// MobileGL - MobileGL/MG_Test/Program/ProgramArtifactsCodecTest.cpp
// Copyright (c) 2025-2026 MobileGL-Dev
// Licensed under the GNU Lesser General Public License v3.0:
//   https://www.gnu.org/licenses/gpl-3.0.txt
//   https://www.gnu.org/licenses/lgpl-3.0.txt
// SPDX-License-Identifier: LGPL-3.0-only
// End of Source File Header

// The reflection ARCHIVE's serializer (P4a): create_shader_state's payload is per-stage SPIR-V
// plus LinkArtifacts + SpirvArtifacts, whole structs, and the codec is what turns them into
// bytes. In monolith it is never called on the hot path - the two structs ride beside the
// record through the apply entry point's companion pointers - so THIS SUITE plus the verify
// lane's round trip are the only things that exercise it until a transport exists.
//
// WHAT IT HAS TO PIN, and each of the three is a different failure:
//   * a fully populated archive survives a round trip FIELD BY FIELD, including both of
//     XfbVarying's spellings (the GL name AND the block instance / member / element triple)
//     and every one of TypeFacts' twenty members - a codec that dropped one would be invisible
//     until a backend read a reflection answer that had quietly become zero;
//   * a TRUNCATED stream is refused rather than guessed at;
//   * a VERSION or wire-schema mismatch is refused before decoding; native STL object
//     sizes do not describe a cross-platform serialized archive.
//
// AND ONE PROPERTY THAT IS NOT ABOUT BYTES AT ALL: LinkArtifacts has 58 members and its
// VisitFields table visits 57. The 58th is the live SharedPtr<glslang::TProgram>, which is
// null for every archived instance by construction and points into an arena no archive owns.
// The codec has no arm for it, and the count is asserted here because that is the only place
// it can be: VisitFields needs an instance, and these structs carry strings, vectors and maps,
// so no static_assert can walk them.
//
// Every case is a visible SKIP in a pull build rather than a vanishing test, so `ctest -N`
// stays name-for-name identical between the pull and the push trees.

#include <gtest/gtest.h>
#include <cstdlib>
#include <cstring>
#include <fstream>
#include <string>

#if !defined(_WIN32)
#include <sys/resource.h>
#include <unistd.h>
#endif

#include "Includes.h"
#include <MG_State/GLState/ProgramState/ProgramArtifactsCodec.h>

using namespace MobileGL;
using namespace MobileGL::MG_State::GLState;

namespace {
    TypeFacts MakeTypeFacts() {
        // Every member set to something that is NOT its default, so a field the codec skips
        // reads back as the default and the comparison names it.
        TypeFacts facts{};
        facts.isArray = true;
        facts.isSizedArray = true;
        facts.isMatrix = true;
        facts.isVector = true;
        facts.isOpaque = true;
        facts.isTexture = true;
        facts.isImage = true;
        facts.isDouble = true;
        facts.isVoid = true;
        facts.isBuffer = true;
        facts.isPatch = true;
        facts.hasIndex = true;
        facts.hasFormat = true;
        facts.vectorSize = 3;
        facts.matrixCols = 4;
        facts.matrixRows = 2;
        facts.layoutIndex = 7;
        facts.layoutFormat = 0x8814u;
        facts.layoutMatrix = 1;
        facts.basicType = 11;
        return facts;
    }

    ResourceReflection MakeReflection(const char* name, Int location) {
        ResourceReflection reflection{};
        reflection.name = name;
        reflection.glDefineType = GL_FLOAT_VEC4;
        reflection.offset = 16;
        reflection.size = 4;
        reflection.index = 2;
        reflection.counterIndex = 3;
        reflection.arrayStride = 16;
        reflection.topLevelArraySize = 5;
        reflection.topLevelArrayStride = 32;
        reflection.binding = 6;
        reflection.location = location;
        reflection.stages = 0x3u;
        reflection.arraySize = 8;
        reflection.type = MakeTypeFacts();
        return reflection;
    }

