[Mesa-dev] [PATCH V2 3/4] mesa: remove overlapping array index validation and extra uniform location lookup

Timothy Arceri t_arceri at yahoo.com.au
Fri Jul 3 15:48:55 PDT 2015


This change removes multiple functions designed to validate an array
subscript and replaces them with a call to a single function.

The change also means that validation is now only done once and the index
is retrived at the same time, as a result the getUniformLocation code can
be simplified saving an extra hash table lookup (and yet another
validation call).

V2: Fix bounds checks for program input/output, split unrelated comment fix
and _mesa_get_uniform_location() removal into their own patch.

Cc: Tapani Pälli <tapani.palli at intel.com>
---
 src/mesa/main/program_resource.c |  66 ++-----------
 src/mesa/main/shader_query.cpp   | 204 ++++++++++++++++-----------------------
 src/mesa/main/shaderapi.h        |   7 +-
 src/mesa/main/uniforms.c         |   7 +-
 4 files changed, 100 insertions(+), 184 deletions(-)

diff --git a/src/mesa/main/program_resource.c b/src/mesa/main/program_resource.c
index d857b84..0a306b8 100644
--- a/src/mesa/main/program_resource.c
+++ b/src/mesa/main/program_resource.c
@@ -173,32 +173,12 @@ is_xfb_marker(const char *str)
    return false;
 }
 
-/**
- * Checks if given name index is legal for GetProgramResourceIndex,
- * check is written to be compatible with GL_ARB_array_of_arrays.
- */
-static bool
-valid_program_resource_index_name(const GLchar *name)
-{
-   const char *array = strstr(name, "[");
-   const char *close = strrchr(name, ']');
-
-   /* Not array, no need for the check. */
-   if (!array)
-      return true;
-
-   /* Last array index has to be zero. */
-   if (!close || *--close != '0')
-      return false;
-
-   return true;
-}
-
 GLuint GLAPIENTRY
 _mesa_GetProgramResourceIndex(GLuint program, GLenum programInterface,
                               const GLchar *name)
 {
    GET_CURRENT_CONTEXT(ctx);
+   unsigned array_index;
    struct gl_program_resource *res;
    struct gl_shader_program *shProg =
       _mesa_lookup_shader_program_err(ctx, program,
@@ -221,12 +201,9 @@ _mesa_GetProgramResourceIndex(GLuint program, GLenum programInterface,
    case GL_PROGRAM_OUTPUT:
    case GL_UNIFORM:
    case GL_TRANSFORM_FEEDBACK_VARYING:
-      /* Validate name syntax for array variables */
-      if (!valid_program_resource_index_name(name))
-         return GL_INVALID_INDEX;
-      /* fall-through */
    case GL_UNIFORM_BLOCK:
-      res = _mesa_program_resource_find_name(shProg, programInterface, name);
+      res = _mesa_program_resource_find_name(shProg, programInterface, name,
+                                             &array_index, true);
       if (!res)
          return GL_INVALID_INDEX;
 
@@ -300,36 +277,6 @@ _mesa_GetProgramResourceiv(GLuint program, GLenum programInterface,
                                 propCount, props, bufSize, length, params);
 }
 
-/**
- * Function verifies syntax of given name for GetProgramResourceLocation
- * and GetProgramResourceLocationIndex for the following cases:
- *
- * "array element portion of a string passed to GetProgramResourceLocation
- * or GetProgramResourceLocationIndex must not have, a "+" sign, extra
- * leading zeroes, or whitespace".
- *
- * Check is written to be compatible with GL_ARB_array_of_arrays.
- */
-static bool
-invalid_array_element_syntax(const GLchar *name)
-{
-   char *first = strchr(name, '[');
-   char *last = strrchr(name, '[');
-
-   if (!first)
-      return false;
-
-   /* No '+' or ' ' allowed anywhere. */
-   if (strchr(first, '+') || strchr(first, ' '))
-      return true;
-
-   /* Check that last array index is 0. */
-   if (last[1] == '0' && last[2] != ']')
-      return true;
-
-   return false;
-}
-
 static struct gl_shader_program *
 lookup_linked_program(GLuint program, const char *caller)
 {
@@ -356,7 +303,7 @@ _mesa_GetProgramResourceLocation(GLuint program, GLenum programInterface,
    struct gl_shader_program *shProg =
       lookup_linked_program(program, "glGetProgramResourceLocation");
 
