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Implement -Wimplicit-fallthrough (take 2): questionable code
- From: Marek Polacek <polacek at redhat dot com>
- To: GCC Patches <gcc-patches at gcc dot gnu dot org>
- Date: Wed, 27 Jul 2016 18:53:39 +0200
- Subject: Implement -Wimplicit-fallthrough (take 2): questionable code
- Authentication-results: sourceware.org; auth=none
These are the cases where I wasn't sure if the falls through were intentional
or not.
This patch has been tested on powerpc64le-unknown-linux-gnu, aarch64-linux-gnu,
and x86_64-redhat-linux.
2016-07-27 Marek Polacek <polacek@redhat.com>
PR c/7652
gcc/
* config/i386/i386.c (ix86_expand_branch): Add gcc_fallthrough..
* cselib.c (cselib_expand_value_rtx_1): Likewise.
* gensupport.c (get_alternatives_number): Likewise.
(subst_dup): Likewise.
* gimplify.c (goa_stabilize_expr): Likewise.
* hsa-gen.c (gen_hsa_insn_for_internal_fn_call): Likewise.
* reg-stack.c (get_true_reg): Likewise.
* tree-complex.c (expand_complex_division): Likewise.
* tree-data-ref.c (get_references_in_stmt): Likewise.
* tree-pretty-print.c (dump_generic_node): Likewise.
* var-tracking.c (adjust_mems): Likewise.
gcc/cp/
* call.c (add_builtin_candidate): Add gcc_fallthrough.
* cxx-pretty-print.c (pp_cxx_unqualified_id): Likewise.
* parser.c (cp_parser_skip_to_end_of_statement): Likewise.
(cp_parser_cache_defarg): Likewise.
gcc/c-family/
* c-ada-spec.c (dump_generic_ada_node): Add gcc_fallthrough.
libcpp/
* pch.c (write_macdef): Add CPP_FALLTHRU.
* lex.c (_cpp_lex_direct): Likewise.
diff --git gcc/gcc/c-family/c-ada-spec.c gcc/gcc/c-family/c-ada-spec.c
index e33fdff..659ffa0 100644
--- gcc/gcc/c-family/c-ada-spec.c
+++ gcc/gcc/c-family/c-ada-spec.c
@@ -1862,6 +1862,8 @@ dump_generic_ada_node (pretty_printer *buffer, tree node, tree type, int spc,
case TREE_BINFO:
dump_generic_ada_node
(buffer, BINFO_TYPE (node), type, spc, limited_access, name_only);
+ /* XXX Really fallthru? */
+ gcc_fallthrough ();
case TREE_VEC:
pp_string (buffer, "--- unexpected node: TREE_VEC");
--- gcc/gcc/config/i386/i386.c
+++ gcc/gcc/config/i386/i386.c
@@ -22484,6 +22495,8 @@ ix86_expand_branch (enum rtx_code code, rtx op0, rtx op1, rtx label)
op0 = force_reg (mode, gen_rtx_XOR (mode, op0, op1));
op1 = const0_rtx;
}
+ /* XXX Really fallthru? */
+ gcc_fallthrough ();
case TImode:
/* Expand DImode branch into multiple compare+branch. */
{
--- gcc/gcc/cp/call.c
+++ gcc/gcc/cp/call.c
@@ -2542,6 +2544,8 @@ add_builtin_candidate (struct z_candidate **candidates, enum tree_code code,
type2 = ptrdiff_type_node;
break;
}
+ /* XXX Really fallthru? */
+ gcc_fallthrough ();
case MULT_EXPR:
case TRUNC_DIV_EXPR:
if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
