Revert "[flang] Improve debug info for functions." (#90444)

Reverts #90083 due to a test suite failure:
https://lab.llvm.org/buildbot/#/builders/184/builds/11961

```
flang-new: ../llvm/mlir/lib/IR/Types.cpp:126: unsigned int mlir::Type::getIntOrFloatBitWidth() const: Assertion `isIntOrFloat() && "only integers and floats have a bitwidth"' failed.
```

Author: DavidSpickett

flang/lib/Optimizer/Transforms/AddDebugInfo.cpp

@@ -11,7 +11,6 @@
 /// This pass populates some debug information for the module and functions.
 //===----------------------------------------------------------------------===//
 
-#include "DebugTypeGenerator.h"
 #include "flang/Common/Version.h"
 #include "flang/Optimizer/Builder/FIRBuilder.h"
 #include "flang/Optimizer/Builder/Todo.h"
@@ -107,27 +106,14 @@ void AddDebugInfoPass::runOnOperation() {
       filePath = llvm::sys::path::parent_path(funcLoc.getFilename().getValue());
     }
 
-    mlir::StringAttr fullName =
-        mlir::StringAttr::get(context, funcOp.getName());
-    auto result = fir::NameUniquer::deconstruct(funcOp.getName());
     mlir::StringAttr funcName =
-        mlir::StringAttr::get(context, result.second.name);
-
-    llvm::SmallVector<mlir::LLVM::DITypeAttr> types;
-    fir::DebugTypeGenerator typeGen(module);
-    for (auto resTy : funcOp.getResultTypes()) {
-      auto tyAttr =
-          typeGen.convertType(resTy, fileAttr, cuAttr, funcOp.getLoc());
-      types.push_back(tyAttr);
-    }
-    for (auto inTy : funcOp.getArgumentTypes()) {
-      auto tyAttr = typeGen.convertType(fir::unwrapRefType(inTy), fileAttr,
-                                        cuAttr, funcOp.getLoc());
-      types.push_back(tyAttr);
-    }
-
+        mlir::StringAttr::get(context, funcOp.getName());
+    mlir::LLVM::DIBasicTypeAttr bT = mlir::LLVM::DIBasicTypeAttr::get(
+        context, llvm::dwarf::DW_TAG_base_type, "void", /*sizeInBits=*/0,
+        /*encoding=*/1);
+    // FIXME: Provide proper type for subroutine
     mlir::LLVM::DISubroutineTypeAttr subTypeAttr =
-        mlir::LLVM::DISubroutineTypeAttr::get(context, CC, types);
+        mlir::LLVM::DISubroutineTypeAttr::get(context, CC, {bT, bT});
     mlir::LLVM::DIFileAttr funcFileAttr =
         mlir::LLVM::DIFileAttr::get(context, fileName, filePath);
 
@@ -144,13 +130,11 @@ void AddDebugInfoPass::runOnOperation() {
       subprogramFlags =
           subprogramFlags | mlir::LLVM::DISubprogramFlags::Definition;
     }
-    unsigned line = 1;
-    if (auto funcLoc = l.dyn_cast<mlir::FileLineColLoc>())
-      line = funcLoc.getLine();
-
+    // FIXME: Provide proper line and scopeline.
     auto spAttr = mlir::LLVM::DISubprogramAttr::get(
-        context, id, compilationUnit, fileAttr, funcName, fullName,
-        funcFileAttr, line, line, subprogramFlags, subTypeAttr);
+        context, id, compilationUnit, fileAttr, funcName, funcName,
+        funcFileAttr, /*line=*/1, /*scopeline=*/1, subprogramFlags,
+        subTypeAttr);
     funcOp->setLoc(builder.getFusedLoc({funcOp->getLoc()}, spAttr));
   });
 }

flang/lib/Optimizer/Transforms/CMakeLists.txt

@@ -22,7 +22,6 @@ add_flang_library(FIRTransforms
   OMPMarkDeclareTarget.cpp
   VScaleAttr.cpp
   FunctionAttr.cpp
-  DebugTypeGenerator.cpp
 
   DEPENDS
   FIRDialect

flang/lib/Optimizer/Transforms/DebugTypeGenerator.cpp

@@ -31,7 +31,7 @@ module attributes {} {
 // CHECK: #[[LOC_INC_FILE:.*]] = loc("{{.*}}inc.f90":1:1)
 // CHECK: #[[LOC_FILE:.*]] = loc("{{.*}}simple.f90":3:1)
 // CHECK: #[[DI_CU:.*]] = #llvm.di_compile_unit<id = distinct[{{.*}}]<>, sourceLanguage = DW_LANG_Fortran95, file = #[[DI_FILE]], producer = "flang{{.*}}", isOptimized = false, emissionKind = LineTablesOnly>
-// CHECK: #[[DI_SP_INC:.*]] = #llvm.di_subprogram<id = distinct[{{.*}}]<>, compileUnit = #[[DI_CU]], scope = #[[DI_FILE]], name = "sinc", linkageName = "_QPsinc", file = #[[DI_INC_FILE]], {{.*}}>
+// CHECK: #[[DI_SP_INC:.*]] = #llvm.di_subprogram<id = distinct[{{.*}}]<>, compileUnit = #[[DI_CU]], scope = #[[DI_FILE]], name = "_QPsinc", linkageName = "_QPsinc", file = #[[DI_INC_FILE]], {{.*}}>
 // CHECK: #[[DI_SP:.*]] = #llvm.di_subprogram<id = distinct[{{.*}}]<>, compileUnit = #[[DI_CU]], scope = #[[DI_FILE]], name = "_QQmain", linkageName = "_QQmain", file = #[[DI_FILE]], {{.*}}>
 // CHECK: #[[FUSED_LOC_INC_FILE]] = loc(fused<#[[DI_SP_INC]]>[#[[LOC_INC_FILE]]])
 // CHECK: #[[FUSED_LOC_FILE]] = loc(fused<#[[DI_SP]]>[#[[LOC_FILE]]])