Fix 'make check' in src/mapi/glapi/tests when builddir != srcdir
[mesa.git] / src / glsl / linker.cpp
index f25dca2109d81e55d08728b39ba6041aed2cf7fc..1366077f7846ca14a6cef6e9d839174e41f1d8d6 100644 (file)
 
 extern "C" {
 #include "main/shaderobj.h"
+#include "main/enums.h"
 }
 
 void linker_error(gl_shader_program *, const char *, ...);
 
+namespace {
+
 /**
  * Visitor that determines whether or not a variable is ever written.
  */
@@ -177,6 +180,105 @@ private:
 };
 
 
+class geom_array_resize_visitor : public ir_hierarchical_visitor {
+public:
+   unsigned num_vertices;
+   gl_shader_program *prog;
+
+   geom_array_resize_visitor(unsigned num_vertices, gl_shader_program *prog)
+   {
+      this->num_vertices = num_vertices;
+      this->prog = prog;
+   }
+
+   virtual ~geom_array_resize_visitor()
+   {
+      /* empty */
+   }
+
+   virtual ir_visitor_status visit(ir_variable *var)
+   {
+      if (!var->type->is_array() || var->mode != ir_var_shader_in)
+         return visit_continue;
+
+      unsigned size = var->type->length;
+
+      /* Generate a link error if the shader has declared this array with an
+       * incorrect size.
+       */
+      if (size && size != this->num_vertices) {
+         linker_error(this->prog, "size of array %s declared as %u, "
+                      "but number of input vertices is %u\n",
+                      var->name, size, this->num_vertices);
+         return visit_continue;
+      }
+
+      /* Generate a link error if the shader attempts to access an input
+       * array using an index too large for its actual size assigned at link
+       * time.
+       */
+      if (var->max_array_access >= this->num_vertices) {
+         linker_error(this->prog, "geometry shader accesses element %i of "
+                      "%s, but only %i input vertices\n",
+                      var->max_array_access, var->name, this->num_vertices);
+         return visit_continue;
+      }
+
+      var->type = glsl_type::get_array_instance(var->type->element_type(),
+                                                this->num_vertices);
+      var->max_array_access = this->num_vertices - 1;
+
+      return visit_continue;
+   }
+
+   /* Dereferences of input variables need to be updated so that their type
+    * matches the newly assigned type of the variable they are accessing. */
+   virtual ir_visitor_status visit(ir_dereference_variable *ir)
+   {
+      ir->type = ir->var->type;
+      return visit_continue;
+   }
+
+   /* Dereferences of 2D input arrays need to be updated so that their type
+    * matches the newly assigned type of the array they are accessing. */
+   virtual ir_visitor_status visit_leave(ir_dereference_array *ir)
+   {
+      const glsl_type *const vt = ir->array->type;
+      if (vt->is_array())
+         ir->type = vt->element_type();
+      return visit_continue;
+   }
+};
+
+
+/**
+ * Visitor that determines whether or not a shader uses ir_end_primitive.
+ */
+class find_end_primitive_visitor : public ir_hierarchical_visitor {
+public:
+   find_end_primitive_visitor()
+      : found(false)
+   {
+      /* empty */
+   }
+
+   virtual ir_visitor_status visit(ir_end_primitive *)
+   {
+      found = true;
+      return visit_stop;
+   }
+
+   bool end_primitive_found()
+   {
+      return found;
+   }
+
+private:
+   bool found;
+};
+
+} /* anonymous namespace */
+
 void
 linker_error(gl_shader_program *prog, const char *fmt, ...)
 {
@@ -264,35 +366,38 @@ parse_program_resource_name(const GLchar *name,
 
 
 void
-link_invalidate_variable_locations(gl_shader *sh, int input_base,
-                                   int output_base)
+link_invalidate_variable_locations(exec_list *ir)
 {
-   foreach_list(node, sh->ir) {
+   foreach_list(node, ir) {
       ir_variable *const var = ((ir_instruction *) node)->as_variable();
 
       if (var == NULL)
          continue;
 
