+ tllvmexceptionstatehandler that emits LLVM landingpad instructions to be

referred by invoke instructions in exception catching blocks
   o for now we won't actually use ABI-compliant exception handling, but we
     need invoke/landingpad combinations for LLVM's control flow analyses to
     correctly handle code involving exception handling

git-svn-id: branches/debug_eh@40401 -

.gitattributes

@@ -343,6 +343,7 @@ compiler/llvm/llvmdef.pas svneol=native#text/plain
 compiler/llvm/llvminfo.pas svneol=native#text/plain
 compiler/llvm/llvmnode.pas svneol=native#text/plain
 compiler/llvm/llvmpara.pas svneol=native#text/plain
+compiler/llvm/llvmpi.pas svneol=native#text/plain
 compiler/llvm/llvmsym.pas svneol=native#text/plain
 compiler/llvm/llvmtarg.pas svneol=native#text/plain
 compiler/llvm/llvmtype.pas svneol=native#text/plain

compiler/llvm/llvmnode.pas

@@ -39,7 +39,7 @@ implementation
     tgllvm,hlcgllvm,
     nllvmadd,nllvmbas,nllvmcal,nllvmcnv,nllvmcon,nllvmflw,nllvminl,nllvmld,
     nllvmmat,nllvmmem,nllvmtcon,nllvmutil,
-    llvmpara,
+    llvmpara,llvmpi,
     symllvm;
 
 end.

compiler/llvm/llvmpi.pas

@@ -0,0 +1,93 @@
+{
+    Copyright (c) 2016 by Jonas Maebe
+
+    Information about the current procedure that is being compiled
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+ ****************************************************************************
+}
+unit llvmpi;
+
+{$i fpcdefs.inc}
+
+interface
+
+    uses
+      cclasses,
+      aasmbase,
+      procinfo,
+      cpupi;
+
+    type
+      tllvmprocinfo = class(tcpuprocinfo)
+       private
+        fexceptlabelstack: tfplist;
+       public
+        constructor create(aparent: tprocinfo); override;
+        destructor destroy; override;
+        procedure pushexceptlabel(lab: TAsmLabel);
+        procedure popexceptlabel(lab: TAsmLabel);
+        function CurrExceptLabel: TAsmLabel; inline;
+      end;
+
+implementation
+
+    uses
+      globtype,verbose,
+      symtable;
+
+
+    constructor tllvmprocinfo.create(aparent: tprocinfo);
+      begin
+        inherited;
+        fexceptlabelstack:=tfplist.create;
+      end;
+
+    destructor tllvmprocinfo.destroy;
+      begin
+        if fexceptlabelstack.Count<>0 then
+          Internalerror(2016121301);
+        fexceptlabelstack.free;
+        inherited;
+      end;
+
+
+    procedure tllvmprocinfo.pushexceptlabel(lab: TAsmLabel);
+      begin
+        fexceptlabelstack.add(lab);
+      end;
+
+
+    procedure tllvmprocinfo.popexceptlabel(lab: TAsmLabel);
+      begin
+        if CurrExceptLabel<>lab then
+          internalerror(2016121302);
+        fexceptlabelstack.count:=fexceptlabelstack.count-1;
+      end;
+
+
+    function tllvmprocinfo.CurrExceptLabel: TAsmLabel; inline;
+      begin
+        result:=TAsmLabel(fexceptlabelstack.last);
+        if not assigned(result) then
+          internalerror(2016121703);
+      end;
+
+
+begin
+  cprocinfo:=tllvmprocinfo;
+end.
+

compiler/llvm/nllvmflw.pas

@@ -26,7 +26,7 @@ unit nllvmflw;
 interface
 
     uses
-      aasmbase,
+      aasmbase,aasmdata,
       nflw, ncgflw, ncgnstfl;
 
     type
@@ -34,6 +34,11 @@ interface
         function getasmlabel: tasmlabel; override;
       end;
 
