shader: Rework gl_PerVertex emission

If the next shader stage doesn't declare an input block,
we should not emit an output block in the current stage.

Fix the remaining compilation issue when using the GLES backend.
error: redeclaration of gl_PerVertex must be a subset of the built-in members of gl_PerVertex

Signed-off-by: Elie Tournier <elie.tournier@collabora.com>
Reviewed-by: Gert Wollny <gert.wollny@collabora.com>

src/vrend_renderer.c

@@ -3209,7 +3209,6 @@ static inline void vrend_fill_shader_key(struct vrend_context *ctx,
    }
 
    if (prev_type != -1 && ctx->sub->shaders[prev_type]) {
-      key->prev_stage_pervertex_out = ctx->sub->shaders[prev_type]->sinfo.has_pervertex_out;
       key->prev_stage_num_clip_out = ctx->sub->shaders[prev_type]->sinfo.num_clip_out;
       key->prev_stage_num_cull_out = ctx->sub->shaders[prev_type]->sinfo.num_cull_out;
       key->num_indirect_generic_inputs = ctx->sub->shaders[prev_type]->sinfo.num_indirect_generic_outputs;
@@ -3254,6 +3253,7 @@ static inline void vrend_fill_shader_key(struct vrend_context *ctx,
    }
 
    if (next_type != -1 && ctx->sub->shaders[next_type]) {
+      key->next_stage_pervertex_in = ctx->sub->shaders[next_type]->sinfo.has_pervertex_in;
       key->num_indirect_generic_outputs = ctx->sub->shaders[next_type]->sinfo.num_indirect_generic_inputs;
       key->num_indirect_patch_outputs = ctx->sub->shaders[next_type]->sinfo.num_indirect_patch_inputs;
       key->generic_outputs_expected_mask = ctx->sub->shaders[next_type]->sinfo.generic_inputs_emitted_mask;

src/vrend_shader.c

@@ -237,11 +237,11 @@ struct dump_ctx {
    int color_in_mask;
    /* only used when cull is enabled */
    uint8_t num_cull_dist_prop, num_clip_dist_prop;
+   bool has_pervertex;
    bool front_face_emitted;
 
    bool has_clipvertex;
    bool has_clipvertex_so;
-   bool vs_has_pervertex;
    bool write_mul_utemp;
    bool write_mul_itemp;
    bool has_sample_input;
@@ -6121,8 +6121,7 @@ static void emit_ios_vs(struct dump_ctx *ctx)
       if (ctx->key->clip_plane_enable) {
          emit_hdr(ctx, "uniform vec4 clipp[8];\n");
       }
-      if (ctx->key->gs_present || ctx->key->tes_present) {
+      if ((ctx->key->gs_present || ctx->key->tes_present) && ctx->key->next_stage_pervertex_in) {
-         ctx->vs_has_pervertex = true;
          emit_hdrf(ctx, "out gl_PerVertex {\n vec4 gl_Position;\n %s%s};\n", clip_buf, cull_buf);
       } else {
          emit_hdrf(ctx, "%s%s", clip_buf, cull_buf);
@@ -6306,7 +6305,7 @@ static void emit_ios_geom(struct dump_ctx *ctx)
 
    emit_winsys_correction(ctx);
 
-   if (ctx->num_in_clip_dist || ctx->key->clip_plane_enable || ctx->key->prev_stage_pervertex_out) {
+   if (ctx->num_in_clip_dist || ctx->key->clip_plane_enable) {
       int clip_dist, cull_dist;
       char clip_var[64] = "";
       char cull_var[64] = "";
@@ -6319,6 +6318,7 @@ static void emit_ios_geom(struct dump_ctx *ctx)
       if (cull_dist)
          snprintf(cull_var, 64, "float gl_CullDistance[%d];\n", cull_dist);
 
+      ctx->has_pervertex = true;
       emit_hdrf(ctx, "in gl_PerVertex {\n vec4 gl_Position; \n %s%s\n} gl_in[];\n", clip_var, cull_var);
    }
    if (ctx->num_clip_dist) {
@@ -6380,7 +6380,7 @@ static void emit_ios_tcs(struct dump_ctx *ctx)
       }
    }
 
-   if (ctx->num_in_clip_dist || ctx->key->prev_stage_pervertex_out) {
+   if (ctx->num_in_clip_dist) {
       int clip_dist, cull_dist;
       char clip_var[64] = "", cull_var[64] = "";
 
@@ -6392,10 +6392,11 @@ static void emit_ios_tcs(struct dump_ctx *ctx)
       if (cull_dist)
          snprintf(cull_var, 64, "float gl_CullDistance[%d];\n", cull_dist);
 
