Some traversers that insert code to main() assume that the main()
function has a non-null body node in place. This assumption was
previously wrong, since functions could be missing the body node
in case the function body was empty.

Fix possible invalid dereferencing of missing function body nodes by
always adding an empty sequence node to represent the body of
functions that have an empty body in the ESSL source. This also
enables simplifying some tree traversers that used to take the
possibility of missing function body nodes into account.

Also fix AddDefaultReturnStatements to check the last statement inside
the function body for a return statement, instead of checking the
first statement.

BUG=angleproject:1539
TEST=angle_unittests, angle_end2end_tests

Change-Id: I2fbd18c78653fa2f1a96dbd9a619accc4874030d
Reviewed-on: https://chromium-review.googlesource.com/392046Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>

This reverts commit 9aa83fe3.

The new test UniformBufferTest.ActiveUniformNumberAndName/ES3_OPENGL is failing on multiple platforms. Examples:
https://build.chromium.org/p/chromium.gpu.fyi/builders/Mac%2010.10%20Release%20%28ATI%29/builds/12285
https://build.chromium.org/p/chromium.gpu.fyi/builders/Linux%20Release%20(ATI)

Change-Id: I78b1a4d58e9a291e40ad304eb32f990e0518f7ee
Reviewed-on: https://chromium-review.googlesource.com/391049Reviewed-by: Kenneth Russell <kbr@chromium.org>

This reverts commit ca40662a.

https://chromium.googlesource.com/angle/angle/+/ca40662aa81f7735d3510fa52e55d28503c7f9ec broke angle_end2end_tests on the Win Debug bots. Examples: 

https://build.chromium.org/p/chromium.gpu.fyi/builders/Win7%20Debug%20%28NVIDIA%29/builds/18718 
https://build.chromium.org/p/chromium.gpu.fyi/builders/Win8%20Debug%20%28NVIDIA%29/builds/15905 

Tests failing: 
Texture2DTest.QueryBinding/ES2_D3D11 
Texture2DTest.QueryBinding/ES2_D3D9 
Texture2DTest.QueryBinding/ES2_D3D11_9_3

Change-Id: If9da864f49e0de3a134d43ae36c2a99e9b5a2a53
Reviewed-on: https://chromium-review.googlesource.com/391130Reviewed-by: John Bauman <jbauman@chromium.org>

BUG=angleproject:1510

Change-Id: I9ed7c877767909ba93e2ea5ef09c4735b0d0bcc7
Reviewed-on: https://chromium-review.googlesource.com/382652
Commit-Queue: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>

BUG=angleproject:1332

Change-Id: I591b9520bc1122eb6232803ac86b6d0322f8c349
Reviewed-on: https://chromium-review.googlesource.com/390323
Commit-Queue: John Bauman <jbauman@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>

This allows specifying data size to all GL functions that provide a pointer to
client memory and a length parameter for all functions in which the driver
writes to client memory.

BUG=angleproject:1354

Change-Id: Ia68be1576b957cb529c87b5e0d1bd638c7dbd371
Reviewed-on: https://chromium-review.googlesource.com/382012
Commit-Queue: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>

BUG=angleproject:1510

Change-Id: I42355607235a05fe276342084acd1eb359c16de4
Reviewed-on: https://chromium-review.googlesource.com/390414Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>

This avoids creating a weird aggregate node with a sequence of
constant union nodes to store the offsets. They're stored neatly
inside a vector instead. This makes code that needs to iterate
over the swizzle offsets much simpler.

BUG=angleproject:1490
TEST=angle_unittests

Change-Id: I156b95723529ee05a94d30295ffb6d0952a98564
Reviewed-on: https://chromium-review.googlesource.com/390832Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>

After experiencing a device loss, Renderer11::resetDevice can fail to
recreate mDevice, leaving it null. In a following call to
testDeviceLost, mDevice will be dereferenced, causing a segfault.

