src/mesa/shader/slang/slang_link.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  7.2
   4  *
   5  * Copyright (C) 2008  Brian Paul   All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included
  15  * in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  21  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25 /**
  26  * \file slang_link.c
  27  * GLSL linker
  28  * \author Brian Paul
  29  */
  30
  31 #include "main/imports.h"
  32 #include "main/context.h"
  33 #include "main/hash.h"
  34 #include "main/macros.h"
  35 #include "shader/program.h"
  36 #include "shader/prog_instruction.h"
  37 #include "shader/prog_parameter.h"
  38 #include "shader/prog_print.h"
  39 #include "shader/prog_statevars.h"
  40 #include "shader/prog_uniform.h"
  41 #include "shader/shader_api.h"
  42 #include "slang_link.h"
  43
  44
  45 /** cast wrapper */
  46 static struct gl_vertex_program *
  47 vertex_program(struct gl_program *prog)
  48 {
  49    assert(prog->Target == GL_VERTEX_PROGRAM_ARB);
  50    return (struct gl_vertex_program *) prog;
  51 }
  52
  53
  54 /** cast wrapper */
  55 static struct gl_fragment_program *
  56 fragment_program(struct gl_program *prog)
  57 {
  58    assert(prog->Target == GL_FRAGMENT_PROGRAM_ARB);
  59    return (struct gl_fragment_program *) prog;
  60 }
  61
  62
  63 /**
  64  * Record a linking error.
  65  */
  66 static void
  67 link_error(struct gl_shader_program *shProg, const char *msg)
  68 {
  69    if (shProg->InfoLog) {
  70       _mesa_free(shProg->InfoLog);
  71    }
  72    shProg->InfoLog = _mesa_strdup(msg);
  73    shProg->LinkStatus = GL_FALSE;
  74 }
  75
  76
  77
  78 /**
  79  * Check if the given bit is either set or clear in both bitfields.
  80  */
  81 static GLboolean
  82 bits_agree(GLbitfield flags1, GLbitfield flags2, GLbitfield bit)
  83 {
  84    return (flags1 & bit) == (flags2 & bit);
  85 }
  86
  87
  88 /**
  89  * Linking varying vars involves rearranging varying vars so that the
  90  * vertex program's output varyings matches the order of the fragment
  91  * program's input varyings.
  92  * We'll then rewrite instructions to replace PROGRAM_VARYING with either
  93  * PROGRAM_INPUT or PROGRAM_OUTPUT depending on whether it's a vertex or
  94  * fragment shader.
  95  * This is also where we set program Input/OutputFlags to indicate
  96  * which inputs are centroid-sampled, invariant, etc.
  97  */
  98 static GLboolean
  99 link_varying_vars(struct gl_shader_program *shProg, struct gl_program *prog)
 100 {
 101    GLuint *map, i, firstVarying, newFile;
 102    GLbitfield *inOutFlags;
 103
 104    map = (GLuint *) malloc(prog->Varying->NumParameters * sizeof(GLuint));
 105    if (!map)
 106       return GL_FALSE;
 107
 108    /* Varying variables are treated like other vertex program outputs
 109     * (and like other fragment program inputs).  The position of the
 110     * first varying differs for vertex/fragment programs...
 111     * Also, replace File=PROGRAM_VARYING with File=PROGRAM_INPUT/OUTPUT.
 112     */
 113    if (prog->Target == GL_VERTEX_PROGRAM_ARB) {
 114       firstVarying = VERT_RESULT_VAR0;
 115       newFile = PROGRAM_OUTPUT;
 116       inOutFlags = prog->OutputFlags;
 117    }
 118    else {
 119       assert(prog->Target == GL_FRAGMENT_PROGRAM_ARB);
 120       firstVarying = FRAG_ATTRIB_VAR0;
 121       newFile = PROGRAM_INPUT;
 122       inOutFlags = prog->InputFlags;
 123    }
 124
 125    for (i = 0; i < prog->Varying->NumParameters; i++) {
 126       /* see if this varying is in the linked varying list */
 127       const struct gl_program_parameter *var = prog->Varying->Parameters + i;
 128       GLint j = _mesa_lookup_parameter_index(shProg->Varying, -1, var->Name);
 129       if (j >= 0) {
 130          /* varying is already in list, do some error checking */
 131          const struct gl_program_parameter *v =
 132             &shProg->Varying->Parameters[j];
 133          if (var->Size != v->Size) {
 134             link_error(shProg, "mismatched varying variable types");
 135             return GL_FALSE;
 136          }
 137          if (!bits_agree(var->Flags, v->Flags, PROG_PARAM_BIT_CENTROID)) {
 138             char msg[100];
 139             snprintf(msg, sizeof(msg),
 140                      "centroid modifier mismatch for '%s'", var->Name);
 141             link_error(shProg, msg);
 142             return GL_FALSE;
 143          }
 144          if (!bits_agree(var->Flags, v->Flags, PROG_PARAM_BIT_INVARIANT)) {
 145             char msg[100];
 146             snprintf(msg, sizeof(msg),
 147                      "invariant modifier mismatch for '%s'", var->Name);
 148             link_error(shProg, msg);
 149             return GL_FALSE;
 150          }
 151       }
 152       else {
 153          /* not already in linked list */
 154          j = _mesa_add_varying(shProg->Varying, var->Name, var->Size,
 155                                var->Flags);
 156       }
 157
 158       /* Map varying[i] to varying[j].