-      int base;
-      switch (var->mode) {
-      case ir_var_shader_in:
-         base = input_base;
-         break;
-      case ir_var_shader_out:
-         base = output_base;
-         break;
-      default:
-         continue;
-      }
-
-      /* Only assign locations for generic attributes / varyings / etc.
+      /* Only assign locations for variables that lack an explicit location.
+       * Explicit locations are set for all built-in variables, generic vertex
+       * shader inputs (via layout(location=...)), and generic fragment shader
+       * outputs (also via layout(location=...)).
        */
-      if ((var->location >= base) && !var->explicit_location)
+      if (!var->explicit_location) {
          var->location = -1;
+         var->location_frac = 0;
+      }
 
-      if ((var->location == -1) && !var->explicit_location) {
+      /* ir_variable::is_unmatched_generic_inout is used by the linker while
+       * connecting outputs from one stage to inputs of the next stage.
+       *
+       * There are two implicit assumptions here.  First, we assume that any
+       * built-in variable (i.e., non-generic in or out) will have
+       * explicit_location set.  Second, we assume that any generic in or out
+       * will not have explicit_location set.
+       *
+       * This second assumption will only be valid until
+       * GL_ARB_separate_shader_objects is supported.  When that extension is
+       * implemented, this function will need some modifications.
+       */
+      if (!var->explicit_location) {
          var->is_unmatched_generic_inout = 1;
-         var->location_frac = 0;
       } else {
          var->is_unmatched_generic_inout = 0;
       }
@@ -300,6 +405,52 @@ link_invalidate_variable_locations(gl_shader *sh, int input_base,
 }
 
 
+/**
+ * Set UsesClipDistance and ClipDistanceArraySize based on the given shader.
+ *
+ * Also check for errors based on incorrect usage of gl_ClipVertex and
+ * gl_ClipDistance.
+ *
+ * Return false if an error was reported.
+ */
+static void
+analyze_clip_usage(const char *shader_type, struct gl_shader_program *prog,
+                   struct gl_shader *shader, GLboolean *UsesClipDistance,
+                   GLuint *ClipDistanceArraySize)
+{
+   *ClipDistanceArraySize = 0;
+
+   if (!prog->IsES && prog->Version >= 130) {
+      /* From section 7.1 (Vertex Shader Special Variables) of the
+       * GLSL 1.30 spec:
+       *
+       *   "It is an error for a shader to statically write both
+       *   gl_ClipVertex and gl_ClipDistance."
+       *
+       * This does not apply to GLSL ES shaders, since GLSL ES defines neither
+       * gl_ClipVertex nor gl_ClipDistance.
+       */
+      find_assignment_visitor clip_vertex("gl_ClipVertex");
+      find_assignment_visitor clip_distance("gl_ClipDistance");
+
+      clip_vertex.run(shader->ir);
+      clip_distance.run(shader->ir);
+      if (clip_vertex.variable_found() && clip_distance.variable_found()) {
+         linker_error(prog, "%s shader writes to both `gl_ClipVertex' "
+                      "and `gl_ClipDistance'\n", shader_type);
+         return;
+      }
+      *UsesClipDistance = clip_distance.variable_found();
+      ir_variable *clip_distance_var =
+         shader->symbols->get_variable("gl_ClipDistance");
+      if (clip_distance_var)
+         *ClipDistanceArraySize = clip_distance_var->type->length;
+   } else {
+      *UsesClipDistance = false;
+   }
+}
+
+
 /**
  * Verify that a vertex shader executable meets all semantic requirements.
  *
@@ -350,34 +501,8 @@ validate_vertex_shader_executable(struct gl_shader_program *prog,
       }
    }
 
