[RFC PATCH 15/78] accel/tcg: add fallthrough pseudo-keyword

[Emmanouil Pitsidianakis]

In preparation of raising -Wimplicit-fallthrough to 5, replace all
fall-through comments with the fallthrough attribute pseudo-keyword.

Signed-off-by: Emmanouil Pitsidianakis <manos.pitsidianakis@linaro.org>
---
 accel/tcg/cputlb.c             | 4 ++--
 accel/tcg/ldst_atomicity.c.inc | 2 +-
 accel/tcg/plugin-gen.c         | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/accel/tcg/cputlb.c b/accel/tcg/cputlb.c
index b8c5e345b8..92b7ab529a 100644
--- a/accel/tcg/cputlb.c
+++ b/accel/tcg/cputlb.c
@@ -2209,53 +2209,53 @@ static Int128 do_ld_whole_be16(CPUState *cpu, uintptr_t 
ra,
 /*
  * Wrapper for the above.
  */
 static uint64_t do_ld_beN(CPUState *cpu, MMULookupPageData *p,
                           uint64_t ret_be, int mmu_idx, MMUAccessType type,
                           MemOp mop, uintptr_t ra)
 {
     MemOp atom;
     unsigned tmp, half_size;
 
     if (unlikely(p->flags & TLB_MMIO)) {
         return do_ld_mmio_beN(cpu, p->full, ret_be, p->addr, p->size,
                               mmu_idx, type, ra);
     }
 
     /*
      * It is a given that we cross a page and therefore there is no
      * atomicity for the load as a whole, but subobjects may need attention.
      */
     atom = mop & MO_ATOM_MASK;
     switch (atom) {
     case MO_ATOM_SUBALIGN:
         return do_ld_parts_beN(p, ret_be);
 
     case MO_ATOM_IFALIGN_PAIR:
     case MO_ATOM_WITHIN16_PAIR:
         tmp = mop & MO_SIZE;
         tmp = tmp ? tmp - 1 : 0;
         half_size = 1 << tmp;
         if (atom == MO_ATOM_IFALIGN_PAIR
             ? p->size == half_size
             : p->size >= half_size) {
             if (!HAVE_al8_fast && p->size < 4) {
                 return do_ld_whole_be4(p, ret_be);
             } else {
                 return do_ld_whole_be8(cpu, ra, p, ret_be);
             }
         }
-        /* fall through */
+        fallthrough;
 
     case MO_ATOM_IFALIGN:
     case MO_ATOM_WITHIN16:
     case MO_ATOM_NONE:
         return do_ld_bytes_beN(p, ret_be);
 
     default:
         g_assert_not_reached();
     }
 }
 
 /*
  * Wrapper for the above, for 8 < size < 16.
  */
@@ -2625,57 +2625,57 @@ static uint64_t do_st16_mmio_leN(CPUState *cpu, 
CPUTLBEntryFull *full,
 /*
  * Wrapper for the above.
  */
 static uint64_t do_st_leN(CPUState *cpu, MMULookupPageData *p,
                           uint64_t val_le, int mmu_idx,
                           MemOp mop, uintptr_t ra)
 {
     MemOp atom;
     unsigned tmp, half_size;
 
     if (unlikely(p->flags & TLB_MMIO)) {
         return do_st_mmio_leN(cpu, p->full, val_le, p->addr,
                               p->size, mmu_idx, ra);
     } else if (unlikely(p->flags & TLB_DISCARD_WRITE)) {
         return val_le >> (p->size * 8);
     }
 
     /*
      * It is a given that we cross a page and therefore there is no atomicity
      * for the store as a whole, but subobjects may need attention.
      */
     atom = mop & MO_ATOM_MASK;
     switch (atom) {
     case MO_ATOM_SUBALIGN:
         return store_parts_leN(p->haddr, p->size, val_le);
 
     case MO_ATOM_IFALIGN_PAIR:
     case MO_ATOM_WITHIN16_PAIR:
         tmp = mop & MO_SIZE;
         tmp = tmp ? tmp - 1 : 0;
         half_size = 1 << tmp;
         if (atom == MO_ATOM_IFALIGN_PAIR
             ? p->size == half_size
             : p->size >= half_size) {
             if (!HAVE_al8_fast && p->size <= 4) {
                 return store_whole_le4(p->haddr, p->size, val_le);
             } else if (HAVE_al8) {
                 return store_whole_le8(p->haddr, p->size, val_le);
             } else {
                 cpu_loop_exit_atomic(cpu, ra);
             }
         }
-        /* fall through */
+        fallthrough;
 