 159        * Plus, set prog->Input/OutputFlags[] as described above.
 160        * Note: the loop here takes care of arrays or large (sz>4) vars.
 161        */
 162       {
 163          GLint sz = var->Size;
 164          while (sz > 0) {
 165             inOutFlags[firstVarying + j] = var->Flags;
 166             /*printf("Link varying from %d to %d\n", i, j);*/
 167             map[i++] = j++;
 168             sz -= 4;
 169          }
 170          i--; /* go back one */
 171       }
 172    }
 173
 174
 175    /* OK, now scan the program/shader instructions looking for varying vars,
 176     * replacing the old index with the new index.
 177     */
 178    for (i = 0; i < prog->NumInstructions; i++) {
 179       struct prog_instruction *inst = prog->Instructions + i;
 180       GLuint j;
 181
 182       if (inst->DstReg.File == PROGRAM_VARYING) {
 183          inst->DstReg.File = newFile;
 184          inst->DstReg.Index = map[ inst->DstReg.Index ] + firstVarying;
 185       }
 186
 187       for (j = 0; j < 3; j++) {
 188          if (inst->SrcReg[j].File == PROGRAM_VARYING) {
 189             inst->SrcReg[j].File = newFile;
 190             inst->SrcReg[j].Index = map[ inst->SrcReg[j].Index ] + firstVarying;
 191          }
 192       }
 193    }
 194
 195    free(map);
 196
 197    /* these will get recomputed before linking is completed */
 198    prog->InputsRead = 0x0;
 199    prog->OutputsWritten = 0x0;
 200
 201    return GL_TRUE;
 202 }
 203
 204
 205 /**
 206  * Build the shProg->Uniforms list.
 207  * This is basically a list/index of all uniforms found in either/both of
 208  * the vertex and fragment shaders.
 209  */
 210 static GLboolean
 211 link_uniform_vars(GLcontext *ctx,
 212                   struct gl_shader_program *shProg,
 213                   struct gl_program *prog,
 214                   GLuint *numSamplers)
 215 {
 216    GLuint samplerMap[MAX_SAMPLERS];
 217    GLuint i;
 218
 219    for (i = 0; i < prog->Parameters->NumParameters; i++) {
 220       const struct gl_program_parameter *p = prog->Parameters->Parameters + i;
 221
 222       /*
 223        * XXX FIX NEEDED HERE
 224        * We should also be adding a uniform if p->Type == PROGRAM_STATE_VAR.
 225        * For example, modelview matrix, light pos, etc.
 226        * Also, we need to update the state-var name-generator code to
 227        * generate GLSL-style names, like "gl_LightSource[0].position".
 228        * Furthermore, we'll need to fix the state-var's size/datatype info.
 229        */
 230
 231       if ((p->Type == PROGRAM_UNIFORM && p->Used) ||
 232           p->Type == PROGRAM_SAMPLER) {
 233          struct gl_uniform *uniform =
 234             _mesa_append_uniform(shProg->Uniforms, p->Name, prog->Target, i);
 235          if (uniform)
 236             uniform->Initialized = p->Initialized;
 237       }
 238
 239       if (p->Type == PROGRAM_SAMPLER) {
 240          /* Allocate a new sampler index */
 241          GLuint sampNum = *numSamplers;
 242          GLuint oldSampNum = (GLuint) prog->Parameters->ParameterValues[i][0];
 243          if (oldSampNum >= ctx->Const.MaxTextureImageUnits) {
 244             char s[100];
 245             sprintf(s, "Too many texture samplers (%u, max is %u)",
 246                     oldSampNum + 1, ctx->Const.MaxTextureImageUnits);
 247             link_error(shProg, s);
 248             return GL_FALSE;
 249          }
 250          samplerMap[oldSampNum] = sampNum;
 251          (*numSamplers)++;
 252       }
 253    }
 254
 255
 256    /* OK, now scan the program/shader instructions looking for sampler vars,
 257     * replacing the old index with the new index.