-   prog->Vert.ClipDistanceArraySize = 0;
-
-   if (!prog->IsES && prog->Version >= 130) {
-      /* From section 7.1 (Vertex Shader Special Variables) of the
-       * GLSL 1.30 spec:
-       *
-       *   "It is an error for a shader to statically write both
-       *   gl_ClipVertex and gl_ClipDistance."
-       *
-       * This does not apply to GLSL ES shaders, since GLSL ES defines neither
-       * gl_ClipVertex nor gl_ClipDistance.
-       */
-      find_assignment_visitor clip_vertex("gl_ClipVertex");
-      find_assignment_visitor clip_distance("gl_ClipDistance");
-
-      clip_vertex.run(shader->ir);
-      clip_distance.run(shader->ir);
-      if (clip_vertex.variable_found() && clip_distance.variable_found()) {
-         linker_error(prog, "vertex shader writes to both `gl_ClipVertex' "
-                      "and `gl_ClipDistance'\n");
-         return;
-      }
-      prog->Vert.UsesClipDistance = clip_distance.variable_found();
-      ir_variable *clip_distance_var =
-         shader->symbols->get_variable("gl_ClipDistance");
-      if (clip_distance_var)
-         prog->Vert.ClipDistanceArraySize = clip_distance_var->type->length;
-   }
+   analyze_clip_usage("vertex", prog, shader, &prog->Vert.UsesClipDistance,
+                      &prog->Vert.ClipDistanceArraySize);
 }
 
 
@@ -408,7 +533,8 @@ validate_fragment_shader_executable(struct gl_shader_program *prog,
 /**
  * Verify that a geometry shader executable meets all semantic requirements
  *
- * Also sets prog->Geom.VerticesIn as a side effect.
+ * Also sets prog->Geom.VerticesIn, prog->Geom.UsesClipDistance, and
+ * prog->Geom.ClipDistanceArraySize as a side effect.
  *
  * \param shader Geometry shader executable to be verified
  */
@@ -421,29 +547,13 @@ validate_geometry_shader_executable(struct gl_shader_program *prog,
 
    unsigned num_vertices = vertices_per_prim(prog->Geom.InputType);
    prog->Geom.VerticesIn = num_vertices;
-}
-
-
-/**
- * Generate a string describing the mode of a variable
- */
-static const char *
-mode_string(const ir_variable *var)
-{
-   switch (var->mode) {
-   case ir_var_auto:
-      return (var->read_only) ? "global constant" : "global variable";
 
-   case ir_var_uniform:    return "uniform";
-   case ir_var_shader_in:  return "shader input";
-   case ir_var_shader_out: return "shader output";
+   analyze_clip_usage("geometry", prog, shader, &prog->Geom.UsesClipDistance,
+                      &prog->Geom.ClipDistanceArraySize);
 
-   case ir_var_const_in:
-   case ir_var_temporary:
-   default:
-      assert(!"Should not get here.");
-      return "invalid variable";
-   }
+   find_end_primitive_visitor end_primitive;
+   end_primitive.run(shader->ir);
+   prog->Geom.UsesEndPrimitive = end_primitive.end_primitive_found();
 }
 
 
@@ -541,6 +651,14 @@ cross_validate_globals(struct gl_shader_program *prog,
                existing->explicit_binding = true;
             }
 
