Initialize destinations variables before calling GL functions

because if the context is lost those variables will
be uninitialized.

TEST=ran chrome, conformance tests, unit tests and hand edited gles2_demo to test
BUG=none

Review URL: http://codereview.chromium.org/5254006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@68480 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 93 insertions, 2 deletions

diff --git a/gpu/command_buffer/build_gles2_cmd_buffer.py b/gpu/command_buffer/build_gles2_cmd_buffer.py
index 01a321f..d6e4661 100755
--- a/gpu/command_buffer/build_gles2_cmd_buffer.py
+++ b/gpu/command_buffer/build_gles2_cmd_buffer.py
@@ -2145,6 +2145,11 @@ TEST_F(%(test_name)s, %(name)sInvalidArgs%(arg_index)d_%(value_index)d) {
     else:
       self.WriteGLES2ImplementationDeclaration(func, file)
 
+  def WriteDestinationInitalizationValidation(self, func, file):
+    """Writes the client side destintion initialization validation."""
+    for arg in func.GetOriginalArgs():
+      arg.WriteDestinationInitalizationValidation(file, func)
+
   def WriteImmediateCmdComputeSize(self, func, file):
     """Writes the size computation code for the immediate version of a cmd."""
     file.Write("  static uint32 ComputeSize(uint32 size_in_bytes) {\n")
@@ -4000,6 +4005,7 @@ class Argument(object):
     'GLfloat': 'float',
     'GLclampf': 'float',
   }
+  need_validation_ = ['GLsizei*', 'GLboolean*', 'GLenum*', 'GLint*']
 
   def __init__(self, name, type):
     self.name = name
@@ -4049,6 +4055,20 @@ class Argument(object):
     """Writes the validation code for an argument."""
     pass
 
+  def WriteDestinationInitalizationValidation(self, file, func):
+    """Writes the client side destintion initialization validation."""
+    pass
+
+  def WriteDestinationInitalizationValidatationIfNeeded(self, file, func):
+    """Writes the client side destintion initialization validation if needed."""
+    parts = self.type.split(" ")
+    if len(parts) > 1:
+      return
+    if parts[0] in self.need_validation_:
+      file.Write("  GL_CLIENT_VALIDATE_DESTINATION_INITALIZATION(%s, %s);\n" %
+          (self.type[:-1], self.name))
+
+
   def WriteGetAddress(self, file):
     """Writes the code to get the address this argument refers to."""
     pass
@@ -4233,6 +4253,10 @@ class ImmediatePointerArgument(Argument):
     """Overridden from Argument."""
     return None
 
+  def WriteDestinationInitalizationValidation(self, file, func):
+    """Overridden from Argument."""
+    self.WriteDestinationInitalizationValidatationIfNeeded(file, func)
+
 
 class BucketPointerArgument(Argument):
   """A class that represents an bucket argument to a function."""
@@ -4258,6 +4282,10 @@ class BucketPointerArgument(Argument):
     """Overridden from Argument."""
     return None
 
+  def WriteDestinationInitalizationValidation(self, file, func):
+    """Overridden from Argument."""
+    self.WriteDestinationInitalizationValidatationIfNeeded(file, func)
+
 
 class PointerArgument(Argument):
   """A class that represents a pointer argument to a function."""
@@ -4328,6 +4356,10 @@ class PointerArgument(Argument):
       return InputStringBucketArgument(self.name, self.type)
     return BucketPointerArgument(self.name, self.type)
 
+  def WriteDestinationInitalizationValidation(self, file, func):
+    """Overridden from Argument."""
+    self.WriteDestinationInitalizationValidatationIfNeeded(file, func)
+
 
 class InputStringBucketArgument(Argument):
   """An string input argument where the string is passed in a bucket."""
@@ -4649,6 +4681,10 @@ class Function(object):
     """Writes the GLES2 Implemention declaration."""
     self.type_handler.WriteGLES2ImplementationHeader(self, file)
 
+  def WriteDestinationInitalizationValidation(self, file):
+    """Writes the client side destintion initialization validation."""
+    self.type_handler.WriteDestinationInitalizationValidation(self, file)
+
   def WriteFormatTest(self, file):
     """Writes the cmd's format test."""
     self.type_handler.WriteFormatTest(self, file)
@@ -5136,6 +5172,7 @@ class GLGenerator(object):
       file.Write("%s GLES2%s(%s) {\n" %
                  (func.return_type, func.name,
                   func.MakeTypedOriginalArgString("")))
+      func.WriteDestinationInitalizationValidation(file)
       comma = ""
       if len(func.GetOriginalArgs()):
         comma = " << "
diff --git a/gpu/command_buffer/client/gles2_c_lib.cc b/gpu/command_buffer/client/gles2_c_lib.cc
index 74cc431..f53067e 100644
--- a/gpu/command_buffer/client/gles2_c_lib.cc
+++ b/gpu/command_buffer/client/gles2_c_lib.cc
@@ -4,8 +4,36 @@
 
 // These functions emluate GLES2 over command buffers for C.
 
