Commit Graph

3 Commits

Author SHA1 Message Date
Siva Chandra
03ff5c8616 Take 2: Use an artifical namespace so that member vars do not hide local vars.
Summary: This relands r259810 with fix for failures on Mac.

Reviewers: spyffe, tfiala

Subscribers: tfiala, lldb-commits

Differential Revision: http://reviews.llvm.org/D16900

llvm-svn: 259902
2016-02-05 19:10:04 +00:00
Siva Chandra
77b326f39d Revert "Use an artifical namespace so that member vars do not hide local vars."
Summary:
This reverts commit 8af14b5f9af68c31ac80945e5b5d56f0a14b38e4.
Reverting as it breaks a few tests on Mac.

Reviewers: spyffe

Subscribers: lldb-commits

Differential Revision: http://reviews.llvm.org/D16895

llvm-svn: 259823
2016-02-04 20:08:40 +00:00
Siva Chandra
375882dddb Use an artifical namespace so that member vars do not hide local vars.
Summary:
While evaluating expressions when stopped in a class method, there was a
problem of member variables hiding local variables. This was happening
because, in the context of a method, clang already knew about member
variables with their name and assumed that they were the only variables
with those names in scope. Consequently, clang never checks with LLDB
about the possibility of local variables with the same name and goes
wrong. This change addresses the problem by using an artificial
namespace "$__lldb_local_vars". All local variables in scope are
declared in the "$__lldb_expr" method as follows:

    using $__lldb_local_vars::<local var 1>;
    using $__lldb_local_vars::<local var 2>;
    ...

This hides the member variables with the same name and forces clang to
enquire about the variables which it thinks are declared in
$__lldb_local_vars. When LLDB notices that clang is enquiring about
variables in $__lldb_local_vars, it looks up local vars and conveys
their information if found. This way, member variables do not hide local
variables, leading to correct evaluation of expressions.

A point to keep in mind is that the above solution does not solve the
problem for one specific case:

    namespace N
    {
        int a;
    }

    class A
    {
    public:
        void Method();
        int a;
    };

    void
    A::Method()
    {
        using N::a;
        ...

        // Since the above solution only touches locals, it does not
        // force clang to enquire about "a" coming from namespace N.
    }

Reviewers: clayborg, spyffe

Subscribers: lldb-commits

Differential Revision: http://reviews.llvm.org/D16746

llvm-svn: 259810
2016-02-04 18:38:35 +00:00