+            if (var->type->contains_atomic() &&
+                var->atomic.offset != existing->atomic.offset) {
+               linker_error(prog, "offset specifications for %s "
+                            "`%s' have differing values\n",
+                            mode_string(var), var->name);
+               return;
+            }
+
            /* Validate layout qualifiers for gl_FragDepth.
             *
             * From the AMD/ARB_conservative_depth specs:
@@ -886,7 +1004,7 @@ get_main_function_signature(gl_shader *sh)
        * We don't have to check for multiple definitions of main (in multiple
        * shaders) because that would have already been caught above.
        */
-      ir_function_signature *sig = f->matching_signature(&void_parameters);
+      ir_function_signature *sig = f->matching_signature(NULL, &void_parameters);
       if ((sig != NULL) && sig->is_defined) {
         return sig;
       }
@@ -903,19 +1021,262 @@ get_main_function_signature(gl_shader *sh)
  */
 class array_sizing_visitor : public ir_hierarchical_visitor {
 public:
+   array_sizing_visitor()
+      : mem_ctx(ralloc_context(NULL)),
+        unnamed_interfaces(hash_table_ctor(0, hash_table_pointer_hash,
+                                           hash_table_pointer_compare))
+   {
+   }
+
+   ~array_sizing_visitor()
+   {
+      hash_table_dtor(this->unnamed_interfaces);
+      ralloc_free(this->mem_ctx);
+   }
+
    virtual ir_visitor_status visit(ir_variable *var)
    {
-      if (var->type->is_array() && (var->type->length == 0)) {
-         const glsl_type *type =
-            glsl_type::get_array_instance(var->type->fields.array,
-                                          var->max_array_access + 1);
-         assert(type != NULL);
-         var->type = type;
+      fixup_type(&var->type, var->max_array_access);
+      if (var->type->is_interface()) {
+         if (interface_contains_unsized_arrays(var->type)) {
+            const glsl_type *new_type =
+               resize_interface_members(var->type, var->max_ifc_array_access);
+            var->type = new_type;
+            var->change_interface_type(new_type);
+         }
+      } else if (var->type->is_array() &&
+                 var->type->fields.array->is_interface()) {
+         if (interface_contains_unsized_arrays(var->type->fields.array)) {
+            const glsl_type *new_type =
+               resize_interface_members(var->type->fields.array,
+                                        var->max_ifc_array_access);
+            var->change_interface_type(new_type);
+            var->type =
+               glsl_type::get_array_instance(new_type, var->type->length);
+         }
+      } else if (const glsl_type *ifc_type = var->get_interface_type()) {
+         /* Store a pointer to the variable in the unnamed_interfaces
+          * hashtable.
+          */
+         ir_variable **interface_vars = (ir_variable **)
+            hash_table_find(this->unnamed_interfaces, ifc_type);
+         if (interface_vars == NULL) {
+            interface_vars = rzalloc_array(mem_ctx, ir_variable *,
+                                           ifc_type->length);
+            hash_table_insert(this->unnamed_interfaces, interface_vars,
+                              ifc_type);
+         }
+         unsigned index = ifc_type->field_index(var->name);
+         assert(index < ifc_type->length);
+         assert(interface_vars[index] == NULL);
+         interface_vars[index] = var;
       }
       return visit_continue;
    }
+
+   /**
+    * For each unnamed interface block that was discovered while running the
+    * visitor, adjust the interface type to reflect the newly assigned array
+    * sizes, and fix up the ir_variable nodes to point to the new interface
+    * type.
+    */
+   void fixup_unnamed_interface_types()
+   {
+      hash_table_call_foreach(this->unnamed_interfaces,
+                              fixup_unnamed_interface_type, NULL);
+   }
+
+private:
+   /**
+    * If the type pointed to by \c type represents an unsized array, replace
+    * it with a sized array whose size is determined by max_array_access.
+    */
+   static void fixup_type(const glsl_type **type, unsigned max_array_access)
+   {
+      if ((*type)->is_unsized_array()) {
+         *type = glsl_type::get_array_instance((*type)->fields.array,
+                                               max_array_access + 1);
+         assert(*type != NULL);
+      }
+   }
+
+   /**
+    * Determine whether the given interface type contains unsized arrays (if
+    * it doesn't, array_sizing_visitor doesn't need to process it).
+    */
+   static bool interface_contains_unsized_arrays(const glsl_type *type)
+   {
+      for (unsigned i = 0; i < type->length; i++) {
+         const glsl_type *elem_type = type->fields.structure[i].type;
+         if (elem_type->is_unsized_array())
+            return true;
+      }
+      return false;
+   }
+
+   /**
+    * Create a new interface type based on the given type, with unsized arrays
+    * replaced by sized arrays whose size is determined by
+    * max_ifc_array_access.
+    */
+   static const glsl_type *
+   resize_interface_members(const glsl_type *type,
+                            const unsigned *max_ifc_array_access)
+   {
+      unsigned num_fields = type->length;
+      glsl_struct_field *fields = new glsl_struct_field[num_fields];
+      memcpy(fields, type->fields.structure,
+             num_fields * sizeof(*fields));
+      for (unsigned i = 0; i < num_fields; i++) {
+         fixup_type(&fields[i].type, max_ifc_array_access[i]);
+      }
+      glsl_interface_packing packing =
+         (glsl_interface_packing) type->interface_packing;
+      const glsl_type *new_ifc_type =
+         glsl_type::get_interface_instance(fields, num_fields,
+                                           packing, type->name);
+      delete [] fields;
+      return new_ifc_type;
+   }
+
+   static void fixup_unnamed_interface_type(const void *key, void *data,
+                                            void *)
+   {
+      const glsl_type *ifc_type = (const glsl_type *) key;
+      ir_variable **interface_vars = (ir_variable **) data;
+      unsigned num_fields = ifc_type->length;
+      glsl_struct_field *fields = new glsl_struct_field[num_fields];
+      memcpy(fields, ifc_type->fields.structure,
+             num_fields * sizeof(*fields));
+      bool interface_type_changed = false;
+      for (unsigned i = 0; i < num_fields; i++) {
+         if (interface_vars[i] != NULL &&
+             fields[i].type != interface_vars[i]->type) {
+            fields[i].type = interface_vars[i]->type;
+            interface_type_changed = true;
+         }
+      }
+      if (!interface_type_changed) {
+         delete [] fields;
+         return;
+      }
+      glsl_interface_packing packing =
+         (glsl_interface_packing) ifc_type->interface_packing;
+      const glsl_type *new_ifc_type =
+         glsl_type::get_interface_instance(fields, num_fields, packing,
+                                           ifc_type->name);
+      delete [] fields;
+      for (unsigned i = 0; i < num_fields; i++) {
+         if (interface_vars[i] != NULL)
+            interface_vars[i]->change_interface_type(new_ifc_type);
+      }
+   }
+
+   /**
+    * Memory context used to allocate the data in \c unnamed_interfaces.
+    */
+   void *mem_ctx;
+
+   /**
+    * Hash table from const glsl_type * to an array of ir_variable *'s
+    * pointing to the ir_variables constituting each unnamed interface block.
+    */
+   hash_table *unnamed_interfaces;
 };
 
