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[John Criswell <criswell AT illinois.edu>]

On 5/30/12 9:03 AM, Baozeng wrote:
> Dear John,
> I added metadata information for global and stack variables(commit
> r157609 and commit r157670). Then I first test global variable with
> the following test:
>
> #include<stdlib.h>
>
> int p[33];
> int main() {
>    p[35] = 8;
>    return 0;
> }
> Then
> #clang -fmemsafety -bbc globaltest.c -o test
> -L/home/sploving/llvm/projects/safecode/Debug/lib
> It shows the following error:
> /tmp/globaltest-GkBpxH.o:globaltest.c:function sourcefile: error:
> undefined reference to 'baggy.metadata1'

I don't see anything immediately wrong.  However, I'd like to point out 
that in the command above, you're not using the -g option, and in the 
command below, you are using the -g option.

Do you get the problem both with and without the -g option?

> Its IR file is as the following(clang -g -fmemsafety -bbc globaltest.c
> -o test_me.bc -c -emit-llvm
> ):
>
> ; ModuleID = '<stdin>'
> target datalayout =
> "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32-n8:16:32-S128"
> target triple = "i386-pc-linux-gnu"
>
> @llvm.global_ctors = appending global [1 x { i32, void ()* }] [{ i32,
> void ()* } { i32 0, void ()* @pool_ctor }]
> @baggy.metadata = common global { i32, i32* }
> @p = common global { [33 x i32], [116 x i8], { i32, i32* } } { [33 x
> i32] zeroinitializer, [116 x i8] zeroinitializer, { i32, i32* }*
> @baggy.metadata }, align 256
> @baggy.metadata1 = internal constant { i32, i32* }
> @sourcefile = internal constant { [28 x i8], [28 x i8], { i32, i32* }
> } { [28 x i8] c"/home/sploving/globaltest.c\00", [28 x i8]
> zeroinitializer, { i32, i32* }* @baggy.metadata1 }, align 64

Try adding a zeroinitializer to the baggy.metadata global variables.  I 
get an error about them not having any initializer when I try to use BBC 
with libLTO.

> [snip]
>
> What is the matter with my commit?
>
> Another thing, are there any classic examples to test whether BBC
> support global and stack variables checking?

No.  To test it, you'll need to write your own sample programs.  
Eventually, we'll want to add lit tests for BBC.

-- John T.