diff mbox series

Remove unreachable returns

Message ID 80qqs862-prn1-369p-94n4-qq8qoq34os1@fhfr.qr
State Committed
Commit 16507dea753527d073f1cfb7200c6612a7fa44aa
Headers show
Series Remove unreachable returns | expand

Commit Message

Richard Biener Nov. 25, 2021, 2:16 p.m. UTC
This removes unreachable return statements as diagnosed by
the -Wunreachable-code patch.  Some cases are more obviously
an improvement than others - in fact some may get you the idea
to replace them with gcc_unreachable () instead, leading to
cases of the 'Remove unreachable gcc_unreachable () at the end
of functions' patch.

Bootstrapped and tested on x86_64-unknown-linux-gnu.

OK?  Comments?  Feel free to approve select cases only.

Thanks,
Richard.

2021-11-25  Richard Biener  <rguenther@suse.de>

	* vec.c (qsort_chk): Do not return the void return value
	from the noreturn qsort_chk_error.
	* ccmp.c (expand_ccmp_expr_1): Remove unreachable return.
	* df-scan.c (df_ref_equal_p): Likewise.
	* dwarf2out.c (is_base_type): Likewise.
	(add_const_value_attribute): Likewise.
	* fixed-value.c (fixed_arithmetic): Likewise.
	* gimple-fold.c (gimple_fold_builtin_fputs): Likewise.
	* gimple-ssa-strength-reduction.c (stmt_cost): Likewise.
	* graphite-isl-ast-to-gimple.c
	(gcc_expression_from_isl_expr_op): Likewise.
	(gcc_expression_from_isl_expression): Likewise.
	* ipa-fnsummary.c (will_be_nonconstant_expr_predicate):
	Likewise.
	* lto-streamer-in.c (lto_input_mode_table): Likewise.

gcc/c-family/
	* c-opts.c (c_common_post_options): Remove unreachable return.
	* c-pragma.c (handle_pragma_target): Likewise.
	(handle_pragma_optimize): Likewise.

gcc/c/
	* c-typeck.c (c_tree_equal): Remove unreachable return.
	* c-parser.c (get_matching_symbol): Likewise.

libgomp/
	* oacc-plugin.c (GOMP_PLUGIN_acc_default_dim): Remove unreachable
	return.
---
 gcc/c-family/c-opts.c               |  5 +----
 gcc/c-family/c-pragma.c             | 10 ++--------
 gcc/c/c-parser.c                    |  1 -
 gcc/c/c-typeck.c                    |  2 --
 gcc/ccmp.c                          |  2 --
 gcc/df-scan.c                       |  1 -
 gcc/dwarf2out.c                     |  3 ---
 gcc/fixed-value.c                   |  1 -
 gcc/gimple-fold.c                   |  1 -
 gcc/gimple-ssa-strength-reduction.c |  1 -
 gcc/graphite-isl-ast-to-gimple.c    |  4 ----
 gcc/ipa-fnsummary.c                 |  1 -
 gcc/lto-streamer-in.c               |  7 ++-----
 gcc/vec.c                           | 10 +++++-----
 libgomp/oacc-plugin.c               |  1 -
 15 files changed, 10 insertions(+), 40 deletions(-)

Comments

Jeff Law Nov. 28, 2021, 7:19 p.m. UTC | #1
On 11/25/2021 7:16 AM, Richard Biener via Gcc-patches wrote:
> This removes unreachable return statements as diagnosed by
> the -Wunreachable-code patch.  Some cases are more obviously
> an improvement than others - in fact some may get you the idea
> to replace them with gcc_unreachable () instead, leading to
> cases of the 'Remove unreachable gcc_unreachable () at the end
> of functions' patch.
>
> Bootstrapped and tested on x86_64-unknown-linux-gnu.
>
> OK?  Comments?  Feel free to approve select cases only.
>
> Thanks,
> Richard.
>
> 2021-11-25  Richard Biener  <rguenther@suse.de>
>
> 	* vec.c (qsort_chk): Do not return the void return value
> 	from the noreturn qsort_chk_error.
> 	* ccmp.c (expand_ccmp_expr_1): Remove unreachable return.
> 	* df-scan.c (df_ref_equal_p): Likewise.
> 	* dwarf2out.c (is_base_type): Likewise.
> 	(add_const_value_attribute): Likewise.
> 	* fixed-value.c (fixed_arithmetic): Likewise.
> 	* gimple-fold.c (gimple_fold_builtin_fputs): Likewise.
> 	* gimple-ssa-strength-reduction.c (stmt_cost): Likewise.
> 	* graphite-isl-ast-to-gimple.c
> 	(gcc_expression_from_isl_expr_op): Likewise.
> 	(gcc_expression_from_isl_expression): Likewise.
> 	* ipa-fnsummary.c (will_be_nonconstant_expr_predicate):
> 	Likewise.
> 	* lto-streamer-in.c (lto_input_mode_table): Likewise.
>
> gcc/c-family/
> 	* c-opts.c (c_common_post_options): Remove unreachable return.
> 	* c-pragma.c (handle_pragma_target): Likewise.
> 	(handle_pragma_optimize): Likewise.
>
> gcc/c/
> 	* c-typeck.c (c_tree_equal): Remove unreachable return.
> 	* c-parser.c (get_matching_symbol): Likewise.
>
> libgomp/
> 	* oacc-plugin.c (GOMP_PLUGIN_acc_default_dim): Remove unreachable
> 	return.
I'd commit the whole set.

