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/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_builtin.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       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(GLcontext *ctx,
 101                   struct gl_shader_program *shProg, struct gl_program *prog)
 102 {
 103    GLuint *map, i, firstVarying, newFile;
 104    GLbitfield *inOutFlags;
 105
 106    map = (GLuint *) malloc(prog->Varying->NumParameters * sizeof(GLuint));
 107    if (!map)
 108       return GL_FALSE;
 109
 110    /* Varying variables are treated like other vertex program outputs
 111     * (and like other fragment program inputs).  The position of the
 112     * first varying differs for vertex/fragment programs...
 113     * Also, replace File=PROGRAM_VARYING with File=PROGRAM_INPUT/OUTPUT.
 114     */
 115    if (prog->Target == GL_VERTEX_PROGRAM_ARB) {
 116       firstVarying = VERT_RESULT_VAR0;
 117       newFile = PROGRAM_OUTPUT;
 118       inOutFlags = prog->OutputFlags;
 119    }
 120    else {
 121       assert(prog->Target == GL_FRAGMENT_PROGRAM_ARB);
 122       firstVarying = FRAG_ATTRIB_VAR0;
 123       newFile = PROGRAM_INPUT;
 124       inOutFlags = prog->InputFlags;
 125    }
 126
 127    for (i = 0; i < prog->Varying->NumParameters; i++) {
 128       /* see if this varying is in the linked varying list */
 129       const struct gl_program_parameter *var = prog->Varying->Parameters + i;
 130       GLint j = _mesa_lookup_parameter_index(shProg->Varying, -1, var->Name);
 131       if (j >= 0) {
 132          /* varying is already in list, do some error checking */
 133          const struct gl_program_parameter *v =
 134             &shProg->Varying->Parameters[j];
 135          if (var->Size != v->Size) {
 136             link_error(shProg, "mismatched varying variable types");
 137             free(map);
 138             return GL_FALSE;
 139          }
 140          if (!bits_agree(var->Flags, v->Flags, PROG_PARAM_BIT_CENTROID)) {
 141             char msg[100];
 142             _mesa_snprintf(msg, sizeof(msg),
 143                            "centroid modifier mismatch for '%s'", var->Name);
 144             link_error(shProg, msg);
 145             free(map);
 146             return GL_FALSE;
 147          }
 148          if (!bits_agree(var->Flags, v->Flags, PROG_PARAM_BIT_INVARIANT)) {
 149             char msg[100];
 150             _mesa_snprintf(msg, sizeof(msg),
 151                            "invariant modifier mismatch for '%s'", var->Name);
 152             link_error(shProg, msg);
 153             free(map);
 154             return GL_FALSE;
 155          }
 156       }
 157       else {
 158          /* not already in linked list */
 159          j = _mesa_add_varying(shProg->Varying, var->Name, var->Size,
 160                                var->Flags);
 161       }
 162
 163       if (shProg->Varying->NumParameters > ctx->Const.MaxVarying) {
 164          link_error(shProg, "Too many varying variables");
 165          free(map);
 166          return GL_FALSE;
 167       }
 168
 169       /* Map varying[i] to varying[j].
 170        * Note: the loop here takes care of arrays or large (sz>4) vars.
 171        */
 172       {
 173          GLint sz = var->Size;
 174          while (sz > 0) {
 175             inOutFlags[firstVarying + j] = var->Flags;
 176             /*printf("Link varying from %d to %d\n", i, j);*/
 177             map[i++] = j++;
 178             sz -= 4;
 179          }
 180          i--; /* go back one */
 181       }
 182    }
 183
 184
 185    /* OK, now scan the program/shader instructions looking for varying vars,
 186     * replacing the old index with the new index.
 187     */
 188    for (i = 0; i < prog->NumInstructions; i++) {
 189       struct prog_instruction *inst = prog->Instructions + i;
 190       GLuint j;
 191
 192       if (inst->DstReg.File == PROGRAM_VARYING) {
 193          inst->DstReg.File = newFile;
 194          inst->DstReg.Index = map[ inst->DstReg.Index ] + firstVarying;
 195       }
 196
 197       for (j = 0; j < 3; j++) {
 198          if (inst->SrcReg[j].File == PROGRAM_VARYING) {
 199             inst->SrcReg[j].File = newFile;
 200             inst->SrcReg[j].Index = map[ inst->SrcReg[j].Index ] + firstVarying;
 201          }
 202       }
 203    }
 204
 205    free(map);
 206
 207    /* these will get recomputed before linking is completed */
 208    prog->InputsRead = 0x0;
 209    prog->OutputsWritten = 0x0;
 210
 211    return GL_TRUE;
 212 }
 213
 214
 215 /**
 216  * Build the shProg->Uniforms list.