     case MO_ATOM_IFALIGN:
     case MO_ATOM_WITHIN16:
     case MO_ATOM_NONE:
         return store_bytes_leN(p->haddr, p->size, val_le);
 
     default:
         g_assert_not_reached();
     }
 }
 
 /*
  * Wrapper for the above, for 8 < size < 16.
  */
diff --git a/accel/tcg/ldst_atomicity.c.inc b/accel/tcg/ldst_atomicity.c.inc
index 1cf5b92166..3752f74214 100644
--- a/accel/tcg/ldst_atomicity.c.inc
+++ b/accel/tcg/ldst_atomicity.c.inc
@@ -22,86 +22,86 @@
 /**
  * required_atomicity:
  *
  * Return the lg2 bytes of atomicity required by @memop for @p.
  * If the operation must be split into two operations to be
  * examined separately for atomicity, return -lg2.
  */
 static int required_atomicity(CPUState *cpu, uintptr_t p, MemOp memop)
 {
     MemOp atom = memop & MO_ATOM_MASK;
     MemOp size = memop & MO_SIZE;
     MemOp half = size ? size - 1 : 0;
     unsigned tmp;
     int atmax;
 
     switch (atom) {
     case MO_ATOM_NONE:
         atmax = MO_8;
         break;
 
     case MO_ATOM_IFALIGN_PAIR:
         size = half;
-        /* fall through */
+        fallthrough;
 
     case MO_ATOM_IFALIGN:
         tmp = (1 << size) - 1;
         atmax = p & tmp ? MO_8 : size;
         break;
 
     case MO_ATOM_WITHIN16:
         tmp = p & 15;
         atmax = (tmp + (1 << size) <= 16 ? size : MO_8);
         break;
 
     case MO_ATOM_WITHIN16_PAIR:
         tmp = p & 15;
         if (tmp + (1 << size) <= 16) {
             atmax = size;
         } else if (tmp + (1 << half) == 16) {
             /*
              * The pair exactly straddles the boundary.
              * Both halves are naturally aligned and atomic.
              */
             atmax = half;
         } else {
             /*
              * One of the pair crosses the boundary, and is non-atomic.
              * The other of the pair does not cross, and is atomic.
              */
             atmax = -half;
         }
         break;
 
     case MO_ATOM_SUBALIGN:
         /*
          * Examine the alignment of p to determine if there are subobjects
          * that must be aligned.  Note that we only really need ctz4() --
          * any more sigificant bits are discarded by the immediately
          * following comparison.
          */
         tmp = ctz32(p);
         atmax = MIN(size, tmp);
         break;
 
     default:
         g_assert_not_reached();
     }
 
     /*
      * Here we have the architectural atomicity of the operation.
      * However, when executing in a serial context, we need no extra
      * host atomicity in order to avoid racing.  This reduction
      * avoids looping with cpu_loop_exit_atomic.
      */
     if (cpu_in_serial_context(cpu)) {
         return MO_8;
     }
     return atmax;
 }
 
 /**
  * load_atomic2:
  * @pv: host address
  *
  * Atomically load 2 aligned bytes from @pv.
  */
diff --git a/accel/tcg/plugin-gen.c b/accel/tcg/plugin-gen.c
index d31c9993ea..ba9a8c8789 100644
--- a/accel/tcg/plugin-gen.c
+++ b/accel/tcg/plugin-gen.c
@@ -179,23 +179,23 @@ static void gen_wrapped(enum plugin_gen_from from,
 static void plugin_gen_empty_callback(enum plugin_gen_from from)
 {
     switch (from) {
     case PLUGIN_GEN_AFTER_INSN:
         gen_wrapped(from, PLUGIN_GEN_DISABLE_MEM_HELPER,
                     gen_empty_mem_helper);
         break;
     case PLUGIN_GEN_FROM_INSN:
         /*
          * Note: plugin_gen_inject() relies on ENABLE_MEM_HELPER being
          * the first callback of an instruction
          */
         gen_wrapped(from, PLUGIN_GEN_ENABLE_MEM_HELPER,
                     gen_empty_mem_helper);
-        /* fall through */
+        fallthrough;
     case PLUGIN_GEN_FROM_TB:
         gen_wrapped(from, PLUGIN_GEN_CB_UDATA, gen_empty_udata_cb);
         gen_wrapped(from, PLUGIN_GEN_CB_INLINE, gen_empty_inline_cb);
         break;
     default:
         g_assert_not_reached();
     }
 }
-- 
2.39.2