Issue #1818 - Part 1: remove a number of old GCC hacks.

12 files changed, 52 insertions, 79 deletions

diff --git a/build/autoconf/compiler-opts.m4 b/build/autoconf/compiler-opts.m4
index 077a3e6f19..99990332f9 100644
--- a/build/autoconf/compiler-opts.m4
+++ b/build/autoconf/compiler-opts.m4
@@ -16,7 +16,7 @@ dnl set DEVELOPER_OPTIONS early; MOZ_DEFAULT_COMPILER is usually the first non-s
       DEVELOPER_OPTIONS=,
       DEVELOPER_OPTIONS=1)
 
-dnl Default to MSVC for win32 and gcc-4.2 for darwin
+dnl Default to MSVC for win32
 dnl ==============================================================
 if test -z "$CROSS_COMPILE"; then
 case "$target" in
@@ -186,7 +186,8 @@ if test "$GNU_CC"; then
 
     if test -z "$CLANG_CC"; then
         case "$CC_VERSION" in
-        4.* | 5.*)
+        4.* | 5.* | 6.*)
+            AC_MSG_ERROR([Unsupported GCC version.])
             ;;
         *)
             # Lifetime Dead Store Elimination level 2 (default in GCC6+) breaks Gecko.
diff --git a/build/unix/build-gcc/build-gcc.sh b/build/unix/build-gcc/build-gcc.sh
index df3bc5dfd3..2c4d7b323d 100755
--- a/build/unix/build-gcc/build-gcc.sh
+++ b/build/unix/build-gcc/build-gcc.sh
@@ -1,6 +1,6 @@
 #!/bin/bash
 
-gcc_version=4.8.5
+gcc_version=7.1.0
 binutils_version=2.25.1
 this_path=$(readlink -f $(dirname $0))
 make_flags='-j12'
diff --git a/dom/media/GraphDriver.cpp b/dom/media/GraphDriver.cpp
index 90680d8c69..daf1ccc989 100644
--- a/dom/media/GraphDriver.cpp
+++ b/dom/media/GraphDriver.cpp
@@ -32,11 +32,6 @@ StaticRefPtr<nsIThreadPool> AsyncCubebTask::sThreadPool;
 
 struct AutoProfilerUnregisterThread
 {
-  // The empty ctor is used to silence a pre-4.8.0 GCC unused variable warning.
-  AutoProfilerUnregisterThread()
-  {
-  }
-
   ~AutoProfilerUnregisterThread()
   {
     profiler_unregister_thread();
diff --git a/dom/media/MediaManager.cpp b/dom/media/MediaManager.cpp
index 54b09e6447..7fd11f1715 100644
--- a/dom/media/MediaManager.cpp
+++ b/dom/media/MediaManager.cpp
@@ -1277,13 +1277,6 @@ GetSources(MediaEngine *engine, MediaSourceEnum aSrcType,
   }
 }
 
-// TODO: Remove once upgraded to GCC 4.8+ on linux. Bogus error on static func:
-// error: 'this' was not captured for this lambda function
-
-static auto& MediaManager_GetInstance = MediaManager::GetInstance;
-static auto& MediaManager_ToJSArray = MediaManager::ToJSArray;
-static auto& MediaManager_AnonymizeDevices = MediaManager::AnonymizeDevices;
-
 already_AddRefed<MediaManager::PledgeChar>
 MediaManager::SelectSettings(
     MediaStreamConstraints& aConstraints,
@@ -1343,7 +1336,7 @@ MediaManager::SelectSettings(
       }
     }
     NS_DispatchToMainThread(NewRunnableFrom([id, badConstraint]() mutable {
-      RefPtr<MediaManager> mgr = MediaManager_GetInstance();
+      RefPtr<MediaManager> mgr = MediaManager::GetInstance();
       RefPtr<PledgeChar> p = mgr->mOutstandingCharPledges.Remove(id);
       if (p) {
         p->Resolve(badConstraint);
@@ -1608,7 +1601,7 @@ MediaManager::EnumerateRawDevices(uint64_t aWindowId,
       fakeBackend = new MediaEngineDefault();
     }
     if ((!fakeCams && hasVideo) || (!fakeMics && hasAudio)) {
-      RefPtr<MediaManager> manager = MediaManager_GetInstance();
+      RefPtr<MediaManager> manager = MediaManager::GetInstance();
       realBackend = manager->GetBackend(aWindowId);
     }
 