-   if (!shProg || !name || invalid_array_element_syntax(name))
+   if (!shProg || !name)
       return -1;
 
    /* Validate programInterface. */
@@ -383,7 +330,8 @@ _mesa_GetProgramResourceLocation(GLuint program, GLenum programInterface,
                   _mesa_lookup_enum_by_nr(programInterface), name);
    }
 
-   return _mesa_program_resource_location(shProg, programInterface, name);
+   return _mesa_program_resource_location(shProg, programInterface, name,
+                                          true);
 }
 
 /**
@@ -397,7 +345,7 @@ _mesa_GetProgramResourceLocationIndex(GLuint program, GLenum programInterface,
    struct gl_shader_program *shProg =
       lookup_linked_program(program, "glGetProgramResourceLocationIndex");
 
-   if (!shProg || !name || invalid_array_element_syntax(name))
+   if (!shProg || !name)
       return -1;
 
    /* From the GL_ARB_program_interface_query spec:
diff --git a/src/mesa/main/shader_query.cpp b/src/mesa/main/shader_query.cpp
index 0473c2e..3b08ea1 100644
--- a/src/mesa/main/shader_query.cpp
+++ b/src/mesa/main/shader_query.cpp
@@ -44,7 +44,8 @@ extern "C" {
 
 static GLint
 program_resource_location(struct gl_shader_program *shProg,
-                          struct gl_program_resource *res, const char *name);
+                          struct gl_program_resource *res, const char *name,
+                          unsigned array_index);
 
 /**
  * Declare convenience functions to return resource data in a given type.
@@ -189,63 +190,6 @@ _mesa_GetActiveAttrib(GLhandleARB program, GLuint desired_index,
                                   (GLint *) type, "glGetActiveAttrib");
 }
 
-/* Locations associated with shader variables (array or non-array) can be
- * queried using its base name or using the base name appended with the
- * valid array index. For example, in case of below vertex shader, valid
- * queries can be made to know the location of "xyz", "array", "array[0]",
- * "array[1]", "array[2]" and "array[3]". In this example index reurned
- * will be 0, 0, 0, 1, 2, 3 respectively.
- *
- * [Vertex Shader]
- * layout(location=0) in vec4 xyz;
- * layout(location=1) in vec4[4] array;
- * void main()
- * { }
- *
- * This requirement came up with the addition of ARB_program_interface_query
- * to OpenGL 4.3 specification. See page 101 (page 122 of the PDF) for details.
- *
- * This utility function is used by:
- * _mesa_GetAttribLocation
- * _mesa_GetFragDataLocation
- * _mesa_GetFragDataIndex
- *
- * Returns 0:
- *    if the 'name' string matches var->name.
- * Returns 'matched index':
- *    if the 'name' string matches var->name appended with valid array index.
- */
-int static inline
-get_matching_index(const ir_variable *const var, const char *name) {
-   unsigned idx = 0;
-   const char *const paren = strchr(name, '[');
-   const unsigned len = (paren != NULL) ? paren - name : strlen(name);
-
-   if (paren != NULL) {
-      if (!var->type->is_array())
-         return -1;
-
-      char *endptr;
-      idx = (unsigned) strtol(paren + 1, &endptr, 10);
-      const unsigned idx_len = endptr != (paren + 1) ? endptr - paren - 1 : 0;
-
-      /* Validate the sub string representing index in 'name' string */
-      if ((idx > 0 && paren[1] == '0') /* leading zeroes */
-          || (idx == 0 && idx_len > 1) /* all zeroes */
-          || paren[1] == ' ' /* whitespace */
-          || endptr[0] != ']' /* closing brace */
-          || endptr[1] != '\0' /* null char */
-          || idx_len == 0 /* missing index */
-          || idx >= var->type->length) /* exceeding array bound */
-         return -1;
-   }
-
-   if (strncmp(var->name, name, len) == 0 && var->name[len] == '\0')
-      return idx;
-
-   return -1;
-}
-
 GLint GLAPIENTRY
 _mesa_GetAttribLocation(GLhandleARB program, const GLcharARB * name)
 {
@@ -271,13 +215,15 @@ _mesa_GetAttribLocation(GLhandleARB program, const GLcharARB * name)
    if (shProg->_LinkedShaders[MESA_SHADER_VERTEX] == NULL)
       return -1;
 
