nir: fix dangling ssadef->name ptrs

In many places, the convention is to pass an existing ssadef name ptr
when construction/initializing a new nir_ssa_def.  But that goes badly
(as noticed by garbage in nir_print output) when the original string
gets freed.

Just use ralloc_strdup() instead, and add ralloc_free() in the two
places that would care (not that the strings wouldn't eventually get
freed anyways).

Also fixup the nir_search code which was directly setting ssadef->name
to use the parent instruction as memctx.

Signed-off-by: Rob Clark <robclark@freedesktop.org>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>

1 files changed, 2 insertions, 0 deletions

diff --git a/src/compiler/nir/nir_to_ssa.c b/src/compiler/nir/nir_to_ssa.c
index 0640607..d588d7d 100644
--- a/src/compiler/nir/nir_to_ssa.c
+++ b/src/compiler/nir/nir_to_ssa.c
@@ -221,6 +221,7 @@ rewrite_def_forwards(nir_dest *dest, void *_state)
    list_del(&dest->reg.def_link);
    nir_ssa_dest_init(state->parent_instr, dest, reg->num_components,
                      reg->bit_size, name);
+   ralloc_free(name);
 
    /* push our SSA destination on the stack */
    state->states[index].index++;
@@ -274,6 +275,7 @@ rewrite_alu_instr_forward(nir_alu_instr *instr, rewrite_state *state)
       list_del(&instr->dest.dest.reg.def_link);
       nir_ssa_dest_init(&instr->instr, &instr->dest.dest, num_components,
                         reg->bit_size, name);
+      ralloc_free(name);
 
       if (nir_op_infos[instr->op].output_size == 0) {
          /*