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incorrect variable capture in uhdm #3718

@Thomasb81

Description

@Thomasb81
  1. on following testcase
module dut ( output var logic a);

assign a = 0;
assign a = 1;

endmodule

The uhdm elaborated tree is

...
  \_port: (a), line:1:31, endln:1:32
    |vpiParent:
    \_module_inst: work@dut (work@dut), file:/home/tom/prog/git/Surelog/test2.sv, line:1:1, endln:6:10
    |vpiName:a
    |vpiDirection:2
    |vpiLowConn:
    \_ref_obj: ([email protected]), line:1:31, endln:1:32
      |vpiParent:
      \_port: (a), line:1:31, endln:1:32
      |vpiName:a
      |vpiFullName:[email protected]
      |vpiActual:
      \_logic_var: ([email protected]), line:1:31, endln:1:32
    |vpiTypedef:
    \_logic_typespec: , line:1:25, endln:1:30
  |vpiContAssign:
  \_cont_assign: , line:3:8, endln:3:13
    |vpiParent:
    \_module_inst: work@dut (work@dut), file:/home/tom/prog/git/Surelog/test2.sv, line:1:1, endln:6:10
    |vpiRhs:
    \_constant: , line:3:12, endln:3:13
      |vpiParent:
      \_cont_assign: , line:3:8, endln:3:13
      |vpiDecompile:0
      |vpiSize:1
      |UINT:0
      |vpiConstType:9
    |vpiLhs:
    \_ref_obj: ([email protected]), line:3:8, endln:3:9
      |vpiParent:
      \_cont_assign: , line:3:8, endln:3:13
      |vpiName:a
      |vpiFullName:[email protected]
      |vpiActual:
      \_logic_net: ([email protected]), line:1:31, endln:1:32                                       <---- should be logic_var ?
  |vpiContAssign:
  \_cont_assign: , line:4:8, endln:4:13
    |vpiParent:
    \_module_inst: work@dut (work@dut), file:/home/tom/prog/git/Surelog/test2.sv, line:1:1, endln:6:10
    |vpiRhs:
    \_constant: , line:4:12, endln:4:13
      |vpiParent:
      \_cont_assign: , line:4:8, endln:4:13
      |vpiDecompile:1
      |vpiSize:1
      |UINT:1
      |vpiConstType:9
    |vpiLhs:
    \_ref_obj: ([email protected]), line:4:8, endln:4:9
      |vpiParent:
      \_cont_assign: , line:4:8, endln:4:13
      |vpiName:a
      |vpiFullName:[email protected]
      |vpiActual:
      \_logic_net: ([email protected]), line:1:31, endln:1:32                                       <---- should be logic_var ?

On both ConsAssign, Lhs vpiActual return a logic_net, while it should probably be logic_var.

As a is declare as a variable, the linter should throw an error. See chapter 6.5 : Alternatively, variables can be written by one continuous assignment or one port.

  1. Another thing odd to me, on a different testcase, but still related to variable:
module dut ();

logic a;
var logic b;
var c;

endmodule

In non-elaborated model, a, b and 'c' are capture has net. While by source code definition the tool should capture them as variable without elaboration step needed. Later in elaborated tree, element take their correct object type.

  |vpiNet:                                                             <---- vpiVariables ?
  \_logic_net: ([email protected]), line:3:7, endln:3:8  <---- logic_var
    |vpiParent:
    \_module_inst: work@dut (work@dut), file:/home/tom/prog/git/Surelog/test5.sv, line:1:1, endln:7:10
    |vpiTypespec:
    \_logic_typespec: , line:3:1, endln:3:6
    |vpiName:a
    |vpiFullName:[email protected]
    |vpiNetType:36                                               <--- inconsistent concequence 
  |vpiNet:                                                                 <---- vpiVariables ?
  \_logic_net: ([email protected]), line:4:11, endln:4:12  <---- logic_var
    |vpiParent:
    \_module_inst: work@dut (work@dut), file:/home/tom/prog/git/Surelog/test5.sv, line:1:1, endln:7:10
    |vpiTypespec:
    \_logic_typespec: , line:4:5, endln:4:10
    |vpiName:b
    |vpiFullName:[email protected]
  |vpiNet:                                                             <---- vpiVariables ?
  \_logic_net: ([email protected]), line:5:5, endln:5:6  <---- vpiVariables ?
    |vpiParent:
    \_module_inst: work@dut (work@dut), file:/home/tom/prog/git/Surelog/test5.sv, line:1:1, endln:7:10
    |vpiName:c
    |vpiFullName:[email protected]


See chapter 6.8 :
image

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