jeff
Richard Biener Nov. 29, 2021, 10:19 a.m. UTC | #2
On Sun, 28 Nov 2021, Jeff Law wrote:

> 
> 
> On 11/25/2021 7:16 AM, Richard Biener via Gcc-patches wrote:
> > This removes unreachable return statements as diagnosed by
> > the -Wunreachable-code patch.  Some cases are more obviously
> > an improvement than others - in fact some may get you the idea
> > to replace them with gcc_unreachable () instead, leading to
> > cases of the 'Remove unreachable gcc_unreachable () at the end
> > of functions' patch.
> >
> > Bootstrapped and tested on x86_64-unknown-linux-gnu.
> >
> > OK?  Comments?  Feel free to approve select cases only.
> >
> > Thanks,
> > Richard.
> >
> > 2021-11-25  Richard Biener  <rguenther@suse.de>
> >
> >  * vec.c (qsort_chk): Do not return the void return value
> >  from the noreturn qsort_chk_error.
> >  * ccmp.c (expand_ccmp_expr_1): Remove unreachable return.
> >  * df-scan.c (df_ref_equal_p): Likewise.
> >  * dwarf2out.c (is_base_type): Likewise.
> >  (add_const_value_attribute): Likewise.
> >  * fixed-value.c (fixed_arithmetic): Likewise.
> >  * gimple-fold.c (gimple_fold_builtin_fputs): Likewise.
> >  * gimple-ssa-strength-reduction.c (stmt_cost): Likewise.
> >  * graphite-isl-ast-to-gimple.c
> >  (gcc_expression_from_isl_expr_op): Likewise.
> >  (gcc_expression_from_isl_expression): Likewise.
> >  * ipa-fnsummary.c (will_be_nonconstant_expr_predicate):
> >  Likewise.
> >  * lto-streamer-in.c (lto_input_mode_table): Likewise.
> >
> > gcc/c-family/
> >  * c-opts.c (c_common_post_options): Remove unreachable return.
> >  * c-pragma.c (handle_pragma_target): Likewise.
> >  (handle_pragma_optimize): Likewise.
> >
> > gcc/c/
> >  * c-typeck.c (c_tree_equal): Remove unreachable return.
> >  * c-parser.c (get_matching_symbol): Likewise.
> >
> > libgomp/
> >  * oacc-plugin.c (GOMP_PLUGIN_acc_default_dim): Remove unreachable
> >  return.
> I'd commit the whole set.

I have pushed it.

Richard.
diff mbox series

Patch

diff --git a/gcc/c-family/c-opts.c b/gcc/c-family/c-opts.c
index 2030eb1a4cd..93845d57dee 100644
--- a/gcc/c-family/c-opts.c
+++ b/gcc/c-family/c-opts.c
@@ -1109,10 +1109,7 @@  c_common_post_options (const char **pfilename)
 	out_stream = fopen (out_fname, "w");
 
       if (out_stream == NULL)
-	{
-	  fatal_error (input_location, "opening output file %s: %m", out_fname);
-	  return false;
-	}
+	fatal_error (input_location, "opening output file %s: %m", out_fname);
 
       init_pp_output (out_stream);
     }
diff --git a/gcc/c-family/c-pragma.c b/gcc/c-family/c-pragma.c
index 3663eb1cfbb..c4ed4205820 100644
--- a/gcc/c-family/c-pragma.c
+++ b/gcc/c-family/c-pragma.c
@@ -916,10 +916,7 @@  handle_pragma_target(cpp_reader *ARG_UNUSED(dummy))
     }
 
   if (token != CPP_STRING)
-    {
-      GCC_BAD_AT (loc, "%<#pragma GCC option%> is not a string");
-      return;
-    }
+    GCC_BAD_AT (loc, "%<#pragma GCC option%> is not a string");
 