+#include <assert.h>
 #include "../client/gles2_lib.h"
 
+// Check that destination pointers point to initialized memory.
+// When the context is lost, calling GL function has no effect so if destination
+// pointers point to initialized memory it can often lead to crash bugs. eg.
+//
+// GLsizei len;
+// glGetShaderSource(shader, max_size, &len, buffer);
+// std::string src(buffer, buffer + len);  // len can be uninitialized here!!!
+//
+// Because this check is not official GL this check happens only on Chrome code,
+// not Pepper.
+//
+// If it was up to us we'd just always write to the destination but the OpenGL
+// spec defines the behavior of OpenGL function, not us. :-(
+#if defined(__native_client__)
+  #define GL_CLIENT_VALIDATE_DESTINATION_INITALIZATION_ASSERT(v)
+#elif defined(GPU_DCHECK)
+  #define GL_CLIENT_VALIDATE_DESTINATION_INITALIZATION_ASSERT(v) GPU_DCHECK(v)
+#elif defined(DCHECK)
+  #define GL_CLIENT_VALIDATE_DESTINATION_INITALIZATION_ASSERT(v) DCHECK(v)
+#else
+  #define GL_CLIENT_VALIDATE_DESTINATION_INITALIZATION_ASSERT(v) ASSERT(v)
+#endif
+
+#define GL_CLIENT_VALIDATE_DESTINATION_INITALIZATION(type, ptr) \
+    GL_CLIENT_VALIDATE_DESTINATION_INITALIZATION_ASSERT(ptr && \
+        (ptr[0] == static_cast<type>(0) || ptr[0] == static_cast<type>(-1)));
+
 extern "C" {
 // Include the auto-generated part of this file. We split this because it means
 // we can easily edit the non-auto generated parts right here in this file
diff --git a/gpu/command_buffer/client/gles2_c_lib_autogen.h b/gpu/command_buffer/client/gles2_c_lib_autogen.h
index 01cb485..13cf792 100644
--- a/gpu/command_buffer/client/gles2_c_lib_autogen.h
+++ b/gpu/command_buffer/client/gles2_c_lib_autogen.h
@@ -279,6 +279,9 @@ void GLES2GenTextures(GLsizei n, GLuint* textures) {
 void GLES2GetActiveAttrib(
     GLuint program, GLuint index, GLsizei bufsize, GLsizei* length, GLint* size,
     GLenum* type, char* name) {
+  GL_CLIENT_VALIDATE_DESTINATION_INITALIZATION(GLsizei, length);
+  GL_CLIENT_VALIDATE_DESTINATION_INITALIZATION(GLint, size);
+  GL_CLIENT_VALIDATE_DESTINATION_INITALIZATION(GLenum, type);
   GPU_CLIENT_LOG(
       "GetActiveAttrib" << "(" << program << ", " << index << ", " << bufsize << ", " << length << ", " << size << ", " << type << ", " << name << ")");  // NOLINT
   gles2::GetGLContext()->GetActiveAttrib(
@@ -287,6 +290,9 @@ void GLES2GetActiveAttrib(
 void GLES2GetActiveUniform(
     GLuint program, GLuint index, GLsizei bufsize, GLsizei* length, GLint* size,
     GLenum* type, char* name) {
+  GL_CLIENT_VALIDATE_DESTINATION_INITALIZATION(GLsizei, length);
+  GL_CLIENT_VALIDATE_DESTINATION_INITALIZATION(GLint, size);
+  GL_CLIENT_VALIDATE_DESTINATION_INITALIZATION(GLenum, type);
   GPU_CLIENT_LOG(
       "GetActiveUniform" << "(" << program << ", " << index << ", " << bufsize << ", " << length << ", " << size << ", " << type << ", " << name << ")");  // NOLINT
   gles2::GetGLContext()->GetActiveUniform(
@@ -294,6 +300,7 @@ void GLES2GetActiveUniform(
 }
 void GLES2GetAttachedShaders(
     GLuint program, GLsizei maxcount, GLsizei* count, GLuint* shaders) {
+  GL_CLIENT_VALIDATE_DESTINATION_INITALIZATION(GLsizei, count);
   GPU_CLIENT_LOG(
       "GetAttachedShaders" << "(" << program << ", " << maxcount << ", " << count << ", " << shaders << ")");  // NOLINT
