[LLVMdev] Ada support for llvm-gcc4

[Chris Lattner]

On Thu, 11 Jan 2007, Duncan Sands wrote:
> I'm trying to get the Ada gcc front-end to work with LLVM.
> This series of patches gets things to the point where the
> Ada compiler builds, though it fails to build itself or the
> runtime.  While I was there I resurrected fortran and
> java: as with Ada, the compilers build but not the runtimes.
> Also, I've replaced the gcc 4.0 Ada front-end with a back-port
> of the Ada front-end from FSF gcc head, since the 4.0 version
> is known to be weak.

Cool.  Can you post these patches individually to llvm-commits in an order 
that is easiest to review?  For example, obvious makefile changes and 
target independent things we can apply now.  Replacing the entire Ada 
front-end should wait until it works better.

Nice work,

-Chris

> All testing done on x86-linux-gnu.  No attempt was made to build
> for other targets.
>
> Patch description:
>
> 1-usehooks.diff
> 	Apple made some backend changes that assume a C-like
> front-end (C, C++ or ObjC): calls are made to decl_constant_value,
> iasm_build_bracket and similar routines that mostly aren't defined
> by the Ada, fortran and java front-ends.  However two of the calls,
> to c_common_type_for_mode and pushdecl, could equivalently be made
> to a langhook.  This patch switches these to langhook calls.
>
> 2-stubs.diff
> 	This adds a new file that provides dummy implementations
> for all the routines mentioned in (1) that can't be turned into
> langhook calls.  Putting these in one place means that Ada, java
> and fortran can be made to compile by simply linking with this
> file, and no longer need to individually define dummy routines.
> I made the dummys be weak symbols because java does define some
> of them.
>
> 3-fortran.diff
> 	Get fortran to compile: use the common stubs and rip out
> the incomplete collection of dummy routines someone already put in.
> With this patch, the fortran build dies at this point:
>
> cc1: llvm/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp:367: void llvm::ScheduleDAG::AddOperand(llvm:
> :MachineInstr*, llvm::SDOperand, unsigned int, const llvm::TargetInstrDescriptor*, std::map<llvm::SDNode*, unsign
> ed int, std::less<llvm::SDNode*>, std::allocator<std::pair<llvm::SDNode* const, unsigned int> > >&): Assertion `R
> egMap->getRegClass(VReg) == RC && "Register class of operand and regclass of use don't agree!"' failed.
> ../../../gcc.llvm.master/libgfortran/runtime/environ.c:619: internal compiler error: Aborted
>
>
> 4-java.diff
> 	Get java to compile: use the common stubs and rip out
> the incomplete collection of dummy routines someone already put in.
> With this patch, the java build dies at this point:
> libffi/src/x86/ffi.c: In function 'ffi_prep_cif_machdep':
> libffi/src/x86/ffi.c:130: error: duplicate case value
> libffi/src/x86/ffi.c:129: error: previously used here
>
> 5-ada-4.3.diff
> 	Replace the ada subdirectory with the one from gcc 4.3.
> I haven't attached this patch to the email, since even compressed
> it weighs in at 2.5MB.  If it is agreed that this patch series should
> go in, I will mail it to the appropriate person.
>
> The remaining patches make the adjustments needed to get the 4.3 Ada
> front-end working with the 4.0 infrastructure and with LLVM.
>
> 6-build.diff
> 	Ada Makefile fixes.
>
> 7-vec.diff
> 	Ada fixes due to VEC changes.
>
> 8-langhooks.diff
> 	Ada fixes due to langhook changes.
>
> 9-misc.diff
> 	Grab-bag of small Ada fixes.
>
> 10-fold_build2.diff
> 	Convert fold_build2 to fold+build2.
>
> 11-tree_invariant.diff
> 	Backport recompute_tree_invariant_for_addr_expr from 4.3.
>
> 12-optimize.diff
> 	The Ada front-end makes use of the optimization level (-O1 etc),
> however the level is not available in gcc-llvm4.  Pretend the optimization
> level is 2, until a better solution is found.
>
> 13-optabs.diff
> 	Remove all uses of optabs by Ada.  These seem to be left-over from
> older gcc versions: while optabs are initialized, they are not actually
> used.
>
> 14-decl_rtl.diff
> 	Use the LLVM version of make_decl_rtl when compiling for LLVM.
>
> 15-gimplifier.diff
> 	Backport some gimplifier fixes from 4.3.  These almost certainly
> will have no effect on languages other than Ada.
>
> With these patches, the Ada build dies at this point:
> Unhandled expression!
> <floor_mod_expr 0x40310c08...
>
> The Ada bootstrap dies at this point:
> <view_convert_expr 0x403c6320...
> llvm-convert.cpp:4248: static llvm::Constant* TreeConstantToLLVM::Convert(tree_node*): Assertion `0 && "Unknown constant to convert!"' failed.
>
>
> Enjoy!
>
> Duncan.
>

-Chris

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