[Mesa-dev] [PATCH 3/5] glsl: Use a consistent technique for tracking link success/failure.
Paul Berry
stereotype441 at gmail.com
Sat Jul 27 15:59:38 PDT 2013
This patch changes link_shaders() so that it sets prog->LinkStatus to
true when it starts, and then relies on linker_error() to set it to
false if a link failure occurs.
Previously, link_shaders() would set prog->LinkStatus to true halfway
through its execution; as a result, linker functions that executed
during the first half of link_shaders() would have to do their own
success/failure tracking; if they didn't, then calling linker_error()
would add an error message to the log, but not cause the link to fail.
Since it wasn't always obvious from looking at a linker function
whether it was called before or after link_shaders() set
prog->LinkStatus to true, this carried a high risk of bugs.
---
src/glsl/link_interface_blocks.cpp | 19 +++---
src/glsl/link_varyings.cpp | 12 ++--
src/glsl/link_varyings.h | 2 +-
src/glsl/linker.cpp | 117 ++++++++++++++++++-------------------
src/glsl/linker.h | 7 ++-
5 files changed, 75 insertions(+), 82 deletions(-)
diff --git a/src/glsl/link_interface_blocks.cpp b/src/glsl/link_interface_blocks.cpp
index 4f67291..ffb4453 100644
--- a/src/glsl/link_interface_blocks.cpp
+++ b/src/glsl/link_interface_blocks.cpp
@@ -31,7 +31,7 @@
#include "linker.h"
#include "main/macros.h"
-bool
+void
validate_intrastage_interface_blocks(struct gl_shader_program *prog,
const gl_shader **shader_list,
unsigned num_shaders)
@@ -65,16 +65,15 @@ validate_intrastage_interface_blocks(struct gl_shader_program *prog,
} else if (old_iface_type != iface_type) {
linker_error(prog, "definitions of interface block `%s' do not"
" match\n", iface_type->name);
- return false;
+ return;
}
}
}
-
- return true;
}
-bool
-validate_interstage_interface_blocks(const gl_shader *producer,
+void
+validate_interstage_interface_blocks(struct gl_shader_program *prog,
+ const gl_shader *producer,
const gl_shader *consumer)
{
glsl_symbol_table interfaces;
@@ -105,9 +104,9 @@ validate_interstage_interface_blocks(const gl_shader *producer,
if (expected_type == NULL)
continue;
- if (var->interface_type != expected_type)
- return false;
+ if (var->interface_type != expected_type) {
+ linker_error(prog, "interface block mismatch between shader stages\n");
+ return;
+ }
}
-
- return true;
}
diff --git a/src/glsl/link_varyings.cpp b/src/glsl/link_varyings.cpp
index 51cbdaa..2c7e451 100644
--- a/src/glsl/link_varyings.cpp
+++ b/src/glsl/link_varyings.cpp
@@ -43,7 +43,7 @@
/**
* Validate that outputs from one stage match inputs of another
*/
-bool
+void
cross_validate_outputs_to_inputs(struct gl_shader_program *prog,
gl_shader *producer, gl_shader *consumer)
{
@@ -106,7 +106,7 @@ cross_validate_outputs_to_inputs(struct gl_shader_program *prog,
producer_stage, output->name,
output->type->name,
consumer_stage, input->type->name);
- return false;
+ return;
}
}
@@ -121,7 +121,7 @@ cross_validate_outputs_to_inputs(struct gl_shader_program *prog,
(output->centroid) ? "has" : "lacks",
consumer_stage,
(input->centroid) ? "has" : "lacks");
- return false;
+ return;
}
if (input->invariant != output->invariant) {
@@ -133,7 +133,7 @@ cross_validate_outputs_to_inputs(struct gl_shader_program *prog,
(output->invariant) ? "has" : "lacks",
consumer_stage,
(input->invariant) ? "has" : "lacks");
- return false;
+ return;
}
if (input->interpolation != output->interpolation) {
@@ -147,12 +147,10 @@ cross_validate_outputs_to_inputs(struct gl_shader_program *prog,
output->interpolation_string(),
consumer_stage,
input->interpolation_string());
- return false;
+ return;
}
}
}
-
- return true;
}
diff --git a/src/glsl/link_varyings.h b/src/glsl/link_varyings.h
index 7f7be35..cfc6e47 100644
--- a/src/glsl/link_varyings.h
+++ b/src/glsl/link_varyings.h
@@ -214,7 +214,7 @@ private:
};
-bool
+void
cross_validate_outputs_to_inputs(struct gl_shader_program *prog,
gl_shader *producer, gl_shader *consumer);
diff --git a/src/glsl/linker.cpp b/src/glsl/linker.cpp
index 3d9c59d..942f906 100644
--- a/src/glsl/linker.cpp
+++ b/src/glsl/linker.cpp
@@ -340,12 +340,12 @@ count_attribute_slots(const glsl_type *t)
*
* \param shader Vertex shader executable to be verified
*/
-bool
+void
validate_vertex_shader_executable(struct gl_shader_program *prog,
