[Mesa-dev] [PATCH 1/2] ir_to_mesa: Allocate temporary instructions on the visitor's ralloc context

[Ian Romanick]

From: Ian Romanick <ian.d.romanick at intel.com>

And don't delete them.  Let ralloc clean them up.  Deleting the
temporary IR leaves dangling references in the prog_instruction.  That
results in a bad dereference when printing the IR with MESA_GLSL=dump.

NOTE: This is a candidate for the 7.10 and 7.11 branches.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=38584
Reviewed-by: Eric Anholt <eric at anholt.net>
---
v2 incorporates review comments from Eric.

 src/mesa/program/ir_to_mesa.cpp |   28 ++++++++++++----------------
 1 files changed, 12 insertions(+), 16 deletions(-)

diff --git a/src/mesa/program/ir_to_mesa.cpp b/src/mesa/program/ir_to_mesa.cpp
index 0086997..9389477 100644
--- a/src/mesa/program/ir_to_mesa.cpp
+++ b/src/mesa/program/ir_to_mesa.cpp
@@ -803,48 +803,44 @@ ir_to_mesa_visitor::visit(ir_loop *ir)
    ir_dereference_variable *counter = NULL;
 
    if (ir->counter != NULL)
-      counter = new(ir) ir_dereference_variable(ir->counter);
+      counter = new(mem_ctx) ir_dereference_variable(ir->counter);
 
    if (ir->from != NULL) {
       assert(ir->counter != NULL);
 
-      ir_assignment *a = new(ir) ir_assignment(counter, ir->from, NULL);
+      ir_assignment *a =
+	new(mem_ctx) ir_assignment(counter, ir->from, NULL);
 
       a->accept(this);
-      delete a;
    }
 
    emit(NULL, OPCODE_BGNLOOP);
 
    if (ir->to) {
       ir_expression *e =
-	 new(ir) ir_expression(ir->cmp, glsl_type::bool_type,
-			       counter, ir->to);
-      ir_if *if_stmt =  new(ir) ir_if(e);
+	 new(mem_ctx) ir_expression(ir->cmp, glsl_type::bool_type,
+					  counter, ir->to);
+      ir_if *if_stmt =  new(mem_ctx) ir_if(e);
 
-      ir_loop_jump *brk = new(ir) ir_loop_jump(ir_loop_jump::jump_break);
+      ir_loop_jump *brk =
+	new(mem_ctx) ir_loop_jump(ir_loop_jump::jump_break);
 
       if_stmt->then_instructions.push_tail(brk);
 
       if_stmt->accept(this);
-
-      delete if_stmt;
-      delete e;
-      delete brk;
    }
 
    visit_exec_list(&ir->body_instructions, this);
 
    if (ir->increment) {
       ir_expression *e =
-	 new(ir) ir_expression(ir_binop_add, counter->type,
-			       counter, ir->increment);
+	 new(mem_ctx) ir_expression(ir_binop_add, counter->type,
+					  counter, ir->increment);
 
-      ir_assignment *a = new(ir) ir_assignment(counter, e, NULL);
+      ir_assignment *a =
+	new(mem_ctx) ir_assignment(counter, e, NULL);
 
       a->accept(this);
-      delete a;
-      delete e;
    }
 
    emit(NULL, OPCODE_ENDLOOP);
-- 
1.7.4.4