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_builtin.h"
  44 #include "slang_link.h"
  45
  46
  47 /** cast wrapper */
  48 static struct gl_vertex_program *
  49 vertex_program(struct gl_program *prog)
  50 {
  51    assert(prog->Target == GL_VERTEX_PROGRAM_ARB);
  52    return (struct gl_vertex_program *) prog;
  53 }
  54
  55
  56 /** cast wrapper */
  57 static struct gl_fragment_program *
  58 fragment_program(struct gl_program *prog)
  59 {
  60    assert(prog->Target == GL_FRAGMENT_PROGRAM_ARB);
  61    return (struct gl_fragment_program *) prog;
  62 }
  63
  64
  65 /**
  66  * Record a linking error.
  67  */
  68 static void
  69 link_error(struct gl_shader_program *shProg, const char *msg)
  70 {
  71    if (shProg->InfoLog) {
  72       _mesa_free(shProg->InfoLog);
  73    }
  74    shProg->InfoLog = _mesa_strdup(msg);
  75    shProg->LinkStatus = GL_FALSE;
  76 }
  77
  78
  79
  80 /**
  81  * Check if the given bit is either set or clear in both bitfields.
  82  */
  83 static GLboolean
  84 bits_agree(GLbitfield flags1, GLbitfield flags2, GLbitfield bit)
  85 {
  86    return (flags1 & bit) == (flags2 & bit);
  87 }
  88
  89
  90 /**
  91  * Linking varying vars involves rearranging varying vars so that the
  92  * vertex program's output varyings matches the order of the fragment
  93  * program's input varyings.
  94  * We'll then rewrite instructions to replace PROGRAM_VARYING with either
  95  * PROGRAM_INPUT or PROGRAM_OUTPUT depending on whether it's a vertex or
  96  * fragment shader.
  97  * This is also where we set program Input/OutputFlags to indicate
  98  * which inputs are centroid-sampled, invariant, etc.
  99  */
 100 static GLboolean
 101 link_varying_vars(GLcontext *ctx,
 102                   struct gl_shader_program *shProg, struct gl_program *prog)
 103 {
 104    GLuint *map, i, firstVarying, newFile;
 105    GLbitfield *inOutFlags;
 106
 107    map = (GLuint *) _mesa_malloc(prog->Varying->NumParameters * sizeof(GLuint));
 108    if (!map)
 109       return GL_FALSE;
 110
 111    /* Varying variables are treated like other vertex program outputs
 112     * (and like other fragment program inputs).  The position of the
 113     * first varying differs for vertex/fragment programs...
 114     * Also, replace File=PROGRAM_VARYING with File=PROGRAM_INPUT/OUTPUT.
 115     */
 116    if (prog->Target == GL_VERTEX_PROGRAM_ARB) {
 117       firstVarying = VERT_RESULT_VAR0;
 118       newFile = PROGRAM_OUTPUT;
 119       inOutFlags = prog->OutputFlags;
 120    }
 121    else {
 122       assert(prog->Target == GL_FRAGMENT_PROGRAM_ARB);
 123       firstVarying = FRAG_ATTRIB_VAR0;
 124       newFile = PROGRAM_INPUT;
 125       inOutFlags = prog->InputFlags;
 126    }
 127
 128    for (i = 0; i < prog->Varying->NumParameters; i++) {
 129       /* see if this varying is in the linked varying list */
 130       const struct gl_program_parameter *var = prog->Varying->Parameters + i;
 131       GLint j = _mesa_lookup_parameter_index(shProg->Varying, -1, var->Name);
 132       if (j >= 0) {
 133          /* varying is already in list, do some error checking */
 134          const struct gl_program_parameter *v =
 135             &shProg->Varying->Parameters[j];
 136          if (var->Size != v->Size) {
 137             link_error(shProg, "mismatched varying variable types");
 138             _mesa_free(map);
 139             return GL_FALSE;
 140          }
 141          if (!bits_agree(var->Flags, v->Flags, PROG_PARAM_BIT_CENTROID)) {
 142             char msg[100];
 143             _mesa_snprintf(msg, sizeof(msg),
 144                            "centroid modifier mismatch for '%s'", var->Name);
 145             link_error(shProg, msg);
 146             _mesa_free(map);
 147             return GL_FALSE;
 148          }
 149          if (!bits_agree(var->Flags, v->Flags, PROG_PARAM_BIT_INVARIANT)) {
 150             char msg[100];
 151             _mesa_snprintf(msg, sizeof(msg),
 152                            "invariant modifier mismatch for '%s'", var->Name);
 153             link_error(shProg, msg);
 154             _mesa_free(map);
 155             return GL_FALSE;
 156          }
 157       }
 158       else {
 159          /* not already in linked list */
 160          j = _mesa_add_varying(shProg->Varying, var->Name, var->Size,
 161                                var->Flags);
 162       }
 163
 164       if (shProg->Varying->NumParameters > ctx->Const.MaxVarying) {
 165          link_error(shProg, "Too many varying variables");
 166          _mesa_free(map);
 167          return GL_FALSE;
 168       }
 169
 170       /* Map varying[i] to varying[j].