+   unsigned array_index = 0;
    struct gl_program_resource *res =
-      _mesa_program_resource_find_name(shProg, GL_PROGRAM_INPUT, name);
+      _mesa_program_resource_find_name(shProg, GL_PROGRAM_INPUT, name,
+                                       &array_index, false);
 
    if (!res)
       return -1;
 
-   GLint loc = program_resource_location(shProg, res, name);
+   GLint loc = program_resource_location(shProg, res, name, array_index);
 
    /* The extra check against against 0 is made because of builtin-attribute
     * locations that have offset applied. Function program_resource_location
@@ -455,13 +401,15 @@ _mesa_GetFragDataLocation(GLuint program, const GLchar *name)
    if (shProg->_LinkedShaders[MESA_SHADER_FRAGMENT] == NULL)
       return -1;
 
+   unsigned array_index = 0;
    struct gl_program_resource *res =
-      _mesa_program_resource_find_name(shProg, GL_PROGRAM_OUTPUT, name);
+      _mesa_program_resource_find_name(shProg, GL_PROGRAM_OUTPUT, name,
+                                       &array_index, false);
 
    if (!res)
       return -1;
 
-   GLint loc = program_resource_location(shProg, res, name);
+   GLint loc = program_resource_location(shProg, res, name, array_index);
 
    /* The extra check against against 0 is made because of builtin-attribute
     * locations that have offset applied. Function program_resource_location
@@ -525,39 +473,32 @@ _mesa_program_resource_array_size(struct gl_program_resource *res)
    return 0;
 }
 
-static int
-array_index_of_resource(struct gl_program_resource *res,
-                        const char *name)
+/**
+ * Checks if array subscript is valid and if so sets array_index.
+ */
+static bool
+valid_array_index(const GLchar *name, unsigned *array_index)
 {
-   assert(res->Data);
+   unsigned idx = 0;
+   const GLchar *out_base_name_end;
 
-   switch (res->Type) {
-   case GL_PROGRAM_INPUT:
-   case GL_PROGRAM_OUTPUT:
-      return get_matching_index(RESOURCE_VAR(res), name);
-   default:
-      assert(!"support for resource type not implemented");
-      return -1;
-   }
+   idx = parse_program_resource_name(name, &out_base_name_end);
+   if (idx < 0)
+      return false;
+
+   if (array_index)
+      *array_index = idx;
+
+   return true;
 }
 
 /* Find a program resource with specific name in given interface.
  */
 struct gl_program_resource *
 _mesa_program_resource_find_name(struct gl_shader_program *shProg,
-                                 GLenum programInterface, const char *name)
+                                 GLenum programInterface, const char *name,
+                                 unsigned *array_index, bool is_program_query)
 {
-   GET_CURRENT_CONTEXT(ctx);
-   const char *full_name = name;
-
-   /* When context has 'VertexID_is_zero_based' set, gl_VertexID has been
-    * lowered to gl_VertexIDMESA.
-    */
-   if (name && ctx->Const.VertexID_is_zero_based) {
-      if (strcmp(name, "gl_VertexID") == 0)
-         full_name = "gl_VertexIDMESA";
-   }
-
    struct gl_program_resource *res = shProg->ProgramResourceList;
    for (unsigned i = 0; i < shProg->NumProgramResourceList; i++, res++) {
       if (res->Type != programInterface)
@@ -567,26 +508,36 @@ _mesa_program_resource_find_name(struct gl_shader_program *shProg,
       const char *rname = _mesa_program_resource_name(res);
       unsigned baselen = strlen(rname);
 
-      switch (programInterface) {
-      case GL_TRANSFORM_FEEDBACK_VARYING:
-      case GL_UNIFORM_BLOCK:
-      case GL_UNIFORM:
-         if (strncmp(rname, name, baselen) == 0) {
+      if (strncmp(rname, name, baselen) == 0) {
+         switch (programInterface) {
+         case GL_UNIFORM_BLOCK:
             /* Basename match, check if array or struct. */
             if (name[baselen] == '\0' ||
                 name[baselen] == '[' ||
                 name[baselen] == '.') {
                return res;
             }
+            break;
+         case GL_TRANSFORM_FEEDBACK_VARYING:
+         case GL_UNIFORM:
+            if (name[baselen] == '.') {
+               return res;
+            }
+            /* fall-through */
+         case GL_PROGRAM_INPUT:
+         case GL_PROGRAM_OUTPUT:
+            if (name[baselen] == '\0') {
+               return res;
+            } else if (name[baselen] == '[' &&
+                valid_array_index(name, array_index)) {
+               if (is_program_query && *array_index > 0)
+                  return NULL;
+               return res;
+            }
+            break;
+         default:
+            assert(!"not implemented for given interface");
          }
-         break;
-      case GL_PROGRAM_INPUT:
-      case GL_PROGRAM_OUTPUT:
-         if (array_index_of_resource(res, full_name) >= 0)
-            return res;
-         break;
-      default:
-         assert(!"not implemented for given interface");
       }
    }
    return NULL;
@@ -736,17 +687,9 @@ _mesa_get_program_resource_name(struct gl_shader_program *shProg,
 
