src/mesa/shader/slang/slang_link.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  7.3
   4  *
   5  * Copyright (C) 2008  Brian Paul   All Rights Reserved.
   6  * Copyright (C) 2009  VMware, Inc.  All Rights Reserved.
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a
   9  * copy of this software and associated documentation files (the "Software"),
  10  * to deal in the Software without restriction, including without limitation
  11  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  12  * and/or sell copies of the Software, and to permit persons to whom the
  13  * Software is furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be included
  16  * in all copies or substantial portions of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  21  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  22  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  23  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  24  */
  25
  26 /**
  27  * \file slang_link.c
  28  * GLSL linker
  29  * \author Brian Paul
  30  */
  31
  32 #include "main/imports.h"
  33 #include "main/context.h"
  34 #include "main/hash.h"
  35 #include "main/macros.h"
  36 #include "shader/program.h"
  37 #include "shader/prog_instruction.h"
  38 #include "shader/prog_parameter.h"
  39 #include "shader/prog_print.h"
  40 #include "shader/prog_statevars.h"
  41 #include "shader/prog_uniform.h"
  42 #include "shader/shader_api.h"
  43 #include "slang_link.h"
  44
  45
  46 /** cast wrapper */
  47 static struct gl_vertex_program *
  48 vertex_program(struct gl_program *prog)
  49 {
  50    assert(prog->Target == GL_VERTEX_PROGRAM_ARB);
  51    return (struct gl_vertex_program *) prog;
  52 }
  53
  54
  55 /** cast wrapper */
  56 static struct gl_fragment_program *
  57 fragment_program(struct gl_program *prog)
  58 {
  59    assert(prog->Target == GL_FRAGMENT_PROGRAM_ARB);
  60    return (struct gl_fragment_program *) prog;
  61 }
  62
  63
  64 /**
  65  * Record a linking error.
  66  */
  67 static void
  68 link_error(struct gl_shader_program *shProg, const char *msg)
  69 {
  70    if (shProg->InfoLog) {
  71       _mesa_free(shProg->InfoLog);
  72    }
  73    shProg->InfoLog = _mesa_strdup(msg);
  74    shProg->LinkStatus = GL_FALSE;
  75 }
  76
  77
  78
  79 /**
  80  * Check if the given bit is either set or clear in both bitfields.
  81  */
  82 static GLboolean
  83 bits_agree(GLbitfield flags1, GLbitfield flags2, GLbitfield bit)
  84 {
  85    return (flags1 & bit) == (flags2 & bit);
  86 }
  87
  88
  89 /**
  90  * Linking varying vars involves rearranging varying vars so that the
  91  * vertex program's output varyings matches the order of the fragment
  92  * program's input varyings.
  93  * We'll then rewrite instructions to replace PROGRAM_VARYING with either
  94  * PROGRAM_INPUT or PROGRAM_OUTPUT depending on whether it's a vertex or
  95  * fragment shader.
  96  * This is also where we set program Input/OutputFlags to indicate
  97  * which inputs are centroid-sampled, invariant, etc.
  98  */
  99 static GLboolean
 100 link_varying_vars(struct gl_shader_program *shProg, struct gl_program *prog)
 101 {
 102    GLuint *map, i, firstVarying, newFile;
 103    GLbitfield *inOutFlags;
 104
 105    map = (GLuint *) malloc(prog->Varying->NumParameters * sizeof(GLuint));
 106    if (!map)
 107       return GL_FALSE;
 108
 109    /* Varying variables are treated like other vertex program outputs
 110     * (and like other fragment program inputs).  The position of the
 111     * first varying differs for vertex/fragment programs...
 112     * Also, replace File=PROGRAM_VARYING with File=PROGRAM_INPUT/OUTPUT.
