glsl: Separate varying linking code to its own file.

linker.cpp is getting pretty big, and we're about to add even more
varying packing code, so split out the linker code that concerns
varyings to its own file.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

src/glsl/Makefile.sources

@@ -46,6 +46,7 @@ LIBGLSL_FILES = \
 	$(GLSL_SRCDIR)/link_functions.cpp \
 	$(GLSL_SRCDIR)/link_uniforms.cpp \
 	$(GLSL_SRCDIR)/link_uniform_initializers.cpp \
+	$(GLSL_SRCDIR)/link_varyings.cpp \
 	$(GLSL_SRCDIR)/loop_analysis.cpp \
 	$(GLSL_SRCDIR)/loop_controls.cpp \
 	$(GLSL_SRCDIR)/loop_unroll.cpp \

src/glsl/link_varyings.h

@@ -0,0 +1,186 @@
+/*
+ * Copyright © 2012 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#pragma once
+#ifndef GLSL_LINK_VARYINGS_H
+#define GLSL_LINK_VARYINGS_H
+
+/**
+ * \file link_varyings.h
+ *
+ * Linker functions related specifically to linking varyings between shader
+ * stages.
+ */
+
+
+#include "main/glheader.h"
+
+
+struct gl_shader_program;
+struct gl_shader;
+class ir_variable;
+
+
+/**
+ * Data structure tracking information about a transform feedback declaration
+ * during linking.
+ */
+class tfeedback_decl
+{
+public:
+   bool init(struct gl_context *ctx, struct gl_shader_program *prog,
+             const void *mem_ctx, const char *input);
+   static bool is_same(const tfeedback_decl &x, const tfeedback_decl &y);
+   bool assign_location(struct gl_context *ctx, struct gl_shader_program *prog,
+                        ir_variable *output_var);
+   unsigned get_num_outputs() const;
+   bool store(struct gl_context *ctx, struct gl_shader_program *prog,
+              struct gl_transform_feedback_info *info, unsigned buffer,
+              const unsigned max_outputs) const;
+   ir_variable *find_output_var(gl_shader_program *prog,
+                                gl_shader *producer) const;
+
+   bool is_next_buffer_separator() const
+   {
+      return this->next_buffer_separator;
+   }
+
+   bool is_varying() const
+   {
+      return !this->next_buffer_separator && !this->skip_components;
+   }
+
+   /**
+    * The total number of varying components taken up by this variable.  Only
+    * valid if assign_location() has been called.
+    */
+   unsigned num_components() const
+   {
+      if (this->is_clip_distance_mesa)
+         return this->size;
+      else
+         return this->vector_elements * this->matrix_columns * this->size;
+   }
+
+private:
+   /**
+    * The name that was supplied to glTransformFeedbackVaryings.  Used for
+    * error reporting and glGetTransformFeedbackVarying().
+    */
+   const char *orig_name;
+
+   /**
+    * The name of the variable, parsed from orig_name.
+    */
+   const char *var_name;
+
+   /**
+    * True if the declaration in orig_name represents an array.
+    */
+   bool is_subscripted;
+
+   /**
+    * If is_subscripted is true, the subscript that was specified in orig_name.
+    */
+   unsigned array_subscript;
+
+   /**
+    * True if the variable is gl_ClipDistance and the driver lowers
+    * gl_ClipDistance to gl_ClipDistanceMESA.
+    */
+   bool is_clip_distance_mesa;
+
+   /**
+    * The vertex shader output location that the linker assigned for this
+    * variable.  -1 if a location hasn't been assigned yet.
+    */
+   int location;
+
+   /**
+    * If non-zero, then this variable may be packed along with other variables
+    * into a single varying slot, so this offset should be applied when
+    * accessing components.  For example, an offset of 1 means that the x
+    * component of this variable is actually stored in component y of the
+    * location specified by \c location.
+    *
+    * Only valid if location != -1.
+    */
+   unsigned location_frac;
+
+   /**
+    * If location != -1, the number of vector elements in this variable, or 1
+    * if this variable is a scalar.
+    */
+   unsigned vector_elements;
+
+   /**
+    * If location != -1, the number of matrix columns in this variable, or 1
+    * if this variable is not a matrix.
+    */
+   unsigned matrix_columns;
+
+   /** Type of the varying returned by glGetTransformFeedbackVarying() */
+   GLenum type;
+
+   /**
+    * If location != -1, the size that should be returned by
+    * glGetTransformFeedbackVarying().
+    */
+   unsigned size;
+
+   /**
+    * How many components to skip. If non-zero, this is
+    * gl_SkipComponents{1,2,3,4} from ARB_transform_feedback3.
+    */
+   unsigned skip_components;
+
+   /**
+    * Whether this is gl_NextBuffer from ARB_transform_feedback3.
+    */
+   bool next_buffer_separator;
+};
+
+
+bool
+cross_validate_outputs_to_inputs(struct gl_shader_program *prog,
+				 gl_shader *producer, gl_shader *consumer);
+
+bool
+parse_tfeedback_decls(struct gl_context *ctx, struct gl_shader_program *prog,
+                      const void *mem_ctx, unsigned num_names,
+                      char **varying_names, tfeedback_decl *decls);
+
+bool
+store_tfeedback_info(struct gl_context *ctx, struct gl_shader_program *prog,
+                     unsigned num_tfeedback_decls,
+                     tfeedback_decl *tfeedback_decls);
+
+bool
+assign_varying_locations(struct gl_context *ctx,
+			 void *mem_ctx,
+			 struct gl_shader_program *prog,
+			 gl_shader *producer, gl_shader *consumer,
+                         unsigned num_tfeedback_decls,
+                         tfeedback_decl *tfeedback_decls);
+
+#endif /* GLSL_LINK_VARYINGS_H */

src/glsl/linker.h

@@ -91,4 +91,13 @@ private:
    void recursion(const glsl_type *t, char **name, size_t name_length);
 };
 
+void
+linker_error(gl_shader_program *prog, const char *fmt, ...);
+
+void
+linker_warning(gl_shader_program *prog, const char *fmt, ...);
+
+unsigned
+count_attribute_slots(const glsl_type *t);
+
 #endif /* GLSL_LINKER_H */