Merge pull request #5359 from WalterBright/dwarfeh32

DwarfEH: 32 bit Linux support

src/backend/backconfig.c

@@ -100,7 +100,7 @@ void out_config_init(
     else
     {
         config.exe = EX_LINUX;
-        config.ehmethod = EH_DM;
+        config.ehmethod = EH_DWARF;
         if (!exe)
             config.flags |= CFGromable; // put switch tables in code segment
     }

src/backend/cgcod.c

@@ -790,7 +790,12 @@ code *prolog()
     regm_t topush = fregsaved & ~mfuncreg;          // mask of registers that need saving
     pushoffuse = false;
     pushoff = NDPoff;
-    if (config.flags4 & CFG4speed && (I32 || I64))
+    /* We don't keep track of all the pushes and pops in a function. Hence,
+     * using POP REG to restore registers in the epilog doesn't work, because the Dwarf unwinder
+     * won't be setting ESP correctly. With pushoffuse, the registers are restored
+     * from EBP, which is kept track of properly.
+     */
+    if ((config.flags4 & CFG4speed || config.ehmethod == EH_DWARF) && (I32 || I64))
     {
         /* Instead of pushing the registers onto the stack one by one,
          * allocate space in the stack frame and copy/restore them there.

src/backend/dwarf.c

@@ -814,8 +814,9 @@ void writeEhFrameFDE(IDXSEC dfseg, Symbol *sfunc)
     buf->write32(length);                               // Length (no Extended Length)
     buf->write32((startsize + 4) - CIE_offset);         // CIE Pointer
 #if ELFOBJ
-    buf->write32(0);                                    // address of function
-    ElfObj::addrel(dfseg, startsize + 8, R_X86_64_PC32, MAP_SEG2SYMIDX(sfunc->Sseg), sfunc->Soffset);
+    int fixup = I64 ? R_X86_64_PC32 : R_386_PC32;
+    buf->write32(I64 ? 0 : sfunc->Soffset);             // address of function
+    ElfObj::addrel(dfseg, startsize + 8, fixup, MAP_SEG2SYMIDX(sfunc->Sseg), sfunc->Soffset);
     //ElfObj::reftoident(dfseg, startsize + 8, sfunc, 0, CFpc32 | CFoff); // PC_begin
 #else
     assert(0);                                          // not supported yet
@@ -826,11 +827,11 @@ void writeEhFrameFDE(IDXSEC dfseg, Symbol *sfunc)
         buf->writeByten(4);                             // Augmentation Data Length
         int etseg = dwarf_getsegment_alloc(except_table_name, 1);
         // if CFG3pic, fixup should be R_X86_64_PC32
-        buf->write32(0);                                // address of LSDA (".gcc_except_table")
+        buf->write32(I64 ? 0 : sfunc->Sfunc->LSDAoffset); // address of LSDA (".gcc_except_table")
         if (config.flags3 & CFG3pic)
         {
 #if ELFOBJ
-            ElfObj::addrel(dfseg, buf->size() - 4, R_X86_64_PC32, MAP_SEG2SYMIDX(etseg), sfunc->Sfunc->LSDAoffset);
+            ElfObj::addrel(dfseg, buf->size() - 4, fixup, MAP_SEG2SYMIDX(etseg), sfunc->Sfunc->LSDAoffset);
 #else
             assert(0);                                  // not supported yet
 #endif

src/backend/elfobj.c

@@ -2888,7 +2888,7 @@ int Obj::reftoident(int seg, targ_size_t offset, Symbol *s, targ_size_t val,
         case SCglobal:
             if (!s->Sxtrnnum)
             {   // not in symbol table yet - class might change
-                //dbg_printf("\tadding %s to fixlist\n",s->Sident);
+                //printf("\tadding %s to fixlist\n",s->Sident);
                 size_t numbyteswritten = addtofixlist(s,offset,seg,val,flags);
                 assert(numbyteswritten == retsize);
                 return retsize;
@@ -3507,8 +3507,6 @@ void Obj::gotref(symbol *s)
  */
 int dwarf_reftoident(int seg, targ_size_t offset, Symbol *s, targ_size_t val)
 {
-    assert(I64);                // I32 not implemented yet
-
     if (config.flags3 & CFG3pic)
     {
         /* fixup: R_X86_64_PC32 sym="DW.ref.name"
@@ -3520,10 +3518,10 @@ int dwarf_reftoident(int seg, targ_size_t offset, Symbol *s, targ_size_t val)
          */
         if (!s->Sdw_ref_idx)
         {
-            int dataDWref_seg = ElfObj::getsegment(".data.DW.ref.", s->Sident, SHT_PROGBITS, SHF_ALLOC|SHF_WRITE, 8);
+            int dataDWref_seg = ElfObj::getsegment(".data.DW.ref.", s->Sident, SHT_PROGBITS, SHF_ALLOC|SHF_WRITE, I64 ? 8 : 4);
             Outbuffer *buf = SegData[dataDWref_seg]->SDbuf;
             assert(buf->size() == 0);
-            ElfObj::reftoident(dataDWref_seg, 0, s, 0, CFoffset64);
+            ElfObj::reftoident(dataDWref_seg, 0, s, 0, I64 ? CFoffset64 : CFoff);
 
             // Add "DW.ref." ~ name to the symtab_strings table
             IDXSTR namidx = symtab_strings->size();
@@ -3533,7 +3531,7 @@ int dwarf_reftoident(int seg, targ_size_t offset, Symbol *s, targ_size_t val)
 
             s->Sdw_ref_idx = elf_addsym(namidx, val, 8, STT_OBJECT, STB_WEAK, MAP_SEG2SECIDX(dataDWref_seg), STV_HIDDEN);
         }
-        ElfObj::writerel(seg, offset, R_X86_64_PC32, s->Sdw_ref_idx, 0);
+        ElfObj::writerel(seg, offset, I64 ? R_X86_64_PC32 : R_386_PC32, s->Sdw_ref_idx, 0);
     }
     else
     {

src/target.d

@@ -84,7 +84,7 @@ struct Target
         if (global.params.is64bit && global.params.isWindows)
             c_long_doublesize = 8;
 
-        cppExceptions = global.params.dwarfeh || (global.params.is64bit && global.params.isLinux);
+        cppExceptions = global.params.dwarfeh || global.params.isLinux;
     }
 
     /******************************

test/fail_compilation/fail3753.d

@@ -31,7 +31,7 @@ void main()
         version (Win32) static assert(0);
         version (linux)
         {
-            version (X86_64) static assert(0);
+            static assert(0);
         }
     }
     else

test/runnable/foreach5.d

@@ -967,6 +967,7 @@ void test12932() @nogc
 
 void test13756()
 {
+    printf("test13756()\n");
     int[int] org = [1:2], aa;
 
     aa = org.dup;
@@ -1075,6 +1076,7 @@ auto scoped14653(T, A...)(A args)
 
 void test14653()
 {
+    printf("test14653()\n");
     foreach (e; scoped14653!RangeClass14653(1))
     {
         result14653 ~= "b";
@@ -1110,6 +1112,7 @@ int main()
     test11291();
     test12103();
     test12739();
+    printf("test12932()\n");
     test12932();
     test13756();
     test14653();