    XfbVarying MakeXfbVarying() {
        XfbVarying varying{};
        // BOTH SPELLINGS. `name` is the GL one ("Block.member"), which the interface queries
        // and the ESSL driver-side capture list need; the triple below is what a SPIR-V
        // backend needs instead, because the decoration target is the block's instance
        // variable and the member index inside it.
        varying.name = "Captured.position";
        varying.type = GL_FLOAT_VEC3;
        varying.size = 2;
        varying.bufferIndex = 1;
        varying.offsetBytes = 12;
        varying.byteSize = 24;
        varying.packedOffsetBytes = 8;
        varying.blockInstanceName = "capturedInstance";
        varying.blockName = "Captured";
        varying.blockMemberIndex = 1;
        varying.blockMemberElement = 3;
        return varying;
    }

    LinkArtifacts MakeLinkArtifacts() {
        LinkArtifacts link{};
        link.uniformReflection = {MakeReflection("uColour", 0), MakeReflection("uMatrix", 1)};
        link.blockReflection = {MakeReflection("Block", -1)};
        link.pipeInputReflection = {MakeReflection("inPosition", 0)};
        link.pipeOutputReflection = {MakeReflection("outColour", 0)};
        link.lastStageIsFragment = true;
        link.computeLocalSize = {8u, 4u, 2u};
        link.uniformIndexByName = {{"uColour", 0}, {"uMatrix", 1}};
        link.attribs = {"inPosition", "inNormal"};
        link.attribTypes = {GL_FLOAT_VEC3, GL_FLOAT_VEC3};
        link.linkedFragDataLocation = {{"outColour", 0u}};
        link.linkedFragDataIndex = {{"outColour", 1u}};
        link.glUniformIndexToTProgram = {0, 1};
        link.tProgramUniformIndexToGl = {0, 1};
        link.glBlockIndexToTProgram = {0};
        link.tProgramBlockIndexToGl = {-1};
        link.glUniformBlockIndexToBlock = {0};
        link.blockIndexToGlUniformBlock = {0};
        link.linkedExplicitUniformLocations = {{"uColour", 3}};
        link.uniformLocations = {{"uColour", 0u}, {"uMatrix", 4u}};
        link.writtenUniformLocationBits = {0x5ull};
        link.writtenUniformIndexBits = {0x3ull};
        link.writtenUniformIndices = {0u, 1u};
        link.uniformIndexInTProgram = {0, 1};
        link.uniformSamplerOrImageUnitIndex = {-1, 2};
        link.explicitOpaqueUniformBindings = {{"uSampler", 5u}};
        link.uniformBlockIndexByName = {{"Block", 0u}};
        link.uniformBlockBinding = {2};
        link.shaderStorageBlockBinding = {{"Storage", 1}};
        link.storageBlocksWithoutBinding = {"Storage"};
        link.uniformBlocksWithoutBinding = {"Block"};
        link.activeUniformCount = 2u;
        link.usesReservedNumSamples = true;
        link.maxUniformLocation = 4u;
        link.uniformNameMaxLength = 9;
        link.attribInNameMaxLength = 11;
        link.uniformBlockNameMaxLength = 6;
        link.infoLog = "linked with warnings";
        link.linkStatus = true;
        link.xfbVaryings = {MakeXfbVarying()};
        link.xfbInterfaceNames = {"gl_NextBuffer", "Captured.position"};
        link.xfbStrides = {32u, 0u};
        link.gsStripTriangles = {3u, 5u};
        link.gsStripCaptureFixup = true;
        link.gsInputPrimitive = GL_TRIANGLES;
        link.tcsOutputVertices = 3;
        link.gsOutputPrimitive = GL_TRIANGLE_STRIP;
        link.gsMaxVertices = 12;
        link.gsInvocations = 2;
        link.tessGenMode = GL_QUADS;
        link.tessGenSpacing = GL_FRACTIONAL_ODD;
        link.tessGenVertexOrder = GL_CW;
        link.tessGenPointMode = true;
        link.xfbBufferMode = GL_SEPARATE_ATTRIBS;
        link.xfbVaryingNameMaxLength = 18;
        link.xfbNeedsScatteredCapture = true;
        link.xfbPackedStride = 24u;