   gles2::GetGLContext()->GetAttachedShaders(program, maxcount, count, shaders);
@@ -305,10 +312,12 @@ GLint GLES2GetAttribLocation(GLuint program, const char* name) {
   return result;
 }
 void GLES2GetBooleanv(GLenum pname, GLboolean* params) {
+  GL_CLIENT_VALIDATE_DESTINATION_INITALIZATION(GLboolean, params);
   GPU_CLIENT_LOG("GetBooleanv" << "(" << pname << ", " << params << ")");
   gles2::GetGLContext()->GetBooleanv(pname, params);
 }
 void GLES2GetBufferParameteriv(GLenum target, GLenum pname, GLint* params) {
+  GL_CLIENT_VALIDATE_DESTINATION_INITALIZATION(GLint, params);
   GPU_CLIENT_LOG(
       "GetBufferParameteriv" << "(" << target << ", " << pname << ", " << params << ")");  // NOLINT
   gles2::GetGLContext()->GetBufferParameteriv(target, pname, params);
@@ -325,45 +334,54 @@ void GLES2GetFloatv(GLenum pname, GLfloat* params) {
 }
 void GLES2GetFramebufferAttachmentParameteriv(
     GLenum target, GLenum attachment, GLenum pname, GLint* params) {
+  GL_CLIENT_VALIDATE_DESTINATION_INITALIZATION(GLint, params);
   GPU_CLIENT_LOG(
       "GetFramebufferAttachmentParameteriv" << "(" << target << ", " << attachment << ", " << pname << ", " << params << ")");  // NOLINT
   gles2::GetGLContext()->GetFramebufferAttachmentParameteriv(
       target, attachment, pname, params);
 }
 void GLES2GetIntegerv(GLenum pname, GLint* params) {
+  GL_CLIENT_VALIDATE_DESTINATION_INITALIZATION(GLint, params);
   GPU_CLIENT_LOG("GetIntegerv" << "(" << pname << ", " << params << ")");
   gles2::GetGLContext()->GetIntegerv(pname, params);
 }
 void GLES2GetProgramiv(GLuint program, GLenum pname, GLint* params) {
+  GL_CLIENT_VALIDATE_DESTINATION_INITALIZATION(GLint, params);
   GPU_CLIENT_LOG(
       "GetProgramiv" << "(" << program << ", " << pname << ", " << params << ")");  // NOLINT
   gles2::GetGLContext()->GetProgramiv(program, pname, params);
 }
 void GLES2GetProgramInfoLog(
     GLuint program, GLsizei bufsize, GLsizei* length, char* infolog) {
+  GL_CLIENT_VALIDATE_DESTINATION_INITALIZATION(GLsizei, length);
   GPU_CLIENT_LOG(
       "GetProgramInfoLog" << "(" << program << ", " << bufsize << ", " << length << ", " << infolog << ")");  // NOLINT
   gles2::GetGLContext()->GetProgramInfoLog(program, bufsize, length, infolog);
 }
 void GLES2GetRenderbufferParameteriv(
     GLenum target, GLenum pname, GLint* params) {
+  GL_CLIENT_VALIDATE_DESTINATION_INITALIZATION(GLint, params);
   GPU_CLIENT_LOG(
       "GetRenderbufferParameteriv" << "(" << target << ", " << pname << ", " << params << ")");  // NOLINT
   gles2::GetGLContext()->GetRenderbufferParameteriv(target, pname, params);
 }
 void GLES2GetShaderiv(GLuint shader, GLenum pname, GLint* params) {
+  GL_CLIENT_VALIDATE_DESTINATION_INITALIZATION(GLint, params);
   GPU_CLIENT_LOG(
       "GetShaderiv" << "(" << shader << ", " << pname << ", " << params << ")");
   gles2::GetGLContext()->GetShaderiv(shader, pname, params);
 }
 void GLES2GetShaderInfoLog(
     GLuint shader, GLsizei bufsize, GLsizei* length, char* infolog) {
+  GL_CLIENT_VALIDATE_DESTINATION_INITALIZATION(GLsizei, length);
   GPU_CLIENT_LOG(
       "GetShaderInfoLog" << "(" << shader << ", " << bufsize << ", " << length << ", " << infolog << ")");  // NOLINT
   gles2::GetGLContext()->GetShaderInfoLog(shader, bufsize, length, infolog);
 }
 void GLES2GetShaderPrecisionFormat(
     GLenum shadertype, GLenum precisiontype, GLint* range, GLint* precision) {