 171        * Note: the loop here takes care of arrays or large (sz>4) vars.
 172        */
 173       {
 174          GLint sz = var->Size;
 175          while (sz > 0) {
 176             inOutFlags[firstVarying + j] = var->Flags;
 177             /*printf("Link varying from %d to %d\n", i, j);*/
 178             map[i++] = j++;
 179             sz -= 4;
 180          }
 181          i--; /* go back one */
 182       }
 183    }
 184
 185
 186    /* OK, now scan the program/shader instructions looking for varying vars,
 187     * replacing the old index with the new index.
 188     */
 189    for (i = 0; i < prog->NumInstructions; i++) {
 190       struct prog_instruction *inst = prog->Instructions + i;
 191       GLuint j;
 192
 193       if (inst->DstReg.File == PROGRAM_VARYING) {
 194          inst->DstReg.File = newFile;
 195          inst->DstReg.Index = map[ inst->DstReg.Index ] + firstVarying;
 196       }
 197
 198       for (j = 0; j < 3; j++) {
 199          if (inst->SrcReg[j].File == PROGRAM_VARYING) {
 200             inst->SrcReg[j].File = newFile;
 201             inst->SrcReg[j].Index = map[ inst->SrcReg[j].Index ] + firstVarying;
 202          }
 203       }
 204    }
 205
 206    _mesa_free(map);
 207
 208    /* these will get recomputed before linking is completed */
 209    prog->InputsRead = 0x0;
 210    prog->OutputsWritten = 0x0;
 211
 212    return GL_TRUE;
 213 }
 214
 215
 216 /**
 217  * Build the shProg->Uniforms list.
 218  * This is basically a list/index of all uniforms found in either/both of
 219  * the vertex and fragment shaders.
 220  *
 221  * About uniforms:
 222  * Each uniform has two indexes, one that points into the vertex
 223  * program's parameter array and another that points into the fragment
 224  * program's parameter array.  When the user changes a uniform's value
 225  * we have to change the value in the vertex and/or fragment program's
 226  * parameter array.
 227  *
 228  * This function will be called twice to set up the two uniform->parameter
 229  * mappings.
 230  *
 231  * If a uniform is only present in the vertex program OR fragment program
 232  * then the fragment/vertex parameter index, respectively, will be -1.
 233  */
 234 static GLboolean
 235 link_uniform_vars(GLcontext *ctx,
 236                   struct gl_shader_program *shProg,
 237                   struct gl_program *prog,
 238                   GLuint *numSamplers)
 239 {
 240    GLuint samplerMap[200]; /* max number of samplers declared, not used */
 241    GLuint i;
 242
 243    for (i = 0; i < prog->Parameters->NumParameters; i++) {
 244       const struct gl_program_parameter *p = prog->Parameters->Parameters + i;
 245
 246       /*
 247        * XXX FIX NEEDED HERE
 248        * We should also be adding a uniform if p->Type == PROGRAM_STATE_VAR.
 249        * For example, modelview matrix, light pos, etc.
 250        * Also, we need to update the state-var name-generator code to
 251        * generate GLSL-style names, like "gl_LightSource[0].position".
 252        * Furthermore, we'll need to fix the state-var's size/datatype info.
 253        */
 254
 255       if ((p->Type == PROGRAM_UNIFORM || p->Type == PROGRAM_SAMPLER)
 256           && p->Used) {
 257          /* add this uniform, indexing into the target's Parameters list */
 258          struct gl_uniform *uniform =
 259             _mesa_append_uniform(shProg->Uniforms, p->Name, prog->Target, i);
 260          if (uniform)
 261             uniform->Initialized = p->Initialized;
 262       }
 263
 264       /* The samplerMap[] table we build here is used to remap/re-index
 265        * sampler references by TEX instructions.