 static GLint
 program_resource_location(struct gl_shader_program *shProg,
-                          struct gl_program_resource *res, const char *name)
+                          struct gl_program_resource *res, const char *name,
+                          unsigned array_index)
 {
-   unsigned index, offset;
-   int array_index = -1;
-
-   if (res->Type == GL_PROGRAM_INPUT || res->Type == GL_PROGRAM_OUTPUT) {
-      array_index = array_index_of_resource(res, name);
-      if (array_index < 0)
-         return -1;
-   }
-
    /* Built-in locations should report GL_INVALID_INDEX. */
    if (is_gl_identifier(name))
       return GL_INVALID_INDEX;
@@ -757,15 +700,29 @@ program_resource_location(struct gl_shader_program *shProg,
     */
    switch (res->Type) {
    case GL_PROGRAM_INPUT:
+      /* If the input is an array, fail if the index is out of bounds. */
+      if (array_index > 0
+          && array_index >= RESOURCE_VAR(res)->type->length) {
+         return -1;
+      }
       return RESOURCE_VAR(res)->data.location + array_index - VERT_ATTRIB_GENERIC0;
    case GL_PROGRAM_OUTPUT:
+      /* If the output is an array, fail if the index is out of bounds. */
+      if (array_index > 0
+          && array_index >= RESOURCE_VAR(res)->type->length) {
+         return -1;
+      }
       return RESOURCE_VAR(res)->data.location + array_index - FRAG_RESULT_DATA0;
    case GL_UNIFORM:
-      index = _mesa_get_uniform_location(shProg, name, &offset);
-
-      if (index == GL_INVALID_INDEX)
+      /* If the uniform is built-in, fail. */
+      if (RESOURCE_UNI(res)->builtin)
          return -1;
 
+      /* If the uniform is an array, fail if the index is out of bounds. */
+      if (array_index > 0
+          && array_index >= RESOURCE_UNI(res)->array_elements) {
+         return -1;
+      }
       /* From the GL_ARB_uniform_buffer_object spec:
        *
        *     "The value -1 will be returned if <name> does not correspond to an
@@ -778,7 +735,7 @@ program_resource_location(struct gl_shader_program *shProg,
          return -1;
 
       /* location in remap table + array element offset */
-      return RESOURCE_UNI(res)->remap_location + offset;
+      return RESOURCE_UNI(res)->remap_location + array_index;
 
    default:
       return -1;
@@ -791,16 +748,19 @@ program_resource_location(struct gl_shader_program *shProg,
  */
 GLint
 _mesa_program_resource_location(struct gl_shader_program *shProg,
-                                GLenum programInterface, const char *name)
+                                GLenum programInterface, const char *name,
+                                bool is_resource_query)
 {
+   unsigned array_index = 0;
    struct gl_program_resource *res =
-      _mesa_program_resource_find_name(shProg, programInterface, name);
+      _mesa_program_resource_find_name(shProg, programInterface, name,
+                                       &array_index, false);
 
    /* Resource not found. */
    if (!res)
       return -1;
 
-   return program_resource_location(shProg, res, name);
+   return program_resource_location(shProg, res, name, array_index);
 }
 
 /**
@@ -812,7 +772,8 @@ _mesa_program_resource_location_index(struct gl_shader_program *shProg,
                                       GLenum programInterface, const char *name)
 {
    struct gl_program_resource *res =
-      _mesa_program_resource_find_name(shProg, programInterface, name);
+      _mesa_program_resource_find_name(shProg, programInterface, name,
+                                       NULL, false);
 
