gimplify.c (gimplify_switch_expr): Also handle GIMPLE_TRY.

	* gimplify.c (gimplify_switch_expr): Also handle GIMPLE_TRY.

	* c-c++-common/Wswitch-unreachable-3.c: New test.
	* g++.dg/warn/Wswitch-unreachable-1.C: New test.

From-SVN: r236924

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index a558a944e5b2732320c6227f74b6c872b3701ae4..59aae29bdc410537460d363bc8010487ab965d47 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,7 @@
+2016-05-31  Marek Polacek  <polacek@redhat.com>
+
+       * gimplify.c (gimplify_switch_expr): Also handle GIMPLE_TRY.
+
 2016-05-31  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
 
        * config/aarch64/aarch64.c (aarch_macro_fusion_pair_p): Use

diff --git a/gcc/gimplify.c b/gcc/gimplify.c
index 8316bb8881f22745b705d6bb9f2e3a1af80d43f4..8b7dddca48a1ffe82224696f1e62d79d6a6629f7 100644 (file)
--- a/gcc/gimplify.c
+++ b/gcc/gimplify.c
@@ -1609,10 +1609,17 @@ gimplify_switch_expr (tree *expr_p, gimple_seq *pre_p)
          while (gimple_code (seq) == GIMPLE_BIND)
            seq = gimple_bind_body (as_a <gbind *> (seq));
          gimple *stmt = gimple_seq_first_stmt (seq);
-         enum gimple_code code = gimple_code (stmt);
-         if (code != GIMPLE_LABEL && code != GIMPLE_TRY)
+         if (gimple_code (stmt) == GIMPLE_TRY)
            {
-             if (code == GIMPLE_GOTO
+             /* A compiler-generated cleanup or a user-written try block.
+                Try to get the first statement in its try-block, for better
+                location.  */
+             if ((seq = gimple_try_eval (stmt)))
+               stmt = gimple_seq_first_stmt (seq);
+           }
+         if (gimple_code (stmt) != GIMPLE_LABEL)
+           {
+             if (gimple_code (stmt) == GIMPLE_GOTO
                  && TREE_CODE (gimple_goto_dest (stmt)) == LABEL_DECL
                  && DECL_ARTIFICIAL (gimple_goto_dest (stmt)))
                /* Don't warn for compiler-generated gotos.  These occur

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 8c5def43270ec9c8e5a4c1d4978fa5ae8e46f26d..a7cf8340d15b6ddaac24581c0cb7cdc4378ed0fc 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2016-05-31  Marek Polacek  <polacek@redhat.com>
+
+       * c-c++-common/Wswitch-unreachable-3.c: New test.
+       * g++.dg/warn/Wswitch-unreachable-1.C: New test.
+
 2016-05-31  Richard Biener  <rguenther@suse.de>
 
        PR tree-optimization/71352

diff --git a/gcc/testsuite/c-c++-common/Wswitch-unreachable-3.c b/gcc/testsuite/c-c++-common/Wswitch-unreachable-3.c
new file mode 100644 (file)
index 0000000..c53cb10
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/Wswitch-unreachable-3.c
@@ -0,0 +1,29 @@
+/* { dg-do compile } */
+
+extern void f (int *);
+
+void
+g (int i)
+{
+  switch (i)
+    {
+      int a[3];
+      __builtin_memset (a, 0, sizeof a); /* { dg-warning "statement will never be executed" } */
+
+    default:
+      f (a);
+    }
+
+  switch (i)
+    {
+      int a[3];
+      int b[3];
+      int c[3];
+      b[1] = 60; /* { dg-warning "statement will never be executed" } */
+
+    default:
+      f (a);
+      f (b);
+      f (c);
+    }
+}

diff --git a/gcc/testsuite/g++.dg/warn/Wswitch-unreachable-1.C b/gcc/testsuite/g++.dg/warn/Wswitch-unreachable-1.C
new file mode 100644 (file)
index 0000000..99d9a83
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wswitch-unreachable-1.C
@@ -0,0 +1,34 @@
+// { dg-do compile }
+
+extern int j;
+
+void
+f (int i)
+{
+  switch (i) // { dg-warning "statement will never be executed" }
+    {
+      try
+      {
+      }
+      catch (...)
+      {
+      }
+    case 1:;
+    }
+}
+
+void
+g (int i)
+{
+  switch (i)
+    {
+      try
+      {
+       j = 42;  // { dg-warning "statement will never be executed" }
+      }
+      catch (...)
+      {
+      }
+    case 1:;
+    }
+}