[Mesa-dev] [PATCH 18/19] glsl: allow AoA to be sized by initializer or constructor

Timothy Arceri t_arceri at yahoo.com.au
Sat Jun 20 05:33:15 PDT 2015


>From Section 4.1.9 of the GLSL ES 3.10 spec:

"Arrays are sized either at compile-time or at run-time.
To size an array at compile-time, either the size
must be specified within the brackets as above or
must be inferred from the type of the initializer."
---
 src/glsl/ast.h               | 21 +++---------
 src/glsl/ast_array_index.cpp |  7 ++--
 src/glsl/ast_function.cpp    | 33 +++++++++++++++++-
 src/glsl/ast_to_hir.cpp      | 80 ++++++++++++++++++++++++++++++++++----------
 src/glsl/glsl_parser.yy      | 11 +++---
 5 files changed, 107 insertions(+), 45 deletions(-)

diff --git a/src/glsl/ast.h b/src/glsl/ast.h
index 3f67907..0f9dbf9 100644
--- a/src/glsl/ast.h
+++ b/src/glsl/ast.h
@@ -181,6 +181,7 @@ enum ast_operators {
    ast_post_dec,
    ast_field_selection,
    ast_array_index,
+   ast_unsized_array_dim,
 
    ast_function_call,
 
@@ -308,16 +309,7 @@ private:
 
 class ast_array_specifier : public ast_node {
 public:
-   /** Unsized array specifier ([]) */
-   explicit ast_array_specifier(const struct YYLTYPE &locp)
-     : is_unsized_array(true)
-   {
-      set_location(locp);
-   }
-
-   /** Sized array specifier ([dim]) */
    ast_array_specifier(const struct YYLTYPE &locp, ast_expression *dim)
-     : is_unsized_array(false)
    {
       set_location(locp);
       array_dimensions.push_tail(&dim->link);
@@ -330,19 +322,14 @@ public:
 
    bool is_single_dimension()
    {
-      return (this->is_unsized_array && this->array_dimensions.is_empty()) ||
-         (!this->is_unsized_array &&
-          this->array_dimensions.tail_pred->prev != NULL &&
-          this->array_dimensions.tail_pred->prev->is_head_sentinel());
+      return this->array_dimensions.tail_pred->prev != NULL &&
+             this->array_dimensions.tail_pred->prev->is_head_sentinel();
    }
 
    virtual void print(void) const;
 
-   /* If true, this means that the array has an unsized outermost dimension. */
-   bool is_unsized_array;
-
    /* This list contains objects of type ast_node containing the
-    * sized dimensions only, in outermost-to-innermost order.
+    * array dimensions in outermost-to-innermost order.
     */
    exec_list array_dimensions;
 };
diff --git a/src/glsl/ast_array_index.cpp b/src/glsl/ast_array_index.cpp
index 752d86f..89c08d8 100644
--- a/src/glsl/ast_array_index.cpp
+++ b/src/glsl/ast_array_index.cpp
@@ -28,13 +28,10 @@
 void
 ast_array_specifier::print(void) const
 {
-   if (this->is_unsized_array) {
-      printf("[ ] ");
-   }
-
    foreach_list_typed (ast_node, array_dimension, link, &this->array_dimensions) {
       printf("[ ");
-      array_dimension->print();
+      if (((ast_expression*)array_dimension)->oper != ast_unsized_array_dim)
+         array_dimension->print();
       printf("] ");
    }
 }
diff --git a/src/glsl/ast_function.cpp b/src/glsl/ast_function.cpp
index 92e26bf..0906040 100644
--- a/src/glsl/ast_function.cpp
+++ b/src/glsl/ast_function.cpp
@@ -870,6 +870,7 @@ process_array_constructor(exec_list *instructions,
    }
 
    bool all_parameters_are_constant = true;
+   const glsl_type *element_type = constructor_type->fields.array;
 
    /* Type cast each parameter and, if possible, fold constants. */
    foreach_in_list_safe(ir_rvalue, ir, &actual_parameters) {
@@ -896,12 +897,34 @@ process_array_constructor(exec_list *instructions,
 	 }
       }
 