 113     */
 114    if (prog->Target == GL_VERTEX_PROGRAM_ARB) {
 115       firstVarying = VERT_RESULT_VAR0;
 116       newFile = PROGRAM_OUTPUT;
 117       inOutFlags = prog->OutputFlags;
 118    }
 119    else {
 120       assert(prog->Target == GL_FRAGMENT_PROGRAM_ARB);
 121       firstVarying = FRAG_ATTRIB_VAR0;
 122       newFile = PROGRAM_INPUT;
 123       inOutFlags = prog->InputFlags;
 124    }
 125
 126    for (i = 0; i < prog->Varying->NumParameters; i++) {
 127       /* see if this varying is in the linked varying list */
 128       const struct gl_program_parameter *var = prog->Varying->Parameters + i;
 129       GLint j = _mesa_lookup_parameter_index(shProg->Varying, -1, var->Name);
 130       if (j >= 0) {
 131          /* varying is already in list, do some error checking */
 132          const struct gl_program_parameter *v =
 133             &shProg->Varying->Parameters[j];
 134          if (var->Size != v->Size) {
 135             link_error(shProg, "mismatched varying variable types");
 136             return GL_FALSE;
 137          }
 138          if (!bits_agree(var->Flags, v->Flags, PROG_PARAM_BIT_CENTROID)) {
 139             char msg[100];
 140             _mesa_snprintf(msg, sizeof(msg),
 141                            "centroid modifier mismatch for '%s'", var->Name);
 142             link_error(shProg, msg);
 143             return GL_FALSE;
 144          }
 145          if (!bits_agree(var->Flags, v->Flags, PROG_PARAM_BIT_INVARIANT)) {
 146             char msg[100];
 147             _mesa_snprintf(msg, sizeof(msg),
 148                            "invariant modifier mismatch for '%s'", var->Name);
 149             link_error(shProg, msg);
 150             return GL_FALSE;
 151          }
 152       }
 153       else {
 154          /* not already in linked list */
 155          j = _mesa_add_varying(shProg->Varying, var->Name, var->Size,
 156                                var->Flags);
 157       }
 158
 159       /* Map varying[i] to varying[j].
 160        * Plus, set prog->Input/OutputFlags[] as described above.
 161        * Note: the loop here takes care of arrays or large (sz>4) vars.
 162        */
 163       {
 164          GLint sz = var->Size;
 165          while (sz > 0) {
 166             inOutFlags[firstVarying + j] = var->Flags;
 167             /*printf("Link varying from %d to %d\n", i, j);*/
 168             map[i++] = j++;
 169             sz -= 4;
 170          }
 171          i--; /* go back one */
 172       }
 173    }
 174
 175
 176    /* OK, now scan the program/shader instructions looking for varying vars,
 177     * replacing the old index with the new index.
 178     */
 179    for (i = 0; i < prog->NumInstructions; i++) {
 180       struct prog_instruction *inst = prog->Instructions + i;
 181       GLuint j;
 182
 183       if (inst->DstReg.File == PROGRAM_VARYING) {
 184          inst->DstReg.File = newFile;
 185          inst->DstReg.Index = map[ inst->DstReg.Index ] + firstVarying;
 186       }
 187
 188       for (j = 0; j < 3; j++) {
 189          if (inst->SrcReg[j].File == PROGRAM_VARYING) {
 190             inst->SrcReg[j].File = newFile;
 191             inst->SrcReg[j].Index = map[ inst->SrcReg[j].Index ] + firstVarying;
 192          }
 193       }
 194    }
 195
 196    free(map);
 197
 198    /* these will get recomputed before linking is completed */
 199    prog->InputsRead = 0x0;
 200    prog->OutputsWritten = 0x0;
 201
 202    return GL_TRUE;
 203 }
 204
 205
 206 /**
 207  * Build the shProg->Uniforms list.
 208  * This is basically a list/index of all uniforms found in either/both of
 209  * the vertex and fragment shaders.
 210  *
 211  * About uniforms:
 212  * Each uniform has two indexes, one that points into the vertex
 213  * program's parameter array and another that points into the fragment
 214  * program's parameter array.  When the user changes a uniform's value
 215  * we have to change the value in the vertex and/or fragment program's
 216  * parameter array.
 217  *
 218  * This function will be called twice to set up the two uniform->parameter
 219  * mappings.
 220  *
 221  * If a uniform is only present in the vertex program OR fragment program
 222  * then the fragment/vertex parameter index, respectively, will be -1.