        // The one glslang-typed member that DOES travel: a plain aggregate of a string,
        // scalars and two vectors. The codec has a hand-written arm for it because
        // ProgramArtifacts.h gives it no VisitFields table.
        glslang::TIntermediate::TUniformInitializer initializer;
        initializer.name = "uInitialised";
        initializer.basicType = glslang::EbtInt;
        initializer.vectorSize = 2;
        initializer.matrixCols = 0;
        initializer.matrixRows = 0;
        initializer.arraySize = 3;
        initializer.intValues = {1, 2, 3, 4, 5, 6};
        initializer.floatValues = {};
        link.uniformInitialValues.push_back(initializer);
        return link;
    }

    // How many archive bytes follow a u64 `count` that is itself followed by `next` - the LAST such
    // spot, so a fixture can find the count of a field near the archive's end. This is
    // Remaining() at the moment TakeCount reads that count. SIZE_MAX when there is no such spot.
    SizeT BytesAfterTheCount(const Vector<Uint8>& bytes, Uint64 count, const Vector<Uint8>& next) {
        Vector<Uint8> needle(sizeof(count));
        std::memcpy(needle.data(), &count, sizeof(count));
        needle.insert(needle.end(), next.begin(), next.end());
        if (bytes.size() < needle.size()) return static_cast<SizeT>(-1);
        for (SizeT at = bytes.size() - needle.size() + 1; at-- > 0;) {
            if (std::memcmp(bytes.data() + at, needle.data(), needle.size()) == 0) {
                return bytes.size() - at - sizeof(count);
            }
        }
        return static_cast<SizeT>(-1);
    }

    // The encoded width of one DEFAULT element of LinkArtifacts::uniformReflection, measured
    // through the encoder itself: an archive with one such element minus an archive with none.
    // A default ResourceReflection has an empty name, so this is the smallest encoding one can
    // have - the charge PH-5's TakeCount makes per element.
    SizeT EncodedBytesOfOneDefaultResourceReflection() {
        Vector<Uint8> none;
        EncodeProgramArtifacts(LinkArtifacts{}, SpirvArtifacts{}, none);
        LinkArtifacts one{};
        one.uniformReflection.resize(1);
        Vector<Uint8> withOne;
        EncodeProgramArtifacts(one, SpirvArtifacts{}, withOne);
        return withOne.size() - none.size();
    }

    SpirvArtifacts MakeSpirvArtifacts() {
        SpirvArtifacts spirv{};
        spirv.generatedSpirv = {{0x07230203u, 0x00010300u, 0u}, {0x07230203u, 0x00010300u, 1u}};
        spirv.enableSpirvValidation = true;
        spirv.uniformOffsets = {0u, 16u, kInvalidUniformOffset};
        spirv.globalUboScratch = {1, 2, 3, 4, 5, 6, 7, 8};
        spirv.reservedNumSamplesOffset = 32u;
        spirv.spirvStatus = true;
        spirv.nativeFloat64 = true;
        spirv.pointSizeDemoted = true;
        return spirv;
    }
} // namespace

// The round trip, field by field. A re-encode equality alone would prove the codec is
// self-consistent and nothing else - a field it skips in BOTH directions round-trips
// perfectly - so the members are read back explicitly first, and the byte comparison is the
// catch-all underneath them.
TEST(ProgramArtifactsCodec, RoundTripsAFullyPopulatedArchive) {
    const LinkArtifacts link = MakeLinkArtifacts();
    const SpirvArtifacts spirv = MakeSpirvArtifacts();

    Vector<Uint8> bytes;
    EncodeProgramArtifacts(link, spirv, bytes);
    ASSERT_FALSE(bytes.empty());

    LinkArtifacts decodedLink;
    SpirvArtifacts decodedSpirv;
    ASSERT_TRUE(DecodeProgramArtifacts(bytes.data(), bytes.size(), decodedLink, decodedSpirv));

    // The four reflection vectors, with their TypeFacts.
    ASSERT_EQ(decodedLink.uniformReflection.size(), 2u);
    EXPECT_EQ(decodedLink.uniformReflection[0].name, "uColour");
    EXPECT_EQ(decodedLink.uniformReflection[1].location, 1);
    EXPECT_EQ(decodedLink.uniformReflection[0].arrayStride, 16);
    EXPECT_EQ(decodedLink.uniformReflection[0].stages, 0x3u);
    EXPECT_TRUE(decodedLink.uniformReflection[0].type.isSizedArray);
    EXPECT_EQ(decodedLink.uniformReflection[0].type.matrixCols, 4);
    EXPECT_EQ(decodedLink.uniformReflection[0].type.layoutFormat, 0x8814u);
    EXPECT_EQ(decodedLink.uniformReflection[0].type.basicType, 11);
    ASSERT_EQ(decodedLink.blockReflection.size(), 1u);
    ASSERT_EQ(decodedLink.pipeInputReflection.size(), 1u);
    ASSERT_EQ(decodedLink.pipeOutputReflection.size(), 1u);

