[Mesa-dev] [RFC] nir/validate: on failure, dump shader w/ offending line annotated

[Rob Clark]

From: Rob Clark <robclark at freedesktop.org>

If we assert in nir_validate_shader(), print the shader with the
offending instruction prefixed with "=>" to make it easier to find what
part of the shader nir_validate is complaining about.

Macro funny-business in nir_validate() was just to avoid changing a
bazillion assert() lines to validate_assert() (or similar) for the point
of an RFC ;-)

Example output: http://hastebin.com/raw/qorirayazu
---
 src/compiler/nir/nir.h          |  1 +
 src/compiler/nir/nir_print.c    | 14 +++++++++++++-
 src/compiler/nir/nir_validate.c | 15 +++++++++++++++
 3 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h
index ade584c..6bb9fbe 100644
--- a/src/compiler/nir/nir.h
+++ b/src/compiler/nir/nir.h
@@ -2196,6 +2196,7 @@ unsigned nir_index_instrs(nir_function_impl *impl);
 void nir_index_blocks(nir_function_impl *impl);
 
 void nir_print_shader(nir_shader *shader, FILE *fp);
+void nir_print_shader_err(nir_shader *shader, FILE *fp, nir_instr *instr);
 void nir_print_instr(const nir_instr *instr, FILE *fp);
 
 nir_shader *nir_shader_clone(void *mem_ctx, const nir_shader *s);
diff --git a/src/compiler/nir/nir_print.c b/src/compiler/nir/nir_print.c
index a36561e..3b25a49 100644
--- a/src/compiler/nir/nir_print.c
+++ b/src/compiler/nir/nir_print.c
@@ -53,6 +53,8 @@ typedef struct {
 
    /* an index used to make new non-conflicting names */
    unsigned index;
+
+   nir_instr *err_instr;
 } print_state;
 
 static void
@@ -916,6 +918,8 @@ print_block(nir_block *block, print_state *state, unsigned tabs)
    free(preds);
 
    nir_foreach_instr(instr, block) {
+      if (instr == state->err_instr)
+         fprintf(fp, "=>");
       print_instr(instr, state, tabs);
       fprintf(fp, "\n");
    }
@@ -1090,11 +1094,13 @@ destroy_print_state(print_state *state)
 }
 
 void
-nir_print_shader(nir_shader *shader, FILE *fp)
+nir_print_shader_err(nir_shader *shader, FILE *fp, nir_instr *instr)
 {
    print_state state;
    init_print_state(&state, shader, fp);
 
+   state.err_instr = instr;
+
    fprintf(fp, "shader: %s\n", gl_shader_stage_name(shader->stage));
 
    if (shader->info.name)
@@ -1144,6 +1150,12 @@ nir_print_shader(nir_shader *shader, FILE *fp)
 }
 
 void
+nir_print_shader(nir_shader *shader, FILE *fp)
+{
+   nir_print_shader_err(shader, fp, NULL);
+}
+
+void
 nir_print_instr(const nir_instr *instr, FILE *fp)
 {
    print_state state = {
diff --git a/src/compiler/nir/nir_validate.c b/src/compiler/nir/nir_validate.c
index 84334d4..b47087f 100644
--- a/src/compiler/nir/nir_validate.c
+++ b/src/compiler/nir/nir_validate.c
@@ -97,6 +97,21 @@ typedef struct {
    struct hash_table *var_defs;
 } validate_state;
 
+
+
+static void
+dump_assert(validate_state *state, const char *failed)
+{
+   fprintf(stderr, "validate failed: %s\n", failed);
+   if (state->instr)
+      nir_print_shader_err(state->shader, stderr, state->instr);
+}
+
+#define __assert assert
+#undef assert
+#define assert(x) do { if (!(x)) { dump_assert(state, #x); __assert_fail(#x, __FILE__, __LINE__, __func__); } } while (0)
+
+
 static void validate_src(nir_src *src, validate_state *state);
 
 static void
-- 
2.5.5