 223  */
 224 static GLboolean
 225 link_uniform_vars(GLcontext *ctx,
 226                   struct gl_shader_program *shProg,
 227                   struct gl_program *prog,
 228                   GLuint *numSamplers)
 229 {
 230    GLuint samplerMap[200]; /* max number of samplers declared, not used */
 231    GLuint i;
 232
 233    for (i = 0; i < prog->Parameters->NumParameters; i++) {
 234       const struct gl_program_parameter *p = prog->Parameters->Parameters + i;
 235
 236       /*
 237        * XXX FIX NEEDED HERE
 238        * We should also be adding a uniform if p->Type == PROGRAM_STATE_VAR.
 239        * For example, modelview matrix, light pos, etc.
 240        * Also, we need to update the state-var name-generator code to
 241        * generate GLSL-style names, like "gl_LightSource[0].position".
 242        * Furthermore, we'll need to fix the state-var's size/datatype info.
 243        */
 244
 245       if ((p->Type == PROGRAM_UNIFORM || p->Type == PROGRAM_SAMPLER)
 246           && p->Used) {
 247          /* add this uniform, indexing into the target's Parameters list */
 248          struct gl_uniform *uniform =
 249             _mesa_append_uniform(shProg->Uniforms, p->Name, prog->Target, i);
 250          if (uniform)
 251             uniform->Initialized = p->Initialized;
 252       }
 253
 254       /* The samplerMap[] table we build here is used to remap/re-index
 255        * sampler references by TEX instructions.
 256        */
 257       if (p->Type == PROGRAM_SAMPLER && p->Used) {
 258          /* Allocate a new sampler index */
 259          GLuint oldSampNum = (GLuint) prog->Parameters->ParameterValues[i][0];
 260          GLuint newSampNum = *numSamplers;
 261          if (newSampNum >= ctx->Const.MaxTextureImageUnits) {
 262             char s[100];
 263             _mesa_sprintf(s, "Too many texture samplers (%u, max is %u)",
 264                           newSampNum, ctx->Const.MaxTextureImageUnits);
 265             link_error(shProg, s);
 266             return GL_FALSE;
 267          }
 268          /* save old->new mapping in the table */
 269          if (oldSampNum < Elements(samplerMap))
 270             samplerMap[oldSampNum] = newSampNum;
 271          /* update parameter's sampler index */
 272          prog->Parameters->ParameterValues[i][0] = (GLfloat) newSampNum;
 273          (*numSamplers)++;
 274       }
 275    }
 276
 277    /* OK, now scan the program/shader instructions looking for texture
 278     * instructions using sampler vars.  Replace old sampler indexes with
 279     * new ones.
 280     */
 281    prog->SamplersUsed = 0x0;
 282    for (i = 0; i < prog->NumInstructions; i++) {
 283       struct prog_instruction *inst = prog->Instructions + i;
 284       if (_mesa_is_tex_instruction(inst->Opcode)) {
 285          const GLint oldSampNum = inst->TexSrcUnit;
 286
 287 #if 0
 288          printf("====== remap sampler from %d to %d\n",
 289                 inst->TexSrcUnit, samplerMap[ inst->TexSrcUnit ]);
 290 #endif
 291
 292          /* here, texUnit is really samplerUnit */
 293          if (oldSampNum < Elements(samplerMap)) {
 294             const GLuint newSampNum = samplerMap[oldSampNum];
 295             inst->TexSrcUnit = newSampNum;
 296             prog->SamplerTargets[newSampNum] = inst->TexSrcTarget;
 297             prog->SamplersUsed |= (1 << newSampNum);
 298          }
 299       }
 300    }
 301
 302    return GL_TRUE;
 303 }
 304
 305
 306 /**
 307  * Resolve binding of generic vertex attributes.
 308  * For example, if the vertex shader declared "attribute vec4 foobar" we'll
 309  * allocate a generic vertex attribute for "foobar" and plug that value into
 310  * the vertex program instructions.
 311  * But if the user called glBindAttributeLocation(), those bindings will
 312  * have priority.
