jump.c (never_reached_warning): Add finish argument.

	* jump.c (never_reached_warning): Add finish argument.
	If finish is NULL, stop on CODE_LABEL, otherwise stop before first
	real insn after end.
	* rtl.h (never_reached_warning): Adjust prototype.
	* cse.c (cse_insn): Pass NULL as finish to never_reached_warning.
	* cfgrtl.c (flow_delete_block): Pass b->end as finish to
	never_reached_warning.

	* gcc.dg/Wunreachable-1.c: New test.
	* gcc.dg/Wunreachable-2.c: New test.

From-SVN: r49713

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 3b3ea3bfaa1edc082628e75a37b9171b2e37563e..b9940e880467810ba6c3337e10a5c2c7030830cd 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,13 @@
+2002-02-12  Jakub Jelinek  <jakub@redhat.com>
+
+       * jump.c (never_reached_warning): Add finish argument.
+       If finish is NULL, stop on CODE_LABEL, otherwise stop before first
+       real insn after end.
+       * rtl.h (never_reached_warning): Adjust prototype.
+       * cse.c (cse_insn): Pass NULL as finish to never_reached_warning.
+       * cfgrtl.c (flow_delete_block): Pass b->end as finish to
+       never_reached_warning.
+
 2002-02-12  Graham Stott  <grahams@redhat.com>
 
        * config/hp/pa.h (GO_IF_LEGITIMATE_ADDRESS): Fix typos.

diff --git a/gcc/cfgrtl.c b/gcc/cfgrtl.c
index 42358b2ccf0d1977d8c591c93100729b07c87641..5b99ab237e258e8587b12de0059f1f5525bbf7f5 100644 (file)
--- a/gcc/cfgrtl.c
+++ b/gcc/cfgrtl.c
@@ -338,7 +338,7 @@ flow_delete_block (b)
 
   insn = b->head;
 
-  never_reached_warning (insn);
+  never_reached_warning (insn, b->end);
 
   if (GET_CODE (insn) == CODE_LABEL)
     maybe_remove_eh_handler (insn);

diff --git a/gcc/cse.c b/gcc/cse.c
index ac9e8860d38cbd047504481d39a8cafd44ce29f1..b88a84c2cea390669b4d63afb3d9e8f5de7d6004 100644 (file)
--- a/gcc/cse.c
+++ b/gcc/cse.c
@@ -5795,7 +5795,7 @@ cse_insn (insn, libcall_insn)
          else
            INSN_CODE (insn) = -1;
 
-         never_reached_warning (insn);
+         never_reached_warning (insn, NULL);
 
          /* Do not bother deleting any unreachable code,
             let jump/flow do that.  */

diff --git a/gcc/jump.c b/gcc/jump.c
index fcb3c61800bbfc8433ab9eba25f020048902d32f..fc6bef07e4898e37c58d135e783b2d13202dcd47 100644 (file)
--- a/gcc/jump.c
+++ b/gcc/jump.c
@@ -1913,13 +1913,12 @@ delete_for_peephole (from, to)
    so it's possible to get spurious warnings from this.  */
 
 void
-never_reached_warning (avoided_insn)
-     rtx avoided_insn;
+never_reached_warning (avoided_insn, finish)
+     rtx avoided_insn, finish;
 {
   rtx insn;
   rtx a_line_note = NULL;
-  int two_avoided_lines = 0;
-  int contains_insn = 0;
+  int two_avoided_lines = 0, contains_insn = 0, reached_end = 0;
 
   if (! warn_notreached)
     return;
@@ -1929,10 +1928,11 @@ never_reached_warning (avoided_insn)
 
   for (insn = avoided_insn; insn != NULL; insn = NEXT_INSN (insn))
     {
-      if (GET_CODE (insn) == CODE_LABEL)
+      if (finish == NULL && GET_CODE (insn) == CODE_LABEL)
        break;
-      else if (GET_CODE (insn) == NOTE         /* A line number note?  */
-              && NOTE_LINE_NUMBER (insn) >= 0)
+
+      if (GET_CODE (insn) == NOTE              /* A line number note?  */
+         && NOTE_LINE_NUMBER (insn) >= 0)
        {
          if (a_line_note == NULL)
            a_line_note = insn;
@@ -1941,7 +1941,14 @@ never_reached_warning (avoided_insn)
                                  != NOTE_LINE_NUMBER (insn));
        }
       else if (INSN_P (insn))
-       contains_insn = 1;
+       {
+         if (reached_end)
+           break;
+         contains_insn = 1;
+       }
+
+      if (insn == finish)
+       reached_end = 1;
     }
   if (two_avoided_lines && contains_insn)
     warning_with_file_and_line (NOTE_SOURCE_FILE (a_line_note),

diff --git a/gcc/rtl.h b/gcc/rtl.h
index ef4c5f8f14609926eadd721f812a8794aed4f142..99fabfcb3ff9728aeed8ffb0a010dfb1613fd8d4 100644 (file)
--- a/gcc/rtl.h
+++ b/gcc/rtl.h
@@ -1808,7 +1808,7 @@ extern enum rtx_code reversed_comparison_code_parts PARAMS ((enum rtx_code,
                                                             rtx, rtx, rtx));
 extern void delete_for_peephole                PARAMS ((rtx, rtx));
 extern int condjump_in_parallel_p      PARAMS ((rtx));
-extern void never_reached_warning      PARAMS ((rtx));
+extern void never_reached_warning      PARAMS ((rtx, rtx));
 extern void purge_line_number_notes    PARAMS ((rtx));
 extern void copy_loop_headers          PARAMS ((rtx));
 

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 2d3c7130f9a8c57f25f4fbd20b21092c7718de2a..d9766b063954027b8d97bc7e61054ee5dfa90c1a 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2002-02-12  Jakub Jelinek  <jakub@redhat.com>
+
+       * gcc.dg/Wunreachable-1.c: New test.
+       * gcc.dg/Wunreachable-2.c: New test.
+
 2002-02-12  Joseph S. Myers  <jsm28@cam.ac.uk>
 
        * gcc.dg/c90-const-expr-3.c, gcc.dg/c99-const-expr-3.c: New tests.

diff --git a/gcc/testsuite/gcc.dg/Wunreachable-1.c b/gcc/testsuite/gcc.dg/Wunreachable-1.c
new file mode 100644 (file)
index 0000000..d6d59b4
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/Wunreachable-1.c
@@ -0,0 +1,24 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -Wunreachable-code" } */
+
+extern void foo (void);
+extern void baz (void);
+
+void bar (int i)
+{
+  if (i < 2)
+    {
+      baz ();
+      return;
+    }
+  else
+    {
+      if (i >= 4 && i <= 5)
+        foo ();
+      return;
+    }
+
+  baz ();      /* { dg-warning "will never be executed" "" } */
+  baz ();
+  baz ();
+}

diff --git a/gcc/testsuite/gcc.dg/Wunreachable-2.c b/gcc/testsuite/gcc.dg/Wunreachable-2.c
new file mode 100644 (file)
index 0000000..8242441
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/Wunreachable-2.c
@@ -0,0 +1,19 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -Wunreachable-code" } */
+
+extern int foo (const char *);
+extern void baz (void);
+const char *a[] = { "one", "two" };
+
+void bar (void)
+{
+  int i;
+
+  for (i = 0; i < 2; i++)
+    if (! foo (a[i]))
+      return;
+
+  baz ();      /* { dg-bogus "will never be executed" } */
+  baz ();
+  baz ();
+}