 217  * This is basically a list/index of all uniforms found in either/both of
 218  * the vertex and fragment shaders.
 219  *
 220  * About uniforms:
 221  * Each uniform has two indexes, one that points into the vertex
 222  * program's parameter array and another that points into the fragment
 223  * program's parameter array.  When the user changes a uniform's value
 224  * we have to change the value in the vertex and/or fragment program's
 225  * parameter array.
 226  *
 227  * This function will be called twice to set up the two uniform->parameter
 228  * mappings.
 229  *
 230  * If a uniform is only present in the vertex program OR fragment program
 231  * then the fragment/vertex parameter index, respectively, will be -1.
 232  */
 233 static GLboolean
 234 link_uniform_vars(GLcontext *ctx,
 235                   struct gl_shader_program *shProg,
 236                   struct gl_program *prog,
 237                   GLuint *numSamplers)
 238 {
 239    GLuint samplerMap[200]; /* max number of samplers declared, not used */
 240    GLuint i;
 241
 242    for (i = 0; i < prog->Parameters->NumParameters; i++) {
 243       const struct gl_program_parameter *p = prog->Parameters->Parameters + i;
 244
 245       /*
 246        * XXX FIX NEEDED HERE
 247        * We should also be adding a uniform if p->Type == PROGRAM_STATE_VAR.
 248        * For example, modelview matrix, light pos, etc.
 249        * Also, we need to update the state-var name-generator code to
 250        * generate GLSL-style names, like "gl_LightSource[0].position".
 251        * Furthermore, we'll need to fix the state-var's size/datatype info.
 252        */
 253
 254       if ((p->Type == PROGRAM_UNIFORM || p->Type == PROGRAM_SAMPLER)
 255           && p->Used) {
 256          /* add this uniform, indexing into the target's Parameters list */
 257          struct gl_uniform *uniform =
 258             _mesa_append_uniform(shProg->Uniforms, p->Name, prog->Target, i);
 259          if (uniform)
 260             uniform->Initialized = p->Initialized;
 261       }
 262
 263       /* The samplerMap[] table we build here is used to remap/re-index
 264        * sampler references by TEX instructions.
 265        */
 266       if (p->Type == PROGRAM_SAMPLER && p->Used) {
 267          /* Allocate a new sampler index */
 268          GLuint oldSampNum = (GLuint) prog->Parameters->ParameterValues[i][0];
 269          GLuint newSampNum = *numSamplers;
 270          if (newSampNum >= ctx->Const.MaxTextureImageUnits) {
 271             char s[100];
 272             _mesa_sprintf(s, "Too many texture samplers (%u, max is %u)",
 273                           newSampNum, ctx->Const.MaxTextureImageUnits);
 274             link_error(shProg, s);
 275             return GL_FALSE;
 276          }
 277          /* save old->new mapping in the table */
 278          if (oldSampNum < Elements(samplerMap))
 279             samplerMap[oldSampNum] = newSampNum;
 280          /* update parameter's sampler index */
 281          prog->Parameters->ParameterValues[i][0] = (GLfloat) newSampNum;
 282          (*numSamplers)++;
 283       }
 284    }
 285
 286    /* OK, now scan the program/shader instructions looking for texture
 287     * instructions using sampler vars.  Replace old sampler indexes with
 288     * new ones.
