[flang][NFC] Retrieve binding table from fir.dispatch_table operations

[clementval]

Summary

Change how the binding tables are retrived. Use the newly lowered
fir.dispatch_table operations instead of the fir.global type infos.

[clementval]

Do not go through dtentries if region is empty.

[jeanPerier]

clang-format issue, LGTM otherwise

[clementval]

clang-format

flang/lib/Optimizer/CodeGen/CodeGen.cpp

auto declaredType =
                 [](auto p) {
                   if (auto seq =
                           p.getEleTy().template dyn_cast<fir::SequenceType>())
                     return seq.getEleTy();
                   return p.getEleTy();
                 })
             .Default([](mlir::Type t) { return t; });
     assert(declaredType.isa<fir::RecordType>() && "expecting fir.type");
-    auto recordType = declaredType.dyn_cast<fir::RecordType>();
-    std::string typeDescName =
-        fir::NameUniquer::getTypeDescriptorName(recordType.getName());
-    std::string typeDescBindingTableName =
-        fir::NameUniquer::getTypeDescriptorBindingTableName(
-            recordType.getName());
+    auto recordType = declaredType.dyn_cast<fir::RecordType>();  
 
     // Lookup for the binding table.
-    auto bindingsIter = bindingTables.find(typeDescBindingTableName);
+    auto bindingsIter = bindingTables.find(recordType.getName());
     if (bindingsIter == bindingTables.end())
       return emitError(loc)
-             << "cannot find binding table for " << typeDescBindingTableName;
+             << "cannot find binding table for " << recordType.getName();
 
     // Lookup for the binding.
     const BindingTable &bindingTable = bindingsIter->second;
     auto bindingIter = bindingTable.find(dispatch.getMethod());
     if (bindingIter == bindingTable.end())
       return emitError(loc)
              << "cannot find binding for " << dispatch.getMethod();
     unsigned bindingIdx = bindingIter->second;
 
     mlir::Value passedObject = dispatch.getObject();
 
     auto module = dispatch.getOperation()->getParentOfType<mlir::ModuleOp>();
     mlir::Type typeDescTy;
+    std::string typeDescName =
+        fir::NameUniquer::getTypeDescriptorName(recordType.getName());
     if (auto global = module.lookupSymbol<fir::GlobalOp>(typeDescName)) {
       typeDescTy = convertType(global.getType());
     } else if (auto global =
                    module.lookupSymbol<mlir::LLVM::GlobalOp>(typeDescName)) {
       // The global may have already been translated to LLVM.
       typeDescTy = global.getType();
     }
 
void runOnOperation() override final {
     // as passes here.
     mlir::OpPassManager mathConvertionPM("builtin.module");
     mathConvertionPM.addPass(mlir::createConvertMathToFuncsPass());
     mathConvertionPM.addPass(mlir::createConvertComplexToStandardPass());
     if (mlir::failed(runPipeline(mathConvertionPM, mod)))
       return signalPassFailure();
 
     // Reconstruct binding tables for dynamic dispatch. The binding tables
-    // are defined in FIR from semantics as fir.global operation with region
-    // initializer. Go through each bining tables and store the procedure name
+    // are defined in FIR from lowering as fir.dispatch_table operation.
+    // Go through each binding tables and store the procedure name
     // and binding index for later use by the fir.dispatch conversion pattern.
     BindingTables bindingTables;
-    for (auto globalOp : mod.getOps<fir::GlobalOp>()) {
-      if (globalOp.getSymName().contains(bindingTableSeparator)) {
-        unsigned bindingIdx = 0;
-        BindingTable bindings;
-        for (auto addrOp : globalOp.getRegion().getOps<fir::AddrOfOp>()) {
-          if (fir::isa_char(fir::unwrapRefType(addrOp.getType()))) {
-            if (auto nameGlobal =
-                    mod.lookupSymbol<fir::GlobalOp>(addrOp.getSymbol())) {
-              auto stringLit = llvm::to_vector(
-                  nameGlobal.getRegion().getOps<fir::StringLitOp>())[0];
-              auto procName =
-                  stringLit.getValue().dyn_cast<mlir::StringAttr>().getValue();
-              bindings[procName] = bindingIdx;
-              ++bindingIdx;
-            }
-          }
-        }
-        bindingTables[globalOp.getSymName()] = bindings;
-      }
+    for (auto dispatchTableOp : mod.getOps<fir::DispatchTableOp>()) {
+      for (auto dtEntry : dispatchTableOp.getBlock().getOps<fir::DTEntryOp>()) {
+        bindings[dtEntry.getMethod()] = bindingIdx;
+      bindingTables[dispatchTableOp.getSymName()] = bindings;
     }
 
