PR11075: -W option to turn warnings into errors

* session.h
* NEWS: Discuss it.
* main.cxx: Parse it.
* session.h (num_errors): Provide it.
* semok/fortyeight.stp, semok/thirtyseven.stp: Test it.

5 files changed, 25 insertions, 2 deletions

diff --git a/NEWS b/NEWS
index 85619f8e..d9f70676 100644
--- a/NEWS
+++ b/NEWS
@@ -1,5 +1,9 @@
 * What's new
 
+- A new command line flag '-W' forces systemtap to abort translation of
+  a script if any warnings are produced.  It is similar to gcc's -Werror.
+  (If '-w' is also supplied to suppress warnings, it wins.)
+
 - A new predicate @defined is available for testing whether a
   particular $variable/expression is resolvable at translate time:
   probe foo { if (@defined($bar)) log ("$bar is available here") }
diff --git a/main.cxx b/main.cxx
index 7073f7d3..c7be3bc1 100644
--- a/main.cxx
+++ b/main.cxx
@@ -93,6 +93,7 @@ usage (systemtap_session& s, int exitcode)
     << "   -k         keep temporary directory" << endl
     << "   -u         unoptimized translation" << (s.unoptimized ? " [set]" : "") << endl
     << "   -w         suppress warnings" << (s.suppress_warnings ? " [set]" : "") << endl
+    << "   -W         turn warnings into errors" << (s.panic_warnings ? " [set]" : "") << endl
     << "   -g         guru mode" << (s.guru_mode ? " [set]" : "") << endl
     << "   -P         prologue-searching for function probes"
     << (s.prologue_searching ? " [set]" : "") << endl
@@ -504,6 +505,7 @@ main (int argc, char * const argv [])
   s.bulk_mode = false;
   s.unoptimized = false;
   s.suppress_warnings = false;
+  s.panic_warnings = false;
   s.listing_mode = false;
   s.listing_mode_vars = false;
 
@@ -640,7 +642,7 @@ main (int argc, char * const argv [])
         { "help", 0, &long_opt, LONG_OPT_HELP },
         { NULL, 0, NULL, 0 }
       };
-      int grc = getopt_long (argc, argv, "hVvtp:I:e:o:R:r:a:m:kgPc:x:D:bs:uqwl:d:L:FS:B:",
+      int grc = getopt_long (argc, argv, "hVvtp:I:e:o:R:r:a:m:kgPc:x:D:bs:uqwl:d:L:FS:B:W",
                              long_options, NULL);
       if (grc < 0)
         break;
@@ -663,6 +665,10 @@ main (int argc, char * const argv [])
 	  s.suppress_warnings = true;
 	  break;
 
+        case 'W':
+	  s.panic_warnings = true;
+	  break;
+
         case 'p':
           s.last_pass = (int)strtoul(optarg, &num_endptr, 10);
           if (*num_endptr != '\0' || s.last_pass < 1 || s.last_pass > 5)
diff --git a/session.h b/session.h
index d43b1f21..18d811e7 100644
--- a/session.h
+++ b/session.h
@@ -110,6 +110,7 @@ struct systemtap_session
   bool bulk_mode;
   bool unoptimized;
   bool suppress_warnings;
+  bool panic_warnings;
   int buffer_size;
   unsigned perfmon;
   bool symtab; /* true: emit symbol table at translation time; false: let staprun do it. */
@@ -214,7 +215,7 @@ struct systemtap_session
 
   std::set<std::string> seen_errors;
   std::set<std::string> seen_warnings;
-  unsigned num_errors () { return seen_errors.size(); }
+  unsigned num_errors () { return seen_errors.size() + (panic_warnings ? seen_warnings.size() : 0); }
 
   std::set<std::string> rpms_to_install;
 
diff --git a/testsuite/semko/fortyeight.stp b/testsuite/semko/fortyeight.stp
new file mode 100755
index 00000000..34bcad01
--- /dev/null
+++ b/testsuite/semko/fortyeight.stp
@@ -0,0 +1,6 @@
+#! stap -Wp2
+
+# PR 11075
+
+global foo  # evokes warning
+probe begin { exit() }
diff --git a/testsuite/semok/thirtyseven.stp b/testsuite/semok/thirtyseven.stp
new file mode 100755
index 00000000..fb378359
--- /dev/null
+++ b/testsuite/semok/thirtyseven.stp
@@ -0,0 +1,6 @@
+#! stap -wWp2
+
+# PR 11075
+
+global foo  # evokes warning
+probe begin { exit() }