 289     */
 290    prog->SamplersUsed = 0x0;
 291    for (i = 0; i < prog->NumInstructions; i++) {
 292       struct prog_instruction *inst = prog->Instructions + i;
 293       if (_mesa_is_tex_instruction(inst->Opcode)) {
 294          /* here, inst->TexSrcUnit is really the sampler unit */
 295          const GLint oldSampNum = inst->TexSrcUnit;
 296
 297 #if 0
 298          printf("====== remap sampler from %d to %d\n",
 299                 inst->TexSrcUnit, samplerMap[ inst->TexSrcUnit ]);
 300 #endif
 301
 302          if (oldSampNum < Elements(samplerMap)) {
 303             const GLuint newSampNum = samplerMap[oldSampNum];
 304             inst->TexSrcUnit = newSampNum;
 305             prog->SamplerTargets[newSampNum] = inst->TexSrcTarget;
 306             prog->SamplersUsed |= (1 << newSampNum);
 307             if (inst->TexShadow) {
 308                prog->ShadowSamplers |= (1 << newSampNum);
 309             }
 310          }
 311       }
 312    }
 313
 314    return GL_TRUE;
 315 }
 316
 317
 318 /**
 319  * Resolve binding of generic vertex attributes.
 320  * For example, if the vertex shader declared "attribute vec4 foobar" we'll
 321  * allocate a generic vertex attribute for "foobar" and plug that value into
 322  * the vertex program instructions.
 323  * But if the user called glBindAttributeLocation(), those bindings will
 324  * have priority.
 325  */
 326 static GLboolean
 327 _slang_resolve_attributes(struct gl_shader_program *shProg,
 328                           const struct gl_program *origProg,
 329                           struct gl_program *linkedProg)
 330 {
 331    GLint attribMap[MAX_VERTEX_GENERIC_ATTRIBS];
 332    GLuint i, j;
 333    GLbitfield usedAttributes; /* generics only, not legacy attributes */
 334    GLbitfield inputsRead = 0x0;
 335
 336    assert(origProg != linkedProg);
 337    assert(origProg->Target == GL_VERTEX_PROGRAM_ARB);
 338    assert(linkedProg->Target == GL_VERTEX_PROGRAM_ARB);
 339
 340    if (!shProg->Attributes)
 341       shProg->Attributes = _mesa_new_parameter_list();
 342
 343    if (linkedProg->Attributes) {
 344       _mesa_free_parameter_list(linkedProg->Attributes);
 345    }
 346    linkedProg->Attributes = _mesa_new_parameter_list();
 347
 348
 349    /* Build a bitmask indicating which attribute indexes have been
 350     * explicitly bound by the user with glBindAttributeLocation().
 351     */
 352    usedAttributes = 0x0;
 353    for (i = 0; i < shProg->Attributes->NumParameters; i++) {
 354       GLint attr = shProg->Attributes->Parameters[i].StateIndexes[0];
 355       usedAttributes |= (1 << attr);
 356    }
 357
 358    /* If gl_Vertex is used, that actually counts against the limit
 359     * on generic vertex attributes.  This avoids the ambiguity of
 360     * whether glVertexAttrib4fv(0, v) sets legacy attribute 0 (vert pos)
 361     * or generic attribute[0].  If gl_Vertex is used, we want the former.
 362     */
 363    if (origProg->InputsRead & VERT_BIT_POS) {
 364       usedAttributes |= 0x1;
 365    }
 366
 367    /* initialize the generic attribute map entries to -1 */
 368    for (i = 0; i < MAX_VERTEX_GENERIC_ATTRIBS; i++) {
 369       attribMap[i] = -1;
 370    }
 371
 372    /*
 373     * Scan program for generic attribute references
 374     */
 375    for (i = 0; i < linkedProg->NumInstructions; i++) {
 376       struct prog_instruction *inst = linkedProg->Instructions + i;
 377       for (j = 0; j < 3; j++) {
 378          if (inst->SrcReg[j].File == PROGRAM_INPUT) {
 379             inputsRead |= (1 << inst->SrcReg[j].Index);
 380          }
 381
 382          if (inst->SrcReg[j].File == PROGRAM_INPUT &&
 383              inst->SrcReg[j].Index >= VERT_ATTRIB_GENERIC0) {
 384             /*
 385              * OK, we've found a generic vertex attribute reference.
 386              */
 387             const GLint k = inst->SrcReg[j].Index - VERT_ATTRIB_GENERIC0;
 388
 389             GLint attr = attribMap[k];
 390
 391             if (attr < 0) {
 392                /* Need to figure out attribute mapping now.
 393                 */
 394                const char *name = origProg->Attributes->Parameters[k].Name;
 395                const GLint size = origProg->Attributes->Parameters[k].Size;
 396                const GLenum type =origProg->Attributes->Parameters[k].DataType;
 397                GLint index;
 398
 399                /* See if there's a user-defined attribute binding for
 400                 * this name.