BUG=angleproject:1457

Change-Id: Ib5be64542929441ceb7088a328c3245ae7e52f17
Reviewed-on: https://chromium-review.googlesource.com/364120Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Geoff Lang <geofflang@chromium.org>

On some Mac drivers with shader version 4.1, they will
treat unused std140 and shared uniform blocks' members as inactive. However,
WebGL2.0 based on OpenGL ES3.0.4 requires all members of a named uniform block
declared with a shared or std140 layout qualifier to be considered active.
The uniform block itself is also considered active.

This workaround is to reference all members of unused std140 and shared uniform blocks
at the beginning of the vertex/fragment shader's main().

BUG=chromium:618464
TEST=UniformBufferTest.ActiveUniformBlockNumber

Change-Id: I1d2c5e3e8da04786ac6a37fd26f7bb9c14cd76ed
Reviewed-on: https://chromium-review.googlesource.com/387169
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>

BUG=angleproject:1512

Change-Id: I4c60472d216bfc5198e635d70fd197a5738dde98
Reviewed-on: https://chromium-review.googlesource.com/390133
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>

On some Intel drivers, calling function isnan() on highp float will get wrong
answer. This patch work arounds this bug by using an expression to emulate
this function.

BUG=chromium:650547

Change-Id: I5bc5e0352c434f42cd2c55103a74f9f7ba51a72c
Reviewed-on: https://chromium-review.googlesource.com/389834
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>

Negating the minimum representable integer overflows, so it
has undefined behavior in C++. Handle this as a special case in the
code.

BUG=chromium:637050
TEST=angle_unittests

Change-Id: Ic6e6d638faddad9b70b5d1637bb4b42ef4f43784
Reviewed-on: https://chromium-review.googlesource.com/390551Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>

Integer operations that overflow are defined to wrap in the ESSL
3.00.6 spec. Constant folding that happens inside the shader
translator should also follow the wrapping rules.

The new implementations of wrapping integer addition and subtraction
use unsigned integers to perform calculations. Unsigned integers are
defined to implement arithmetic in modulo 2^n in the C++ spec. This
behavior is also leveraged to implement wrapping unsigned integer
multiplication.

The implementation of wrapping signed integer multiplication is
slightly trickier. The operands are casted to a wider type to perform
the multiplication in a way that doesn't overflow, and then the result
is truncated and casted back to the narrower integer type.

Incorrect tests that expected errors to be generated from integer
overflow in constant folding are removed.

BUG=chromium:637050
TEST=angle_unittests

Change-Id: I0de7e25881d254803455fbf22907c192f49d09ff
Reviewed-on: https://chromium-review.googlesource.com/390252
Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>

Implements workarounds for:
 - The pack state making rows overlap in memory, which causes crashes on
   some drivers.
 - The driver adding an extra last row padding when checking if the
   pixel pack buffer is large enough for the readPixels.

BUG=angleproject:1512

Change-Id: I120ff58649bb523e8b01da6ef03d8fcadaf076b2
Reviewed-on: https://chromium-review.googlesource.com/388029
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>

BUG=angleproject:1386

Change-Id: I44da3a4cb2b23f98978349f26b80d6bb3a6dc8b5
Reviewed-on: https://chromium-review.googlesource.com/388784
Commit-Queue: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>

ESSL has undefined behavior when the integer modulus operator is used
on negative operands. Generate a warning and fold the result to zero
in this case.

In case the minimum representable signed integer is divided by -1, the
result is defined to be either the maximum or minimum representable
value. We choose to fold the calculation to the maximum representable
value in this case.

BUG=angleproject:1537
TEST=angle_unittests

Change-Id: I57fac6b54a3553b7a0f0e36cc6ba0ed59a88eea9
Reviewed-on: https://chromium-review.googlesource.com/390251Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>

BUG=angleproject:1512

Change-Id: Ia6bac628c35f04bc5d3adfde1569902475519698
Reviewed-on: https://chromium-review.googlesource.com/387668
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>

The code used to incorrectly assert that the right-hand side of shift
should have the same signedness as the left-hand side. Instead simply
assert that both the lhs and rhs are integer typed, and also don't
rely on aliasing via union when accessing bit shift operands.