 258     */
 259    prog->SamplersUsed = 0x0;
 260    for (i = 0; i < prog->NumInstructions; i++) {
 261       struct prog_instruction *inst = prog->Instructions + i;
 262       if (_mesa_is_tex_instruction(inst->Opcode)) {
 263          /*
 264          printf("====== remap sampler from %d to %d\n",
 265                 inst->Sampler, map[ inst->Sampler ]);
 266          */
 267          /* here, texUnit is really samplerUnit */
 268          assert(inst->TexSrcUnit < MAX_SAMPLERS);
 269          inst->TexSrcUnit = samplerMap[inst->TexSrcUnit];
 270          prog->SamplerTargets[inst->TexSrcUnit] = inst->TexSrcTarget;
 271          prog->SamplersUsed |= (1 << inst->TexSrcUnit);
 272       }
 273    }
 274
 275    return GL_TRUE;
 276 }
 277
 278
 279 /**
 280  * Resolve binding of generic vertex attributes.
 281  * For example, if the vertex shader declared "attribute vec4 foobar" we'll
 282  * allocate a generic vertex attribute for "foobar" and plug that value into
 283  * the vertex program instructions.
 284  * But if the user called glBindAttributeLocation(), those bindings will
 285  * have priority.
 286  */
 287 static GLboolean
 288 _slang_resolve_attributes(struct gl_shader_program *shProg,
 289                           const struct gl_program *origProg,
 290                           struct gl_program *linkedProg)
 291 {
 292    GLint attribMap[MAX_VERTEX_ATTRIBS];
 293    GLuint i, j;
 294    GLbitfield usedAttributes;
 295
 296    assert(origProg != linkedProg);
 297    assert(origProg->Target == GL_VERTEX_PROGRAM_ARB);
 298    assert(linkedProg->Target == GL_VERTEX_PROGRAM_ARB);
 299
 300    if (!shProg->Attributes)
 301       shProg->Attributes = _mesa_new_parameter_list();
 302
 303    if (linkedProg->Attributes) {
 304       _mesa_free_parameter_list(linkedProg->Attributes);
 305    }
 306    linkedProg->Attributes = _mesa_new_parameter_list();
 307
 308
 309    /* Build a bitmask indicating which attribute indexes have been
 310     * explicitly bound by the user with glBindAttributeLocation().
 311     */
 312    usedAttributes = 0x0;
 313    for (i = 0; i < shProg->Attributes->NumParameters; i++) {
 314       GLint attr = shProg->Attributes->Parameters[i].StateIndexes[0];
 315       usedAttributes |= (1 << attr);
 316    }
 317
 318    /* initialize the generic attribute map entries to -1 */
 319    for (i = 0; i < MAX_VERTEX_ATTRIBS; i++) {
 320       attribMap[i] = -1;
 321    }
 322
 323    /*
 324     * Scan program for generic attribute references
 325     */
 326    for (i = 0; i < linkedProg->NumInstructions; i++) {
 327       struct prog_instruction *inst = linkedProg->Instructions + i;
 328       for (j = 0; j < 3; j++) {
 329          if (inst->SrcReg[j].File == PROGRAM_INPUT &&
 330              inst->SrcReg[j].Index >= VERT_ATTRIB_GENERIC0) {
 331             /*
 332              * OK, we've found a generic vertex attribute reference.
 333              */
 334             const GLint k = inst->SrcReg[j].Index - VERT_ATTRIB_GENERIC0;
 335
 336             GLint attr = attribMap[k];
 337
 338             if (attr < 0) {
 339                /* Need to figure out attribute mapping now.
 340                 */
 341                const char *name = origProg->Attributes->Parameters[k].Name;
 342                const GLint size = origProg->Attributes->Parameters[k].Size;
 343                const GLenum type =origProg->Attributes->Parameters[k].DataType;
 344                GLint index;
 345
 346                /* See if there's a user-defined attribute binding for
 347                 * this name.
