glsl: When constructing a variable with an interface type, set interface_type

Ever since the addition of interface blocks with instance names, we have
had an implicit invariant:

    var->type->is_interface() ==
        (var->type == var->interface_type)

The odd use of == here is intentional because !var->type->is_interface()
implies var->type != var->interface_type.

Further, if var->type->is_array() is true, we have a related implicit
invariant:

    var->type->fields.array->is_interface() ==
        (var->type->fields.array == var->interface_type)

However, the ir_variable constructor doesn't maintain either invariant.
That seems kind of silly... and I tripped over it while writing some
other code.  This patch makes the constructor do the right thing, and it
introduces some tests to verify that behavior.

v2: Add general-ir-test to .gitignore.  Update the description of the
ir_variable invariant for arrays in the commit message.  Both suggested
by Paul.

Signed-off-by: Ian Romanick <[email protected]>
Reviewed-by: Paul Berry <[email protected]>

1 files changed, 9 insertions, 2 deletions

diff --git a/src/glsl/ir.cpp b/src/glsl/ir.cpp
index de9613e8fa1..54a8e400c16 100644
--- a/src/glsl/ir.cpp
+++ b/src/glsl/ir.cpp
@@ -1603,8 +1603,15 @@ ir_variable::ir_variable(const struct glsl_type *type, const char *name,
    this->depth_layout = ir_depth_layout_none;
    this->used = false;
 
-   if (type && type->base_type == GLSL_TYPE_SAMPLER)
-      this->read_only = true;
+   if (type != NULL) {
+      if (type->base_type == GLSL_TYPE_SAMPLER)
+         this->read_only = true;
+
+      if (type->is_interface())
+         this->init_interface_type(type);
+      else if (type->is_array() && type->fields.array->is_interface())
+         this->init_interface_type(type->fields.array);
+   }
 }