 401                 */
 402                index = _mesa_lookup_parameter_index(shProg->Attributes,
 403                                                     -1, name);
 404                if (index >= 0) {
 405                   /* Found a user-defined binding */
 406                   attr = shProg->Attributes->Parameters[index].StateIndexes[0];
 407                }
 408                else {
 409                   /* No user-defined binding, choose our own attribute number.
 410                    * Start at 1 since generic attribute 0 always aliases
 411                    * glVertex/position.
 412                    */
 413                   for (attr = 0; attr < MAX_VERTEX_GENERIC_ATTRIBS; attr++) {
 414                      if (((1 << attr) & usedAttributes) == 0)
 415                         break;
 416                   }
 417                   if (attr == MAX_VERTEX_GENERIC_ATTRIBS) {
 418                      link_error(shProg, "Too many vertex attributes");
 419                      return GL_FALSE;
 420                   }
 421
 422                   /* mark this attribute as used */
 423                   usedAttributes |= (1 << attr);
 424                }
 425
 426                attribMap[k] = attr;
 427
 428                /* Save the final name->attrib binding so it can be queried
 429                 * with glGetAttributeLocation().
 430                 */
 431                _mesa_add_attribute(linkedProg->Attributes, name,
 432                                    size, type, attr);
 433             }
 434
 435             assert(attr >= 0);
 436
 437             /* update the instruction's src reg */
 438             inst->SrcReg[j].Index = VERT_ATTRIB_GENERIC0 + attr;
 439          }
 440       }
 441    }
 442
 443    /* Handle pre-defined attributes here (gl_Vertex, gl_Normal, etc).
 444     * When the user queries the active attributes we need to include both
 445     * the user-defined attributes and the built-in ones.
 446     */
 447    for (i = VERT_ATTRIB_POS; i < VERT_ATTRIB_GENERIC0; i++) {
 448       if (inputsRead & (1 << i)) {
 449          _mesa_add_attribute(linkedProg->Attributes,
 450                              _slang_vert_attrib_name(i),
 451                              4, /* size in floats */
 452                              _slang_vert_attrib_type(i),
 453                              -1 /* attrib/input */);
 454       }
 455    }
 456
 457    return GL_TRUE;
 458 }
 459
 460
 461 /**
 462  * Scan program instructions to update the program's NumTemporaries field.
 463  * Note: this implemenation relies on the code generator allocating
 464  * temps in increasing order (0, 1, 2, ... ).
 465  */
 466 static void
 467 _slang_count_temporaries(struct gl_program *prog)
 468 {
 469    GLuint i, j;
 470    GLint maxIndex = -1;
 471
 472    for (i = 0; i < prog->NumInstructions; i++) {
 473       const struct prog_instruction *inst = prog->Instructions + i;
 474       const GLuint numSrc = _mesa_num_inst_src_regs(inst->Opcode);
 475       for (j = 0; j < numSrc; j++) {
 476          if (inst->SrcReg[j].File == PROGRAM_TEMPORARY) {
 477             if (maxIndex < inst->SrcReg[j].Index)
 478                maxIndex = inst->SrcReg[j].Index;
 479          }
 480          if (inst->DstReg.File == PROGRAM_TEMPORARY) {
 481             if (maxIndex < (GLint) inst->DstReg.Index)
 482                maxIndex = inst->DstReg.Index;
 483          }
 484       }
 485    }
 486
 487    prog->NumTemporaries = (GLuint) (maxIndex + 1);
 488 }
 489
 490
 491 /**
 492  * Scan program instructions to update the program's InputsRead and
 493  * OutputsWritten fields.