 348                 */
 349                index = _mesa_lookup_parameter_index(shProg->Attributes,
 350                                                     -1, name);
 351                if (index >= 0) {
 352                   /* Found a user-defined binding */
 353                   attr = shProg->Attributes->Parameters[index].StateIndexes[0];
 354                }
 355                else {
 356                   /* No user-defined binding, choose our own attribute number.
 357                    * Start at 1 since generic attribute 0 always aliases
 358                    * glVertex/position.
 359                    */
 360                   for (attr = 1; attr < MAX_VERTEX_ATTRIBS; attr++) {
 361                      if (((1 << attr) & usedAttributes) == 0)
 362                         break;
 363                   }
 364                   if (attr == MAX_VERTEX_ATTRIBS) {
 365                      link_error(shProg, "Too many vertex attributes");
 366                      return GL_FALSE;
 367                   }
 368
 369                   /* mark this attribute as used */
 370                   usedAttributes |= (1 << attr);
 371                }
 372
 373                attribMap[k] = attr;
 374
 375                /* Save the final name->attrib binding so it can be queried
 376                 * with glGetAttributeLocation().
 377                 */
 378                _mesa_add_attribute(linkedProg->Attributes, name,
 379                                    size, type, attr);
 380             }
 381
 382             assert(attr >= 0);
 383
 384             /* update the instruction's src reg */
 385             inst->SrcReg[j].Index = VERT_ATTRIB_GENERIC0 + attr;
 386          }
 387       }
 388    }
 389
 390    return GL_TRUE;
 391 }
 392
 393
 394 /**
 395  * Scan program instructions to update the program's NumTemporaries field.
 396  * Note: this implemenation relies on the code generator allocating
 397  * temps in increasing order (0, 1, 2, ... ).
 398  */
 399 static void
 400 _slang_count_temporaries(struct gl_program *prog)
 401 {
 402    GLuint i, j;
 403    GLint maxIndex = -1;
 404
 405    for (i = 0; i < prog->NumInstructions; i++) {
 406       const struct prog_instruction *inst = prog->Instructions + i;
 407       const GLuint numSrc = _mesa_num_inst_src_regs(inst->Opcode);
 408       for (j = 0; j < numSrc; j++) {
 409          if (inst->SrcReg[j].File == PROGRAM_TEMPORARY) {
 410             if (maxIndex < inst->SrcReg[j].Index)
 411                maxIndex = inst->SrcReg[j].Index;
 412          }
 413          if (inst->DstReg.File == PROGRAM_TEMPORARY) {
 414             if (maxIndex < (GLint) inst->DstReg.Index)
 415                maxIndex = inst->DstReg.Index;
 416          }
 417       }
 418    }
 419
 420    prog->NumTemporaries = (GLuint) (maxIndex + 1);
 421 }
 422
 423
 424 /**
 425  * Scan program instructions to update the program's InputsRead and
 426  * OutputsWritten fields.
 427  */
 428 static void
 429 _slang_update_inputs_outputs(struct gl_program *prog)
 430 {
 431    GLuint i, j;
 432    GLuint maxAddrReg = 0;
 433
 434    prog->InputsRead = 0x0;
 435    prog->OutputsWritten = 0x0;
 436
 437    for (i = 0; i < prog->NumInstructions; i++) {
 438       const struct prog_instruction *inst = prog->Instructions + i;
 439       const GLuint numSrc = _mesa_num_inst_src_regs(inst->Opcode);
 440       for (j = 0; j < numSrc; j++) {
 441          if (inst->SrcReg[j].File == PROGRAM_INPUT) {
 442             prog->InputsRead |= 1 << inst->SrcReg[j].Index;
 443             if (prog->Target == GL_FRAGMENT_PROGRAM_ARB &&
 444                 inst->SrcReg[j].Index == FRAG_ATTRIB_FOGC) {
 445                /* The fragment shader FOGC input is used for fog,
 446                 * front-facing and sprite/point coord.