 313  */
 314 static GLboolean
 315 _slang_resolve_attributes(struct gl_shader_program *shProg,
 316                           const struct gl_program *origProg,
 317                           struct gl_program *linkedProg)
 318 {
 319    GLint attribMap[MAX_VERTEX_ATTRIBS];
 320    GLuint i, j;
 321    GLbitfield usedAttributes;
 322
 323    assert(origProg != linkedProg);
 324    assert(origProg->Target == GL_VERTEX_PROGRAM_ARB);
 325    assert(linkedProg->Target == GL_VERTEX_PROGRAM_ARB);
 326
 327    if (!shProg->Attributes)
 328       shProg->Attributes = _mesa_new_parameter_list();
 329
 330    if (linkedProg->Attributes) {
 331       _mesa_free_parameter_list(linkedProg->Attributes);
 332    }
 333    linkedProg->Attributes = _mesa_new_parameter_list();
 334
 335
 336    /* Build a bitmask indicating which attribute indexes have been
 337     * explicitly bound by the user with glBindAttributeLocation().
 338     */
 339    usedAttributes = 0x0;
 340    for (i = 0; i < shProg->Attributes->NumParameters; i++) {
 341       GLint attr = shProg->Attributes->Parameters[i].StateIndexes[0];
 342       usedAttributes |= (1 << attr);
 343    }
 344
 345    /* initialize the generic attribute map entries to -1 */
 346    for (i = 0; i < MAX_VERTEX_ATTRIBS; i++) {
 347       attribMap[i] = -1;
 348    }
 349
 350    /*
 351     * Scan program for generic attribute references
 352     */
 353    for (i = 0; i < linkedProg->NumInstructions; i++) {
 354       struct prog_instruction *inst = linkedProg->Instructions + i;
 355       for (j = 0; j < 3; j++) {
 356          if (inst->SrcReg[j].File == PROGRAM_INPUT &&
 357              inst->SrcReg[j].Index >= VERT_ATTRIB_GENERIC0) {
 358             /*
 359              * OK, we've found a generic vertex attribute reference.
 360              */
 361             const GLint k = inst->SrcReg[j].Index - VERT_ATTRIB_GENERIC0;
 362
 363             GLint attr = attribMap[k];
 364
 365             if (attr < 0) {
 366                /* Need to figure out attribute mapping now.
 367                 */
 368                const char *name = origProg->Attributes->Parameters[k].Name;
 369                const GLint size = origProg->Attributes->Parameters[k].Size;
 370                const GLenum type =origProg->Attributes->Parameters[k].DataType;
 371                GLint index;
 372
 373                /* See if there's a user-defined attribute binding for
 374                 * this name.
 375                 */
 376                index = _mesa_lookup_parameter_index(shProg->Attributes,
 377                                                     -1, name);
 378                if (index >= 0) {
 379                   /* Found a user-defined binding */
 380                   attr = shProg->Attributes->Parameters[index].StateIndexes[0];
 381                }
 382                else {
 383                   /* No user-defined binding, choose our own attribute number.
 384                    * Start at 1 since generic attribute 0 always aliases
 385                    * glVertex/position.
 386                    */
 387                   for (attr = 1; attr < MAX_VERTEX_ATTRIBS; attr++) {
 388                      if (((1 << attr) & usedAttributes) == 0)
 389                         break;
 390                   }
 391                   if (attr == MAX_VERTEX_ATTRIBS) {
 392                      link_error(shProg, "Too many vertex attributes");
 393                      return GL_FALSE;
 394                   }
 395
 396                   /* mark this attribute as used */
 397                   usedAttributes |= (1 << attr);
 398                }
 399
 400                attribMap[k] = attr;
 401
 402                /* Save the final name->attrib binding so it can be queried
 403                 * with glGetAttributeLocation().
 404                 */
 405                _mesa_add_attribute(linkedProg->Attributes, name,
 406                                    size, type, attr);
 407             }
 408
 409             assert(attr >= 0);
 410
 411             /* update the instruction's src reg */
 412             inst->SrcReg[j].Index = VERT_ATTRIB_GENERIC0 + attr;
 413          }
 414       }
 415    }
 416
 417    return GL_TRUE;
 418 }
 419
 420
 421 /**
 422  * Scan program instructions to update the program's NumTemporaries field.
 423  * Note: this implemenation relies on the code generator allocating
 424  * temps in increasing order (0, 1, 2, ... ).