+/**
+ * Performs the cross-validation of geometry shader max_vertices and
+ * primitive type layout qualifiers for the attached geometry shaders,
+ * and propagates them to the linked GS and linked shader program.
+ */
+static void
+link_gs_inout_layout_qualifiers(struct gl_shader_program *prog,
+                               struct gl_shader *linked_shader,
+                               struct gl_shader **shader_list,
+                               unsigned num_shaders)
+{
+   linked_shader->Geom.VerticesOut = 0;
+   linked_shader->Geom.InputType = PRIM_UNKNOWN;
+   linked_shader->Geom.OutputType = PRIM_UNKNOWN;
+
+   /* No in/out qualifiers defined for anything but GLSL 1.50+
+    * geometry shaders so far.
+    */
+   if (linked_shader->Type != GL_GEOMETRY_SHADER || prog->Version < 150)
+      return;
+
+   /* From the GLSL 1.50 spec, page 46:
+    *
+    *     "All geometry shader output layout declarations in a program
+    *      must declare the same layout and same value for
+    *      max_vertices. There must be at least one geometry output
+    *      layout declaration somewhere in a program, but not all
+    *      geometry shaders (compilation units) are required to
+    *      declare it."
+    */
+
+   for (unsigned i = 0; i < num_shaders; i++) {
+      struct gl_shader *shader = shader_list[i];
+
+      if (shader->Geom.InputType != PRIM_UNKNOWN) {
+        if (linked_shader->Geom.InputType != PRIM_UNKNOWN &&
+            linked_shader->Geom.InputType != shader->Geom.InputType) {
+           linker_error(prog, "geometry shader defined with conflicting "
+                        "input types\n");
+           return;
+        }
+        linked_shader->Geom.InputType = shader->Geom.InputType;
+      }
+
+      if (shader->Geom.OutputType != PRIM_UNKNOWN) {
+        if (linked_shader->Geom.OutputType != PRIM_UNKNOWN &&
+            linked_shader->Geom.OutputType != shader->Geom.OutputType) {
+           linker_error(prog, "geometry shader defined with conflicting "
+                        "output types\n");
+           return;
+        }
+        linked_shader->Geom.OutputType = shader->Geom.OutputType;
+      }
+
+      if (shader->Geom.VerticesOut != 0) {
+        if (linked_shader->Geom.VerticesOut != 0 &&
+            linked_shader->Geom.VerticesOut != shader->Geom.VerticesOut) {
+           linker_error(prog, "geometry shader defined with conflicting "
+                        "output vertex count (%d and %d)\n",
+                        linked_shader->Geom.VerticesOut,
+                        shader->Geom.VerticesOut);
+           return;
+        }
+        linked_shader->Geom.VerticesOut = shader->Geom.VerticesOut;
+      }
+   }
+
+   /* Just do the intrastage -> interstage propagation right now,
+    * since we already know we're in the right type of shader program
+    * for doing it.
+    */
+   if (linked_shader->Geom.InputType == PRIM_UNKNOWN) {
+      linker_error(prog,
+                  "geometry shader didn't declare primitive input type\n");
+      return;
+   }
+   prog->Geom.InputType = linked_shader->Geom.InputType;
+
+   if (linked_shader->Geom.OutputType == PRIM_UNKNOWN) {
+      linker_error(prog,
+                  "geometry shader didn't declare primitive output type\n");
+      return;
+   }
+   prog->Geom.OutputType = linked_shader->Geom.OutputType;
+
+   if (linked_shader->Geom.VerticesOut == 0) {
+      linker_error(prog,
+                  "geometry shader didn't declare max_vertices\n");
+      return;
+   }
+   prog->Geom.VerticesOut = linked_shader->Geom.VerticesOut;
+}
+
 /**
  * Combine a group of shaders for a single stage to generate a linked shader
  *
@@ -974,14 +1335,14 @@ link_intrastage_shaders(void *mem_ctx,
               ir_function_signature *sig =
                  (ir_function_signature *) iter.get();
 