 266        */
 267       if (p->Type == PROGRAM_SAMPLER && p->Used) {
 268          /* Allocate a new sampler index */
 269          GLuint oldSampNum = (GLuint) prog->Parameters->ParameterValues[i][0];
 270          GLuint newSampNum = *numSamplers;
 271          if (newSampNum >= ctx->Const.MaxTextureImageUnits) {
 272             char s[100];
 273             _mesa_sprintf(s, "Too many texture samplers (%u, max is %u)",
 274                           newSampNum, ctx->Const.MaxTextureImageUnits);
 275             link_error(shProg, s);
 276             return GL_FALSE;
 277          }
 278          /* save old->new mapping in the table */
 279          if (oldSampNum < Elements(samplerMap))
 280             samplerMap[oldSampNum] = newSampNum;
 281          /* update parameter's sampler index */
 282          prog->Parameters->ParameterValues[i][0] = (GLfloat) newSampNum;
 283          (*numSamplers)++;
 284       }
 285    }
 286
 287    /* OK, now scan the program/shader instructions looking for texture
 288     * instructions using sampler vars.  Replace old sampler indexes with
 289     * new ones.
 290     */
 291    prog->SamplersUsed = 0x0;
 292    for (i = 0; i < prog->NumInstructions; i++) {
 293       struct prog_instruction *inst = prog->Instructions + i;
 294       if (_mesa_is_tex_instruction(inst->Opcode)) {
 295          /* here, inst->TexSrcUnit is really the sampler unit */
 296          const GLint oldSampNum = inst->TexSrcUnit;
 297
 298 #if 0
 299          printf("====== remap sampler from %d to %d\n",
 300                 inst->TexSrcUnit, samplerMap[ inst->TexSrcUnit ]);
 301 #endif
 302
 303          if (oldSampNum < Elements(samplerMap)) {
 304             const GLuint newSampNum = samplerMap[oldSampNum];
 305             inst->TexSrcUnit = newSampNum;
 306             prog->SamplerTargets[newSampNum] = inst->TexSrcTarget;
 307             prog->SamplersUsed |= (1 << newSampNum);
 308             if (inst->TexShadow) {
 309                prog->ShadowSamplers |= (1 << newSampNum);
 310             }
 311          }
 312       }
 313    }
 314
 315    return GL_TRUE;
 316 }
 317
 318
 319 /**
 320  * Resolve binding of generic vertex attributes.
 321  * For example, if the vertex shader declared "attribute vec4 foobar" we'll
 322  * allocate a generic vertex attribute for "foobar" and plug that value into
 323  * the vertex program instructions.
 324  * But if the user called glBindAttributeLocation(), those bindings will
 325  * have priority.
 326  */
 327 static GLboolean
 328 _slang_resolve_attributes(struct gl_shader_program *shProg,
 329                           const struct gl_program *origProg,
 330                           struct gl_program *linkedProg)
 331 {
 332    GLint attribMap[MAX_VERTEX_GENERIC_ATTRIBS];
 333    GLuint i, j;
 334    GLbitfield usedAttributes; /* generics only, not legacy attributes */
 335    GLbitfield inputsRead = 0x0;
 336
 337    assert(origProg != linkedProg);
 338    assert(origProg->Target == GL_VERTEX_PROGRAM_ARB);
 339    assert(linkedProg->Target == GL_VERTEX_PROGRAM_ARB);
 340
 341    if (!shProg->Attributes)
 342       shProg->Attributes = _mesa_new_parameter_list();
 343
 344    if (linkedProg->Attributes) {
 345       _mesa_free_parameter_list(linkedProg->Attributes);
 346    }
 347    linkedProg->Attributes = _mesa_new_parameter_list();
 348
 349
 350    /* Build a bitmask indicating which attribute indexes have been
 351     * explicitly bound by the user with glBindAttributeLocation().
 352     */
 353    usedAttributes = 0x0;
 354    for (i = 0; i < shProg->Attributes->NumParameters; i++) {
 355       GLint attr = shProg->Attributes->Parameters[i].StateIndexes[0];
 356       usedAttributes |= (1 << attr);
 357    }
 358
 359    /* If gl_Vertex is used, that actually counts against the limit
 360     * on generic vertex attributes.  This avoids the ambiguity of
 361     * whether glVertexAttrib4fv(0, v) sets legacy attribute 0 (vert pos)
 362     * or generic attribute[0].  If gl_Vertex is used, we want the former.