--- gcc/gcc/cp/cxx-pretty-print.c
+++ gcc/gcc/cp/cxx-pretty-print.c
@@ -142,6 +142,8 @@ pp_cxx_unqualified_id (cxx_pretty_printer *pp, tree t)
case OVERLOAD:
t = OVL_CURRENT (t);
+ /* XXX Really fallthru? */
+ gcc_fallthrough ();
case VAR_DECL:
case PARM_DECL:
case CONST_DECL:
--- gcc/gcc/cp/parser.c
+++ gcc/gcc/cp/parser.c
@@ -3488,6 +3488,8 @@ cp_parser_skip_to_end_of_statement (cp_parser* parser)
cp_lexer_consume_token (parser->lexer);
return;
}
+ /* XXX Really fallthru? */
+ gcc_fallthrough ();
case CPP_OPEN_BRACE:
++nesting_depth;
@@ -27640,6 +27646,8 @@ cp_parser_cache_defarg (cp_parser *parser, bool nsdmi)
parser->in_template_argument_list_p = saved_italp;
break;
}
+ /* XXX Really fallthru? */
+ gcc_fallthrough ();
case CPP_CLOSE_PAREN:
case CPP_ELLIPSIS:
/* If we run into a non-nested `;', `}', or `]',
--- gcc/gcc/cselib.c
+++ gcc/gcc/cselib.c
@@ -1619,6 +1619,8 @@ cselib_expand_value_rtx_1 (rtx orig, struct expand_value_data *evd,
return orig;
}
}
+ /* XXX Really fallthru? */
+ gcc_fallthrough ();
CASE_CONST_ANY:
case SYMBOL_REF:
diff --git gcc/gcc/gensupport.c gcc/gcc/gensupport.c
index 0eb4591..795f88c 100644
--- gcc/gcc/gensupport.c
+++ gcc/gcc/gensupport.c
@@ -1038,6 +1038,8 @@ get_alternatives_number (rtx pattern, int *n_alt, file_location loc)
case 'V':
if (XVEC (pattern, i) == NULL)
break;
+ /* XXX Really fallthru? */
+ gcc_fallthrough ();
case 'E':
for (j = XVECLEN (pattern, i) - 1; j >= 0; --j)
@@ -2156,6 +2158,8 @@ subst_dup (rtx pattern, int n_alt, int n_subst_alt)
case 'V':
if (XVEC (pattern, i) == NULL)
break;
+ /* XXX Really fallthru? */
+ gcc_fallthrough ();
case 'E':
if (code != MATCH_DUP && code != MATCH_OP_DUP)
for (j = XVECLEN (pattern, i) - 1; j >= 0; --j)
--- gcc/gcc/gimplify.c
+++ gcc/gcc/gimplify.c
@@ -10320,6 +10324,8 @@ goa_stabilize_expr (tree *expr_p, gimple_seq *pre_p, tree lhs_addr,
case tcc_comparison:
saw_lhs |= goa_stabilize_expr (&TREE_OPERAND (expr, 1), pre_p, lhs_addr,
lhs_var);
+ /* XXX Really fallthru? */
+ gcc_fallthrough ();
case tcc_unary:
saw_lhs |= goa_stabilize_expr (&TREE_OPERAND (expr, 0), pre_p, lhs_addr,
lhs_var);
@@ -10334,6 +10340,8 @@ goa_stabilize_expr (tree *expr_p, gimple_seq *pre_p, tree lhs_addr,
case TRUTH_XOR_EXPR:
saw_lhs |= goa_stabilize_expr (&TREE_OPERAND (expr, 1), pre_p,
lhs_addr, lhs_var);
+ /* XXX Really fallthru? */
+ gcc_fallthrough ();
case TRUTH_NOT_EXPR:
saw_lhs |= goa_stabilize_expr (&TREE_OPERAND (expr, 0), pre_p,
lhs_addr, lhs_var);
--- gcc/gcc/hsa-gen.c
+++ gcc/gcc/hsa-gen.c
@@ -5039,6 +5039,8 @@ gen_hsa_insn_for_internal_fn_call (gcall *stmt, hsa_bb *hbb)
case IFN_FMIN:
case IFN_FMAX:
gen_hsa_insns_for_call_of_internal_fn (stmt, hbb);
+ /* XXX Really fallthru? */