-      if (result->type != constructor_type->fields.array) {
+      if (constructor_type->fields.array->is_unsized_array()) {
+         /* As the inner parameters of the constructor are created without
+          * knowledge of each other we need to check to make sure unsized
+          * parameters of unsized constructors all end up with the same size.
+          *
+          * e.g we make sure to fail for a constructor like this:
+          * vec4[][] a = vec4[][](vec4[](vec4(0.0), vec4(1.0)),
+          *                       vec4[](vec4(0.0), vec4(1.0), vec4(1.0)),
+          *                       vec4[](vec4(0.0), vec4(1.0)));
+          */
+         if (element_type->is_unsized_array()) {
+             /* This is the first parameter so just get the type */
+            element_type = result->type;
+         } else if (element_type != result->type) {
+            _mesa_glsl_error(loc, state, "type error in array constructor: "
+                             "expected: %s, found %s",
+                             element_type->name,
+                             result->type->name);
+            return ir_rvalue::error_value(ctx);
+         }
+      } else if (result->type != constructor_type->fields.array) {
 	 _mesa_glsl_error(loc, state, "type error in array constructor: "
 			  "expected: %s, found %s",
 			  constructor_type->fields.array->name,
 			  result->type->name);
          return ir_rvalue::error_value(ctx);
+      } else {
+         element_type = result->type;
       }
 
       /* Attempt to convert the parameter to a constant valued expression.
@@ -918,6 +941,14 @@ process_array_constructor(exec_list *instructions,
       ir->replace_with(result);
    }
 
+   if (constructor_type->fields.array->is_unsized_array()) {
+      constructor_type =
+	 glsl_type::get_array_instance(element_type,
+				       parameter_count);
+      assert(constructor_type != NULL);
+      assert(constructor_type->length == parameter_count);
+   }
+
    if (all_parameters_are_constant)
       return new(ctx) ir_constant(constructor_type, &actual_parameters);
 
diff --git a/src/glsl/ast_to_hir.cpp b/src/glsl/ast_to_hir.cpp
index de13060..6d2dc2e 100644
--- a/src/glsl/ast_to_hir.cpp
+++ b/src/glsl/ast_to_hir.cpp
@@ -677,8 +677,30 @@ validate_assignment(struct _mesa_glsl_parse_state *state,
     * Note: Whole-array assignments are not permitted in GLSL 1.10, but this
     * is handled by ir_dereference::is_lvalue.
     */
-   if (lhs_type->is_unsized_array() && rhs->type->is_array()
-       && (lhs_type->fields.array == rhs->type->fields.array)) {
+   const glsl_type *lhs_t = lhs_type;
+   const glsl_type *rhs_t = rhs->type;
+   bool unsized_array = false;
+   while(lhs_t->is_array()) {
+      if (rhs_t == lhs_t)
+         break; /* the rest of the inner arrays match so break out early */
+      if (!rhs_t->is_array()) {
+         unsized_array = false;
+         break; /* number of dimensions mismatch */
+      }
+      if (lhs_t->length == rhs_t->length) {
+         lhs_t = lhs_t->fields.array;
+         rhs_t = rhs_t->fields.array;
+         continue;
+      } else if (lhs_t->is_unsized_array()) {
+         unsized_array = true;
+      } else {
+         unsized_array = false;
+         break; /* sized array mismatch */
+      }
+      lhs_t = lhs_t->fields.array;
+      rhs_t = rhs_t->fields.array;
+   }
+   if (unsized_array) {
       if (is_initializer) {
          return rhs;
       } else {
@@ -1682,6 +1704,10 @@ ast_expression::do_hir(exec_list *instructions,
       break;
    }
 
+   case ast_unsized_array_dim:
+      assert(!"ast_unsized_array_dim: Should never get here.");
+      break;
+
    case ast_function_call:
       /* Should *NEVER* get here.  ast_function_call should always be handled
        * by ast_function_expression::hir.
@@ -1845,6 +1871,14 @@ process_array_size(exec_node *node,
    exec_list dummy_instructions;
 
    ast_node *array_size = exec_node_data(ast_node, node, link);
+
+   /**
+    * Dimensions other than the outermost dimension can by unsized if they
+    * are immediately sized by a constructor or initializer.
+    */
+   if (((ast_expression*)array_size)->oper == ast_unsized_array_dim)
+      return 0;
+
    ir_rvalue *const ir = array_size->hir(& dummy_instructions, state);
    YYLTYPE loc = array_size->get_location();
 
@@ -1913,14 +1947,6 @@ process_array_type(YYLTYPE *loc, const glsl_type *base,
                              base->name);
             return glsl_type::error_type;
          }
-
-         if (base->length == 0) {
-            _mesa_glsl_error(loc, state,
-                             "only the outermost array dimension can "
-                             "be unsized",
-                             base->name);
-            return glsl_type::error_type;
-         }
       }
 
       for (exec_node *node = array_specifier->array_dimensions.tail_pred;
@@ -1928,9 +1954,6 @@ process_array_type(YYLTYPE *loc, const glsl_type *base,
          unsigned array_size = process_array_size(node, state);
          array_type = glsl_type::get_array_instance(array_type, array_size);
       }
-
-      if (array_specifier->is_unsized_array)
-         array_type = glsl_type::get_array_instance(array_type, 0);
    }
 
    return array_type;
@@ -2407,6 +2430,25 @@ is_conflicting_fragcoord_redeclaration(struct _mesa_glsl_parse_state *state,
    return false;
 }
 