 363     */
 364    if (origProg->InputsRead & VERT_BIT_POS) {
 365       usedAttributes |= 0x1;
 366    }
 367
 368    /* initialize the generic attribute map entries to -1 */
 369    for (i = 0; i < MAX_VERTEX_GENERIC_ATTRIBS; i++) {
 370       attribMap[i] = -1;
 371    }
 372
 373    /*
 374     * Scan program for generic attribute references
 375     */
 376    for (i = 0; i < linkedProg->NumInstructions; i++) {
 377       struct prog_instruction *inst = linkedProg->Instructions + i;
 378       for (j = 0; j < 3; j++) {
 379          if (inst->SrcReg[j].File == PROGRAM_INPUT) {
 380             inputsRead |= (1 << inst->SrcReg[j].Index);
 381          }
 382
 383          if (inst->SrcReg[j].File == PROGRAM_INPUT &&
 384              inst->SrcReg[j].Index >= VERT_ATTRIB_GENERIC0) {
 385             /*
 386              * OK, we've found a generic vertex attribute reference.
 387              */
 388             const GLint k = inst->SrcReg[j].Index - VERT_ATTRIB_GENERIC0;
 389
 390             GLint attr = attribMap[k];
 391
 392             if (attr < 0) {
 393                /* Need to figure out attribute mapping now.
 394                 */
 395                const char *name = origProg->Attributes->Parameters[k].Name;
 396                const GLint size = origProg->Attributes->Parameters[k].Size;
 397                const GLenum type =origProg->Attributes->Parameters[k].DataType;
 398                GLint index;
 399
 400                /* See if there's a user-defined attribute binding for
 401                 * this name.
 402                 */
 403                index = _mesa_lookup_parameter_index(shProg->Attributes,
 404                                                     -1, name);
 405                if (index >= 0) {
 406                   /* Found a user-defined binding */
 407                   attr = shProg->Attributes->Parameters[index].StateIndexes[0];
 408                }
 409                else {
 410                   /* No user-defined binding, choose our own attribute number.
 411                    * Start at 1 since generic attribute 0 always aliases
 412                    * glVertex/position.
 413                    */
 414                   for (attr = 0; attr < MAX_VERTEX_GENERIC_ATTRIBS; attr++) {
 415                      if (((1 << attr) & usedAttributes) == 0)
 416                         break;
 417                   }
 418                   if (attr == MAX_VERTEX_GENERIC_ATTRIBS) {
 419                      link_error(shProg, "Too many vertex attributes");
 420                      return GL_FALSE;
 421                   }
 422
 423                   /* mark this attribute as used */
 424                   usedAttributes |= (1 << attr);
 425                }
 426
 427                attribMap[k] = attr;
 428
 429                /* Save the final name->attrib binding so it can be queried
 430                 * with glGetAttributeLocation().
 431                 */
 432                _mesa_add_attribute(linkedProg->Attributes, name,
 433                                    size, type, attr);
 434             }
 435
 436             assert(attr >= 0);
 437
 438             /* update the instruction's src reg */
 439             inst->SrcReg[j].Index = VERT_ATTRIB_GENERIC0 + attr;
 440          }
 441       }
 442    }
 443
 444    /* Handle pre-defined attributes here (gl_Vertex, gl_Normal, etc).
 445     * When the user queries the active attributes we need to include both
 446     * the user-defined attributes and the built-in ones.
 447     */
 448    for (i = VERT_ATTRIB_POS; i < VERT_ATTRIB_GENERIC0; i++) {
 449       if (inputsRead & (1 << i)) {
 450          _mesa_add_attribute(linkedProg->Attributes,
 451                              _slang_vert_attrib_name(i),
 452                              4, /* size in floats */
 453                              _slang_vert_attrib_type(i),
 454                              -1 /* attrib/input */);
 455       }
 456    }
 457
 458    return GL_TRUE;
 459 }
 460
 461
 462 /**
 463  * Scan program instructions to update the program's NumTemporaries field.
 464  * Note: this implemenation relies on the code generator allocating
 465  * temps in increasing order (0, 1, 2, ... ).