struct gl_shader *shader)
{
if (shader == NULL)
- return true;
+ return;
/* From the GLSL 1.10 spec, page 48:
*
@@ -378,7 +378,7 @@ validate_vertex_shader_executable(struct gl_shader_program *prog,
find.run(shader->ir);
if (!find.variable_found()) {
linker_error(prog, "vertex shader does not write to `gl_Position'\n");
- return false;
+ return;
}
}
@@ -402,7 +402,7 @@ validate_vertex_shader_executable(struct gl_shader_program *prog,
if (clip_vertex.variable_found() && clip_distance.variable_found()) {
linker_error(prog, "vertex shader writes to both `gl_ClipVertex' "
"and `gl_ClipDistance'\n");
- return false;
+ return;
}
prog->Vert.UsesClipDistance = clip_distance.variable_found();
ir_variable *clip_distance_var =
@@ -410,8 +410,6 @@ validate_vertex_shader_executable(struct gl_shader_program *prog,
if (clip_distance_var)
prog->Vert.ClipDistanceArraySize = clip_distance_var->type->length;
}
-
- return true;
}
@@ -420,12 +418,12 @@ validate_vertex_shader_executable(struct gl_shader_program *prog,
*
* \param shader Fragment shader executable to be verified
*/
-bool
+void
validate_fragment_shader_executable(struct gl_shader_program *prog,
struct gl_shader *shader)
{
if (shader == NULL)
- return true;
+ return;
find_assignment_visitor frag_color("gl_FragColor");
find_assignment_visitor frag_data("gl_FragData");
@@ -436,10 +434,7 @@ validate_fragment_shader_executable(struct gl_shader_program *prog,
if (frag_color.variable_found() && frag_data.variable_found()) {
linker_error(prog, "fragment shader writes to both "
"`gl_FragColor' and `gl_FragData'\n");
- return false;
}
-
- return true;
}
@@ -469,7 +464,7 @@ mode_string(const ir_variable *var)
/**
* Perform validation of global variables used across multiple shaders
*/
-bool
+void
cross_validate_globals(struct gl_shader_program *prog,
struct gl_shader **shader_list,
unsigned num_shaders,
@@ -524,7 +519,7 @@ cross_validate_globals(struct gl_shader_program *prog,
mode_string(var),
var->name, var->type->name,
existing->type->name);
- return false;
+ return;
}
}
@@ -534,7 +529,7 @@ cross_validate_globals(struct gl_shader_program *prog,
linker_error(prog, "explicit locations for %s "
"`%s' have differing values\n",
mode_string(var), var->name);
- return false;
+ return;
}
existing->location = var->location;
@@ -553,7 +548,7 @@ cross_validate_globals(struct gl_shader_program *prog,
linker_error(prog, "explicit bindings for %s "
"`%s' have differing values\n",
mode_string(var), var->name);
- return false;
+ return;
}
existing->binding = var->binding;
@@ -614,7 +609,7 @@ cross_validate_globals(struct gl_shader_program *prog,
linker_error(prog, "initializers for %s "
"`%s' have differing values\n",
mode_string(var), var->name);
- return false;
+ return;
}
} else {
/* If the first-seen instance of a particular uniform did not
@@ -643,7 +638,7 @@ cross_validate_globals(struct gl_shader_program *prog,
"shared global variable `%s' has multiple "
"non-constant initializers.\n",
var->name);
- return false;
+ return;
}
/* Some instance had an initializer, so keep track of that. In
@@ -658,31 +653,29 @@ cross_validate_globals(struct gl_shader_program *prog,
linker_error(prog, "declarations for %s `%s' have "
"mismatching invariant qualifiers\n",
mode_string(var), var->name);
- return false;
+ return;
}
if (existing->centroid != var->centroid) {
linker_error(prog, "declarations for %s `%s' have "
"mismatching centroid qualifiers\n",
mode_string(var), var->name);
- return false;
+ return;
}
} else
variables.add_variable(var);
}
}
-
- return true;
}
/**
* Perform validation of uniforms used across multiple shader stages
*/
-bool
+void
cross_validate_uniforms(struct gl_shader_program *prog)
{
- return cross_validate_globals(prog, prog->_LinkedShaders,
- MESA_SHADER_TYPES, true);
+ cross_validate_globals(prog, prog->_LinkedShaders,
+ MESA_SHADER_TYPES, true);
}
/**
@@ -955,14 +948,15 @@ link_intrastage_shaders(void *mem_ctx,
/* Check that global variables defined in multiple shaders are consistent.
*/
- if (!cross_validate_globals(prog, shader_list, num_shaders, false))
+ cross_validate_globals(prog, shader_list, num_shaders, false);
+ if (!prog->LinkStatus)
return NULL;
/* Check that interface blocks defined in multiple shaders are consistent.