 425  */
 426 static void
 427 _slang_count_temporaries(struct gl_program *prog)
 428 {
 429    GLuint i, j;
 430    GLint maxIndex = -1;
 431
 432    for (i = 0; i < prog->NumInstructions; i++) {
 433       const struct prog_instruction *inst = prog->Instructions + i;
 434       const GLuint numSrc = _mesa_num_inst_src_regs(inst->Opcode);
 435       for (j = 0; j < numSrc; j++) {
 436          if (inst->SrcReg[j].File == PROGRAM_TEMPORARY) {
 437             if (maxIndex < inst->SrcReg[j].Index)
 438                maxIndex = inst->SrcReg[j].Index;
 439          }
 440          if (inst->DstReg.File == PROGRAM_TEMPORARY) {
 441             if (maxIndex < (GLint) inst->DstReg.Index)
 442                maxIndex = inst->DstReg.Index;
 443          }
 444       }
 445    }
 446
 447    prog->NumTemporaries = (GLuint) (maxIndex + 1);
 448 }
 449
 450
 451 /**
 452  * Scan program instructions to update the program's InputsRead and
 453  * OutputsWritten fields.
 454  */
 455 static void
 456 _slang_update_inputs_outputs(struct gl_program *prog)
 457 {
 458    GLuint i, j;
 459    GLuint maxAddrReg = 0;
 460
 461    prog->InputsRead = 0x0;
 462    prog->OutputsWritten = 0x0;
 463
 464    for (i = 0; i < prog->NumInstructions; i++) {
 465       const struct prog_instruction *inst = prog->Instructions + i;
 466       const GLuint numSrc = _mesa_num_inst_src_regs(inst->Opcode);
 467       for (j = 0; j < numSrc; j++) {
 468          if (inst->SrcReg[j].File == PROGRAM_INPUT) {
 469             prog->InputsRead |= 1 << inst->SrcReg[j].Index;
 470             if (prog->Target == GL_FRAGMENT_PROGRAM_ARB &&
 471                 inst->SrcReg[j].Index == FRAG_ATTRIB_FOGC) {
 472                /* The fragment shader FOGC input is used for fog,
 473                 * front-facing and sprite/point coord.
 474                 */
 475                struct gl_fragment_program *fp = fragment_program(prog);
 476                const GLint swz = GET_SWZ(inst->SrcReg[j].Swizzle, 0);
 477                if (swz == SWIZZLE_X)
 478                   fp->UsesFogFragCoord = GL_TRUE;
 479                else if (swz == SWIZZLE_Y)
 480                   fp->UsesFrontFacing = GL_TRUE;
 481                else if (swz == SWIZZLE_Z || swz == SWIZZLE_W)
 482                   fp->UsesPointCoord = GL_TRUE;
 483             }
 484          }
 485          else if (inst->SrcReg[j].File == PROGRAM_ADDRESS) {
 486             maxAddrReg = MAX2(maxAddrReg, (GLuint) (inst->SrcReg[j].Index + 1));
 487          }
 488       }
 489       if (inst->DstReg.File == PROGRAM_OUTPUT) {
 490          prog->OutputsWritten |= 1 << inst->DstReg.Index;
 491       }
 492       else if (inst->DstReg.File == PROGRAM_ADDRESS) {
 493          maxAddrReg = MAX2(maxAddrReg, inst->DstReg.Index + 1);
 494       }
 495    }
 496    prog->NumAddressRegs = maxAddrReg;
 497 }
 498
 499
 500 /**
 501  * Shader linker.  Currently:
 502  *
 503  * 1. The last attached vertex shader and fragment shader are linked.
 504  * 2. Varying vars in the two shaders are combined so their locations
 505  *    agree between the vertex and fragment stages.  They're treated as
 506  *    vertex program output attribs and as fragment program input attribs.
 507  * 3. The vertex and fragment programs are cloned and modified to update
 508  *    src/dst register references so they use the new, linked varying
 509  *    storage locations.
