From 2b431ba179258e63a1a80e611e4294265e61b27c Mon Sep 17 00:00:00 2001
From: Martin Quinson <martin.quinson@ens-rennes.fr>
Date: Tue, 11 Jun 2019 21:56:37 +0200
Subject: [PATCH] mc: don't catch exceptions we cannot deal with

+ cosmetics using xbt_assert to improve coverage
---
 src/mc/Session.cpp            | 30 +++++-----------
 src/mc/checker/simgrid_mc.cpp | 66 ++++++++++++++---------------------
 2 files changed, 35 insertions(+), 61 deletions(-)

diff --git a/src/mc/Session.cpp b/src/mc/Session.cpp
index 4d73338e5f..8c0926ef6a 100644
--- a/src/mc/Session.cpp
+++ b/src/mc/Session.cpp
@@ -27,18 +27,14 @@ static void setup_child_environment(int socket)
   // Make sure we do not outlive our parent:
   sigset_t mask;
   sigemptyset (&mask);
-  if (sigprocmask(SIG_SETMASK, &mask, nullptr) < 0)
-    throw simgrid::xbt::errno_error("Could not unblock signals");
-  if (prctl(PR_SET_PDEATHSIG, SIGHUP) != 0)
-    throw simgrid::xbt::errno_error("Could not PR_SET_PDEATHSIG");
+  xbt_assert(sigprocmask(SIG_SETMASK, &mask, nullptr) >= 0, "Could not unblock signals");
+  xbt_assert(prctl(PR_SET_PDEATHSIG, SIGHUP) == 0, "Could not PR_SET_PDEATHSIG");
 #endif
 
-  int res;
-
   // Remove CLOEXEC in order to pass the socket to the exec-ed program:
   int fdflags = fcntl(socket, F_GETFD, 0);
-  if (fdflags == -1 || fcntl(socket, F_SETFD, fdflags & ~FD_CLOEXEC) == -1)
-    throw simgrid::xbt::errno_error("Could not remove CLOEXEC for socket");
+  xbt_assert(fdflags != -1 && fcntl(socket, F_SETFD, fdflags & ~FD_CLOEXEC) != -1,
+             "Could not remove CLOEXEC for socket");
 
   // Set environment:
   setenv(MC_ENV_VARIABLE, "1", 1);
@@ -49,9 +45,8 @@ static void setup_child_environment(int socket)
   setenv("LC_BIND_NOW", "1", 1);
 
   char buffer[64];
-  res = std::snprintf(buffer, sizeof(buffer), "%i", socket);
-  if ((size_t) res >= sizeof(buffer) || res == -1)
-    std::abort();
+  int res = std::snprintf(buffer, sizeof(buffer), "%i", socket);
+  xbt_assert((size_t)res < sizeof(buffer) && res != -1);
   setenv(MC_ENV_SOCKET_FD, buffer, 1);
 }
 
@@ -61,20 +56,13 @@ static inline
 pid_t do_fork(F code)
 {
   pid_t pid = fork();
-  if (pid < 0)
-    throw simgrid::xbt::errno_error("Could not fork model-checked process");
+  xbt_assert(pid >= 0, "Could not fork model-checked process");
   if (pid != 0)
     return pid;
 
   // Child-process:
-  try {
-    code();
-    _exit(EXIT_SUCCESS);
-  }
-  catch(...) {
-    // The callback should catch exceptions:
-    std::terminate();
-  }
+  code();
+  _exit(EXIT_SUCCESS);
 }
 
 Session::Session(const std::function<void()>& code)
diff --git a/src/mc/checker/simgrid_mc.cpp b/src/mc/checker/simgrid_mc.cpp
index 0c59749710..010cbfecca 100644
--- a/src/mc/checker/simgrid_mc.cpp
+++ b/src/mc/checker/simgrid_mc.cpp
@@ -25,7 +25,7 @@ char** argvdup(int argc, char** argv)
   return argv_copy;
 }
 
-static std::unique_ptr<simgrid::mc::Checker> createChecker(simgrid::mc::Session& session)
+static std::unique_ptr<simgrid::mc::Checker> create_checker(simgrid::mc::Session& session)
 {
   if (_sg_mc_comms_determinism || _sg_mc_send_determinism)
     return std::unique_ptr<simgrid::mc::Checker>(simgrid::mc::createCommunicationDeterminismChecker(session));
@@ -37,48 +37,34 @@ static std::unique_ptr<simgrid::mc::Checker> createChecker(simgrid::mc::Session&
 
 int main(int argc, char** argv)
 {
-  using simgrid::mc::Session;
+  if (argc < 2)
+    xbt_die("Missing arguments.\n");
 
-  try {
-    if (argc < 2)
-      xbt_die("Missing arguments.\n");
-
-    // Currently, we need this before sg_config_init:
-    _sg_do_model_check = 1;
+  // Currently, we need this before sg_config_init:
+  _sg_do_model_check = 1;
 
-    // The initialization function can touch argv.
-    // We make a copy of argv before modifying it in order to pass the original
-    // value to the model-checked:
-    char** argv_copy = argvdup(argc, argv);
-    xbt_log_init(&argc, argv);
-    sg_config_init(&argc, argv);
+  // The initialization function can touch argv.
+  // We make a copy of argv before modifying it in order to pass the original
+  // value to the model-checked:
+  char** argv_copy = argvdup(argc, argv);
+  xbt_log_init(&argc, argv);
+  sg_config_init(&argc, argv);
 
-    simgrid::mc::session = new Session([argv_copy] {
-        execvp(argv_copy[1], argv_copy+1);
-      });
-    delete[] argv_copy;
+  simgrid::mc::session = new simgrid::mc::Session([argv_copy] { execvp(argv_copy[1], argv_copy + 1); });
+  delete[] argv_copy;
 
-    std::unique_ptr<simgrid::mc::Checker> checker = createChecker(*simgrid::mc::session);
-    int res = SIMGRID_MC_EXIT_SUCCESS;
-    try {
-      checker->run();
-    } catch (const simgrid::mc::DeadlockError&) {
-      res = SIMGRID_MC_EXIT_DEADLOCK;
-    } catch (const simgrid::mc::TerminationError&) {
-      res = SIMGRID_MC_EXIT_NON_TERMINATION;
-    } catch (const simgrid::mc::LivenessError&) {
-      res = SIMGRID_MC_EXIT_LIVENESS;
-    }
-    checker = nullptr;
-    simgrid::mc::session->close();
-    return res;
-  }
-  catch(std::exception& e) {
-    XBT_ERROR("Exception: %s", e.what());
-    return SIMGRID_MC_EXIT_ERROR;
-  }
-  catch(...) {
-    XBT_ERROR("Unknown exception");
-    return SIMGRID_MC_EXIT_ERROR;
+  std::unique_ptr<simgrid::mc::Checker> checker = create_checker(*simgrid::mc::session);
+  int res                                       = SIMGRID_MC_EXIT_SUCCESS;
+  try {
+    checker->run();
+  } catch (const simgrid::mc::DeadlockError&) {
+    res = SIMGRID_MC_EXIT_DEADLOCK;
+  } catch (const simgrid::mc::TerminationError&) {
+    res = SIMGRID_MC_EXIT_NON_TERMINATION;
+  } catch (const simgrid::mc::LivenessError&) {
+    res = SIMGRID_MC_EXIT_LIVENESS;
   }
+  checker = nullptr;
+  simgrid::mc::session->close();
+  return res;
 }
-- 
2.20.1