   /* Strings are user options.  */
   else
@@ -991,10 +988,7 @@  handle_pragma_optimize (cpp_reader *ARG_UNUSED(dummy))
     }
 
   if (token != CPP_STRING && token != CPP_NUMBER)
-    {
-      GCC_BAD ("%<#pragma GCC optimize%> is not a string or number");
-      return;
-    }
+    GCC_BAD ("%<#pragma GCC optimize%> is not a string or number");
 
   /* Strings/numbers are user options.  */
   else
diff --git a/gcc/c/c-parser.c b/gcc/c/c-parser.c
index f312630448f..af2bb5bc8cc 100644
--- a/gcc/c/c-parser.c
+++ b/gcc/c/c-parser.c
@@ -1132,7 +1132,6 @@  get_matching_symbol (enum cpp_ttype type)
     {
     default:
       gcc_unreachable ();
-      return "";
     case CPP_CLOSE_PAREN:
       return "(";
     case CPP_CLOSE_BRACE:
diff --git a/gcc/c/c-typeck.c b/gcc/c/c-typeck.c
index b71358e1821..7524304f2bd 100644
--- a/gcc/c/c-typeck.c
+++ b/gcc/c/c-typeck.c
@@ -15984,8 +15984,6 @@  c_tree_equal (tree t1, tree t2)
     default:
       gcc_unreachable ();
     }
-  /* We can get here with --disable-checking.  */
-  return false;
 }
 
 /* Returns true when the function declaration FNDECL is implicit,
diff --git a/gcc/ccmp.c b/gcc/ccmp.c
index d581cfadf06..616fe035e79 100644
--- a/gcc/ccmp.c
+++ b/gcc/ccmp.c
@@ -273,8 +273,6 @@  expand_ccmp_expr_1 (gimple *g, rtx_insn **prep_seq, rtx_insn **gen_seq)
 	return NULL_RTX;
       return expand_ccmp_next (op1, code, tmp, prep_seq, gen_seq);
     }
-
-  return NULL_RTX;
 }
 
 /* Main entry to expand conditional compare statement G.
diff --git a/gcc/df-scan.c b/gcc/df-scan.c
index 3dbda7aa52c..1baa6e7350b 100644
--- a/gcc/df-scan.c
+++ b/gcc/df-scan.c
@@ -2059,7 +2059,6 @@  df_ref_equal_p (df_ref ref1, df_ref ref2)
     default:
       gcc_unreachable ();
     }
-  return false;
 }
 
 
diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
index e1d6a79ecd7..1677923a439 100644
--- a/gcc/dwarf2out.c
+++ b/gcc/dwarf2out.c
@@ -13359,8 +13359,6 @@  is_base_type (tree type)
 	return 0;
       gcc_unreachable ();
     }
-
-  return 0;
 }
 
 /* Given a pointer to a tree node, assumed to be some kind of a ..._TYPE
@@ -20240,7 +20238,6 @@  add_const_value_attribute (dw_die_ref die, machine_mode mode, rtx rtl)
       /* No other kinds of rtx should be possible here.  */
       gcc_unreachable ();
     }
-  return false;
 }
 
 /* Determine whether the evaluation of EXPR references any variables
diff --git a/gcc/fixed-value.c b/gcc/fixed-value.c
index 78134bc510f..fdfb700ae66 100644
--- a/gcc/fixed-value.c
+++ b/gcc/fixed-value.c
@@ -756,7 +756,6 @@  fixed_arithmetic (FIXED_VALUE_TYPE *f, int icode, const FIXED_VALUE_TYPE *op0,
     default:
       gcc_unreachable ();
     }
-  return false;
 }
 
 /* Compare fixed-point values by tree_code.
diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c
index 73f090bb14c..1f54219fe43 100644
--- a/gcc/gimple-fold.c
+++ b/gcc/gimple-fold.c
@@ -2993,7 +2993,6 @@  gimple_fold_builtin_fputs (gimple_stmt_iterator *gsi,
     default:
       gcc_unreachable ();
     }
-  return false;
 }
 