 510  */
 511 void
 512 _slang_link(GLcontext *ctx,
 513             GLhandleARB programObj,
 514             struct gl_shader_program *shProg)
 515 {
 516    const struct gl_vertex_program *vertProg;
 517    const struct gl_fragment_program *fragProg;
 518    GLuint numSamplers = 0;
 519    GLuint i;
 520
 521    _mesa_clear_shader_program_data(ctx, shProg);
 522
 523    /* check that all programs compiled successfully */
 524    for (i = 0; i < shProg->NumShaders; i++) {
 525       if (!shProg->Shaders[i]->CompileStatus) {
 526          link_error(shProg, "linking with uncompiled shader\n");
 527          return;
 528       }
 529    }
 530
 531    shProg->Uniforms = _mesa_new_uniform_list();
 532    shProg->Varying = _mesa_new_parameter_list();
 533
 534    /**
 535     * Find attached vertex, fragment shaders defining main()
 536     */
 537    vertProg = NULL;
 538    fragProg = NULL;
 539    for (i = 0; i < shProg->NumShaders; i++) {
 540       struct gl_shader *shader = shProg->Shaders[i];
 541       if (shader->Type == GL_VERTEX_SHADER) {
 542          if (shader->Main)
 543             vertProg = vertex_program(shader->Program);
 544       }
 545       else if (shader->Type == GL_FRAGMENT_SHADER) {
 546          if (shader->Main)
 547             fragProg = fragment_program(shader->Program);
 548       }
 549       else {
 550          _mesa_problem(ctx, "unexpected shader target in slang_link()");
 551       }
 552    }
 553
 554 #if FEATURE_es2_glsl
 555    /* must have both a vertex and fragment program for ES2 */
 556    if (!vertProg) {
 557       link_error(shProg, "missing vertex shader\n");
 558       return;
 559    }
 560    if (!fragProg) {
 561       link_error(shProg, "missing fragment shader\n");
 562       return;
 563    }
 564 #endif
 565
 566    /*
 567     * Make copies of the vertex/fragment programs now since we'll be
 568     * changing src/dst registers after merging the uniforms and varying vars.
 569     */
 570    _mesa_reference_vertprog(ctx, &shProg->VertexProgram, NULL);
 571    if (vertProg) {
 572       struct gl_vertex_program *linked_vprog =
 573          vertex_program(_mesa_clone_program(ctx, &vertProg->Base));
 574       shProg->VertexProgram = linked_vprog; /* refcount OK */
 575       ASSERT(shProg->VertexProgram->Base.RefCount == 1);
 576    }
 577
 578    _mesa_reference_fragprog(ctx, &shProg->FragmentProgram, NULL);
 579    if (fragProg) {
 580       struct gl_fragment_program *linked_fprog =
 581          fragment_program(_mesa_clone_program(ctx, &fragProg->Base));
 582       shProg->FragmentProgram = linked_fprog; /* refcount OK */
 583       ASSERT(shProg->FragmentProgram->Base.RefCount == 1);
 584    }
 585
 586    /* link varying vars */
 587    if (shProg->VertexProgram) {
 588       if (!link_varying_vars(shProg, &shProg->VertexProgram->Base))
 589          return;
 590    }
 591    if (shProg->FragmentProgram) {
 592       if (!link_varying_vars(shProg, &shProg->FragmentProgram->Base))
 593          return;
 594    }
 595
 596    /* link uniform vars */
 597    if (shProg->VertexProgram) {
 598       if (!link_uniform_vars(ctx, shProg, &shProg->VertexProgram->Base,
 599                              &numSamplers)) {
 600          return;
 601       }
 602    }
 603    if (shProg->FragmentProgram) {
 604       if (!link_uniform_vars(ctx, shProg, &shProg->FragmentProgram->Base,
 605                              &numSamplers)) {
 606          return;
 607       }
 608    }
 609
 610    /*_mesa_print_uniforms(shProg->Uniforms);*/
 611
 612    if (shProg->VertexProgram) {
 613       if (!_slang_resolve_attributes(shProg, &vertProg->Base,
 614                                      &shProg->VertexProgram->Base)) {
 615          return;
 616       }
 617    }
 618
 619    if (shProg->VertexProgram) {
 620       _slang_update_inputs_outputs(&shProg->VertexProgram->Base);
 621       _slang_count_temporaries(&shProg->VertexProgram->Base);
 622       if (!(shProg->VertexProgram->Base.OutputsWritten & (1 << VERT_RESULT_HPOS))) {
 623          /* the vertex program did not compute a vertex position */
 624          link_error(shProg,
 625                     "gl_Position was not written by vertex shader\n");
 626          return;
 627       }
 628    }
 629    if (shProg->FragmentProgram) {
 630       _slang_count_temporaries(&shProg->FragmentProgram->Base);
 631       _slang_update_inputs_outputs(&shProg->FragmentProgram->Base);
 632    }
 633
 634    /* Check that all the varying vars needed by the fragment shader are
 635     * actually produced by the vertex shader.