    // BOTH XfbVarying SPELLINGS.
    ASSERT_EQ(decodedLink.xfbVaryings.size(), 1u);
    EXPECT_EQ(decodedLink.xfbVaryings[0].name, "Captured.position");
    EXPECT_EQ(decodedLink.xfbVaryings[0].blockInstanceName, "capturedInstance");
    EXPECT_EQ(decodedLink.xfbVaryings[0].blockName, "Captured");
    EXPECT_EQ(decodedLink.xfbVaryings[0].blockMemberIndex, 1);
    EXPECT_EQ(decodedLink.xfbVaryings[0].blockMemberElement, 3);
    EXPECT_EQ(decodedLink.xfbVaryings[0].packedOffsetBytes, 8u);

    // The maps, the set and the fixed array - the four container shapes the archive is made
    // of, each with a reader that has to agree with its writer about the length prefix.
    EXPECT_EQ(decodedLink.uniformIndexByName.size(), 2u);
    EXPECT_EQ(decodedLink.uniformIndexByName.at("uMatrix"), 1);
    EXPECT_EQ(decodedLink.shaderStorageBlockBinding.at("Storage"), 1);
    EXPECT_EQ(decodedLink.storageBlocksWithoutBinding.count("Storage"), 1u);
    EXPECT_EQ(decodedLink.uniformBlocksWithoutBinding.count("Block"), 1u);
    EXPECT_EQ(decodedLink.computeLocalSize[0], 8u);
    EXPECT_EQ(decodedLink.computeLocalSize[2], 2u);

    // The glslang-typed aggregate, through the codec's one hand-written arm.
    ASSERT_EQ(decodedLink.uniformInitialValues.size(), 1u);
    EXPECT_EQ(decodedLink.uniformInitialValues[0].name, "uInitialised");
    EXPECT_EQ(decodedLink.uniformInitialValues[0].basicType, glslang::EbtInt);
    EXPECT_EQ(decodedLink.uniformInitialValues[0].arraySize, 3);
    ASSERT_EQ(decodedLink.uniformInitialValues[0].intValues.size(), 6u);
    EXPECT_EQ(decodedLink.uniformInitialValues[0].intValues[5], 6);
    EXPECT_TRUE(decodedLink.uniformInitialValues[0].floatValues.empty());

    // The scalars at the tail, which is where a length-prefix that drifted by one would first
    // read as garbage rather than as a short read.
    EXPECT_EQ(decodedLink.infoLog, "linked with warnings");
    EXPECT_TRUE(decodedLink.linkStatus);
    EXPECT_EQ(decodedLink.tessGenSpacing, static_cast<GLenum>(GL_FRACTIONAL_ODD));
    EXPECT_TRUE(decodedLink.tessGenPointMode);
    EXPECT_EQ(decodedLink.xfbPackedStride, 24u);

    // SpirvArtifacts, including the nested vector of SPIR-V words and the sentinel offset.
    ASSERT_EQ(decodedSpirv.generatedSpirv.size(), 2u);
    ASSERT_EQ(decodedSpirv.generatedSpirv[0].size(), 3u);
    EXPECT_EQ(decodedSpirv.generatedSpirv[1][2], 1u);
    ASSERT_EQ(decodedSpirv.uniformOffsets.size(), 3u);
    EXPECT_EQ(decodedSpirv.uniformOffsets[2], kInvalidUniformOffset);
    EXPECT_EQ(decodedSpirv.globalUboScratch.size(), 8u);
    EXPECT_EQ(decodedSpirv.reservedNumSamplesOffset, 32u);
    EXPECT_TRUE(decodedSpirv.nativeFloat64);
    EXPECT_TRUE(decodedSpirv.pointSizeDemoted);

