Merge pull request #5138 from smowton/smowton/feature/lexical-loops

Add lexical loop analysis

Author: smowton

regression/goto-instrument/lexical-loops1/test.c

@@ -0,0 +1,10 @@
+
+int main(int argc, char **argv)
+{
+  for(int i = 0; i < 10; ++i)
+  {
+    ++argc;
+  }
+
+  return argc;
+}

regression/goto-instrument/lexical-loops1/test.desc

@@ -0,0 +1,8 @@
+CORE
+test.c
+--show-lexical-loops
+2 is head of \{ 2, 3, 4, 5 \(backedge\) \}
+^EXIT=0$
+^SIGNAL=0$
+--
+^warning: ignoring

regression/goto-instrument/lexical-loops2/test.c

@@ -0,0 +1,13 @@
+
+int main(int argc, char **argv)
+{
+  int i = 0;
+
+  while(i < 10)
+  {
+    ++i;
+    argc--;
+  }
+
+  return argc;
+}

regression/goto-instrument/lexical-loops2/test.desc

@@ -0,0 +1,8 @@
+CORE
+test.c
+--show-lexical-loops
+2 is head of \{ 2, 3, 4, 5 \(backedge\) \}
+^EXIT=0$
+^SIGNAL=0$
+--
+^warning: ignoring

regression/goto-instrument/lexical-loops3/test.c

@@ -0,0 +1,13 @@
+
+int main(int argc, char **argv)
+{
+  int i = 0;
+
+  do
+  {
+    ++i;
+    argc--;
+  } while(i < 10);
+
+  return argc;
+}

regression/goto-instrument/lexical-loops3/test.desc

@@ -0,0 +1,8 @@
+CORE
+test.c
+--show-lexical-loops
+2 is head of \{ 2, 3, 4 \(backedge\) \}
+^EXIT=0$
+^SIGNAL=0$
+--
+^warning: ignoring

regression/goto-instrument/lexical-loops4/test.c

@@ -0,0 +1,13 @@
+
+int main(int argc, char **argv)
+{
+  int i = 0;
+
+head:
+  ++i;
+  argc--;
+  if(i < 10)
+    goto head;
+
+  return argc;
+}

regression/goto-instrument/lexical-loops4/test.desc

@@ -0,0 +1,8 @@
+CORE
+test.c
+--show-lexical-loops
+2 is head of \{ 2, 3, 4 \(backedge\) \}
+^EXIT=0$
+^SIGNAL=0$
+--
+^warning: ignoring

regression/goto-instrument/lexical-loops5/test.c

@@ -0,0 +1,13 @@
+
+int main(int argc, char **argv)
+{
+  for(int i = 0; i < 5; ++i)
+  {
+    for(int j = 0; j < 5; ++j)
+    {
+      argc++;
+    }
+  }
+
+  return argc;
+}

regression/goto-instrument/lexical-loops5/test.desc

@@ -0,0 +1,9 @@
+CORE
+test.c
+--show-lexical-loops
+2 is head of \{ 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 \(backedge\) \}
+5 is head of \{ 5, 6, 7, 8 \(backedge\) \}
+^EXIT=0$
+^SIGNAL=0$
+--
+^warning: ignoring

regression/goto-instrument/lexical-loops6/test.c

@@ -0,0 +1,17 @@
+
+int main(int argc, char **argv)
+{
+  int i = 0;
+
+  if(argc % 2)
+    goto head2;
+
+head:
+  argc--;
+head2:
+  ++i;
+  if(i < 10)
+    goto head;
+
+  return argc;
+}

regression/goto-instrument/lexical-loops6/test.desc

@@ -0,0 +1,12 @@
+CORE
+test.c
+--show-lexical-loops
+^Note not all loops were in lexical loop form$
+^EXIT=0$
+^SIGNAL=0$
+--
+is head of
+^warning: ignoring
+--
+This checks that a loop with multiple entry edges is correctly identified as
+having an unusual form

regression/goto-instrument/lexical-loops7/test.c

@@ -0,0 +1,15 @@
+
+int main(int argc, char **argv)
+{
+  int i = 0;
+
+head:
+  argc--;
+  ++i;
+  if(i < 10 && i % 2)
+    goto head;
+  else if(i < 10)
+    goto head;
+
+  return argc;
+}

regression/goto-instrument/lexical-loops7/test.desc

@@ -0,0 +1,12 @@
+CORE
+test.c
+--show-lexical-loops
+^Note not all loops were in lexical loop form$
+^2 is head of \{ 2, 3, 4, 5 \(backedge\) \}
+^EXIT=0$
+^SIGNAL=0$
+--
+^warning: ignoring
+--
+This checks that a loop with multiple back-edges results in a
+warning that not all back-edges are in simple lexical loop form

regression/goto-instrument/lexical-loops8/test.c

@@ -0,0 +1,17 @@
+
+int main(int argc, char **argv)
+{
+  int i = 0;
+
+  while(i < 10)
+  {
+    if(argc == 5)
+      break;
+    ++i;
+    if(argc % 7)
+      continue;
+    argc--;
+  }
+
+  return argc;
+}

regression/goto-instrument/lexical-loops8/test.desc

@@ -0,0 +1,11 @@
+CORE
+test.c
+--show-lexical-loops
+^2 is head of \{ 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 \(backedge\) \}$
+^EXIT=0$
+^SIGNAL=0$
+--
+^warning: ignoring
+--
+This checks that a loop with a break edge and a continue edge nontheless
+gets classified as a lexical loop

regression/goto-instrument/lexical-loops9/test.c

@@ -0,0 +1,18 @@
+
+int main(int argc, char **argv)
+{
+  int i = 0;
+
+  while(i < 10)
+  {
+    ++i;
+    if(argc == 5)
+    {
+      ++i;
+      break;
+    }
+    argc--;
+  }
+
+  return argc;
+}

regression/goto-instrument/lexical-loops9/test.desc

@@ -0,0 +1,12 @@
+CORE
+test.c
+--show-lexical-loops
+^2 is head of \{ 2, 3, 4, 7, 8, 9 \(backedge\) \}$
+^EXIT=0$
+^SIGNAL=0$
+--
+^warning: ignoring
+--
+This checks that we identify a loop with a "hole" as a lexical loop. The hole is made from
+instructions that cannot reach the back-edge (they are postdominated by a 'break' instruction)
+but which are lexically included in the loop.

src/analyses/Makefile

@@ -25,7 +25,6 @@ SRC = ai.cpp \
       local_may_alias.cpp \
       local_safe_pointers.cpp \
       locals.cpp \
-      natural_loops.cpp \
       reaching_definitions.cpp \
       sese_regions.cpp \
       static_analysis.cpp \