 494  */
 495 static void
 496 _slang_update_inputs_outputs(struct gl_program *prog)
 497 {
 498    GLuint i, j;
 499    GLuint maxAddrReg = 0;
 500
 501    prog->InputsRead = 0x0;
 502    prog->OutputsWritten = 0x0;
 503
 504    for (i = 0; i < prog->NumInstructions; i++) {
 505       const struct prog_instruction *inst = prog->Instructions + i;
 506       const GLuint numSrc = _mesa_num_inst_src_regs(inst->Opcode);
 507       for (j = 0; j < numSrc; j++) {
 508          if (inst->SrcReg[j].File == PROGRAM_INPUT) {
 509             prog->InputsRead |= 1 << inst->SrcReg[j].Index;
 510          }
 511          else if (inst->SrcReg[j].File == PROGRAM_ADDRESS) {
 512             maxAddrReg = MAX2(maxAddrReg, (GLuint) (inst->SrcReg[j].Index + 1));
 513          }
 514       }
 515
 516       if (inst->DstReg.File == PROGRAM_OUTPUT) {
 517          prog->OutputsWritten |= BITFIELD64_BIT(inst->DstReg.Index);
 518          if (inst->DstReg.RelAddr) {
 519             /* If the output attribute is indexed with relative addressing
 520              * we know that it must be a varying or texcoord such as
 521              * gl_TexCoord[i] = v;  In this case, mark all the texcoords
 522              * or varying outputs as being written.  It's not an error if
 523              * a vertex shader writes varying vars that aren't used by the
 524              * fragment shader.  But it is an error for a fragment shader
 525              * to use varyings that are not written by the vertex shader.
 526              */
 527             if (prog->Target == GL_VERTEX_PROGRAM_ARB) {
 528                if (inst->DstReg.Index == VERT_RESULT_TEX0) {
 529                   /* mark all texcoord outputs as written */
 530                   const GLbitfield64 mask =
 531                      BITFIELD64_RANGE(VERT_RESULT_TEX0,
 532                                       (VERT_RESULT_TEX0
 533                                        + MAX_TEXTURE_COORD_UNITS - 1));
 534                   prog->OutputsWritten |= mask;
 535                }
 536                else if (inst->DstReg.Index == VERT_RESULT_VAR0) {
 537                   /* mark all generic varying outputs as written */
 538                   const GLbitfield64 mask =
 539                      BITFIELD64_RANGE(VERT_RESULT_VAR0,
 540                                       (VERT_RESULT_VAR0 + MAX_VARYING - 1));
 541                   prog->OutputsWritten |= mask;
 542                }
 543             }
 544          }
 545       }
 546       else if (inst->DstReg.File == PROGRAM_ADDRESS) {
 547          maxAddrReg = MAX2(maxAddrReg, inst->DstReg.Index + 1);
 548       }
 549    }
 550    prog->NumAddressRegs = maxAddrReg;
 551 }
 552
 553
 554
 555 /**
 556  * Remove extra #version directives from the concatenated source string.
 557  * Disable the extra ones by converting first two chars to //, a comment.
 558  * This is a bit of hack to work around a preprocessor bug that only
 559  * allows one #version directive per source.
 560  */
 561 static void
 562 remove_extra_version_directives(GLchar *source)
 563 {
 564    GLuint verCount = 0;
 565    while (1) {
 566       char *ver = strstr(source, "#version");
 567       if (ver) {
 568          verCount++;
 569          if (verCount > 1) {
 570             ver[0] = '/';
 571             ver[1] = '/';
 572          }
 573          source += 8;
 574       }
 575       else {
 576          break;
 577       }
 578    }
 579 }
 580
 581
 582
 583 /**
 584  * Return a new shader whose source code is the concatenation of
 585  * all the shader sources of the given type.
