Bug 1420355 - Don't initialize DMD if the DMD environment variable is not given. r=njn

This makes things slightly more inconvenient (having to set two
environment variables instead of one for the simplest case) until a few
patches down the line, when DMD is statically linked, at which point it
will get down to one environment variable every time.

--HG--
extra : rebase_source : 08dc3c05318b572ae1026227d0369fa8bf21b20f

memory/replace/dmd/DMD.cpp

@@ -1256,7 +1256,7 @@ FreeCallback(void* aPtr, Thread* aT, DeadBlock* aDeadBlock)
 // malloc/free interception
 //---------------------------------------------------------------------------
 
-static void Init(malloc_table_t* aMallocTable);
+static bool Init(malloc_table_t* aMallocTable);
 
 } // namespace dmd
 } // namespace mozilla
@@ -1368,11 +1368,12 @@ replace_free(void* aPtr)
 void
 replace_init(malloc_table_t* aMallocTable, ReplaceMallocBridge** aBridge)
 {
-  mozilla::dmd::Init(aMallocTable);
+  if (mozilla::dmd::Init(aMallocTable)) {
 #define MALLOC_FUNCS MALLOC_FUNCS_MALLOC_BASE
 #define MALLOC_DECL(name, ...) aMallocTable->name = replace_ ## name;
 #include "malloc_decls.h"
-  *aBridge = mozilla::dmd::gDMDBridge;
+    *aBridge = mozilla::dmd::gDMDBridge;
+  }
 }
 
 namespace mozilla {
@@ -1439,9 +1440,6 @@ Options::Options(const char* aDMDEnvVar)
   , mStacks(Stacks::Partial)
   , mShowDumpStats(false)
 {
-  // It's no longer necessary to set the DMD env var to "1" if you want default
-  // options (you can leave it undefined) but we still accept "1" for
-  // backwards compatibility.
   char* e = mDMDEnvVar;
   if (e && strcmp(e, "1") != 0) {
     bool isEnd = false;
@@ -1551,10 +1549,21 @@ postfork()
 // have run.  For this reason, non-scalar globals such as gStateLock and
 // gStackTraceTable are allocated dynamically (so we can guarantee their
 // construction in this function) rather than statically.
-static void
+static bool
 Init(malloc_table_t* aMallocTable)
 {
+  // DMD is controlled by the |DMD| environment variable.
+  const char* e = getenv("DMD");
+
+  if (!e) {
+    return false;
+  }
+  // Initialize the function table first, because StatusMsg uses
+  // InfallibleAllocPolicy::malloc_, which uses it.
   gMallocTable = *aMallocTable;
+
+  StatusMsg("$DMD = '%s'\n", e);
+
   gDMDBridge = InfallibleAllocPolicy::new_<DMDBridge>();
 
 #ifndef XP_WIN
@@ -1566,16 +1575,6 @@ Init(malloc_table_t* aMallocTable)
   // system malloc a chance to insert its own atfork handler.
   pthread_atfork(prefork, postfork, postfork);
 #endif
-
-  // DMD is controlled by the |DMD| environment variable.
-  const char* e = getenv("DMD");
-
-  if (e) {
-    StatusMsg("$DMD = '%s'\n", e);
-  } else {
-    StatusMsg("$DMD is undefined\n");
-  }
-
   // Parse $DMD env var.
   gOptions = InfallibleAllocPolicy::new_<Options>(e);
 
@@ -1604,6 +1603,7 @@ Init(malloc_table_t* aMallocTable)
     MOZ_ALWAYS_TRUE(gDeadBlockTable->init(tableSize));
   }
 
+  return true;
 }
 
 //---------------------------------------------------------------------------

memory/replace/dmd/test/script-diff-dark-matter-expected.txt

@@ -7,7 +7,7 @@ Invocation 1 {
 }
 
 Invocation 2 {
-  $DMD is undefined
+  $DMD = '1'
   Mode = 'dark-matter'
 }
 

memory/replace/dmd/test/script-diff-dark-matter2.json

@@ -1,7 +1,7 @@
 {
  "version": 5,
  "invocation": {
-  "dmdEnvVar": null,
+  "dmdEnvVar": "1",
   "mode": "dark-matter"
  },
  "blockList": [

memory/replace/dmd/test/script-ignore-alloc-fns-expected.txt

@@ -2,7 +2,7 @@
 # dmd.py --filter-stacks-for-testing -o script-ignore-alloc-fns-actual.txt --ignore-alloc-fns script-ignore-alloc-fns.json
 
 Invocation {
-  $DMD is undefined
+  $DMD = '1'
   Mode = 'dark-matter'
 }
 

memory/replace/dmd/test/script-ignore-alloc-fns.json

@@ -1,7 +1,7 @@
 {
  "version": 5,
  "invocation": {
-  "dmdEnvVar": null,
+  "dmdEnvVar": "1",
   "mode": "dark-matter"
  },
  "blockList": [

memory/replace/dmd/test/test_dmd.js

@@ -136,6 +136,7 @@ function run_test() {
   // in-place (to fix stacks) when it runs dmd.py, and that's not safe to do
   // asynchronously.
 
+  gEnv.set('DMD', '1');
   gEnv.set(gEnv.get("DMD_PRELOAD_VAR"), gEnv.get("DMD_PRELOAD_VALUE"));
 
   runProcess(gDmdTestFile, []);

python/mozbuild/mozbuild/mach_commands.py

@@ -945,6 +945,8 @@ class RunProgram(MachCommandBase):
 
             if dmd_params:
                 env_vars[arch]["DMD"] = " ".join(dmd_params)
+            else:
+                env_vars[arch]["DMD"] = "1"
 
             extra_env.update(env_vars.get(arch, {}))
 

testing/awsy/mach_commands.py

@@ -170,6 +170,8 @@ class MachCommands(MachCommandBase):
             arch = self.substs['OS_ARCH']
             for k, v in env_vars[arch].iteritems():
                 os.environ[k] = v
+            if 'DMD' not in os.environ:
+                os.environ['DMD'] = '1'
 
             # Also add the bin dir to the python path so we can use dmd.py
             if bin_dir not in sys.path:

testing/mochitest/runtests.py

@@ -1634,6 +1634,9 @@ toolbar#nav-bar {
         if options.headless:
             browserEnv["MOZ_HEADLESS"] = '1'
 
+        if options.dmd:
+            browserEnv["DMD"] = os.environ.get('DMD', '1')
+
         # These variables are necessary for correct application startup; change
         # via the commandline at your own risk.
         browserEnv["XPCOM_DEBUG_BREAK"] = "stack"

testing/mochitest/runtestsremote.py

@@ -280,6 +280,8 @@ class MochiRemote(MochitestDesktop):
         browserEnv["MOZ_LOG_FILE"] = os.path.join(
             self.remoteMozLog,
             self.mozLogName)
+        if options.dmd:
+            browserEnv['DMD'] = '1'
         return browserEnv
 
     def runApp(self, *args, **kwargs):