 447                 */
 448                struct gl_fragment_program *fp = fragment_program(prog);
 449                const GLint swz = GET_SWZ(inst->SrcReg[j].Swizzle, 0);
 450                if (swz == SWIZZLE_X)
 451                   fp->UsesFogFragCoord = GL_TRUE;
 452                else if (swz == SWIZZLE_Y)
 453                   fp->UsesFrontFacing = GL_TRUE;
 454                else if (swz == SWIZZLE_Z || swz == SWIZZLE_W)
 455                   fp->UsesPointCoord = GL_TRUE;
 456             }
 457          }
 458          else if (inst->SrcReg[j].File == PROGRAM_ADDRESS) {
 459             maxAddrReg = MAX2(maxAddrReg, (GLuint) (inst->SrcReg[j].Index + 1));
 460          }
 461       }
 462       if (inst->DstReg.File == PROGRAM_OUTPUT) {
 463          prog->OutputsWritten |= 1 << inst->DstReg.Index;
 464       }
 465       else if (inst->DstReg.File == PROGRAM_ADDRESS) {
 466          maxAddrReg = MAX2(maxAddrReg, inst->DstReg.Index + 1);
 467       }
 468    }
 469
 470    prog->NumAddressRegs = maxAddrReg;
 471 }
 472
 473
 474 /**
 475  * Shader linker.  Currently:
 476  *
 477  * 1. The last attached vertex shader and fragment shader are linked.
 478  * 2. Varying vars in the two shaders are combined so their locations
 479  *    agree between the vertex and fragment stages.  They're treated as
 480  *    vertex program output attribs and as fragment program input attribs.
 481  * 3. The vertex and fragment programs are cloned and modified to update
 482  *    src/dst register references so they use the new, linked varying
 483  *    storage locations.
 484  */
 485 void
 486 _slang_link(GLcontext *ctx,
 487             GLhandleARB programObj,
 488             struct gl_shader_program *shProg)
 489 {
 490    const struct gl_vertex_program *vertProg;
 491    const struct gl_fragment_program *fragProg;
 492    GLuint numSamplers = 0;
 493    GLuint i;
 494
 495    _mesa_clear_shader_program_data(ctx, shProg);
 496
 497    /* check that all programs compiled successfully */
 498    for (i = 0; i < shProg->NumShaders; i++) {
 499       if (!shProg->Shaders[i]->CompileStatus) {
 500          link_error(shProg, "linking with uncompiled shader\n");
 501          return;
 502       }
 503    }
 504
 505    shProg->Uniforms = _mesa_new_uniform_list();
 506    shProg->Varying = _mesa_new_parameter_list();
 507
 508    /**
 509     * Find attached vertex, fragment shaders defining main()
 510     */
 511    vertProg = NULL;
 512    fragProg = NULL;
 513    for (i = 0; i < shProg->NumShaders; i++) {
 514       struct gl_shader *shader = shProg->Shaders[i];
 515       if (shader->Type == GL_VERTEX_SHADER) {
 516          if (shader->Main)
 517             vertProg = vertex_program(shader->Program);
 518       }
 519       else if (shader->Type == GL_FRAGMENT_SHADER) {
 520          if (shader->Main)
 521             fragProg = fragment_program(shader->Program);
 522       }
 523       else {
 524          _mesa_problem(ctx, "unexpected shader target in slang_link()");
 525       }
 526    }
 527
 528 #if FEATURE_es2_glsl
 529    /* must have both a vertex and fragment program for ES2 */
 530    if (!vertProg) {
 531       link_error(shProg, "missing vertex shader\n");
 532       return;
 533    }
 534    if (!fragProg) {
 535       link_error(shProg, "missing fragment shader\n");
 536       return;
 537    }
 538 #endif
 539
 540    /*
 541     * Make copies of the vertex/fragment programs now since we'll be
 542     * changing src/dst registers after merging the uniforms and varying vars.
