[flang][debuginfo] Module variable needs to be qualified with module name.

[abidh]

To evalaute the variable in a module, we need to qualify it with the module name.

module helper
  integer var1
end module

PROGRAM minimal
  use helper
  var1 = 2
  print *, var1
end

In the above program, when stopped at line print *, var1, if I need to get the value of var1, I need to qualify it with the module name. With the right debug info, it should work without need to qualify the name with the module name.

(gdb) p var1
No symbol "var1" in current context.
(gdb) p helper::var1
$1 = 2

[llvmbot]

@llvm/issue-subscribers-flang-ir

Author: Abid Qadeer (abidh)

To evalaute the variable in a module, we need to qualify it with the module name.

module helper
  integer var1
end module

PROGRAM minimal
  use helper
  var1 = 2
  print *, var1
end

In the above program, when stopped at line print *, var1, if I need to get the value of var1, I need to qualify it with the module name. With the right debug info, it should work without need to qualify the name with the module name.

(gdb) p var1
No symbol "var1" in current context.
(gdb) p helper::var1
$1 = 2

[llvmbot]

@llvm/issue-subscribers-debuginfo

Author: Abid Qadeer (abidh)

To evalaute the variable in a module, we need to qualify it with the module name.

module helper
  integer var1
end module

PROGRAM minimal
  use helper
  var1 = 2
  print *, var1
end

In the above program, when stopped at line print *, var1, if I need to get the value of var1, I need to qualify it with the module name. With the right debug info, it should work without need to qualify the name with the module name.

(gdb) p var1
No symbol "var1" in current context.
(gdb) p helper::var1
$1 = 2

[kiranchandramohan]

@abidh Do you have a patch in progress for this? Is this just about adding the DI Imported Module tag?

[abidh]

@abidh Do you have a patch in progress for this? Is this just about adding the DI Imported Module tag?

I have been working on a fix. But it is proving difficult. You are right that it requires a !DIImportedEntity(tag: DIImportedModule) in the IR. Also imports field of the !DICompileUnit needs to be populated with the correct reference.

Problem I am facing is that when I create DIImportedEntityAttr in AddDebugInfo pass, I have no good place to attach it to. I thought that I could add a new field in DICompileUnitAttr and attach the list of DIImportedEntityAttr to it when all functions have been processed. This does not work because DICompileUnitAttr can't be changed once created. I am now working on the idea that I can perhaps attach it to ModuleOp as attr and then process it in the MLIR and generate the required debug metadata.