+      tllvmexceptionstatehandler = class(tcgexceptionstatehandler)
+        class procedure new_exception(list: TAsmList; const t: texceptiontemps; out exceptstate: texceptionstate); override;
+        class procedure emit_except_label(list: TAsmList; var exceptionstate: texceptionstate); override;
+      end;
+
 
 implementation
 
@@ -42,8 +47,11 @@ implementation
 *****************************************************************************}
 
     uses
-      aasmdata;
-
+      systems,
+      symconst,symdef,llvmdef,
+      cgbase,cgutils,hlcgobj,
+      llvmbase,aasmllvm,
+      procinfo,llvmpi;
 
     function tllvmlabelnode.getasmlabel: tasmlabel;
       begin
@@ -61,7 +69,73 @@ implementation
         result:=asmlabel
       end;
 
+
+{*****************************************************************************
+                     tllvmexceptionstatehandler
+*****************************************************************************}
+
+    class procedure tllvmexceptionstatehandler.new_exception(list: TAsmList; const t: texceptiontemps; out exceptstate: texceptionstate);
+      var
+        landingpadlabel: TAsmLabel;
+      begin
+        inherited;
+        { all calls inside the exception block have to be invokes instead,
+          which refer to the exception label. We can't use the same label as the
+          one used by the setjmp/longjmp, because only invoke operations are
+          allowed to refer to a landingpad label -> create an extra label and
+          emit:
+            landingpadlabel:
+              %reg = landingpad ..
+            exceptstate.exceptionlabel:
+              <exception handling code>
+        }
+        current_asmdata.getjumplabel(landingpadlabel);
+        { for consistency checking when popping }
+        tllvmprocinfo(current_procinfo).pushexceptlabel(exceptstate.exceptionlabel);
+        tllvmprocinfo(current_procinfo).pushexceptlabel(landingpadlabel);
+      end;
+
+
+    class procedure tllvmexceptionstatehandler.emit_except_label(list: TAsmList; var exceptionstate: texceptionstate);
+      var
+        reg: tregister;
+        clause: taillvm;
+        exc: treference;
+        landingpaddef: trecorddef;
+      begin
+        { prevent fallthrough into the landingpad, not allowed }
+        hlcg.a_jmp_always(list,exceptionstate.exceptionlabel);
+        hlcg.a_label(list,tllvmprocinfo(current_procinfo).CurrExceptLabel);
+        { indicate that we will catch everything to LLVM's control flow
+          analysis; our personality function will (for now) indicate that it
+          doesn't actually want to handle any exceptions, so the stack unwinders
+          will ignore us anyway (our own exceptions are still handled via
+          setjmp/longjmp) }
+        clause:=taillvm.exceptclause(
+          la_catch,voidpointertype,nil,nil);
+        { dummy register (for now): we use the same code as on other platforms
+          to determine the exception type, our "personality function" won't
+          return anything useful }
+        reg:=hlcg.getintregister(list,u32inttype);
+        { use packrecords 1 because we don't want padding (LLVM 4.0+ requires
+          exactly two fields in this struct) }
+        landingpaddef:=llvmgettemprecorddef([voidpointertype,u32inttype],
+          1,
+          targetinfos[target_info.system]^.alignment.recordalignmin,
+          targetinfos[target_info.system]^.alignment.maxCrecordalign);
+        list.concat(taillvm.landingpad(reg,landingpaddef,clause));
+        { remove current exception label from the stack }
+        tllvmprocinfo(current_procinfo).popexceptlabel(tllvmprocinfo(current_procinfo).CurrExceptLabel);
+        { consistency check }
+        tllvmprocinfo(current_procinfo).popexceptlabel(exceptionstate.exceptionlabel);
+        inherited;
+
+      end;
+
+
+
 begin
   clabelnode:=tllvmlabelnode;
+  cexceptionstatehandler:=tllvmexceptionstatehandler;
 end.