 543     */
 544    _mesa_reference_vertprog(ctx, &shProg->VertexProgram, NULL);
 545    if (vertProg) {
 546       struct gl_vertex_program *linked_vprog =
 547          vertex_program(_mesa_clone_program(ctx, &vertProg->Base));
 548       shProg->VertexProgram = linked_vprog; /* refcount OK */
 549       ASSERT(shProg->VertexProgram->Base.RefCount == 1);
 550    }
 551
 552    _mesa_reference_fragprog(ctx, &shProg->FragmentProgram, NULL);
 553    if (fragProg) {
 554       struct gl_fragment_program *linked_fprog =
 555          fragment_program(_mesa_clone_program(ctx, &fragProg->Base));
 556       shProg->FragmentProgram = linked_fprog; /* refcount OK */
 557       ASSERT(shProg->FragmentProgram->Base.RefCount == 1);
 558    }
 559
 560    /* link varying vars */
 561    if (shProg->VertexProgram) {
 562       if (!link_varying_vars(shProg, &shProg->VertexProgram->Base))
 563          return;
 564    }
 565    if (shProg->FragmentProgram) {
 566       if (!link_varying_vars(shProg, &shProg->FragmentProgram->Base))
 567          return;
 568    }
 569
 570    /* link uniform vars */
 571    if (shProg->VertexProgram) {
 572       if (!link_uniform_vars(ctx, shProg, &shProg->VertexProgram->Base,
 573                              &numSamplers)) {
 574          return;
 575       }
 576    }
 577    if (shProg->FragmentProgram) {
 578       if (!link_uniform_vars(ctx, shProg, &shProg->FragmentProgram->Base,
 579                              &numSamplers)) {
 580          return;
 581       }
 582    }
 583
 584    /*_mesa_print_uniforms(shProg->Uniforms);*/
 585
 586    if (shProg->VertexProgram) {
 587       if (!_slang_resolve_attributes(shProg, &vertProg->Base,
 588                                      &shProg->VertexProgram->Base)) {
 589          return;
 590       }
 591    }
 592
 593    if (shProg->VertexProgram) {
 594       _slang_update_inputs_outputs(&shProg->VertexProgram->Base);
 595       _slang_count_temporaries(&shProg->VertexProgram->Base);
 596       if (!(shProg->VertexProgram->Base.OutputsWritten & (1 << VERT_RESULT_HPOS))) {
 597          /* the vertex program did not compute a vertex position */
 598          link_error(shProg,
 599                     "gl_Position was not written by vertex shader\n");
 600          return;
 601       }
 602    }
 603    if (shProg->FragmentProgram) {
 604       _slang_count_temporaries(&shProg->FragmentProgram->Base);
 605       _slang_update_inputs_outputs(&shProg->FragmentProgram->Base);
 606    }
 607
 608    /* Check that all the varying vars needed by the fragment shader are
 609     * actually produced by the vertex shader.
 610     */
 611    if (shProg->FragmentProgram) {
 612       const GLbitfield varyingRead
 613          = shProg->FragmentProgram->Base.InputsRead >> FRAG_ATTRIB_VAR0;
 614       const GLbitfield varyingWritten = shProg->VertexProgram ?
 615          shProg->VertexProgram->Base.OutputsWritten >> VERT_RESULT_VAR0 : 0x0;
 616       if ((varyingRead & varyingWritten) != varyingRead) {
 617          link_error(shProg,
 618           "Fragment program using varying vars not written by vertex shader\n");
 619          return;
 620       }
 621    }
 622
 623
 624    if (fragProg && shProg->FragmentProgram) {
 625       /* Compute initial program's TexturesUsed info */
 626       _mesa_update_shader_textures_used(&shProg->FragmentProgram->Base);
 627
 628       /* notify driver that a new fragment program has been compiled/linked */
 629       ctx->Driver.ProgramStringNotify(ctx, GL_FRAGMENT_PROGRAM_ARB,
 630                                       &shProg->FragmentProgram->Base);
 631       if (MESA_VERBOSE & VERBOSE_GLSL_DUMP) {
 632          printf("Mesa original fragment program:\n");
 633          _mesa_print_program(&fragProg->Base);
 634          _mesa_print_program_parameters(ctx, &fragProg->Base);
 635
 636          printf("Mesa post-link fragment program:\n");
 637          _mesa_print_program(&shProg->FragmentProgram->Base);
 638          _mesa_print_program_parameters(ctx, &shProg->FragmentProgram->Base);
 639       }
 640    }
 641
 642    if (vertProg && shProg->VertexProgram) {
 643       /* Compute initial program's TexturesUsed info */
 644       _mesa_update_shader_textures_used(&shProg->VertexProgram->Base);
 645
 646       /* notify driver that a new vertex program has been compiled/linked */
 647       ctx->Driver.ProgramStringNotify(ctx, GL_VERTEX_PROGRAM_ARB,
 648                                       &shProg->VertexProgram->Base);
 649       if (MESA_VERBOSE & VERBOSE_GLSL_DUMP) {
 650          printf("Mesa original vertex program:\n");
 651          _mesa_print_program(&vertProg->Base);
 652          _mesa_print_program_parameters(ctx, &vertProg->Base);
 653
 654          printf("Mesa post-link vertex program:\n");
 655          _mesa_print_program(&shProg->VertexProgram->Base);
 656          _mesa_print_program_parameters(ctx, &shProg->VertexProgram->Base);
 657       }
 658    }
 659
 660    if (MESA_VERBOSE & VERBOSE_GLSL_DUMP) {
 661       printf("Varying vars:\n");
 662       _mesa_print_parameter_list(shProg->Varying);
 663    }
 664
 665    shProg->LinkStatus = (shProg->VertexProgram || shProg->FragmentProgram);
 666 }
 667