannot have pointers in CDATA.
-     * Should check s->Sdt and make it CDATA if it has no pointers.
-     */
-#endif
 #if OMFOBJ
     // Haven't really worked out where immutable read-only data can go.
 #endif