 466  */
 467 static void
 468 _slang_count_temporaries(struct gl_program *prog)
 469 {
 470    GLuint i, j;
 471    GLint maxIndex = -1;
 472
 473    for (i = 0; i < prog->NumInstructions; i++) {
 474       const struct prog_instruction *inst = prog->Instructions + i;
 475       const GLuint numSrc = _mesa_num_inst_src_regs(inst->Opcode);
 476       for (j = 0; j < numSrc; j++) {
 477          if (inst->SrcReg[j].File == PROGRAM_TEMPORARY) {
 478             if (maxIndex < inst->SrcReg[j].Index)
 479                maxIndex = inst->SrcReg[j].Index;
 480          }
 481          if (inst->DstReg.File == PROGRAM_TEMPORARY) {
 482             if (maxIndex < (GLint) inst->DstReg.Index)
 483                maxIndex = inst->DstReg.Index;
 484          }
 485       }
 486    }
 487
 488    prog->NumTemporaries = (GLuint) (maxIndex + 1);
 489 }
 490
 491
 492 /**
 493  * Scan program instructions to update the program's InputsRead and
 494  * OutputsWritten fields.
 495  */
 496 static void
 497 _slang_update_inputs_outputs(struct gl_program *prog)
 498 {
 499    GLuint i, j;
 500    GLuint maxAddrReg = 0;
 501
 502    prog->InputsRead = 0x0;
 503    prog->OutputsWritten = 0x0;
 504
 505    for (i = 0; i < prog->NumInstructions; i++) {
 506       const struct prog_instruction *inst = prog->Instructions + i;
 507       const GLuint numSrc = _mesa_num_inst_src_regs(inst->Opcode);
 508       for (j = 0; j < numSrc; j++) {
 509          if (inst->SrcReg[j].File == PROGRAM_INPUT) {
 510             prog->InputsRead |= 1 << inst->SrcReg[j].Index;
 511          }
 512          else if (inst->SrcReg[j].File == PROGRAM_ADDRESS) {
 513             maxAddrReg = MAX2(maxAddrReg, (GLuint) (inst->SrcReg[j].Index + 1));
 514          }
 515       }
 516
 517       if (inst->DstReg.File == PROGRAM_OUTPUT) {
 518          prog->OutputsWritten |= 1 << inst->DstReg.Index;
 519          if (inst->DstReg.RelAddr) {
 520             /* If the output attribute is indexed with relative addressing
 521              * we know that it must be a varying or texcoord such as
 522              * gl_TexCoord[i] = v;  In this case, mark all the texcoords
 523              * or varying outputs as being written.  It's not an error if
 524              * a vertex shader writes varying vars that aren't used by the
 525              * fragment shader.  But it is an error for a fragment shader
 526              * to use varyings that are not written by the vertex shader.
 527              */
 528             if (prog->Target == GL_VERTEX_PROGRAM_ARB) {
 529                if (inst->DstReg.Index == VERT_RESULT_TEX0) {
 530                   /* mark all texcoord outputs as written */
 531                   const GLbitfield mask =
 532                      ((1 << MAX_TEXTURE_COORD_UNITS) - 1) << VERT_RESULT_TEX0;
 533                   prog->OutputsWritten |= mask;
 534                }
 535                else if (inst->DstReg.Index == VERT_RESULT_VAR0) {
 536                   /* mark all generic varying outputs as written */
 537                   const GLbitfield mask =
 538                      ((1 << MAX_VARYING) - 1) << VERT_RESULT_VAR0;
 539                   prog->OutputsWritten |= mask;
 540                }
 541             }
 542          }
 543       }
 544       else if (inst->DstReg.File == PROGRAM_ADDRESS) {
 545          maxAddrReg = MAX2(maxAddrReg, inst->DstReg.Index + 1);
 546       }
 547    }
 548    prog->NumAddressRegs = maxAddrReg;
 549 }
 550
 551
 552
 553 /**
 554  * Remove extra #version directives from the concatenated source string.
 555  * Disable the extra ones by converting first two chars to //, a comment.
 556  * This is a bit of hack to work around a preprocessor bug that only
 557  * allows one #version directive per source.
 558  */
 559 static void
 560 remove_extra_version_directives(GLchar *source)
 561 {
 562    GLuint verCount = 0;
 563    while (1) {
 564       char *ver = _mesa_strstr(source, "#version");
 565       if (ver) {
 566          verCount++;
 567          if (verCount > 1) {
 568             ver[0] = '/';
 569             ver[1] = '/';
 570          }
 571          source += 8;
 572       }
 573       else {
 574          break;
 575       }
 576    }
 577 }
 578
 579
 580
 581 /**
 582  * Return a new shader whose source code is the concatenation of
 583  * all the shader sources of the given type.