    // THE LIVE TProgram IS NEVER CARRIED and never reconstructed.
    EXPECT_EQ(decodedLink.program, nullptr);

    // The catch-all: re-encoding what came back has to produce the same bytes, which covers
    // every member the explicit reads above do not name.
    Vector<Uint8> reencoded;
    EncodeProgramArtifacts(decodedLink, decodedSpirv, reencoded);
    EXPECT_EQ(reencoded, bytes);
}

// A COMPACT archive - one whose wire form is SMALLER than its in-memory form - is still an archive
// this encoder wrote, and it has to come back (codex closeout finding 3). Ten one-character
// xfbInterfaceNames are 90 bytes on the wire and ten 32-byte std::strings in memory; with every
// vector behind them empty, the bytes that remain at their count are fewer than 10 x sizeof(String),
// and PH-5's first bound - which charged sizeof(value_type) per element - refused the archive. The
// same holds one level down for SpirvArtifacts::generatedSpirv: ten EMPTY modules are ten u64
// counts on the wire and ten 24-byte vectors in memory (the next case). Red with TakeCount's vector
// charge put back to sizeof(Element): the decode answers false. Each case's ASSERT_LT is the
// fixture's own proof that it can go red that way.
TEST(ProgramArtifactsCodec, ACompactArchiveOfTenShortXfbNamesRoundTrips) {
    {
        LinkArtifacts link{};
        link.xfbInterfaceNames = {"a", "b", "c", "d", "e", "f", "g", "h", "i", "j"};
        Vector<Uint8> bytes;
        EncodeProgramArtifacts(link, SpirvArtifacts{}, bytes);
        const Uint64 one = 1;
        Vector<Uint8> firstName(sizeof(one));
        std::memcpy(firstName.data(), &one, sizeof(one));
        firstName.push_back(static_cast<Uint8>('a'));
        const SizeT remaining = BytesAfterTheCount(bytes, link.xfbInterfaceNames.size(), firstName);
        ASSERT_LT(remaining, link.xfbInterfaceNames.size() * sizeof(String))
            << "fixture: a sizeof(value_type) charge would admit this count, so the case could not go red";

        LinkArtifacts decodedLink;
        SpirvArtifacts decodedSpirv;
        ASSERT_TRUE(DecodeProgramArtifacts(bytes.data(), bytes.size(), decodedLink, decodedSpirv))
            << "a LinkArtifacts with ten short XFB interface names, which this encoder wrote, was refused";
        EXPECT_EQ(decodedLink.xfbInterfaceNames, link.xfbInterfaceNames);
        EXPECT_TRUE(decodedLink.xfbStrides.empty());
        EXPECT_TRUE(decodedLink.gsStripTriangles.empty());
        Vector<Uint8> reencoded;
        EncodeProgramArtifacts(decodedLink, decodedSpirv, reencoded);
        EXPECT_EQ(reencoded, bytes);
    }
}

// The same compact shape one level down: a Vector<Vector<unsigned>> element (one SPIR-V module) is
// its u64 count on the wire when empty and a 24-byte object in memory.
TEST(ProgramArtifactsCodec, ACompactArchiveOfTenEmptySpirvModulesRoundTrips) {
    {
        SpirvArtifacts spirv{};
        spirv.generatedSpirv.resize(10);
        Vector<Uint8> bytes;
        EncodeProgramArtifacts(LinkArtifacts{}, spirv, bytes);
        const SizeT remaining = BytesAfterTheCount(bytes, spirv.generatedSpirv.size(),
                                                   Vector<Uint8>(10 * sizeof(Uint64), 0));
        ASSERT_LT(remaining, spirv.generatedSpirv.size() * sizeof(Vector<unsigned>))
            << "fixture: a sizeof(value_type) charge would admit this count, so the case could not go red";

        LinkArtifacts decodedLink;
        SpirvArtifacts decodedSpirv;
        ASSERT_TRUE(DecodeProgramArtifacts(bytes.data(), bytes.size(), decodedLink, decodedSpirv))
            << "a SpirvArtifacts with ten empty modules, which this encoder wrote, was refused";
        ASSERT_EQ(decodedSpirv.generatedSpirv.size(), 10u);
        for (const auto& module : decodedSpirv.generatedSpirv) EXPECT_TRUE(module.empty());
        Vector<Uint8> reencoded;
        EncodeProgramArtifacts(decodedLink, decodedSpirv, reencoded);
        EXPECT_EQ(reencoded, bytes);
    }
}

