mem: Resolve TrafficGen trace relative to the config

The traffic generator currently resolves relative trace paths relative
to gem5's current working directory. This can lead to surprising
results for relative paths where the expectation would normally be
that they are resolved relative to the configuration file. This
changeset implements config-relative trace file lookups. The old
behavior is kept as a fallback for configs that expect that behavior.

Change-Id: I1bda4e16725842666ffc37dcb6838c23a6ff138c
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>

1 files changed, 26 insertions, 1 deletions

diff --git a/src/cpu/testers/traffic_gen/traffic_gen.cc b/src/cpu/testers/traffic_gen/traffic_gen.cc
index af1976784..1a12b7675 100644
--- a/src/cpu/testers/traffic_gen/traffic_gen.cc
+++ b/src/cpu/testers/traffic_gen/traffic_gen.cc
@@ -38,12 +38,15 @@
  *          Andreas Hansson
  *          Sascha Bischoff
  */
+#include "cpu/testers/traffic_gen/traffic_gen.hh"
+
+#include <libgen.h>
+#include <unistd.h>
 
 #include <sstream>
 
 #include "base/intmath.hh"
 #include "base/random.hh"
-#include "cpu/testers/traffic_gen/traffic_gen.hh"
 #include "debug/Checkpoint.hh"
 #include "debug/TrafficGen.hh"
 #include "sim/stats.hh"
@@ -229,6 +232,27 @@ TrafficGen::update()
     }
 }
 
+std::string
+TrafficGen::resolveFile(const std::string &name)
+{
+    // Do nothing for empty and absolute file names
+    if (name.empty() || name[0] == '/')
+        return name;
+
+    char *config_path = strdup(configFile.c_str());
+    char *config_dir = dirname(config_path);
+    const std::string config_rel = csprintf("%s/%s", config_dir, name);
+    free(config_path);
+
+    // Check the path relative to the config file first
+    if (access(config_rel.c_str(), R_OK) == 0)
+        return config_rel;
+
+    // Fall back to the old behavior and search relative to the
+    // current working directory.
+    return name;
+}
+
 void
 TrafficGen::parseConfig()
 {
@@ -273,6 +297,7 @@ TrafficGen::parseConfig()
                     Addr addrOffset;
 
                     is >> traceFile >> addrOffset;
+                    traceFile = resolveFile(traceFile);
 
                     states[id] = new TraceGen(name(), masterID, duration,
                                               traceFile, addrOffset);