glsl: Use alignment of container record for its first field

The first field of a record in a UBO has the aligment of the record
itself.

Fixes piglit vs-struct-pad, fs-struct-pad, and (with the patch posted to
the piglit list that extends the test) layout-std140.

NOTE: The bit of strangeness with the version of visit_field without the
record_type poitner is because that method is pure virtual in the base
class.  The original implementation of the class did this to ensure
derived classes remembered to implement that flavor.  Now they can
implement either flavor but not both.  I don't know a C++ way to enforce
that.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Paul Berry <stereotype441@gmail.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=68195
Cc: "9.2 9.1" mesa-stable@lists.freedesktop.org
(cherry picked from commit 574e4843e9e26aa6affa31c80ac42f745b68268b)

2 files changed, 28 insertions, 2 deletions

diff --git a/src/glsl/link_uniform_blocks.cpp b/src/glsl/link_uniform_blocks.cpp
index c72d1d8f1de..e475147e51e 100644
--- a/src/glsl/link_uniform_blocks.cpp
+++ b/src/glsl/link_uniform_blocks.cpp
@@ -59,6 +59,15 @@ private:
    virtual void visit_field(const glsl_type *type, const char *name,
                             bool row_major)
    {
+      (void) type;
+      (void) name;
+      (void) row_major;
+      assert(!"Should not get here.");
+   }
+
+   virtual void visit_field(const glsl_type *type, const char *name,
+                            bool row_major, const glsl_type *record_type)
+   {
       assert(this->index < this->num_variables);
 
       gl_uniform_buffer_variable *v = &this->variables[this->index++];
@@ -85,7 +94,9 @@ private:
          v->IndexName = v->Name;
       }
 
-      unsigned alignment = type->std140_base_alignment(v->RowMajor);
+      const unsigned alignment = record_type
+	 ? record_type->std140_base_alignment(v->RowMajor)
+	 : type->std140_base_alignment(v->RowMajor);
       unsigned size = type->std140_size(v->RowMajor);
 
       this->offset = glsl_align(this->offset, alignment);
@@ -107,6 +118,10 @@ private:
 
    virtual void visit_field(const glsl_struct_field *field)
    {
+      /* FINISHME: When support for doubles (dvec4, etc.) is added to the
+       * FINISHME: compiler, this may be incorrect for a structure in a UBO
+       * FINISHME: like struct s { struct { float f } s1; dvec4 v; };.
+       */
       this->offset = glsl_align(this->offset,
                                 field->type->std140_base_alignment(false));
    }
diff --git a/src/glsl/link_uniforms.cpp b/src/glsl/link_uniforms.cpp
index 095895bf27e..fa77157f78d 100644
--- a/src/glsl/link_uniforms.cpp
+++ b/src/glsl/link_uniforms.cpp
@@ -402,6 +402,15 @@ private:
    virtual void visit_field(const glsl_type *type, const char *name,
                             bool row_major)
    {
+      (void) type;
+      (void) name;
+      (void) row_major;
+      assert(!"Should not get here.");
+   }
+
+   virtual void visit_field(const glsl_type *type, const char *name,
+                            bool row_major, const glsl_type *record_type)
+   {
       assert(!type->is_record());
       assert(!(type->is_array() && type->fields.array->is_record()));
       assert(!type->is_interface());
@@ -446,7 +455,9 @@ private:
       if (this->ubo_block_index != -1) {
 	 this->uniforms[id].block_index = this->ubo_block_index;
 
-	 unsigned alignment = type->std140_base_alignment(ubo_row_major);
+	 const unsigned alignment = record_type
+	    ? record_type->std140_base_alignment(ubo_row_major)
+	    : type->std140_base_alignment(ubo_row_major);
 	 this->ubo_byte_offset = glsl_align(this->ubo_byte_offset, alignment);
 	 this->uniforms[id].offset = this->ubo_byte_offset;
 	 this->ubo_byte_offset += type->std140_size(ubo_row_major);