// Negative control 1. Every prefix length is checked against the bytes that REMAIN, so a
// stream cut anywhere has to come back false with both outputs defaulted - never a partially
// filled archive, and never a resize driven by a count the stream cannot back.
TEST(ProgramArtifactsCodec, ATruncatedStreamIsRefusedNotGuessed) {
    Vector<Uint8> bytes;
    EncodeProgramArtifacts(MakeLinkArtifacts(), MakeSpirvArtifacts(), bytes);
    ASSERT_GT(bytes.size(), 64u);

    // Cut at a spread of points rather than one: the header, a length prefix, the middle of a
    // string and the last byte all fail through different branches.
    for (const SizeT cut : {SizeT{0}, SizeT{4}, SizeT{9}, bytes.size() / 3, bytes.size() / 2,
                            bytes.size() - 1}) {
        LinkArtifacts link;
        SpirvArtifacts spirv;
        link.infoLog = "must be cleared";
        EXPECT_FALSE(DecodeProgramArtifacts(bytes.data(), cut, link, spirv))
            << "a stream truncated at " << cut << " was accepted";
        EXPECT_TRUE(link.infoLog.empty()) << "a refused decode left the output half-filled";
        EXPECT_TRUE(link.uniformReflection.empty());
        EXPECT_TRUE(spirv.generatedSpirv.empty());
    }

    // And TRAILING bytes are a mismatch too: the format accounts for every byte it writes, so
    // anything left over means the reader and the writer disagree about the shape.
    Vector<Uint8> withTail = bytes;
    withTail.push_back(0);
    LinkArtifacts link;
    SpirvArtifacts spirv;
    EXPECT_FALSE(DecodeProgramArtifacts(withTail.data(), withTail.size(), link, spirv));
}

// A count is not permission to reserve a container larger than the bytes left in the
// untrusted archive can back. This mutates the first LinkArtifacts vector count to the boundary
// value one element past PH-5's bound - the smallest count the remaining bytes cannot hold at
// the element's minimum encoded size - which the former raw <= Remaining check accepted. (Not
// discriminating on its own: under the byte bound the resize is small and the element reads run
// out of bytes, so the decode is false either way. ACountOnlyTheByteBoundAdmitsIsRefusedBeforeItsResize
// is the case that goes red.)
TEST(ProgramArtifactsCodec, AVectorCountCannotReservePastTheRemainingArchiveBytes) {
    Vector<Uint8> bytes;
    EncodeProgramArtifacts(LinkArtifacts{}, SpirvArtifacts{}, bytes);
    constexpr SizeT countOffset = sizeof(Uint32) + sizeof(Uint64);
    ASSERT_GT(bytes.size(), countOffset + sizeof(Uint64));
    const SizeT available = bytes.size() - countOffset - sizeof(Uint64);
    const SizeT perElement = EncodedBytesOfOneDefaultResourceReflection();
    // What finding 3 is about, stated: an element's wire floor is below its object size, and
    // above the one byte the former bound charged.
    ASSERT_GT(perElement, 1u);
    ASSERT_LT(perElement, sizeof(UniformReflection));
    const Uint64 forgedCount = static_cast<Uint64>(available / perElement) + 1;
    ASSERT_LT(forgedCount, static_cast<Uint64>(available))
        << "fixture must pass the old count <= remaining check";
    std::memcpy(bytes.data() + countOffset, &forgedCount, sizeof(forgedCount));

    LinkArtifacts link;
    SpirvArtifacts spirv;
    EXPECT_FALSE(DecodeProgramArtifacts(bytes.data(), bytes.size(), link, spirv));
    EXPECT_TRUE(link.uniformReflection.empty());
    EXPECT_TRUE(spirv.generatedSpirv.empty());
}