 /* Fold a call to the __mem{cpy,pcpy,move,set}_chk builtin.
diff --git a/gcc/gimple-ssa-strength-reduction.c b/gcc/gimple-ssa-strength-reduction.c
index a92cf03c1f3..8943c57b7a9 100644
--- a/gcc/gimple-ssa-strength-reduction.c
+++ b/gcc/gimple-ssa-strength-reduction.c
@@ -763,7 +763,6 @@  stmt_cost (gimple *gs, bool speed)
     }
   
   gcc_unreachable ();
-  return 0;
 }
 
 /* Look up the defining statement for BASE_IN and return a pointer
diff --git a/gcc/graphite-isl-ast-to-gimple.c b/gcc/graphite-isl-ast-to-gimple.c
index 1ad68a1d473..8c5cd33f451 100644
--- a/gcc/graphite-isl-ast-to-gimple.c
+++ b/gcc/graphite-isl-ast-to-gimple.c
@@ -526,8 +526,6 @@  gcc_expression_from_isl_expr_op (tree type, __isl_take isl_ast_expr *expr,
     default:
       gcc_unreachable ();
     }
-
-  return NULL_TREE;
 }
 
 /* Converts an isl AST expression E back to a GCC expression tree of
@@ -557,8 +555,6 @@  gcc_expression_from_isl_expression (tree type, __isl_take isl_ast_expr *expr,
     default:
       gcc_unreachable ();
     }
-
-  return NULL_TREE;
 }
 
 /* Creates a new LOOP corresponding to isl_ast_node_for.  Inserts an
diff --git a/gcc/ipa-fnsummary.c b/gcc/ipa-fnsummary.c
index cb13d2e4b3c..6c1cdf17e47 100644
--- a/gcc/ipa-fnsummary.c
+++ b/gcc/ipa-fnsummary.c
@@ -2042,7 +2042,6 @@  will_be_nonconstant_expr_predicate (ipa_func_body_info *fbi,
       debug_tree (expr);
       gcc_unreachable ();
     }
-  return false;
 }
 
 
diff --git a/gcc/lto-streamer-in.c b/gcc/lto-streamer-in.c
index eb8a7dc57b0..536de3a71b7 100644
--- a/gcc/lto-streamer-in.c
+++ b/gcc/lto-streamer-in.c
@@ -1963,11 +1963,8 @@  lto_input_mode_table (struct lto_file_decl_data *file_data)
   const char *data
     = lto_get_summary_section_data (file_data, LTO_section_mode_table, &len);
   if (! data)
-    {
-      internal_error ("cannot read LTO mode table from %s",
-		      file_data->file_name);
-      return;
-    }
+    internal_error ("cannot read LTO mode table from %s",
+		    file_data->file_name);
 
   unsigned char *table = ggc_cleared_vec_alloc<unsigned char> (1 << 8);
   file_data->mode_table = table;
diff --git a/gcc/vec.c b/gcc/vec.c
index 6d767cc12c1..bdbd1ad6e04 100644
--- a/gcc/vec.c
+++ b/gcc/vec.c
@@ -229,23 +229,23 @@  qsort_chk (void *base, size_t n, size_t size, sort_r_cmp_fn *cmp, void *data)
 	if (CMP (i1, i2))
 	  break;
 	else if (CMP (i2, i1))
-	  return ERR2 (i1, i2);
+	  ERR2 (i1, i2);
       size_t lim1 = LIM (i2 - i1), lim2 = LIM (n - i2);
       /* Verify that other pairs within current span compare equal.  */
       for (i = i1 + 1; i + 1 < i2; i++)
 	for (j = i + 1; j < i1 + lim1; j++)
 	  if (CMP (i, j))
-	    return ERR3 (i, i1, j);
+	    ERR3 (i, i1, j);
 	  else if (CMP (j, i))
-	    return ERR2 (i, j);
+	    ERR2 (i, j);
       /* Verify that elements within this span compare less than
          elements beyond the span.  */
       for (i = i1; i < i2; i++)
 	for (j = i2; j < i2 + lim2; j++)
 	  if (CMP (i, j) >= 0)
-	    return ERR3 (i, i1, j);
+	    ERR3 (i, i1, j);
 	  else if (CMP (j, i) <= 0)
-	    return ERR2 (i, j);
+	    ERR2 (i, j);
     }
 #undef ERR3
 #undef ERR2
diff --git a/libgomp/oacc-plugin.c b/libgomp/oacc-plugin.c
index e25b462eff0..98166fe5cd1 100644
--- a/libgomp/oacc-plugin.c
+++ b/libgomp/oacc-plugin.c
@@ -62,7 +62,6 @@  GOMP_PLUGIN_acc_default_dim (unsigned int i)
   if (i >= GOMP_DIM_MAX)
     {
       gomp_fatal ("invalid dimension argument: %d", i);
-      return -1;
     }
   return goacc_default_dims[i];
 }