 636     */
 637    if (shProg->FragmentProgram) {
 638       const GLbitfield varyingRead
 639          = shProg->FragmentProgram->Base.InputsRead >> FRAG_ATTRIB_VAR0;
 640       const GLbitfield varyingWritten = shProg->VertexProgram ?
 641          shProg->VertexProgram->Base.OutputsWritten >> VERT_RESULT_VAR0 : 0x0;
 642       if ((varyingRead & varyingWritten) != varyingRead) {
 643          link_error(shProg,
 644           "Fragment program using varying vars not written by vertex shader\n");
 645          return;
 646       }
 647    }
 648
 649    /* check that gl_FragColor and gl_FragData are not both written to */
 650    if (shProg->FragmentProgram) {
 651       GLbitfield outputsWritten = shProg->FragmentProgram->Base.OutputsWritten;
 652       if ((outputsWritten & ((1 << FRAG_RESULT_COLR))) &&
 653           (outputsWritten >= (1 << FRAG_RESULT_DATA0))) {
 654          link_error(shProg, "Fragment program cannot write both gl_FragColor"
 655                     " and gl_FragData[].\n");
 656          return;
 657       }
 658    }
 659
 660
 661    if (fragProg && shProg->FragmentProgram) {
 662       /* Compute initial program's TexturesUsed info */
 663       _mesa_update_shader_textures_used(&shProg->FragmentProgram->Base);
 664
 665       /* notify driver that a new fragment program has been compiled/linked */
 666       ctx->Driver.ProgramStringNotify(ctx, GL_FRAGMENT_PROGRAM_ARB,
 667                                       &shProg->FragmentProgram->Base);
 668       if (MESA_VERBOSE & VERBOSE_GLSL_DUMP) {
 669          printf("Mesa original fragment program:\n");
 670          _mesa_print_program(&fragProg->Base);
 671          _mesa_print_program_parameters(ctx, &fragProg->Base);
 672
 673          printf("Mesa post-link fragment program:\n");
 674          _mesa_print_program(&shProg->FragmentProgram->Base);
 675          _mesa_print_program_parameters(ctx, &shProg->FragmentProgram->Base);
 676       }
 677    }
 678
 679    if (vertProg && shProg->VertexProgram) {
 680       /* Compute initial program's TexturesUsed info */
 681       _mesa_update_shader_textures_used(&shProg->VertexProgram->Base);
 682
 683       /* notify driver that a new vertex program has been compiled/linked */
 684       ctx->Driver.ProgramStringNotify(ctx, GL_VERTEX_PROGRAM_ARB,
 685                                       &shProg->VertexProgram->Base);
 686       if (MESA_VERBOSE & VERBOSE_GLSL_DUMP) {
 687          printf("Mesa original vertex program:\n");
 688          _mesa_print_program(&vertProg->Base);
 689          _mesa_print_program_parameters(ctx, &vertProg->Base);
 690
 691          printf("Mesa post-link vertex program:\n");
 692          _mesa_print_program(&shProg->VertexProgram->Base);
 693          _mesa_print_program_parameters(ctx, &shProg->VertexProgram->Base);
 694       }
 695    }
 696
 697    if (MESA_VERBOSE & VERBOSE_GLSL_DUMP) {
 698       printf("Varying vars:\n");
 699       _mesa_print_parameter_list(shProg->Varying);
 700    }
 701
 702    shProg->LinkStatus = (shProg->VertexProgram || shProg->FragmentProgram);
 703 }
 704