-              if (!sig->is_defined || sig->is_builtin)
+              if (!sig->is_defined || sig->is_builtin())
                  continue;
 
               ir_function_signature *other_sig =
-                 other->exact_matching_signature(sig->parameters);
+                 other->exact_matching_signature(NULL, &sig->parameters);
 
               if ((other_sig != NULL) && other_sig->is_defined
-                  && !other_sig->is_builtin) {
+                  && !other_sig->is_builtin()) {
                  linker_error(prog, "function `%s' is multiply defined",
                               f->name);
                  return NULL;
@@ -1020,6 +1381,8 @@ link_intrastage_shaders(void *mem_ctx,
    linked->NumUniformBlocks = num_uniform_blocks;
    ralloc_steal(linked, linked->UniformBlocks);
 
+   link_gs_inout_layout_qualifiers(prog, linked, shader_list, num_shaders);
+
    populate_symbol_table(linked);
 
    /* The a pointer to the main function in the final linked shader (i.e., the
@@ -1066,7 +1429,8 @@ link_intrastage_shaders(void *mem_ctx,
    if (!link_function_calls(prog, linked, linking_shaders,
                            num_linking_shaders)) {
       ctx->Driver.DeleteShader(ctx, linked);
-      linked = NULL;
+      free(linking_shaders);
+      return NULL;
    }
 
    free(linking_shaders);
@@ -1074,18 +1438,25 @@ link_intrastage_shaders(void *mem_ctx,
    /* At this point linked should contain all of the linked IR, so
     * validate it to make sure nothing went wrong.
     */
-   if (linked)
-      validate_ir_tree(linked->ir);
+   validate_ir_tree(linked->ir);
+
+   /* Set the size of geometry shader input arrays */
+   if (linked->Type == GL_GEOMETRY_SHADER) {
+      unsigned num_vertices = vertices_per_prim(prog->Geom.InputType);
+      geom_array_resize_visitor input_resize_visitor(num_vertices, prog);
+      foreach_iter(exec_list_iterator, iter, *linked->ir) {
+         ir_instruction *ir = (ir_instruction *)iter.get();
+         ir->accept(&input_resize_visitor);
+      }
+   }
 
    /* Make a pass over all variable declarations to ensure that arrays with
     * unspecified sizes have a size specified.  The size is inferred from the
     * max_array_access field.
     */
-   if (linked != NULL) {
-      array_sizing_visitor v;
-
-      v.run(linked->ir);
-   }
+   array_sizing_visitor v;
+   v.run(linked->ir);
+   v.fixup_unnamed_interface_types();
 
    return linked;
 }
@@ -1122,8 +1493,12 @@ update_array_sizes(struct gl_shader_program *prog)
         /* GL_ARB_uniform_buffer_object says that std140 uniforms
          * will not be eliminated.  Since we always do std140, just
          * don't resize arrays in UBOs.
+          *
+          * Atomic counters are supposed to get deterministic
+          * locations assigned based on the declaration ordering and
+          * sizes, array compaction would mess that up.
          */
-        if (var->is_in_uniform_block())
+        if (var->is_in_uniform_block() || var->type->contains_atomic())
            continue;
 
         unsigned int size = var->max_array_access;
@@ -1628,6 +2003,10 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
       prog->UniformBlockStageIndex[i] = NULL;
    }
 