 584  */
 585 static struct gl_shader *
 586 concat_shaders(struct gl_shader_program *shProg, GLenum shaderType)
 587 {
 588    struct gl_shader *newShader;
 589    const struct gl_shader *firstShader = NULL;
 590    GLuint shaderLengths[100];
 591    GLchar *source;
 592    GLuint totalLen = 0, len = 0;
 593    GLuint i;
 594
 595    /* compute total size of new shader source code */
 596    for (i = 0; i < shProg->NumShaders; i++) {
 597       const struct gl_shader *shader = shProg->Shaders[i];
 598       if (shader->Type == shaderType) {
 599          shaderLengths[i] = _mesa_strlen(shader->Source);
 600          totalLen += shaderLengths[i];
 601          if (!firstShader)
 602             firstShader = shader;
 603       }
 604    }
 605
 606    if (totalLen == 0)
 607       return NULL;
 608
 609    source = (GLchar *) _mesa_malloc(totalLen + 1);
 610    if (!source)
 611       return NULL;
 612
 613    /* concatenate shaders */
 614    for (i = 0; i < shProg->NumShaders; i++) {
 615       const struct gl_shader *shader = shProg->Shaders[i];
 616       if (shader->Type == shaderType) {
 617          _mesa_memcpy(source + len, shader->Source, shaderLengths[i]);
 618          len += shaderLengths[i];
 619       }
 620    }
 621    source[len] = '\0';
 622    /*
 623    _mesa_printf("---NEW CONCATENATED SHADER---:\n%s\n------------\n", source);
 624    */
 625
 626    remove_extra_version_directives(source);
 627
 628    newShader = CALLOC_STRUCT(gl_shader);
 629    newShader->Type = shaderType;
 630    newShader->Source = source;
 631    newShader->Pragmas = firstShader->Pragmas;
 632
 633    return newShader;
 634 }
 635
 636
 637 /**
 638  * Search the shader program's list of shaders to find the one that
 639  * defines main().
 640  * This will involve shader concatenation and recompilation if needed.
 641  */
 642 static struct gl_shader *
 643 get_main_shader(GLcontext *ctx,
 644                 struct gl_shader_program *shProg, GLenum type)
 645 {
 646    struct gl_shader *shader = NULL;
 647    GLuint i;
 648
 649    /*
 650     * Look for a shader that defines main() and has no unresolved references.
 651     */
 652    for (i = 0; i < shProg->NumShaders; i++) {
 653       shader = shProg->Shaders[i];
 654       if (shader->Type == type &&
 655           shader->Main &&
 656           !shader->UnresolvedRefs) {
 657          /* All set! */
 658          return shader;
 659       }
 660    }
 661
 662    /*
 663     * There must have been unresolved references during the original
 664     * compilation.  Try concatenating all the shaders of the given type
 665     * and recompile that.
 666     */
 667    shader = concat_shaders(shProg, type);
 668
 669    if (shader) {
 670       _slang_compile(ctx, shader);
 671
 672       /* Finally, check if recompiling failed */
 673       if (!shader->CompileStatus ||
 674           !shader->Main ||
 675           shader->UnresolvedRefs) {
 676          link_error(shProg, "Unresolved symbols");
 677          _mesa_free_shader(ctx, shader);
 678          return NULL;
 679       }
 680    }
 681
 682    return shader;
 683 }
 684
 685
 686 /**
 687  * Shader linker.  Currently:
 688  *
 689  * 1. The last attached vertex shader and fragment shader are linked.
 690  * 2. Varying vars in the two shaders are combined so their locations
 691  *    agree between the vertex and fragment stages.  They're treated as
 692  *    vertex program output attribs and as fragment program input attribs.
 693  * 3. The vertex and fragment programs are cloned and modified to update
 694  *    src/dst register references so they use the new, linked varying
 695  *    storage locations.