+  GL_CLIENT_VALIDATE_DESTINATION_INITALIZATION(GLint, range);
+  GL_CLIENT_VALIDATE_DESTINATION_INITALIZATION(GLint, precision);
   GPU_CLIENT_LOG(
       "GetShaderPrecisionFormat" << "(" << shadertype << ", " << precisiontype << ", " << range << ", " << precision << ")");  // NOLINT
   gles2::GetGLContext()->GetShaderPrecisionFormat(
@@ -371,6 +389,7 @@ void GLES2GetShaderPrecisionFormat(
 }
 void GLES2GetShaderSource(
     GLuint shader, GLsizei bufsize, GLsizei* length, char* source) {
+  GL_CLIENT_VALIDATE_DESTINATION_INITALIZATION(GLsizei, length);
   GPU_CLIENT_LOG(
       "GetShaderSource" << "(" << shader << ", " << bufsize << ", " << length << ", " << source << ")");  // NOLINT
   gles2::GetGLContext()->GetShaderSource(shader, bufsize, length, source);
@@ -387,6 +406,7 @@ void GLES2GetTexParameterfv(GLenum target, GLenum pname, GLfloat* params) {
   gles2::GetGLContext()->GetTexParameterfv(target, pname, params);
 }
 void GLES2GetTexParameteriv(GLenum target, GLenum pname, GLint* params) {
+  GL_CLIENT_VALIDATE_DESTINATION_INITALIZATION(GLint, params);
   GPU_CLIENT_LOG(
       "GetTexParameteriv" << "(" << target << ", " << pname << ", " << params << ")");  // NOLINT
   gles2::GetGLContext()->GetTexParameteriv(target, pname, params);
@@ -397,6 +417,7 @@ void GLES2GetUniformfv(GLuint program, GLint location, GLfloat* params) {
   gles2::GetGLContext()->GetUniformfv(program, location, params);
 }
 void GLES2GetUniformiv(GLuint program, GLint location, GLint* params) {
+  GL_CLIENT_VALIDATE_DESTINATION_INITALIZATION(GLint, params);
   GPU_CLIENT_LOG(
       "GetUniformiv" << "(" << program << ", " << location << ", " << params << ")");  // NOLINT
   gles2::GetGLContext()->GetUniformiv(program, location, params);
@@ -414,6 +435,7 @@ void GLES2GetVertexAttribfv(GLuint index, GLenum pname, GLfloat* params) {
   gles2::GetGLContext()->GetVertexAttribfv(index, pname, params);
 }
 void GLES2GetVertexAttribiv(GLuint index, GLenum pname, GLint* params) {
+  GL_CLIENT_VALIDATE_DESTINATION_INITALIZATION(GLint, params);
   GPU_CLIENT_LOG(
       "GetVertexAttribiv" << "(" << index << ", " << pname << ", " << params << ")");  // NOLINT
   gles2::GetGLContext()->GetVertexAttribiv(index, pname, params);
diff --git a/gpu/command_buffer/client/gles2_demo_cc.cc b/gpu/command_buffer/client/gles2_demo_cc.cc
index cb33f8c..e271a0f 100644
--- a/gpu/command_buffer/client/gles2_demo_cc.cc
+++ b/gpu/command_buffer/client/gles2_demo_cc.cc
@@ -47,7 +47,7 @@ GLuint LoadShader(GLenum type, const char* shaderSrc) {
   // Compile the shader
   glCompileShader(shader);
   // Check the compile status
-  GLint value;
+  GLint value = 0;
   glGetShaderiv(shader, GL_COMPILE_STATUS, &value);
   if (value == 0) {
     char buffer[1024];
@@ -100,7 +100,7 @@ void InitShaders() {
   // Link the program
   glLinkProgram(programObject);
   // Check the link status
-  GLint linked;
+  GLint linked = 0;
   glGetProgramiv(programObject, GL_LINK_STATUS, &linked);
   if (linked == 0) {
     char buffer[1024];
@@ -173,6 +173,10 @@ void GLFromCPPInit() {
   g_texture = CreateCheckerboardTexture();
   InitShaders();
   CheckGLError("GLFromCPPInit", __LINE__);
+
+  char buf[128];
+  glReadPixels(0, 0, 1, 1, 0, 0, buf);
+  CheckGLError("GLFromCPPInit:ReadPixels", __LINE__);
 }
 
 void GLFromCPPDraw() {