@@ -1633,7 +1626,7 @@ MediaManager::EnumerateRawDevices(uint64_t aWindowId,
     SourceSet* handoff = result.release();
     NS_DispatchToMainThread(NewRunnableFrom([id, handoff]() mutable {
       UniquePtr<SourceSet> result(handoff); // grab result
-      RefPtr<MediaManager> mgr = MediaManager_GetInstance();
+      RefPtr<MediaManager> mgr = MediaManager::GetInstance();
       if (!mgr) {
         return NS_OK;
       }
@@ -1922,7 +1915,7 @@ int MediaManager::AddDeviceChangeCallback(DeviceChangeCallback* aCallback)
 {
   bool fakeDeviceChangeEventOn = mPrefs.mFakeDeviceChangeEventOn;
   MediaManager::PostTask(NewTaskFrom([fakeDeviceChangeEventOn]() {
-    RefPtr<MediaManager> manager = MediaManager_GetInstance();
+    RefPtr<MediaManager> manager = MediaManager::GetInstance();
     manager->GetBackend(0)->AddDeviceChangeCallback(manager);
     if (fakeDeviceChangeEventOn)
       manager->GetBackend(0)->SetFakeDeviceChangeEvents();
@@ -2445,7 +2438,7 @@ MediaManager::EnumerateDevicesImpl(uint64_t aWindowId,
   p->Then([id, aWindowId, aVideoType, aAudioType,
            aFake](const nsCString& aOriginKey) mutable {
     MOZ_ASSERT(NS_IsMainThread());
-    RefPtr<MediaManager> mgr = MediaManager_GetInstance();
+    RefPtr<MediaManager> mgr = MediaManager::GetInstance();
 
     RefPtr<PledgeSourceSet> p = mgr->EnumerateRawDevices(aWindowId, aVideoType,
                                                          aAudioType, aFake);
@@ -2453,7 +2446,7 @@ MediaManager::EnumerateDevicesImpl(uint64_t aWindowId,
       UniquePtr<SourceSet> devices(aDevices); // secondary result
 
       // Only run if window is still on our active list.
-      RefPtr<MediaManager> mgr = MediaManager_GetInstance();
+      RefPtr<MediaManager> mgr = MediaManager::GetInstance();
       if (!mgr) {
         return NS_OK;
       }
@@ -2461,7 +2454,7 @@ MediaManager::EnumerateDevicesImpl(uint64_t aWindowId,
       if (!p || !mgr->IsWindowStillActive(aWindowId)) {
         return NS_OK;
       }
-      MediaManager_AnonymizeDevices(*devices, aOriginKey);
+      MediaManager::AnonymizeDevices(*devices, aOriginKey);
       p->Resolve(devices.release());
       return NS_OK;
     });
@@ -2500,12 +2493,12 @@ MediaManager::EnumerateDevices(nsPIDOMWindowInner* aWindow,
                                                      fake);
   p->Then([onSuccess, windowId, listener](SourceSet*& aDevices) mutable {
     UniquePtr<SourceSet> devices(aDevices); // grab result
-    RefPtr<MediaManager> mgr = MediaManager_GetInstance();
+    RefPtr<MediaManager> mgr = MediaManager::GetInstance();
     mgr->RemoveFromWindowList(windowId, listener);
-    nsCOMPtr<nsIWritableVariant> array = MediaManager_ToJSArray(*devices);
+    nsCOMPtr<nsIWritableVariant> array = MediaManager::ToJSArray(*devices);
     onSuccess->OnSuccess(array);
   }, [onFailure, windowId, listener](MediaStreamError*& reason) mutable {
-    RefPtr<MediaManager> mgr = MediaManager_GetInstance();
+    RefPtr<MediaManager> mgr = MediaManager::GetInstance();
     mgr->RemoveFromWindowList(windowId, listener);
     onFailure->OnError(reason);
   });
@@ -2542,7 +2535,7 @@ MediaManager::GetUserMediaDevices(nsPIDOMWindowInner* aWindow,
     RefPtr<GetUserMediaTask> task;
     if (!aCallID.Length() || aCallID == callID) {
       if (mActiveCallbacks.Get(callID, getter_AddRefs(task))) {
-        nsCOMPtr<nsIWritableVariant> array = MediaManager_ToJSArray(*task->mSourceSet);
+        nsCOMPtr<nsIWritableVariant> array = MediaManager::ToJSArray(*task->mSourceSet);
         onSuccess->OnSuccess(array);
         return NS_OK;
       }
@@ -3356,7 +3349,7 @@ GetUserMediaCallbackMediaStreamListener::ApplyConstraintsToTrack(
     NS_DispatchToMainThread(NewRunnableFrom([id, windowId, rv,
                                              badConstraint]() mutable {
       MOZ_ASSERT(NS_IsMainThread());
-      RefPtr<MediaManager> mgr = MediaManager_GetInstance();
+      RefPtr<MediaManager> mgr = MediaManager::GetInstance();
       if (!mgr) {
         return NS_OK;
       }
diff --git a/dom/media/MediaManager.h b/dom/media/MediaManager.h
index 1255f6c90b..1ee61f1196 100644
--- a/dom/media/MediaManager.h
+++ b/dom/media/MediaManager.h
@@ -268,7 +268,6 @@ private:
 