 586  */
 587 static struct gl_shader *
 588 concat_shaders(struct gl_shader_program *shProg, GLenum shaderType)
 589 {
 590    struct gl_shader *newShader;
 591    const struct gl_shader *firstShader = NULL;
 592    GLuint *shaderLengths;
 593    GLchar *source;
 594    GLuint totalLen = 0, len = 0;
 595    GLuint i;
 596
 597    shaderLengths = (GLuint *)malloc(shProg->NumShaders * sizeof(GLuint));
 598    if (!shaderLengths) {
 599       return NULL;
 600    }
 601
 602    /* compute total size of new shader source code */
 603    for (i = 0; i < shProg->NumShaders; i++) {
 604       const struct gl_shader *shader = shProg->Shaders[i];
 605       if (shader->Type == shaderType) {
 606          shaderLengths[i] = strlen(shader->Source);
 607          totalLen += shaderLengths[i];
 608          if (!firstShader)
 609             firstShader = shader;
 610       }
 611    }
 612
 613    if (totalLen == 0) {
 614       free(shaderLengths);
 615       return NULL;
 616    }
 617
 618    source = (GLchar *) malloc(totalLen + 1);
 619    if (!source) {
 620       free(shaderLengths);
 621       return NULL;
 622    }
 623
 624    /* concatenate shaders */
 625    for (i = 0; i < shProg->NumShaders; i++) {
 626       const struct gl_shader *shader = shProg->Shaders[i];
 627       if (shader->Type == shaderType) {
 628          memcpy(source + len, shader->Source, shaderLengths[i]);
 629          len += shaderLengths[i];
 630       }
 631    }
 632    source[len] = '\0';
 633    /*
 634    _mesa_printf("---NEW CONCATENATED SHADER---:\n%s\n------------\n", source);
 635    */
 636
 637    free(shaderLengths);
 638
 639    remove_extra_version_directives(source);
 640
 641    newShader = CALLOC_STRUCT(gl_shader);
 642    if (!newShader) {
 643       free(source);
 644       return NULL;
 645    }
 646
 647    newShader->Type = shaderType;
 648    newShader->Source = source;
 649    newShader->Pragmas = firstShader->Pragmas;
 650
 651    return newShader;
 652 }
 653
 654
 655 /**
 656  * Search the shader program's list of shaders to find the one that
 657  * defines main().
 658  * This will involve shader concatenation and recompilation if needed.
 659  */
 660 static struct gl_shader *
 661 get_main_shader(GLcontext *ctx,
 662                 struct gl_shader_program *shProg, GLenum type)
 663 {
 664    struct gl_shader *shader = NULL;
 665    GLuint i;
 666
 667    /*
 668     * Look for a shader that defines main() and has no unresolved references.
 669     */
 670    for (i = 0; i < shProg->NumShaders; i++) {
 671       shader = shProg->Shaders[i];
 672       if (shader->Type == type &&
 673           shader->Main &&
 674           !shader->UnresolvedRefs) {
 675          /* All set! */
 676          return shader;
 677       }
 678    }
 679
 680    /*
 681     * There must have been unresolved references during the original
 682     * compilation.  Try concatenating all the shaders of the given type
 683     * and recompile that.
 684     */
 685    shader = concat_shaders(shProg, type);
 686
 687    if (shader) {
 688       _slang_compile(ctx, shader);
 689
 690       /* Finally, check if recompiling failed */
 691       if (!shader->CompileStatus ||
 692           !shader->Main ||
 693           shader->UnresolvedRefs) {
 694          link_error(shProg, "Unresolved symbols");
 695          _mesa_free_shader(ctx, shader);
 696          return NULL;
 697       }
 698    }
 699
 700    return shader;
 701 }
 702
 703
 704 /**
 705  * Shader linker.  Currently:
 706  *
 707  * 1. The last attached vertex shader and fragment shader are linked.
 708  * 2. Varying vars in the two shaders are combined so their locations
 709  *    agree between the vertex and fragment stages.  They're treated as
 710  *    vertex program output attribs and as fragment program input attribs.
 711  * 3. The vertex and fragment programs are cloned and modified to update
 712  *    src/dst register references so they use the new, linked varying
 713  *    storage locations.
 714  */
 715 void
 716 _slang_link(GLcontext *ctx,
 717             GLhandleARB programObj,
 718             struct gl_shader_program *shProg)
 719 {
 720    const struct gl_vertex_program *vertProg = NULL;
 721    const struct gl_fragment_program *fragProg = NULL;
 722    GLboolean vertNotify = GL_TRUE, fragNotify = GL_TRUE;
 723    GLuint numSamplers = 0;
 724    GLuint i;
 725
 726    _mesa_clear_shader_program_data(ctx, shProg);
 727
 728    /* Initialize LinkStatus to "success".  Will be cleared if error. */
 729    shProg->LinkStatus = GL_TRUE;
 730
 731    /* check that all programs compiled successfully */
 732    for (i = 0; i < shProg->NumShaders; i++) {
 733       if (!shProg->Shaders[i]->CompileStatus) {
 734          link_error(shProg, "linking with uncompiled shader\n");
 735          return;
 736       }
 737    }
 738
 739    shProg->Uniforms = _mesa_new_uniform_list();
 740    shProg->Varying = _mesa_new_parameter_list();
 741
 742    /*
 743     * Find the vertex and fragment shaders which define main()
 744     */
 745    {
 746       struct gl_shader *vertShader, *fragShader;
 747       vertShader = get_main_shader(ctx, shProg, GL_VERTEX_SHADER);
 748       fragShader = get_main_shader(ctx, shProg, GL_FRAGMENT_SHADER);
 749       if (vertShader)
 750          vertProg = vertex_program(vertShader->Program);
 751       if (fragShader)
 752          fragProg = fragment_program(fragShader->Program);
 753       if (!shProg->LinkStatus)
 754          return;
 755    }
 756
 757 #if FEATURE_es2_glsl
 758    /* must have both a vertex and fragment program for ES2 */
 759    if (!vertProg) {
 760       link_error(shProg, "missing vertex shader\n");
 761       return;
 762    }
 763    if (!fragProg) {
 764       link_error(shProg, "missing fragment shader\n");
 765       return;
 766    }
 767 #endif
 768
 769    /*
 770     * Make copies of the vertex/fragment programs now since we'll be
 771     * changing src/dst registers after merging the uniforms and varying vars.