+static inline void
+validate_array_dimensions(const glsl_type *t,
+                          struct _mesa_glsl_parse_state *state,
+                          YYLTYPE *loc) {
+   if (t->is_array()) {
+      t = t->fields.array;
+      while (t->is_array()) {
+         if (t->is_unsized_array()) {
+            _mesa_glsl_error(loc, state,
+                             "only the outermost array dimension can "
+                             "be unsized",
+                             t->name);
+            break;
+         }
+         t = t->fields.array;
+      }
+   }
+}
+
 static void
 apply_type_qualifier_to_variable(const struct ast_type_qualifier *qual,
                                  ir_variable *var,
@@ -3927,6 +3969,8 @@ ast_declarator_list::hir(exec_list *instructions,
          result = process_initializer((earlier == NULL) ? var : earlier,
                                       decl, this->type,
                                       &initializer_instructions, state);
+      } else {
+         validate_array_dimensions(var_type, state, &loc);
       }
 
       /* From page 23 (page 29 of the PDF) of the GLSL 1.10 spec:
@@ -5384,6 +5428,7 @@ ast_process_structure_or_interface_block(exec_list *instructions,
 
          field_type = process_array_type(&loc, decl_type,
                                          decl->array_specifier, state);
+         validate_array_dimensions(field_type, state, &loc);
          fields[i].type = field_type;
          fields[i].name = decl->identifier;
          fields[i].location = -1;
@@ -5810,6 +5855,9 @@ ast_interface_block::hir(exec_list *instructions,
       ir_variable *var;
 
       if (this->array_specifier != NULL) {
+         const glsl_type *block_array_type =
+            process_array_type(&loc, block_type, this->array_specifier, state);
+
          /* Section 4.3.7 (Interface Blocks) of the GLSL 1.50 spec says:
           *
           *     For uniform blocks declared an array, each individual array
@@ -5829,16 +5877,14 @@ ast_interface_block::hir(exec_list *instructions,
           * interface array size *doesn't* need to be specified is on a
           * geometry shader input.
           */
-         if (this->array_specifier->is_unsized_array &&
+         if (block_array_type->is_unsized_array() &&
              (state->stage != MESA_SHADER_GEOMETRY || !this->layout.flags.q.in)) {
             _mesa_glsl_error(&loc, state,
                              "only geometry shader inputs may be unsized "
                              "instance block arrays");
 
          }
-
-         const glsl_type *block_array_type =
-            process_array_type(&loc, block_type, this->array_specifier, state);
+//TODO: make sure no other array dimensions are unsized arrays ??
 
           /* From section 4.3.9 (Interface Blocks) of the GLSL ES 3.10 spec:
           *
diff --git a/src/glsl/glsl_parser.yy b/src/glsl/glsl_parser.yy
index 3ce9e10..1f08893 100644
--- a/src/glsl/glsl_parser.yy
+++ b/src/glsl/glsl_parser.yy
@@ -1840,7 +1840,9 @@ array_specifier:
    '[' ']'
    {
       void *ctx = state;
-      $$ = new(ctx) ast_array_specifier(@1);
+      $$ = new(ctx) ast_array_specifier(@1, new(ctx) ast_expression(
+                                                  ast_unsized_array_dim, NULL,
+                                                  NULL, NULL));
       $$->set_location_range(@1, @2);
    }
    | '[' constant_expression ']'
@@ -1851,17 +1853,16 @@ array_specifier:
    }
    | array_specifier '[' ']'
    {
+      void *ctx = state;
       $$ = $1;
 
       if (!state->ARB_arrays_of_arrays_enable) {
          _mesa_glsl_error(& @1, state,
                           "GL_ARB_arrays_of_arrays "
                           "required for defining arrays of arrays");
-      } else {
-         _mesa_glsl_error(& @1, state,
-                          "only the outermost array dimension can "
-                          "be unsized");
       }
+      $$->add_dimension(new(ctx) ast_expression(ast_unsized_array_dim, NULL,
+                                                NULL, NULL));
    }
    | array_specifier '[' constant_expression ']'
    {
-- 
2.1.0



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