   static nsresult GenerateUUID(nsAString& aResult);
   static nsresult AnonymizeId(nsAString& aId, const nsACString& aOriginKey);
-public: // TODO: make private once we upgrade to GCC 4.8+ on linux.
   static void AnonymizeDevices(SourceSet& aDevices, const nsACString& aOriginKey);
   static already_AddRefed<nsIWritableVariant> ToJSArray(SourceSet& aDevices);
 private:
diff --git a/dom/plugins/base/npfunctions.h b/dom/plugins/base/npfunctions.h
index 7638a64882..83c8a9762c 100644
--- a/dom/plugins/base/npfunctions.h
+++ b/dom/plugins/base/npfunctions.h
@@ -189,8 +189,8 @@ typedef struct _NPNetscapeFuncs {
 #endif
 
 #if defined(XP_UNIX)
-/* GCC 3.3 and later support the visibility attribute. */
-#if defined(__GNUC__) && ((__GNUC__ >= 4) || (__GNUC__ == 3 && __GNUC_MINOR__ >= 3))
+/* GCC supports the visibility attribute. */
+#if defined(__GNUC__)
 #define NP_VISIBILITY_DEFAULT __attribute__((visibility("default")))
 #elif defined(__SUNPRO_C) || defined(__SUNPRO_CC)
 #define NP_VISIBILITY_DEFAULT __global
diff --git a/dom/plugins/base/nptypes.h b/dom/plugins/base/nptypes.h
index d0cef65406..1f8eba3c53 100644
--- a/dom/plugins/base/nptypes.h
+++ b/dom/plugins/base/nptypes.h
@@ -13,7 +13,7 @@
 
 #if defined(WIN32)
   /*
-   * Win32 and OS/2 don't know C99, so define [u]int_16/32/64 here. The bool
+   * Win32 doesn't know C99, so define [u]int_16/32/64 here. The bool
    * is predefined tho, both in C and C++.
    */
   typedef short int16_t;
@@ -61,28 +61,15 @@
     #include <inttypes.h>
     #include <stdbool.h>
   #endif
-#elif defined(BEOS)
-  #include <inttypes.h>
 #else
   /*
    * For those that ship a standard C99 stdint.h header file, include
-   * it. Can't do the same for stdbool.h tho, since some systems ship
-   * with a stdbool.h file that doesn't compile!
+   * it.
    */
   #include <stdint.h>
 
   #ifndef __cplusplus
-    #if !defined(__GNUC__) || (__GNUC__ > 2 || __GNUC_MINOR__ > 95)
-      #include <stdbool.h>
-    #else
-      /*
-       * GCC 2.91 can't deal with a typedef for bool, but a #define
-       * works.
-       */
-      #define bool int
-      #define true   1
-      #define false  0
-    #endif
+    #include <stdbool.h>
   #endif
 #endif
 
diff --git a/layout/style/nsCSSParser.cpp b/layout/style/nsCSSParser.cpp
index b409bfed7e..720a123d51 100644
--- a/layout/style/nsCSSParser.cpp
+++ b/layout/style/nsCSSParser.cpp
@@ -9843,7 +9843,22 @@ CSSParserImpl::ParseGridLine(nsCSSValue& aValue)
   // Make the contained value be defined even though we really want a
   // Nothing here.  This works around an otherwise difficult to avoid
   // Memcheck false positive when this is compiled by gcc-5.3 -O2.
-  // See bug 1301856.
+  // The problem is that gcc 5.4 and later, when using high
+  // optimization, inline Maybe::{isSome,ref} here
+  // 
+  //     if (integer.isSome() && integer.ref() < 0) {
+  // 
+  // and then proceed to evaluate the expression right-to-left, as if it
+  // had been written
+  // 
+  //     integer.ref() < 0 && integer.isSome()
+  // 
+  // This is a legitimate transformation because gcc presumably can prove
+  // via dataflow analysis that integer.isSome() is false whenever integer.ref()
+  // is undefined, so the overall expression result is still defined.  
+  // Valgrind/Memcheck assumes that all conditional branches in the program
+  // are important, and that assumption is deeply wired in, so there is no
+  // easy way to avoid the warning apart from to force-initialise |integer|.
   integer.emplace(0);
   integer.reset();
 #endif
@@ -15314,17 +15329,17 @@ CSSParserImpl::ParseFontFeatureSettings(nsCSSValue& aValue)
   return true;
 }
 
-bool

-CSSParserImpl::ParseFontVariationSettings(nsCSSValue& aValue)

-{

-  // TODO: Actually implement this.