Also disallow constant folded bit shifts where the right hand side is
greater than 31. Shifting with values greater than the width of the
type has undefined results in both ESSL and C++.

BUG=chromium:648135
TEST=angle_unittests

Change-Id: I84a99abc55f0eeda549b4781e954d17ba7b87552
Reviewed-on: https://chromium-review.googlesource.com/389351Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>

- Use full header paths in includes
- Use ASSERT instead of assert
- Use angle::NonCopyable instead of PP_DISALLOW_COPY_AND_ASSIGN
- Use range-for in a couple places
- Remove pp_utils.h

BUG=angleproject:1522

Change-Id: If107fef89e8465bca65cf664926d1051c5d1e232
Reviewed-on: https://chromium-review.googlesource.com/387212
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>

This will allow the OpenGL driver to reclaim GPU memory.

BUG=angleproject:1512

Change-Id: If063e1ff9f4a544012ca78c37e198054cb4edcac
Reviewed-on: https://chromium-review.googlesource.com/388771
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>

Fails on Win7 Release (AMD R7 240) bot

BUG=angleproject:1535

Change-Id: I5e8d0552867bfe0d81f3e189536c50b36f530089
Reviewed-on: https://chromium-review.googlesource.com/389233Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
Commit-Queue: Yuly Novikov <ynovikov@chromium.org>

We would advertise ES3 in some cases when we didn't support it.

BUG=angleproject:1381
BUG=chromium:649101

Change-Id: I2a5bbc1d6153cdfc6c9c577aa0b82caf8482a42d
Reviewed-on: https://chromium-review.googlesource.com/388190
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>

The ES3 spec and this extension lead to some awkward interactions. The
extension doesn't mention allowed filtering modes, so be default it
allows both linear and nearest. ES3 however, very clearly restricts
any depth texture (any texture with effective internal format which
has depth or stencil bits) to only use nearest filtering. This then
breaks compatibility with the legazy unsized formats.

Choose to be slightly non-conformant here, and allow linear filtering
for the older unsized formats. Although this could lead to problems
down the line, it is consistent with existing ES drivers in practice.

Other future options might be to override the behaviour of the filter
to use nearest when using WebGL validation compatibility.

BUG=chromium:649200

Change-Id: I4ee7608dd04d1fd238385aefee32c8c9c1e80ca0
Reviewed-on: https://chromium-review.googlesource.com/388759Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>

Because 2D and external textures have the same HLSL texture type, they were
generating texture functions with the same name.  This causes conflicts when
both 2D and external textures are used in the same shader.

BUG=angleproject:1534
BUG=645532

Change-Id: I4b324014b7d9b4851d358730cf4e31fc8461584c
Reviewed-on: https://chromium-review.googlesource.com/388551Reviewed-by: Corentin Wallez <cwallez@chromium.org>

BUG=angleproject:1518

Change-Id: I662f7b07da5c97831496f2617b0adadf9858bdc9
Reviewed-on: https://chromium-review.googlesource.com/386799Reviewed-by: Antoine Labour <piman@chromium.org>
Commit-Queue: Geoff Lang <geofflang@chromium.org>

BUG=chromium:648135

Change-Id: I41581f63af650564a0f61c1baeeb38017c8513ed
Reviewed-on: https://chromium-review.googlesource.com/387470
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>

BUG=angleproject:1512

Change-Id: Ifdb8d4c38e3c90e03eee42ba9fd6390dffd61363
Reviewed-on: https://chromium-review.googlesource.com/388611Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>

BUG=angleproject:1522
BUG=chromium:648074

Change-Id: Ibf0858aaeb81933dd221ac82a49160169b48a495
Reviewed-on: https://chromium-review.googlesource.com/387211Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>

The validation for ReadPixels allows for two combations of format/type:
  1. Based on the current framebuffer's component type.
    * GL_RGBA/GL_UNSIGNED_BYTE if the framebuffer is a normalized (signed
      or unsigned).
    * GL_RGBA_INTEGER/GL_INTEGER if the framebuffer is an
      integer format.
    * GL_RGBA_INTEGER/GL_UNSIGNED_INTEGER if the framebuffer is an
      unsigned integer format.
    * GL_RGBA/GL_FLOAT if the framebuffer is any type of float
      framebuffer (added in EXT_color_buffer_float).
    * These combations are detailed in the ES2 spec on pg 105 or ES3 on pg
      193.
  2. The implementation read format/type returned from glGetIntegerv.
    * These formats are added by specs, OES_texture_float, EXT_texture_rg,
      EXT_read_format_bgra, etc.