+ gcc_fallthrough ();
default:
HSA_SORRY_ATV (gimple_location (stmt),
diff --git gcc/gcc/reg-stack.c gcc/gcc/reg-stack.c
index c931349..a4a3ac2 100644
--- gcc/gcc/reg-stack.c
+++ gcc/gcc/reg-stack.c
@@ -423,6 +423,8 @@ get_true_reg (rtx *pat)
GET_MODE (subreg));
return pat;
}
+ /* XXX Really fallthru? */
+ gcc_fallthrough ();
}
case FLOAT:
case FIX:
diff --git gcc/gcc/tree-complex.c gcc/gcc/tree-complex.c
index d7baf22..9cb8986 100644
--- gcc/gcc/tree-complex.c
+++ gcc/gcc/tree-complex.c
@@ -1336,6 +1336,8 @@ expand_complex_division (gimple_stmt_iterator *gsi, tree inner_type,
rr = gimplify_build2 (gsi, code, inner_type, ai, bi);
ri = gimplify_build2 (gsi, code, inner_type, ar, bi);
ri = gimplify_build1 (gsi, NEGATE_EXPR, inner_type, ri);
+ /* XXX Really fallthru? */
+ gcc_fallthrough ();
case PAIR (ONLY_REAL, VARYING):
case PAIR (ONLY_IMAG, VARYING):
--- gcc/gcc/tree-data-ref.c
+++ gcc/gcc/tree-data-ref.c
@@ -3889,7 +3890,9 @@ get_references_in_stmt (gimple *stmt, vec<data_ref_loc, va_heap> *references)
case IFN_MASK_LOAD:
if (gimple_call_lhs (stmt) == NULL_TREE)
break;
+ /* XXX Really fallthru? */
ref.is_read = true;
+ gcc_fallthrough ();
case IFN_MASK_STORE:
ptr = build_int_cst (TREE_TYPE (gimple_call_arg (stmt, 1)), 0);
align = tree_to_shwi (gimple_call_arg (stmt, 1));
--- gcc/gcc/tree-pretty-print.c
+++ gcc/gcc/tree-pretty-print.c
@@ -2946,6 +2947,8 @@ dump_generic_node (pretty_printer *pp, tree node, int spc, int flags,
dump_omp_loop:
dump_omp_clauses (pp, OMP_FOR_CLAUSES (node), spc, flags);
+ /* XXX Really fallthru? */
+ gcc_fallthrough ();
dump_omp_loop_cilk_for:
if (!(flags & TDF_SLIM))
--- gcc/gcc/var-tracking.c
+++ gcc/gcc/var-tracking.c
@@ -1056,6 +1056,8 @@ adjust_mems (rtx loc, const_rtx old_rtx, void *data)
? GET_MODE_SIZE (amd->mem_mode)
: -GET_MODE_SIZE (amd->mem_mode),
GET_MODE (loc)));
+ /* XXX Really fallthru? */
+ gcc_fallthrough ();
case POST_INC:
case POST_DEC:
if (addr == loc)
@@ -1076,6 +1078,8 @@ adjust_mems (rtx loc, const_rtx old_rtx, void *data)
return addr;
case PRE_MODIFY:
addr = XEXP (loc, 1);
+ /* XXX Really fallthru? */
+ gcc_fallthrough ();
case POST_MODIFY:
if (addr == loc)
addr = XEXP (loc, 0);
--- gcc/libcpp/pch.c
+++ gcc/libcpp/pch.c
@@ -55,6 +55,8 @@ write_macdef (cpp_reader *pfile, cpp_hashnode *hn, void *file_p)
case NT_VOID:
if (! (hn->flags & NODE_POISONED))
return 1;
+ /* XXX Really fallthru? */
+ CPP_FALLTHRU;
case NT_MACRO:
if ((hn->flags & NODE_BUILTIN)
--- gcc/libcpp/lex.c
+++ gcc/libcpp/lex.c
@@ -2815,6 +2817,8 @@ _cpp_lex_direct (cpp_reader *pfile)
}
buffer->cur++;
}
+ /* XXX Really fallthru? */
+ CPP_FALLTHRU;
default:
create_literal (pfile, result, buffer->cur - 1, 1, CPP_OTHER);
Marek