 696  */
 697 void
 698 _slang_link(GLcontext *ctx,
 699             GLhandleARB programObj,
 700             struct gl_shader_program *shProg)
 701 {
 702    const struct gl_vertex_program *vertProg = NULL;
 703    const struct gl_fragment_program *fragProg = NULL;
 704    GLuint numSamplers = 0;
 705    GLuint i;
 706
 707    _mesa_clear_shader_program_data(ctx, shProg);
 708
 709    /* Initialize LinkStatus to "success".  Will be cleared if error. */
 710    shProg->LinkStatus = GL_TRUE;
 711
 712    /* check that all programs compiled successfully */
 713    for (i = 0; i < shProg->NumShaders; i++) {
 714       if (!shProg->Shaders[i]->CompileStatus) {
 715          link_error(shProg, "linking with uncompiled shader\n");
 716          return;
 717       }
 718    }
 719
 720    shProg->Uniforms = _mesa_new_uniform_list();
 721    shProg->Varying = _mesa_new_parameter_list();
 722
 723    /*
 724     * Find the vertex and fragment shaders which define main()
 725     */
 726    {
 727       struct gl_shader *vertShader, *fragShader;
 728       vertShader = get_main_shader(ctx, shProg, GL_VERTEX_SHADER);
 729       fragShader = get_main_shader(ctx, shProg, GL_FRAGMENT_SHADER);
 730       if (vertShader)
 731          vertProg = vertex_program(vertShader->Program);
 732       if (fragShader)
 733          fragProg = fragment_program(fragShader->Program);
 734       if (!shProg->LinkStatus)
 735          return;
 736    }
 737
 738 #if FEATURE_es2_glsl
 739    /* must have both a vertex and fragment program for ES2 */
 740    if (!vertProg) {
 741       link_error(shProg, "missing vertex shader\n");
 742       return;
 743    }
 744    if (!fragProg) {
 745       link_error(shProg, "missing fragment shader\n");
 746       return;
 747    }
 748 #endif
 749
 750    /*
 751     * Make copies of the vertex/fragment programs now since we'll be
 752     * changing src/dst registers after merging the uniforms and varying vars.
 753     */
 754    _mesa_reference_vertprog(ctx, &shProg->VertexProgram, NULL);
 755    if (vertProg) {
 756       struct gl_vertex_program *linked_vprog =
 757          vertex_program(_mesa_clone_program(ctx, &vertProg->Base));
 758       shProg->VertexProgram = linked_vprog; /* refcount OK */
 759       /* vertex program ID not significant; just set Id for debugging purposes */
 760       shProg->VertexProgram->Base.Id = shProg->Name;
 761       ASSERT(shProg->VertexProgram->Base.RefCount == 1);
 762    }
 763
 764    _mesa_reference_fragprog(ctx, &shProg->FragmentProgram, NULL);
 765    if (fragProg) {
 766       struct gl_fragment_program *linked_fprog =
 767          fragment_program(_mesa_clone_program(ctx, &fragProg->Base));
 768       shProg->FragmentProgram = linked_fprog; /* refcount OK */
 769       /* vertex program ID not significant; just set Id for debugging purposes */
 770       shProg->FragmentProgram->Base.Id = shProg->Name;
 771       ASSERT(shProg->FragmentProgram->Base.RefCount == 1);
 772    }
 773
 774    /* link varying vars */
 775    if (shProg->VertexProgram) {
 776       if (!link_varying_vars(ctx, shProg, &shProg->VertexProgram->Base))
 777          return;
 778    }
 779    if (shProg->FragmentProgram) {
 780       if (!link_varying_vars(ctx, shProg, &shProg->FragmentProgram->Base))
 781          return;
 782    }
 783
 784    /* link uniform vars */
 785    if (shProg->VertexProgram) {
 786       if (!link_uniform_vars(ctx, shProg, &shProg->VertexProgram->Base,
 787                              &numSamplers)) {
 788          return;
 789       }
 790    }
 791    if (shProg->FragmentProgram) {
 792       if (!link_uniform_vars(ctx, shProg, &shProg->FragmentProgram->Base,
 793                              &numSamplers)) {
 794          return;
 795       }
 796    }
 797
 798    /*_mesa_print_uniforms(shProg->Uniforms);*/
 799
 800    if (shProg->VertexProgram) {
 801       if (!_slang_resolve_attributes(shProg, &vertProg->Base,
 802                                      &shProg->VertexProgram->Base)) {
 803          return;
 804       }
 805    }
 806
 807    if (shProg->VertexProgram) {
 808       _slang_update_inputs_outputs(&shProg->VertexProgram->Base);
 809       _slang_count_temporaries(&shProg->VertexProgram->Base);
 810       if (!(shProg->VertexProgram->Base.OutputsWritten & (1 << VERT_RESULT_HPOS))) {
 811          /* the vertex program did not compute a vertex position */
 812          link_error(shProg,
 813                     "gl_Position was not written by vertex shader\n");
 814          return;
 815       }
 816    }
 817    if (shProg->FragmentProgram) {
 818       _slang_count_temporaries(&shProg->FragmentProgram->Base);
 819       _slang_update_inputs_outputs(&shProg->FragmentProgram->Base);
 820    }
 821
 822    /* Check that all the varying vars needed by the fragment shader are
 823     * actually produced by the vertex shader.