Update the GL and D3D backends to perform the conversion from GL_HALF_FLOAT
to GL_HALF_FLOAT_OES.

Continue allowing reading as BGRA_EXT to support Skia.  Should be removed in
the future.

BUG=607283
BUG=angleproject:1478

Change-Id: I0312cad4d5f138ab036f383d221f8ccd19a77f6d
Reviewed-on: https://chromium-review.googlesource.com/346232
Commit-Queue: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>

Using the same policy as for system memory storage, we release
the staging buffer if it has been unmodified for several uses.

We could further extend this technique to other storage buffers
using a nearly identical policy. We might need to mitigate the
cost of iterating over all the storages of all the buffers.

BUG=angleproject:516

Change-Id: Ib24ef03cf4184ef6f0c24f83347538df82de5f58
Reviewed-on: https://chromium-review.googlesource.com/387200Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>

In preparation for making them robust.

BUG=chromium:648135

Change-Id: I88fc87d8887064fda04087c56de05d8725a6fe5f
Reviewed-on: https://chromium-review.googlesource.com/387469Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>

BUG=chromium:648031
BUG=angleproject:1522

Change-Id: I825cea9e736a2c99133408249cfcd525431d31de
Reviewed-on: https://chromium-review.googlesource.com/386853
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>

Remove useTemporaryIndex() in function RewriteTexelFetchOffset since
no temporary variables will be created in this function.

BUG=angleproject:1469

Change-Id: Ibed56f0ba5c89b6ae1ab1611de39514c3fbb600f
Reviewed-on: https://chromium-review.googlesource.com/387198Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>

When uploading textures from an unpack buffer, some drivers expect an
extra row paading, causing them to think the pixel buffer is not big enough.
We work around this by uploading the last row separately.

BUG=angleproject:1512

Change-Id: I52fb8b35dc450b957f1fafb0b405c81bf0504157
Reviewed-on: https://chromium-review.googlesource.com/385193
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>

DrawBuffersTest.FirstAndLast/ES2_OPENGL
DrawBuffersTest.FirstHalfNULL/ES2_OPENGL
Hang on Win7 Release (ATI) and Win7 Debug (ATI) bots.

BUG=angleproject:1533

Change-Id: I6e37893fbcdbcc7a2a76c1cab6e8ef1f7ebaec19
Reviewed-on: https://chromium-review.googlesource.com/387714Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
Commit-Queue: Yuly Novikov <ynovikov@chromium.org>

BUG=648063

Change-Id: Ia90d12c8cb4ae0a694227145267e78ca02dcc2b0
Reviewed-on: https://chromium-review.googlesource.com/387114
Commit-Queue: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>

BUG=648063

Change-Id: I82d9fbdaf8791a396dd71eeb57d93967ba5d65bf
Reviewed-on: https://chromium-review.googlesource.com/387115Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>

Since the CallDAG is needed to check for the call graph depth, its
creation code must be robust to very deep call graphs.

BUG=angleproject:1517

Change-Id: I753ab84ad4ced6363a212f0fe94a89aabf4e3c3e
Reviewed-on: https://chromium-review.googlesource.com/385496Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>

BUG=angleproject:1523

Change-Id: I6fecb5055ed8087665aeee34b3a066ea8f38d51b
Reviewed-on: https://chromium-review.googlesource.com/386281Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Antoine Labour <piman@chromium.org>
Commit-Queue: Geoff Lang <geofflang@chromium.org>