From 6f0fdac9e7248c4e82ba2c9f6331694db0174bb2 Mon Sep 17 00:00:00 2001
From: hendrikw <hendrikw@chromium.org>
Date: Wed, 23 Sep 2015 11:35:55 -0700
Subject: [PATCH] skia: Add support for ANGLE on linux

This will allow the ANGLE guys to test the ANGLE gl backend
with nanobench and DM

Review URL: https://codereview.chromium.org/1343193005
---
 gyp/common.gypi                               |  4 +--
 gyp/common_conditions.gypi                    | 11 ++++++++
 gyp/common_variables.gypi                     | 12 ++++++++-
 include/views/SkOSWindow_Unix.h               |  3 +++
 src/gpu/gl/angle/GrGLCreateANGLEInterface.cpp | 27 ++++++++++++++-----
 5 files changed, 47 insertions(+), 10 deletions(-)

diff --git a/gyp/common.gypi b/gyp/common.gypi
index a3ce66e362..46ae9f37e7 100644
--- a/gyp/common.gypi
+++ b/gyp/common.gypi
@@ -30,8 +30,8 @@
         [ 'skia_mesa and skia_os not in ["mac", "linux"]', {
           'error': '<!(skia_mesa=1 only supported with skia_os="mac" or "linux".)',
         }],
-        [ 'skia_angle and not skia_os == "win"', {
-          'error': '<!(skia_angle=1 only supported with skia_os="win".)',
+        [ 'skia_angle and not (skia_os == "win" or skia_os == "linux")', {
+          'error': '<!(skia_angle=1 only supported with skia_os="win" or skia_os="linux".)',
         }],
         [ 'skia_os == "chromeos" and OS != "linux"', {
           'error': '<!(Skia ChromeOS build is only supported on Linux.)',
diff --git a/gyp/common_conditions.gypi b/gyp/common_conditions.gypi
index 54fa54345e..60020ed23a 100644
--- a/gyp/common_conditions.gypi
+++ b/gyp/common_conditions.gypi
@@ -250,6 +250,17 @@
                   '-m32',
                 ],
               }],
+              [ 'skia_angle == 1' , {
+                'cflags!': [
+                  '-fstrict-aliasing',
+                ],
+                'cflags_cc!': [
+                  '-Wnon-virtual-dtor',
+                ],
+                'cflags_cc': [
+                  '-Wno-unknown-pragmas',
+                ],
+              }],
             ],
           }],
           [ 'skia_warnings_as_errors', {
diff --git a/gyp/common_variables.gypi b/gyp/common_variables.gypi
index 3f122a5a78..e8a835541c 100644
--- a/gyp/common_variables.gypi
+++ b/gyp/common_variables.gypi
@@ -89,6 +89,11 @@
         }, {
           'os_posix%': 1,
         }],
+        [ 'skia_os == "linux"', {
+          # ANGLE on linux require these two variable be defined.
+          'chromeos%': 0,
+          'use_x11%': 1,
+        }],
         [ 'skia_os == "android"', {
           'skia_static_initializers%': 0,
           'skia_egl%': 1,
@@ -164,6 +169,11 @@
       }, {
         'skia_release_optimization_level%': '<(skia_default_gcc_optimization_level)',
       }],
+      [ 'skia_os == "linux"', {
+        # ANGLE on linux require these two variable be defined.
+        'chromeos%': 0,
+        'use_x11%': 1,
+      }],
       [ 'skia_sanitizer', {
         'skia_clang_build': 1,
         'skia_keep_frame_pointer': 1,
@@ -171,7 +181,7 @@
         'skia_clang_build%': 0,
         'skia_keep_frame_pointer%': 0,
       }],
-      [ 'skia_shared_lib or skia_sanitizer or skia_os == "android"', {
+      [ 'skia_shared_lib or skia_sanitizer or skia_os == "android" or (skia_os == "linux" and skia_angle == 1)', {
           'skia_pic%' : 1,
         }, {
           'skia_pic%' : 0,
diff --git a/include/views/SkOSWindow_Unix.h b/include/views/SkOSWindow_Unix.h
index 62705b441e..d7fcf6e392 100644
--- a/include/views/SkOSWindow_Unix.h
+++ b/include/views/SkOSWindow_Unix.h
@@ -36,6 +36,9 @@ public:
     enum SkBackEndTypes {
         kNone_BackEndType,
         kNativeGL_BackEndType,
+#if SK_ANGLE
+        kANGLE_BackEndType,
+#endif // SK_ANGLE
     };
 
     bool attach(SkBackEndTypes attachType, int msaaSampleCount, AttachmentInfo*);
diff --git a/src/gpu/gl/angle/GrGLCreateANGLEInterface.cpp b/src/gpu/gl/angle/GrGLCreateANGLEInterface.cpp
index 51e461a0d8..9a4dffb4b1 100644
--- a/src/gpu/gl/angle/GrGLCreateANGLEInterface.cpp
+++ b/src/gpu/gl/angle/GrGLCreateANGLEInterface.cpp
@@ -10,12 +10,21 @@
 #include "gl/GrGLInterface.h"
 #include "gl/GrGLAssembleInterface.h"
 
+#if defined _WIN32
 #define WIN32_LEAN_AND_MEAN
 #include <windows.h>
+#else
+#include <dlfcn.h>
+#endif // defined _WIN32
+
 #include <EGL/egl.h>
 
 static GrGLFuncPtr angle_get_gl_proc(void* ctx, const char name[]) {
+#if defined _WIN32
     GrGLFuncPtr proc = (GrGLFuncPtr) GetProcAddress((HMODULE)ctx, name);
+#else
+    GrGLFuncPtr proc = (GrGLFuncPtr) dlsym(ctx, name);
+#endif // defined _WIN32
     if (proc) {
         return proc;
     }
@@ -23,17 +32,21 @@ static GrGLFuncPtr angle_get_gl_proc(void* ctx, const char name[]) {
 }
 
 const GrGLInterface* GrGLCreateANGLEInterface() {
+    static void* gANGLELib = nullptr;
 
-    static HMODULE ghANGLELib = nullptr;
-
-    if (nullptr == ghANGLELib) {
+    if (nullptr == gANGLELib) {
         // We load the ANGLE library and never let it go
-        ghANGLELib = LoadLibrary("libGLESv2.dll");
+#if defined _WIN32
+        gANGLELib = LoadLibrary("libGLESv2.dll");
+#else
+        gANGLELib = dlopen("libGLESv2.so", RTLD_LAZY);
+#endif // defined _WIN32
     }
-    if (nullptr == ghANGLELib) {
-        // We can't setup the interface correctly w/o the DLL
+
+    if (nullptr == gANGLELib) {
+        // We can't setup the interface correctly w/o the so
         return nullptr;
     }
 
-    return GrGLAssembleGLESInterface(ghANGLELib, angle_get_gl_proc);
+    return GrGLAssembleGLESInterface(gANGLELib, angle_get_gl_proc);
 }
-- 
2.34.1