 824     */
 825    if (shProg->FragmentProgram) {
 826       const GLbitfield varyingRead
 827          = shProg->FragmentProgram->Base.InputsRead >> FRAG_ATTRIB_VAR0;
 828       const GLbitfield varyingWritten = shProg->VertexProgram ?
 829          shProg->VertexProgram->Base.OutputsWritten >> VERT_RESULT_VAR0 : 0x0;
 830       if ((varyingRead & varyingWritten) != varyingRead) {
 831          link_error(shProg,
 832           "Fragment program using varying vars not written by vertex shader\n");
 833          return;
 834       }
 835    }
 836
 837    /* check that gl_FragColor and gl_FragData are not both written to */
 838    if (shProg->FragmentProgram) {
 839       GLbitfield outputsWritten = shProg->FragmentProgram->Base.OutputsWritten;
 840       if ((outputsWritten & ((1 << FRAG_RESULT_COLOR))) &&
 841           (outputsWritten >= (1 << FRAG_RESULT_DATA0))) {
 842          link_error(shProg, "Fragment program cannot write both gl_FragColor"
 843                     " and gl_FragData[].\n");
 844          return;
 845       }
 846    }
 847
 848
 849    if (fragProg && shProg->FragmentProgram) {
 850       /* Compute initial program's TexturesUsed info */
 851       _mesa_update_shader_textures_used(&shProg->FragmentProgram->Base);
 852
 853       /* notify driver that a new fragment program has been compiled/linked */
 854       ctx->Driver.ProgramStringNotify(ctx, GL_FRAGMENT_PROGRAM_ARB,
 855                                       &shProg->FragmentProgram->Base);
 856       if (ctx->Shader.Flags & GLSL_DUMP) {
 857          _mesa_printf("Mesa pre-link fragment program:\n");
 858          _mesa_print_program(&fragProg->Base);
 859          _mesa_print_program_parameters(ctx, &fragProg->Base);
 860
 861          _mesa_printf("Mesa post-link fragment program:\n");
 862          _mesa_print_program(&shProg->FragmentProgram->Base);
 863          _mesa_print_program_parameters(ctx, &shProg->FragmentProgram->Base);
 864       }
 865    }
 866
 867    if (vertProg && shProg->VertexProgram) {
 868       /* Compute initial program's TexturesUsed info */
 869       _mesa_update_shader_textures_used(&shProg->VertexProgram->Base);
 870
 871       /* notify driver that a new vertex program has been compiled/linked */
 872       ctx->Driver.ProgramStringNotify(ctx, GL_VERTEX_PROGRAM_ARB,
 873                                       &shProg->VertexProgram->Base);
 874       if (ctx->Shader.Flags & GLSL_DUMP) {
 875          _mesa_printf("Mesa pre-link vertex program:\n");
 876          _mesa_print_program(&vertProg->Base);
 877          _mesa_print_program_parameters(ctx, &vertProg->Base);
 878
 879          _mesa_printf("Mesa post-link vertex program:\n");
 880          _mesa_print_program(&shProg->VertexProgram->Base);
 881          _mesa_print_program_parameters(ctx, &shProg->VertexProgram->Base);
 882       }
 883    }
 884
 885    /* Debug: */
 886    if (0) {
 887       if (shProg->VertexProgram)
 888          _mesa_postprocess_program(ctx, &shProg->VertexProgram->Base);
 889       if (shProg->FragmentProgram)
 890          _mesa_postprocess_program(ctx, &shProg->FragmentProgram->Base);
 891    }
 892
 893    if (ctx->Shader.Flags & GLSL_DUMP) {
 894       _mesa_printf("Varying vars:\n");
 895       _mesa_print_parameter_list(shProg->Varying);
 896       if (shProg->InfoLog) {
 897          _mesa_printf("Info Log: %s\n", shProg->InfoLog);
 898       }
 899    }
 900
 901    shProg->LinkStatus = (shProg->VertexProgram || shProg->FragmentProgram);
 902 }
 903