     auto *context = getModule().getContext();
     fir::LLVMTypeConverter typeConverter{getModule()};
     mlir::RewritePatternSet pattern(context);
     pattern.insert<
         AbsentOpConversion, AddcOpConversion, AddrOfOpConversion,
         AllocaOpConversion, AllocMemOpConversion, BoxAddrOpConversion,

flang/test/Fir/dispatch.f90

contains
     procedure :: display2 => display2_p2
     procedure :: display3
     procedure :: get_value => get_value_p2
     procedure :: proc_with_values => proc_p2
     procedure, nopass :: proc_nopass => proc_nopass_p2
     procedure, pass(this) :: proc_pass => proc_pass_p2
   end type
 
+  type, abstract :: a1
+    integer a
+  contains
+    procedure :: a1_proc
+  end type
+
+  type, extends(a1) :: a2
+    integer b
+  contains
+    procedure :: a1_proc => a2_proc
+  end type
+
 contains
 
   subroutine display1_p1(this)
     class(p1) :: this
     print*,'call display1_p1'
   end subroutine
 
   subroutine display2_p1(this)
subroutine no_pass_array_allocatable(a)
     call a(1)%proc_nopass()
   end subroutine
 
   subroutine no_pass_array_pointer(a)
     class(p1), allocatable :: a(:)
     call a(1)%proc_nopass()
   end subroutine
 
+  subroutine a1_proc(this)
+    class(a1) :: this
+  end subroutine
+
+  subroutine a2_proc(this)
+    class(a2) :: this
+  end subroutine
+
+  subroutine call_a1_proc(p)
+    class(a1), pointer :: p
+    call p%a1_proc()
+  end subroutine
+
 end module
 
 program test_type_to_class
   use dispatch1
   type(p1) :: t1 = p1(1,2)
   type(p2) :: t2 = p2(1,2,3)
 
   call display_class(t1)

 ! CHECK: %[[BUILTIN_FUNC_PTR:.*]] = extractvalue %_QM__fortran_type_infoTbinding %[[LOADED_BINDING]], 0
 ! CHECK: %[[FUNC_ADDR:.*]] = extractvalue %_QM__fortran_builtinsT__builtin_c_funptr %[[BUILTIN_FUNC_PTR]], 0
 ! CHECK: %[[FUNC_PTR:.*]] = inttoptr i64 %[[FUNC_ADDR]] to ptr
 ! CHECK: call void %[[FUNC_PTR]](ptr %[[INT32]], ptr %[[CLASS]])
 
 ! CHECK-LABEL: _QMdispatch1Pno_pass_array
 ! CHECK-LABEL: _QMdispatch1Pno_pass_array_allocatable
 ! CHECK-LABEL: _QMdispatch1Pno_pass_array_pointer
+! CHECK-LABEL: _QMdispatch1Pcall_a1_proc
 
 ! Check the layout of the binding table. This is easier to do in FIR than in 
 ! LLVM IR.
 
-! BT-LABEL: fir.global linkonce_odr @_QMdispatch1E.v.p1 constant target : !fir.array<7x!fir.type<_QM__fortran_type_infoTbinding{proc:!fir.type<_QM__fortran_builtinsT__builtin_c_funptr{__address:i64}>,name:!fir.box<!fir.ptr<!fir.char<1,?>>>}>> {
-! BT: %{{.*}} = fir.address_of(@_QMdispatch1Paproc) : (!fir.class<!fir.type<_QMdispatch1Tp1{a:i32,b:i32}>>) -> ()
-! BT: %{{.*}} = fir.address_of(@_QMdispatch1Pdisplay1_p1) : (!fir.class<!fir.type<_QMdispatch1Tp1{a:i32,b:i32}>>) -> ()
-! BT: %{{.*}} = fir.address_of(@_QMdispatch1Pdisplay2_p1) : (!fir.class<!fir.type<_QMdispatch1Tp1{a:i32,b:i32}>>) -> ()
-! BT: %{{.*}} = fir.address_of(@_QMdispatch1Pget_value_p1) : (!fir.class<!fir.type<_QMdispatch1Tp1{a:i32,b:i32}>>) -> i32
-! BT: %{{.*}} = fir.address_of(@_QMdispatch1Pproc_nopass_p1) : () -> ()
-! BT: %{{.*}} = fir.address_of(@_QMdispatch1Pproc_pass_p1) : (!fir.ref<i32>, !fir.class<!fir.type<_QMdispatch1Tp1{a:i32,b:i32}>>) -> ()
-! BT: %{{.*}} = fir.address_of(@_QMdispatch1Pproc_p1) : (!fir.class<!fir.type<_QMdispatch1Tp1{a:i32,b:i32}>>, !fir.ref<f32>) -> ()
+! BT-LABEL: fir.dispatch_table @_QMdispatch1Tp1 {
+! BT: fir.dt_entry "aproc", @_QMdispatch1Paproc
+! BT: fir.dt_entry "display1", @_QMdispatch1Pdisplay1_p1
+! BT: fir.dt_entry "display2", @_QMdispatch1Pdisplay2_p1
+! BT: fir.dt_entry "get_value", @_QMdispatch1Pget_value_p1
+! BT: fir.dt_entry "proc_nopass", @_QMdispatch1Pproc_nopass_p1
+! BT: fir.dt_entry "proc_pass", @_QMdispatch1Pproc_pass_p1
+! BT: fir.dt_entry "proc_with_values", @_QMdispatch1Pproc_p1
 ! BT: }
 