+      ctx->has_pervertex = true;
       emit_hdrf(ctx, "in gl_PerVertex {\n vec4 gl_Position; \n %s%s} gl_in[];\n", clip_var, cull_var);
    }
-   if (ctx->num_clip_dist) {
+   if (ctx->num_clip_dist && ctx->key->next_stage_pervertex_in) {
-      emit_hdrf(ctx, "out gl_PerVertex {\n vec4 gl_Position;\n float gl_ClipDistance[%d];\n} gl_out[];\n", ctx->num_clip_dist ? ctx->num_clip_dist : 8);
+      emit_hdrf(ctx, "out gl_PerVertex {\n vec4 gl_Position;\n float gl_ClipDistance[%d];\n} gl_out[];\n", ctx->num_clip_dist);
       emit_hdr(ctx, "vec4 clip_dist_temp[2];\n");
    }
 }
@@ -6431,7 +6432,7 @@ static void emit_ios_tes(struct dump_ctx *ctx)
 
    emit_winsys_correction(ctx);
 
-   if (ctx->num_in_clip_dist || ctx->key->prev_stage_pervertex_out) {
+   if (ctx->num_in_clip_dist) {
       int clip_dist, cull_dist;
       char clip_var[64] = "", cull_var[64] = "";
 
@@ -6443,10 +6444,11 @@ static void emit_ios_tes(struct dump_ctx *ctx)
       if (cull_dist)
          snprintf(cull_var, 64, "float gl_CullDistance[%d];\n", cull_dist);
 
+      ctx->has_pervertex = true;
       emit_hdrf(ctx, "in gl_PerVertex {\n vec4 gl_Position; \n %s%s} gl_in[];\n", clip_var, cull_var);
    }
-   if (ctx->num_clip_dist) {
+   if (ctx->num_clip_dist && ctx->key->next_stage_pervertex_in) {
-      emit_hdrf(ctx, "out gl_PerVertex {\n vec4 gl_Position;\n float gl_ClipDistance[%d];\n} gl_out[];\n", ctx->num_clip_dist ? ctx->num_clip_dist : 8);
+      emit_hdrf(ctx, "out gl_PerVertex {\n vec4 gl_Position;\n float gl_ClipDistance[%d];\n} gl_out[];\n", ctx->num_clip_dist);
       emit_hdr(ctx, "vec4 clip_dist_temp[2];\n");
    }
 }
@@ -6603,7 +6605,7 @@ static boolean analyze_instruction(struct tgsi_iterate_context *iter,
 static void fill_sinfo(struct dump_ctx *ctx, struct vrend_shader_info *sinfo)
 {
    sinfo->num_ucp = ctx->key->clip_plane_enable ? 8 : 0;
-   sinfo->has_pervertex_out = ctx->vs_has_pervertex;
+   sinfo->has_pervertex_in = ctx->has_pervertex;
    sinfo->has_sample_input = ctx->has_sample_input;
    bool has_prop = (ctx->num_clip_dist_prop + ctx->num_cull_dist_prop) > 0;
    sinfo->num_clip_out = has_prop ? ctx->num_clip_dist_prop : (ctx->num_clip_dist ? ctx->num_clip_dist : 8);

src/vrend_shader.h

@@ -56,6 +56,7 @@ struct vrend_shader_info {
    uint32_t ubo_used_mask;
    uint32_t ssbo_used_mask;
    uint32_t num_generic_and_patch_outputs;
+   bool has_pervertex_in;
    bool guest_sent_io_arrays;
    struct vrend_layout_info generic_outputs_layout[64];
    int num_consts;
@@ -70,7 +71,6 @@ struct vrend_shader_info {
    uint32_t generic_inputs_emitted_mask;
    int num_ucp;
    int glsl_ver;
-   bool has_pervertex_out;
    bool has_sample_input;
    uint8_t num_clip_out;
    uint8_t num_cull_out;
@@ -105,7 +105,6 @@ struct vrend_shader_key {
    bool tcs_present;
    bool tes_present;
    bool flatshade;
-   bool prev_stage_pervertex_out;
    bool guest_sent_io_arrays;
    bool fs_logicop_enabled;
    bool fs_logicop_emulate_coherent;
@@ -117,6 +116,7 @@ struct vrend_shader_key {
 
    uint8_t prev_stage_num_clip_out;
    uint8_t prev_stage_num_cull_out;
+   bool next_stage_pervertex_in;
    uint32_t cbufs_are_a8_bitmask;
    uint8_t num_indirect_generic_outputs;
    uint8_t num_indirect_patch_outputs;