 772     */
 773    _mesa_reference_vertprog(ctx, &shProg->VertexProgram, NULL);
 774    if (vertProg) {
 775       struct gl_vertex_program *linked_vprog =
 776          _mesa_clone_vertex_program(ctx, vertProg);
 777       shProg->VertexProgram = linked_vprog; /* refcount OK */
 778       /* vertex program ID not significant; just set Id for debugging purposes */
 779       shProg->VertexProgram->Base.Id = shProg->Name;
 780       ASSERT(shProg->VertexProgram->Base.RefCount == 1);
 781    }
 782
 783    _mesa_reference_fragprog(ctx, &shProg->FragmentProgram, NULL);
 784    if (fragProg) {
 785       struct gl_fragment_program *linked_fprog =
 786          _mesa_clone_fragment_program(ctx, fragProg);
 787       shProg->FragmentProgram = linked_fprog; /* refcount OK */
 788       /* vertex program ID not significant; just set Id for debugging purposes */
 789       shProg->FragmentProgram->Base.Id = shProg->Name;
 790       ASSERT(shProg->FragmentProgram->Base.RefCount == 1);
 791    }
 792
 793    /* link varying vars */
 794    if (shProg->VertexProgram) {
 795       if (!link_varying_vars(ctx, shProg, &shProg->VertexProgram->Base))
 796          return;
 797    }
 798    if (shProg->FragmentProgram) {
 799       if (!link_varying_vars(ctx, shProg, &shProg->FragmentProgram->Base))
 800          return;
 801    }
 802
 803    /* link uniform vars */
 804    if (shProg->VertexProgram) {
 805       if (!link_uniform_vars(ctx, shProg, &shProg->VertexProgram->Base,
 806                              &numSamplers)) {
 807          return;
 808       }
 809    }
 810    if (shProg->FragmentProgram) {
 811       if (!link_uniform_vars(ctx, shProg, &shProg->FragmentProgram->Base,
 812                              &numSamplers)) {
 813          return;
 814       }
 815    }
 816
 817    /*_mesa_print_uniforms(shProg->Uniforms);*/
 818
 819    if (shProg->VertexProgram) {
 820       if (!_slang_resolve_attributes(shProg, &vertProg->Base,
 821                                      &shProg->VertexProgram->Base)) {
 822          return;
 823       }
 824    }
 825
 826    if (shProg->VertexProgram) {
 827       _slang_update_inputs_outputs(&shProg->VertexProgram->Base);
 828       _slang_count_temporaries(&shProg->VertexProgram->Base);
 829       if (!(shProg->VertexProgram->Base.OutputsWritten
 830             & BITFIELD64_BIT(VERT_RESULT_HPOS))) {
 831          /* the vertex program did not compute a vertex position */
 832          link_error(shProg,
 833                     "gl_Position was not written by vertex shader\n");
 834          return;
 835       }
 836    }
 837    if (shProg->FragmentProgram) {
 838       _slang_count_temporaries(&shProg->FragmentProgram->Base);
 839       _slang_update_inputs_outputs(&shProg->FragmentProgram->Base);
 840    }
 841
 842    /* Check that all the varying vars needed by the fragment shader are
 843     * actually produced by the vertex shader.