    /* Non-existent variable or resource is not referenced by fragment stage. */
    if (!res || !(res->StageReferences & (1 << MESA_SHADER_FRAGMENT)))
@@ -884,7 +845,8 @@ get_buffer_property(struct gl_shader_program *shProg,
          for (unsigned i = 0; i < RESOURCE_UBO(res)->NumUniforms; i++) {
             const char *iname = RESOURCE_UBO(res)->Uniforms[i].IndexName;
             struct gl_program_resource *uni =
-               _mesa_program_resource_find_name(shProg, GL_UNIFORM, iname);
+               _mesa_program_resource_find_name(shProg, GL_UNIFORM, iname,
+                                                NULL, false);
             if (!uni)
                continue;
             (*val)++;
@@ -894,7 +856,8 @@ get_buffer_property(struct gl_shader_program *shProg,
          for (unsigned i = 0; i < RESOURCE_UBO(res)->NumUniforms; i++) {
             const char *iname = RESOURCE_UBO(res)->Uniforms[i].IndexName;
             struct gl_program_resource *uni =
-               _mesa_program_resource_find_name(shProg, GL_UNIFORM, iname);
+               _mesa_program_resource_find_name(shProg, GL_UNIFORM, iname,
+                                                NULL, false);
             if (!uni)
                continue;
             *val++ =
@@ -1032,7 +995,8 @@ _mesa_program_resource_prop(struct gl_shader_program *shProg,
       case GL_PROGRAM_INPUT:
       case GL_PROGRAM_OUTPUT:
          *val = program_resource_location(shProg, res,
-                                          _mesa_program_resource_name(res));
+                                          _mesa_program_resource_name(res),
+                                          0);
          return 1;
       default:
          goto invalid_operation;
diff --git a/src/mesa/main/shaderapi.h b/src/mesa/main/shaderapi.h
index aba6d5d..186b10d 100644
--- a/src/mesa/main/shaderapi.h
+++ b/src/mesa/main/shaderapi.h
@@ -232,7 +232,9 @@ _mesa_program_resource_index(struct gl_shader_program *shProg,
 
 extern struct gl_program_resource *
 _mesa_program_resource_find_name(struct gl_shader_program *shProg,
-                                 GLenum programInterface, const char *name);
+                                 GLenum programInterface, const char *name,
+                                 unsigned *array_index,
+                                 bool is_resource_query);
 
 extern struct gl_program_resource *
 _mesa_program_resource_find_index(struct gl_shader_program *shProg,
@@ -246,7 +248,8 @@ _mesa_get_program_resource_name(struct gl_shader_program *shProg,
 
 extern GLint
 _mesa_program_resource_location(struct gl_shader_program *shProg,
-                                GLenum programInterface, const char *name);
+                                GLenum programInterface, const char *name,
+                                bool is_resource_query);
 
 extern GLint
 _mesa_program_resource_location_index(struct gl_shader_program *shProg,
diff --git a/src/mesa/main/uniforms.c b/src/mesa/main/uniforms.c
index 5548d1d..7c9ff7e 100644
--- a/src/mesa/main/uniforms.c
+++ b/src/mesa/main/uniforms.c
@@ -930,7 +930,7 @@ _mesa_GetUniformLocation(GLuint programObj, const GLcharARB *name)
       return -1;
    }
 
-   return _mesa_program_resource_location(shProg, GL_UNIFORM, name);
+   return _mesa_program_resource_location(shProg, GL_UNIFORM, name, false);
 }
 
 GLuint GLAPIENTRY
@@ -952,7 +952,7 @@ _mesa_GetUniformBlockIndex(GLuint program,
 
    struct gl_program_resource *res =
       _mesa_program_resource_find_name(shProg, GL_UNIFORM_BLOCK,
-                                       uniformBlockName);
+                                       uniformBlockName, NULL, false);
    if (!res)
       return GL_INVALID_INDEX;
 
@@ -987,7 +987,8 @@ _mesa_GetUniformIndices(GLuint program,
 
    for (i = 0; i < uniformCount; i++) {
       struct gl_program_resource *res =
-         _mesa_program_resource_find_name(shProg, GL_UNIFORM, uniformNames[i]);
+         _mesa_program_resource_find_name(shProg, GL_UNIFORM, uniformNames[i],
+                                          NULL, false);
       uniformIndices[i] = _mesa_program_resource_index(shProg, res);
    }
 }
-- 
2.4.3



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