-! BT-LABEL: fir.global linkonce_odr @_QMdispatch1E.v.p2 constant target : !fir.array<8x!fir.type<_QM__fortran_type_infoTbinding{proc:!fir.type<_QM__fortran_builtinsT__builtin_c_funptr{__address:i64}>,name:!fir.box<!fir.ptr<!fir.char<1,?>>>}>> {
-! BT: %{{.*}} = fir.address_of(@_QMdispatch1Paproc) : (!fir.class<!fir.type<_QMdispatch1Tp1{a:i32,b:i32}>>) -> ()
-! BT: %{{.*}} = fir.address_of(@_QMdispatch1Pdisplay1_p2) : (!fir.class<!fir.type<_QMdispatch1Tp2{a:i32,b:i32,c:i32}>>) -> ()
-! BT: %{{.*}} = fir.address_of(@_QMdispatch1Pdisplay2_p2) : (!fir.class<!fir.type<_QMdispatch1Tp2{a:i32,b:i32,c:i32}>>) -> ()
-! BT: %{{.*}} = fir.address_of(@_QMdispatch1Pget_value_p2) : (!fir.class<!fir.type<_QMdispatch1Tp2{a:i32,b:i32,c:i32}>>) -> i32
-! BT: %{{.*}} = fir.address_of(@_QMdispatch1Pproc_nopass_p2) : () -> ()
-! BT: %{{.*}} = fir.address_of(@_QMdispatch1Pproc_pass_p2) : (!fir.ref<i32>, !fir.class<!fir.type<_QMdispatch1Tp2{a:i32,b:i32,c:i32}>>) -> ()
-! BT: %{{.*}} = fir.address_of(@_QMdispatch1Pproc_p2) : (!fir.class<!fir.type<_QMdispatch1Tp2{a:i32,b:i32,c:i32}>>, !fir.ref<f32>) -> ()
-! BT: %{{.*}} = fir.address_of(@_QMdispatch1Pdisplay3) : (!fir.class<!fir.type<_QMdispatch1Tp2{a:i32,b:i32,c:i32}>>) -> ()
+! BT-LABEL: fir.dispatch_table @_QMdispatch1Ta1 {
+! BT: fir.dt_entry "a1_proc", @_QMdispatch1Pa1_proc
 ! BT: }
 
+! BT-LABEL: fir.dispatch_table @_QMdispatch1Ta2 extends("_QMdispatch1Ta1") {
+! BT:  fir.dt_entry "a1_proc", @_QMdispatch1Pa2_proc
+! BT: }
+
+! BT-LABEL: fir.dispatch_table @_QMdispatch1Tp2 extends("_QMdispatch1Tp1") {
+! BT:  fir.dt_entry "aproc", @_QMdispatch1Paproc
+! BT:  fir.dt_entry "display1", @_QMdispatch1Pdisplay1_p2
+! BT:  fir.dt_entry "display2", @_QMdispatch1Pdisplay2_p2
+! BT:  fir.dt_entry "get_value", @_QMdispatch1Pget_value_p2
+! BT:  fir.dt_entry "proc_nopass", @_QMdispatch1Pproc_nopass_p2
+! BT:  fir.dt_entry "proc_pass", @_QMdispatch1Pproc_pass_p2
+! BT:  fir.dt_entry "proc_with_values", @_QMdispatch1Pproc_p2
+! BT:  fir.dt_entry "display3", @_QMdispatch1Pdisplay3
+! BT: }