 844     */
 845    if (shProg->FragmentProgram) {
 846       const GLbitfield varyingRead
 847          = shProg->FragmentProgram->Base.InputsRead >> FRAG_ATTRIB_VAR0;
 848       const GLbitfield64 varyingWritten = shProg->VertexProgram ?
 849          shProg->VertexProgram->Base.OutputsWritten >> VERT_RESULT_VAR0 : 0x0;
 850       if ((varyingRead & varyingWritten) != varyingRead) {
 851          link_error(shProg,
 852           "Fragment program using varying vars not written by vertex shader\n");
 853          return;
 854       }
 855    }
 856
 857    /* check that gl_FragColor and gl_FragData are not both written to */
 858    if (shProg->FragmentProgram) {
 859       const GLbitfield64 outputsWritten =
 860          shProg->FragmentProgram->Base.OutputsWritten;
 861       if ((outputsWritten & BITFIELD64_BIT(FRAG_RESULT_COLOR)) &&
 862           (outputsWritten >= BITFIELD64_BIT(FRAG_RESULT_DATA0))) {
 863          link_error(shProg, "Fragment program cannot write both gl_FragColor"
 864                     " and gl_FragData[].\n");
 865          return;
 866       }
 867    }
 868
 869
 870    if (fragProg && shProg->FragmentProgram) {
 871       /* Compute initial program's TexturesUsed info */
 872       _mesa_update_shader_textures_used(&shProg->FragmentProgram->Base);
 873
 874       /* notify driver that a new fragment program has been compiled/linked */
 875       vertNotify = ctx->Driver.ProgramStringNotify(ctx, GL_FRAGMENT_PROGRAM_ARB,
 876                                                  &shProg->FragmentProgram->Base);
 877       if (ctx->Shader.Flags & GLSL_DUMP) {
 878          _mesa_printf("Mesa pre-link fragment program:\n");
 879          _mesa_print_program(&fragProg->Base);
 880          _mesa_print_program_parameters(ctx, &fragProg->Base);
 881
 882          _mesa_printf("Mesa post-link fragment program:\n");
 883          _mesa_print_program(&shProg->FragmentProgram->Base);
 884          _mesa_print_program_parameters(ctx, &shProg->FragmentProgram->Base);
 885       }
 886    }
 887
 888    if (vertProg && shProg->VertexProgram) {
 889       /* Compute initial program's TexturesUsed info */
 890       _mesa_update_shader_textures_used(&shProg->VertexProgram->Base);
 891
 892       /* notify driver that a new vertex program has been compiled/linked */
 893       fragNotify = ctx->Driver.ProgramStringNotify(ctx, GL_VERTEX_PROGRAM_ARB,
 894                                                    &shProg->VertexProgram->Base);
 895       if (ctx->Shader.Flags & GLSL_DUMP) {
 896          _mesa_printf("Mesa pre-link vertex program:\n");
 897          _mesa_print_program(&vertProg->Base);
 898          _mesa_print_program_parameters(ctx, &vertProg->Base);
 899
 900          _mesa_printf("Mesa post-link vertex program:\n");
 901          _mesa_print_program(&shProg->VertexProgram->Base);
 902          _mesa_print_program_parameters(ctx, &shProg->VertexProgram->Base);
 903       }
 904    }
 905
 906    /* Debug: */
 907    if (0) {
 908       if (shProg->VertexProgram)
 909          _mesa_postprocess_program(ctx, &shProg->VertexProgram->Base);
 910       if (shProg->FragmentProgram)
 911          _mesa_postprocess_program(ctx, &shProg->FragmentProgram->Base);
 912    }
 913
 914    if (ctx->Shader.Flags & GLSL_DUMP) {
 915       _mesa_printf("Varying vars:\n");
 916       _mesa_print_parameter_list(shProg->Varying);
 917       if (shProg->InfoLog) {
 918          _mesa_printf("Info Log: %s\n", shProg->InfoLog);
 919       }
 920    }
 921
 922    if (!vertNotify || !fragNotify) {
 923       /* driver rejected one/both of the vertex/fragment programs */
 924       link_error(shProg, "Vertex and/or fragment program rejected by driver\n");
 925    }
 926    else {
 927       shProg->LinkStatus = (shProg->VertexProgram || shProg->FragmentProgram);
 928    }
 929 }
 930