*/
- if (!validate_intrastage_interface_blocks(prog,
- (const gl_shader **)shader_list,
- num_shaders))
+ validate_intrastage_interface_blocks(prog, (const gl_shader **)shader_list,
+ num_shaders);
+ if (!prog->LinkStatus)
return NULL;
/* Link up uniform blocks defined within this stage. */
@@ -1528,7 +1522,7 @@ store_fragdepth_layout(struct gl_shader_program *prog)
/**
* Validate the resources used by a program versus the implementation limits
*/
-static bool
+static void
check_resources(struct gl_context *ctx, struct gl_shader_program *prog)
{
static const char *const shader_names[MESA_SHADER_TYPES] = {
@@ -1625,8 +1619,6 @@ check_resources(struct gl_context *ctx, struct gl_shader_program *prog)
}
}
}
-
- return prog->LinkStatus;
}
void
@@ -1637,7 +1629,7 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
void *mem_ctx = ralloc_context(NULL); // temporary linker context
- prog->LinkStatus = false;
+ prog->LinkStatus = true; /* All error paths will set this to false */
prog->Validated = false;
prog->_Used = false;
@@ -1723,10 +1715,11 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
link_intrastage_shaders(mem_ctx, ctx, prog, vert_shader_list,
num_vert_shaders);
- if (sh == NULL)
+ if (!prog->LinkStatus)
goto done;
- if (!validate_vertex_shader_executable(prog, sh))
+ validate_vertex_shader_executable(prog, sh);
+ if (!prog->LinkStatus)
goto done;
_mesa_reference_shader(ctx, &prog->_LinkedShaders[MESA_SHADER_VERTEX],
@@ -1738,10 +1731,11 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
link_intrastage_shaders(mem_ctx, ctx, prog, frag_shader_list,
num_frag_shaders);
- if (sh == NULL)
+ if (!prog->LinkStatus)
goto done;
- if (!validate_fragment_shader_executable(prog, sh))
+ validate_fragment_shader_executable(prog, sh);
+ if (!prog->LinkStatus)
goto done;
_mesa_reference_shader(ctx, &prog->_LinkedShaders[MESA_SHADER_FRAGMENT],
@@ -1752,36 +1746,36 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
* performed, then locations are assigned for uniforms, attributes, and
* varyings.
*/
- if (cross_validate_uniforms(prog)) {
- unsigned prev;
+ cross_validate_uniforms(prog);
+ if (!prog->LinkStatus)
+ goto done;
- for (prev = 0; prev < MESA_SHADER_TYPES; prev++) {
- if (prog->_LinkedShaders[prev] != NULL)
- break;
- }
+ unsigned prev;
- /* Validate the inputs of each stage with the output of the preceding
- * stage.
- */
- for (unsigned i = prev + 1; i < MESA_SHADER_TYPES; i++) {
- if (prog->_LinkedShaders[i] == NULL)
- continue;
+ for (prev = 0; prev < MESA_SHADER_TYPES; prev++) {
+ if (prog->_LinkedShaders[prev] != NULL)
+ break;
+ }
- if (!validate_interstage_interface_blocks(prog->_LinkedShaders[prev],
- prog->_LinkedShaders[i])) {
- linker_error(prog, "interface block mismatch between shader stages\n");
- goto done;
- }
+ /* Validate the inputs of each stage with the output of the preceding
+ * stage.
+ */
+ for (unsigned i = prev + 1; i < MESA_SHADER_TYPES; i++) {
+ if (prog->_LinkedShaders[i] == NULL)
+ continue;
- if (!cross_validate_outputs_to_inputs(prog,
- prog->_LinkedShaders[prev],
- prog->_LinkedShaders[i]))
- goto done;
+ validate_interstage_interface_blocks(prog, prog->_LinkedShaders[prev],
+ prog->_LinkedShaders[i]);
+ if (!prog->LinkStatus)
+ goto done;
- prev = i;
- }
+ cross_validate_outputs_to_inputs(prog,
+ prog->_LinkedShaders[prev],
+ prog->_LinkedShaders[i]);
+ if (!prog->LinkStatus)
+ goto done;
- prog->LinkStatus = true;
+ prev = i;
}
@@ -1970,7 +1964,8 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
link_assign_uniform_locations(prog);
store_fragdepth_layout(prog);
- if (!check_resources(ctx, prog))
+ check_resources(ctx, prog);
+ if (!prog->LinkStatus)
goto done;
/* OpenGL ES requires that a vertex shader and a fragment shader both be
diff --git a/src/glsl/linker.h b/src/glsl/linker.h
index 9f5deb5..0ce747d 100644
--- a/src/glsl/linker.h
+++ b/src/glsl/linker.h
@@ -60,13 +60,14 @@ link_uniform_blocks(void *mem_ctx,
unsigned num_shaders,
struct gl_uniform_block **blocks_ret);
-bool
+void
validate_intrastage_interface_blocks(struct gl_shader_program *prog,
const gl_shader **shader_list,
unsigned num_shaders);
-bool
-validate_interstage_interface_blocks(const gl_shader *producer,
+void
+validate_interstage_interface_blocks(struct gl_shader_program *prog,
+ const gl_shader *producer,
const gl_shader *consumer);
/**
--
1.8.3.4
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