How to get the value of an i8*?

Hi all,
sorry to ask again but this problem is killing me :slight_smile:

So I have the following C code:

#include<stdio.h>

int main(int argc, char *argv[]) {

printf("%s\n", argv[0]);
return argc;
}

That is translated into

; ModuleID = ‘argv.bc’
source_filename = “argv.c”
target datalayout = “e-m:e-i64:64-f80:128-n8:16:32:64-S128”
target triple = “x86_64-pc-linux-gnu”

@.str = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1

; Function Attrs: noinline nounwind optnone uwtable
define i32 @main(i32, i8**) #0 {
%3 = alloca i32, align 4
%4 = alloca i32, align 4
%5 = alloca i8**, align 8
store i32 0, i32* %3, align 4
store i32 %0, i32* %4, align 4
store i8** %1, i8*** %5, align 8
%6 = load i8**, i8*** %5, align 8
%7 = getelementptr inbounds i8*, i8** %6, i64 0
%8 = load i8*, i8** %7, align 8
%9 = call i32 (i8*, …) @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str, i32 0, i32 0), i8* %8)
%10 = load i32, i32* %4, align 4
ret i32 %10
}

declare i32 @printf(i8*, …) #1

attributes #0 = { noinline nounwind optnone uwtable “correctly-rounded-divide-sqrt-fp-math”=“false” “disable-tail-calls”=“false” “less-precise-fpmad”=“false” “no-frame-pointer-elim”=“true” “no-frame-pointer-elim-non-leaf” “no-infs-fp-math”=“false” “no-jump-tables”=“false” “no-nans-fp-math”=“false” “no-signed-zeros-fp-math”=“false” “no-trapping-math”=“false” “stack-protector-buffer-size”=“8” “target-cpu”=“x86-64” “target-features”="+fxsr,+mmx,+sse,+sse2,+x87" “unsafe-fp-math”=“false” “use-soft-float”=“false” }
attributes #1 = { “correctly-rounded-divide-sqrt-fp-math”=“false” “disable-tail-calls”=“false” “less-precise-fpmad”=“false” “no-frame-pointer-elim”=“true” “no-frame-pointer-elim-non-leaf” “no-infs-fp-math”=“false” “no-nans-fp-math”=“false” “no-signed-zeros-fp-math”=“false” “no-trapping-math”=“false” “stack-protector-buffer-size”=“8” “target-cpu”=“x86-64” “target-features”="+fxsr,+mmx,+sse,+sse2,+x87" “unsafe-fp-math”=“false” “use-soft-float”=“false” }

!llvm.module.flags = !{!0}
!llvm.ident = !{!1}

!0 = !{i32 1, !“wchar_size”, i32 4}
!1 = !{!“clang version 6.0.1-svn334776-1~exp1~20181018152737.116 (branches/release_60)”}

I’m still experimenting with the Interpreter class…

I know that %8 holds the pointer to argv[0] and I would like to extract the value. I though the right approach would have been to do what it is done inside visitLoadInst:

ExecutionContext &SF = ECStack.back();
GenericValue SRC = getOperandValue(I.getPointerOperand(), SF);
GenericValue Ptr = (GenericValue)GVTOP(SRC);
GenericValue Result;
LoadValueFromMemory(Result, Ptr, I.getType());

Instead of I.getType() I used getInt32Ty(context) and instead of Ptr I used the result returned by first LoadValueFromMemory. After that I print “newResult.Int” but I always have 0 as a result. I cannot understand why.

Can someone help me to have argv[0] taken from the memory?

Thanks a lot