From d0ea9877b830ab2fe8948e70846efb5fff78cf0c Mon Sep 17 00:00:00 2001
From: Connor Abbott <cwabbott0@gmail.com>
Date: Thu, 2 May 2019 22:22:01 +0200
Subject: [PATCH] nir/algebraic: Don't emit empty initializers for MSVC

Just don't emit the transform array at all if there are no transforms

v2:
- Don't use len(array) > 0 (Dylan)
- Keep using ARRAY_SIZE to make the generated C code easier to read
(Jason).
---
 src/compiler/nir/nir_algebraic.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/compiler/nir/nir_algebraic.py b/src/compiler/nir/nir_algebraic.py
index 6db749e9248..47f374bfabd 100644
--- a/src/compiler/nir/nir_algebraic.py
+++ b/src/compiler/nir/nir_algebraic.py
@@ -993,11 +993,13 @@ static const uint16_t CONST_STATE = 1;
 % endfor
 
 % for state_id, state_xforms in enumerate(automaton.state_patterns):
+% if state_xforms: # avoid emitting a 0-length array for MSVC
 static const struct transform ${pass_name}_state${state_id}_xforms[] = {
 % for i in state_xforms:
   { ${xforms[i].search.c_ptr(cache)}, ${xforms[i].replace.c_value_ptr(cache)}, ${xforms[i].condition_index} },
 % endfor
 };
+% endif
 % endfor
 
 static const struct per_op_table ${pass_name}_table[nir_num_search_ops] = {
@@ -1080,6 +1082,7 @@ ${pass_name}_block(nir_builder *build, nir_block *block,
       switch (states[alu->dest.dest.ssa.index]) {
 % for i in range(len(automaton.state_patterns)):
       case ${i}:
+         % if automaton.state_patterns[i]:
          for (unsigned i = 0; i < ARRAY_SIZE(${pass_name}_state${i}_xforms); i++) {
             const struct transform *xform = &${pass_name}_state${i}_xforms[i];
             if (condition_flags[xform->condition_offset] &&
@@ -1088,6 +1091,7 @@ ${pass_name}_block(nir_builder *build, nir_block *block,
                break;
             }
          }
+         % endif
          break;
 % endfor
       default: assert(0);
-- 
2.30.2