+   ralloc_free(prog->AtomicBuffers);
+   prog->AtomicBuffers = NULL;
+   prog->NumAtomicBuffers = 0;
+
    /* Separate the shaders into groups based on their type.
     */
    struct gl_shader **vert_shader_list;
@@ -1674,14 +2053,10 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
       }
    }
 
-   /* Previous to GLSL version 1.30, different compilation units could mix and
-    * match shading language versions.  With GLSL 1.30 and later, the versions
-    * of all shaders must match.
-    *
-    * GLSL ES has never allowed mixing of shading language versions.
+   /* In desktop GLSL, different shader versions may be linked together.  In
+    * GLSL ES, all shader versions must be the same.
     */
-   if ((is_es_prog || max_version >= 130)
-       && min_version != max_version) {
+   if (is_es_prog && min_version != max_version) {
       linker_error(prog, "all shaders must use same shading "
                   "language version\n");
       goto done;
@@ -1690,6 +2065,14 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
    prog->Version = max_version;
    prog->IsES = is_es_prog;
 
+   /* Geometry shaders have to be linked with vertex shaders.
+    */
+   if (num_geom_shaders > 0 && num_vert_shaders == 0) {
+      linker_error(prog, "Geometry shader must be linked with "
+                  "vertex shader\n");
+      goto done;
+   }
+
    for (unsigned int i = 0; i < MESA_SHADER_TYPES; i++) {
       if (prog->_LinkedShaders[i] != NULL)
         ctx->Driver.DeleteShader(ctx, prog->_LinkedShaders[i]);
@@ -1710,6 +2093,7 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
       validate_vertex_shader_executable(prog, sh);
       if (!prog->LinkStatus)
         goto done;
+      prog->LastClipDistanceArraySize = prog->Vert.ClipDistanceArraySize;
 
       _mesa_reference_shader(ctx, &prog->_LinkedShaders[MESA_SHADER_VERTEX],
                             sh);
@@ -1742,6 +2126,7 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
       validate_geometry_shader_executable(prog, sh);
       if (!prog->LinkStatus)
         goto done;
+      prog->LastClipDistanceArraySize = prog->Geom.ClipDistanceArraySize;
 
       _mesa_reference_shader(ctx, &prog->_LinkedShaders[MESA_SHADER_GEOMETRY],
                             sh);
@@ -1769,8 +2154,8 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
       if (prog->_LinkedShaders[i] == NULL)
          continue;
 
-      validate_interstage_interface_blocks(prog, prog->_LinkedShaders[prev],
-                                           prog->_LinkedShaders[i]);
+      validate_interstage_inout_blocks(prog, prog->_LinkedShaders[prev],
+                                       prog->_LinkedShaders[i]);
       if (!prog->LinkStatus)
          goto done;
 
@@ -1783,6 +2168,11 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
       prev = i;
    }
 
+   /* Cross-validate uniform blocks between shader stages */
+   validate_interstage_uniform_blocks(prog, prog->_LinkedShaders,
+                                      MESA_SHADER_TYPES);
+   if (!prog->LinkStatus)
+      goto done;
 
