[lldb-dev] r260768 (Removed many JIT workarounds from IRForTarget) broke expression parser with function on Hexagon

[Ted Woodward via lldb-dev]

Background: Hexagon clang doesn't have JIT support, so lldb for Hexagon only
uses the IR Interpreter (Codeplay wrote it for us).

 

Sean, r260768 broke the expression parser with functions.

 

Without connecting to a target, I can't get the info for main:

(lldb) e main

error: Can't run the expression locally: Interpreter doesn't handle one of
the expression's operands

 

Connected to a target, I can't run a function:

(lldb) e factorial(5)

error: Can't run the expression locally: Interpreter doesn't handle one of
the expression's operands

 

 

I've traced the failure to the call to CanResolveConstant() in
IRInterpreter::CanIntepret(). The failure happens on the 2nd operand. In the
working case, the Value ID is 0xa - Value::ConstantExprVal. In the failing
case, it is 0x5. Since it's defined in a .def file, I can't be sure, but my
guess is its Value::FunctionVal.

 

 

Where is the Value ID set?

 

 

 

Some info from the expr log:

 

; Function Attrs: nounwind

define void @"_Z12$__lldb_exprPv"(i8* %"$__lldb_arg") #0 {

entry:

  %"$__lldb_arg.addr" = alloca i8*, align 4, !clang.decl.ptr !4

  store i8* %"$__lldb_arg", i8** %"$__lldb_arg.addr", align 4

  %0 = load i8, i8* @"_ZGVZ12$__lldb_exprPvE19$__lldb_expr_result", align 1

  %guard.uninitialized = icmp eq i8 %0, 0

  br i1 %guard.uninitialized, label %init.check, label %init.end

 

init.check:                                       ; preds = %entry

  %call = call i32 @factorial(i32 5)

  store i32 %call, i32* @"_ZZ12$__lldb_exprPvE19$__lldb_expr_result", align
4

  store i8 1, i8* @"_ZGVZ12$__lldb_exprPvE19$__lldb_expr_result", align 1

  br label %init.end

 

init.end:                                         ; preds = %init.check,
%entry

  ret void

}

 

 

Unsupported constant: declare i32 @factorial(i32) #1

 

 

Ted

 

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