-  

-  // This stub is here because websites insist on considering this

-  // very hardware-dependent and O.S.-variable low-level font-control

-  // as a "critical feature" which it isn't as there is 0 guarantee

-  // that font variation settings are supported or honored by any

-  // operating system used by the client.

-  return true;

+bool
+CSSParserImpl::ParseFontVariationSettings(nsCSSValue& aValue)
+{
+  // TODO: Actually implement this.
+  
+  // This stub is here because websites insist on considering this
+  // very hardware-dependent and O.S.-variable low-level font-control
+  // as a "critical feature" which it isn't as there is 0 guarantee
+  // that font variation settings are supported or honored by any
+  // operating system used by the client.
+  return true;
 }
 
 bool
diff --git a/python/pyyaml/ext/_yaml.c b/python/pyyaml/ext/_yaml.c
index f4a5bc5242..8a66c0fd3e 100644
--- a/python/pyyaml/ext/_yaml.c
+++ b/python/pyyaml/ext/_yaml.c
@@ -501,14 +501,8 @@ bad:
 
 
 #ifdef __GNUC__
-  /* Test for GCC > 2.95 */
-  #if __GNUC__ > 2 || (__GNUC__ == 2 && (__GNUC_MINOR__ > 95))
-    #define likely(x)   __builtin_expect(!!(x), 1)
-    #define unlikely(x) __builtin_expect(!!(x), 0)
-  #else /* __GNUC__ > 2 ... */
-    #define likely(x)   (x)
-    #define unlikely(x) (x)
-  #endif /* __GNUC__ > 2 ... */
+  #define likely(x)   __builtin_expect(!!(x), 1)
+  #define unlikely(x) __builtin_expect(!!(x), 0)
 #else /* __GNUC__ */
   #define likely(x)   (x)
   #define unlikely(x) (x)
diff --git a/xpcom/base/nscore.h b/xpcom/base/nscore.h
index c667a8ae31..6300099ef6 100644
--- a/xpcom/base/nscore.h
+++ b/xpcom/base/nscore.h
@@ -134,18 +134,10 @@
  *
  *  where nsIFoo::typeFunc is any method declared as
  *  NS_IMETHOD typeFunc(nsISupports*);
- *
- *  XXX this can be simplified to always use the non-typeof implementation
- *  when http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11893 is fixed.
  */
 
-#ifdef __GNUC__
-#define NS_STDCALL_FUNCPROTO(ret, name, class, func, args) \
-  typeof(&class::func) name
-#else
 #define NS_STDCALL_FUNCPROTO(ret, name, class, func, args) \
   ret (NS_STDCALL class::*name) args
-#endif
 
 /**
  * Deprecated declarations.
diff --git a/xpcom/glue/nsCOMPtr.h b/xpcom/glue/nsCOMPtr.h
index 7ab6a143c5..3b1833c359 100644
--- a/xpcom/glue/nsCOMPtr.h
+++ b/xpcom/glue/nsCOMPtr.h
@@ -59,10 +59,8 @@
 
 #ifdef __GNUC__
   // Our use of nsCOMPtr_base::mRawPtr violates the C++ standard's aliasing
-  // rules. Mark it with the may_alias attribute so that gcc 3.3 and higher
-  // don't reorder instructions based on aliasing assumptions for
-  // this variable.  Fortunately, gcc versions < 3.3 do not do any
-  // optimizations that break nsCOMPtr.
+  // rules. Mark it with the may_alias attribute so that gcc doesn't reorder
+  // instructions based on aliasing assumptions for this variable.
 
   #define NS_MAY_ALIAS_PTR(t)    t*  __attribute__((__may_alias__))
 #else
diff --git a/xpcom/string/nsTSubstring.h b/xpcom/string/nsTSubstring.h
index 8e3b417441..a1c1264193 100644
--- a/xpcom/string/nsTSubstring.h
+++ b/xpcom/string/nsTSubstring.h
@@ -991,7 +991,6 @@ protected:
   friend class nsTObsoleteAStringThunk_CharT;
   friend class nsTSubstringTuple_CharT;
 
-  // XXX GCC 3.4 needs this :-(
   friend class nsTPromiseFlatString_CharT;
 
   char_type*  mData;