    for (unsigned int i = 0; i < MESA_SHADER_TYPES; i++) {
       if (prog->_LinkedShaders[i] != NULL)
@@ -1830,18 +2220,15 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
    /* Mark all generic shader inputs and outputs as unpaired. */
    if (prog->_LinkedShaders[MESA_SHADER_VERTEX] != NULL) {
       link_invalidate_variable_locations(
-            prog->_LinkedShaders[MESA_SHADER_VERTEX],
-            VERT_ATTRIB_GENERIC0, VARYING_SLOT_VAR0);
+            prog->_LinkedShaders[MESA_SHADER_VERTEX]->ir);
    }
    if (prog->_LinkedShaders[MESA_SHADER_GEOMETRY] != NULL) {
       link_invalidate_variable_locations(
-            prog->_LinkedShaders[MESA_SHADER_GEOMETRY],
-            VARYING_SLOT_VAR0, VARYING_SLOT_VAR0);
+            prog->_LinkedShaders[MESA_SHADER_GEOMETRY]->ir);
    }
    if (prog->_LinkedShaders[MESA_SHADER_FRAGMENT] != NULL) {
       link_invalidate_variable_locations(
-            prog->_LinkedShaders[MESA_SHADER_FRAGMENT],
-            VARYING_SLOT_VAR0, FRAG_RESULT_DATA0);
+            prog->_LinkedShaders[MESA_SHADER_FRAGMENT]->ir);
    }
 
    /* FINISHME: The value of the max_attribute_index parameter is
@@ -1904,11 +2291,12 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
           */
          if (!assign_varying_locations(ctx, mem_ctx, prog,
                                        sh, NULL,
-                                       num_tfeedback_decls, tfeedback_decls))
+                                       num_tfeedback_decls, tfeedback_decls,
+                                       0))
             goto done;
       }
 
-      do_dead_builtin_varyings(ctx, sh->ir, NULL,
+      do_dead_builtin_varyings(ctx, sh, NULL,
                                num_tfeedback_decls, tfeedback_decls);
 
       demote_shader_inputs_and_outputs(sh, ir_var_shader_out);
@@ -1923,7 +2311,7 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
        */
       gl_shader *const sh = prog->_LinkedShaders[first];
 
-      do_dead_builtin_varyings(ctx, NULL, sh->ir,
+      do_dead_builtin_varyings(ctx, NULL, sh,
                                num_tfeedback_decls, tfeedback_decls);
 
       demote_shader_inputs_and_outputs(sh, ir_var_shader_in);
@@ -1939,13 +2327,15 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
 
       gl_shader *const sh_i = prog->_LinkedShaders[i];
       gl_shader *const sh_next = prog->_LinkedShaders[next];
+      unsigned gs_input_vertices =
+         next == MESA_SHADER_GEOMETRY ? prog->Geom.VerticesIn : 0;
 
       if (!assign_varying_locations(ctx, mem_ctx, prog, sh_i, sh_next,
                 next == MESA_SHADER_FRAGMENT ? num_tfeedback_decls : 0,
-                tfeedback_decls))
+                tfeedback_decls, gs_input_vertices))
          goto done;
 
-      do_dead_builtin_varyings(ctx, sh_i->ir, sh_next->ir,
+      do_dead_builtin_varyings(ctx, sh_i, sh_next,
                 next == MESA_SHADER_FRAGMENT ? num_tfeedback_decls : 0,
                 tfeedback_decls);
 
@@ -1960,7 +2350,9 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
          ;
 
       /* This must be done after all dead varyings are eliminated. */
-      if (!check_against_varying_limit(ctx, prog, sh_next))
+      if (!check_against_output_limit(ctx, prog, sh_i))
+         goto done;
+      if (!check_against_input_limit(ctx, prog, sh_next))
          goto done;
 
       next = i;
@@ -1971,9 +2363,12 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
 
    update_array_sizes(prog);
    link_assign_uniform_locations(prog);
+   link_assign_atomic_counter_resources(ctx, prog);
    store_fragdepth_layout(prog);
 
    check_resources(ctx, prog);
+   link_check_atomic_counter_resources(ctx, prog);
+
    if (!prog->LinkStatus)
       goto done;
 
@@ -2001,6 +2396,11 @@ done:
       if (prog->_LinkedShaders[i] == NULL)
         continue;
 
+      /* Do a final validation step to make sure that the IR wasn't
+       * invalidated by any modifications performed after intrastage linking.
+       */
+      validate_ir_tree(prog->_LinkedShaders[i]->ir);
+
       /* Retain any live IR, but trash the rest. */
       reparent_ir(prog->_LinkedShaders[i]->ir, prog->_LinkedShaders[i]->ir);