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re PR middle-end/17544 (incorrect -Wunreachable-code warning for mains with a return statement)
* emit-rtl.c (add_insn_before): Fix comment typo. PR middle-end/17544 * c-decl.c (finish_function): If compiling C99, annotate the compiler generated return with the current file name and line 0. * tree-cfg.c (remove_useless_stmts_warn_notreached): Only warn if the source line is greater than 0. (remove_bb): Likewise. cp/ PR middle-end/17544 * decl.c (finish_function): Fix comment. Annotate the compiler generated return with the current file name and line 0. testsuite/ * gcc.dg/20041231-1.C: New test. * g++.dg/warn/Wunreachable-code-1.C: New test. From-SVN: r92784
This commit is contained in:
Steven Bosscher
Steven Bosscher
parent
8e1d2e8278
commit
43e05e45bc
@ -1,3 +1,12 @@
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2005-01-01 Steven Bosscher <stevenb@suse.de>
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PR middle-end/17544
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* c-decl.c (finish_function): If compiling C99, annotate the
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compiler generated return with the current file name and line 0.
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* tree-cfg.c (remove_useless_stmts_warn_notreached): Only warn if
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the source line is greater than 0.
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(remove_bb): Likewise.
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2004-12-31 Richard Henderson <rth@redhat.com>
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PR tree-opt/19042
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11
gcc/c-decl.c
11
gcc/c-decl.c
@ -1,6 +1,6 @@
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/* Process declarations and variables for C compiler.
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Copyright (C) 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
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2001, 2002, 2003, 2004 Free Software Foundation, Inc.
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2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
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This file is part of GCC.
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@ -29,6 +29,7 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
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#include "config.h"
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#include "system.h"
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#include "coretypes.h"
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#include "input.h"
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#include "tm.h"
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#include "intl.h"
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#include "tree.h"
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@ -6287,7 +6288,13 @@ finish_function (void)
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else
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{
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if (flag_isoc99)
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c_finish_return (integer_zero_node);
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{
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tree stmt = c_finish_return (integer_zero_node);
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/* Hack. We don't want the middle-end to warn that this
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return is unreachable, so put the statement on the
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special line 0. */
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annotate_with_file_line (stmt, input_filename, 0);
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}
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}
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}
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@ -1,3 +1,9 @@
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2005-01-01 Steven Bosscher <stevenb@suse.de>
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PR middle-end/17544
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* decl.c (finish_function): Fix comment. Annotate the compiler
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generated return with the current file name and line 0.
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2004-12-31 Richard Henderson <rth@redhat.com>
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PR middle-end/17799
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@ -1,6 +1,6 @@
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/* Process declarations and variables for C++ compiler.
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Copyright (C) 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
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2001, 2002, 2003, 2004 Free Software Foundation, Inc.
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2001, 2002, 2003, 2004,2005 Free Software Foundation, Inc.
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Contributed by Michael Tiemann (tiemann@cygnus.com)
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This file is part of GCC.
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@ -10635,12 +10635,19 @@ finish_function (int flags)
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{
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if (DECL_MAIN_P (current_function_decl))
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{
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/* Make it so that `main' always returns 0 by default. */
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tree stmt;
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/* Make it so that `main' always returns 0 by default (or
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1 for VMS). */
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#if VMS_TARGET
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finish_return_stmt (integer_one_node);
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stmt = finish_return_stmt (integer_one_node);
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#else
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finish_return_stmt (integer_zero_node);
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stmt = finish_return_stmt (integer_zero_node);
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#endif
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/* Hack. We don't want the middle-end to warn that this
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return is unreachable, so put the statement on the
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special line 0. */
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annotate_with_file_line (stmt, input_filename, 0);
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}
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/* Finish dealing with exception specifiers. */
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@ -1,6 +1,6 @@
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/* Emit RTL for the GCC expander.
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Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
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1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
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1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
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This file is part of GCC.
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@ -3473,7 +3473,7 @@ add_insn_before (rtx insn, rtx before)
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if (INSN_P (insn))
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bb->flags |= BB_DIRTY;
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/* Should not happen as first in the BB is always either NOTE or
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LABEl. */
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LABEL. */
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gcc_assert (BB_HEAD (bb) != insn
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/* Avoid clobbering of structure when creating new BB. */
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|| BARRIER_P (insn)
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@ -1,3 +1,8 @@
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2005-01-01 Steven Bosscher <stevenb@suse.de>
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* gcc.dg/20041231-1.C: New test.
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* g++.dg/warn/Wunreachable-code-1.C: New test.
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2004-12-30 David Edelsohn <edelsohn@gnu.org>
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* gfortran.fortran-torture/execute/read_eof.f90: Open scratch
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22
gcc/testsuite/g++.dg/warn/Wunreachable-code-1.C
Normal file
22
gcc/testsuite/g++.dg/warn/Wunreachable-code-1.C
Normal file
@ -0,0 +1,22 @@
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/* PR17544 Incorrect -Wunreachable-code warning
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Origin: sebor@roguewave.com
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G++ appends a "return 0;" when finishing a function, but it was not
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given a source location. The gimplifier thinks a return statement
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needs a locus so it would add one, making the compiler generated code
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visible to the unreachable code warning. */
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/* { dg-do compile } */
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/* { dg-options "-O -Wunreachable-code" } */
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int
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main (int argc, char *argv[])
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{
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const char* const s = argc < 2 ? "" : argv [1];
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int i = 0;
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do {
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++i;
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} while (i < s [0]);
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return i;
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}
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15
gcc/testsuite/gcc.dg/20041231-1.c
Normal file
15
gcc/testsuite/gcc.dg/20041231-1.c
Normal file
@ -0,0 +1,15 @@
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/* PR17544 Incorrect -Wunreachable-code warning
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Origin: Giovanni Bajo
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In C99 we append a "return 0;" when finishing a function, but it was
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not given a source location. The gimplifier thinks a return statement
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needs a locus so it would add one, making the compiler generated code
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visible to the unreachable code warning. */
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/* { dg-do compile } */
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/* { dg-options "-std=c99 -O -Wunreachable-code" } */
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int main (void) // 1
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{ // 2
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return 0; // 3
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} // 4
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@ -1,5 +1,5 @@
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/* Control flow functions for trees.
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Copyright (C) 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
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Copyright (C) 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
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Contributed by Diego Novillo <dnovillo@redhat.com>
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This file is part of GCC.
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@ -1323,8 +1323,11 @@ remove_useless_stmts_warn_notreached (tree stmt)
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if (EXPR_HAS_LOCATION (stmt))
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{
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location_t loc = EXPR_LOCATION (stmt);
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warning ("%Hwill never be executed", &loc);
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return true;
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if (LOCATION_LINE (loc) > 0)
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{
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warning ("%Hwill never be executed", &loc);
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return true;
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}
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}
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switch (TREE_CODE (stmt))
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@ -2021,11 +2024,17 @@ remove_bb (basic_block bb)
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since this way we lose warnings for gotos in the original
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program that are indeed unreachable. */
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if (TREE_CODE (stmt) != GOTO_EXPR && EXPR_HAS_LOCATION (stmt) && !loc)
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{
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source_locus t;
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#ifdef USE_MAPPED_LOCATION
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loc = EXPR_LOCATION (stmt);
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t = EXPR_LOCATION (stmt);
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#else
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loc = EXPR_LOCUS (stmt);
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t = EXPR_LOCUS (stmt);
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#endif
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if (t && LOCATION_LINE (*t) > 0)
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loc = t;
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}
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}
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/* If requested, give a warning that the first statement in the
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