// PH-5's DISCRIMINATING control (P7 F2 latch). The case above cannot fail on PH-5's account: its
// count is one element past PH-5's bound, and with TakeCount put back to the old one-byte-per-
// element charge the same count is admitted, resize() is tiny, and the element reads run out of
// bytes - DecodeProgramArtifacts answers false either way (red-once: it stays green). What PH-5
// actually changed is the ALLOCATION a count may cause before the reads, so this case forges the
// count BETWEEN the two bounds - `count == Remaining()`, in an archive padded to 7 MiB - and
// decodes it in a forked child whose address space has 64 MiB of headroom. PH-5 charges each
// element its minimum encoded size (a ResourceReflection's is ~100 bytes; the codex closeout
// finding 3 fix, not sizeof), refuses before the resize, and the child exits 0; the old bound
// resizes to Remaining() elements of sizeof(UniformReflection) each, far past the headroom, and
// the child dies of std::bad_alloc. The same shape crosses the wire in PeerLatchTest's
// D11ArchiveVectorCount row.
#if !defined(_WIN32)
namespace {
    [[noreturn]] void DecodeACountOnlyTheByteBoundAdmitsUnderACapAndExit() {
        Vector<Uint8> bytes;
        EncodeProgramArtifacts(LinkArtifacts{}, SpirvArtifacts{}, bytes);
        constexpr SizeT countOffset = sizeof(Uint32) + sizeof(Uint64);
        bytes.resize(SizeT{7} << 20, 0);
        const Uint64 remaining = bytes.size() - countOffset - sizeof(Uint64);
        std::memcpy(bytes.data() + countOffset, &remaining, sizeof(remaining));
        constexpr Uint64 kHeadroom = Uint64{64} << 20;
        if (remaining * sizeof(UniformReflection) < 4 * kHeadroom) ::_exit(64); // the case would prove nothing
        Uint64 vmKb = 0;
        {
            std::ifstream status("/proc/self/status");
            std::string line;
            while (std::getline(status, line)) {
                if (line.rfind("VmSize:", 0) == 0) vmKb = std::strtoull(line.c_str() + 7, nullptr, 10);
            }
        }
        if (vmKb == 0) ::_exit(65);
        rlimit cap{};
        if (::getrlimit(RLIMIT_AS, &cap) != 0) ::_exit(66);
        cap.rlim_cur = static_cast<rlim_t>(vmKb * 1024 + kHeadroom);
        if (::setrlimit(RLIMIT_AS, &cap) != 0) ::_exit(67);
        LinkArtifacts link;
        SpirvArtifacts spirv;
        const Bool decoded = DecodeProgramArtifacts(bytes.data(), bytes.size(), link, spirv);
        ::_exit(!decoded && link.uniformReflection.empty() ? 0 : 3);
    }
} // namespace
#endif

TEST(ProgramArtifactsCodec, ACountOnlyTheByteBoundAdmitsIsRefusedBeforeItsResize) {
#if !defined(_WIN32)
    EXPECT_EXIT(DecodeACountOnlyTheByteBoundAdmitsUnderACapAndExit(), ::testing::ExitedWithCode(0), ".*")
        << "std::bad_alloc escaping the child is the resize PH-5 exists to refuse: the vector count was "
           "charged one byte per element instead of its minimum encoded size; exit 3 is a decode that "
           "did not refuse; 64+ is the fixture";
#else
    GTEST_SKIP() << "MOBILEGL_PIPE_PUSH is off (the archive codec is push-only), or no RLIMIT_AS / fork here";
#endif
}

// Negative control 2: both the version and schema word must refuse mismatches.
// Monolith v1 retains the old native-size echo in that second word.
TEST(ProgramArtifactsCodec, AVersionMismatchIsRefused) {
    Vector<Uint8> bytes;
    EncodeProgramArtifacts(MakeLinkArtifacts(), MakeSpirvArtifacts(), bytes);
    ASSERT_GT(bytes.size(), 12u);

    LinkArtifacts link;
    SpirvArtifacts spirv;
    ASSERT_TRUE(DecodeProgramArtifacts(bytes.data(), bytes.size(), link, spirv));

    // The version word first: a reader that saw a format it does not know must not try to
    // guess the layout.
    Vector<Uint8> wrongVersion = bytes;
    ++wrongVersion[0];
    EXPECT_FALSE(DecodeProgramArtifacts(wrongVersion.data(), wrongVersion.size(), link, spirv));

    // Then the wire schema (v2) or local native-size echo (v1). Neither may be ignored.
    Vector<Uint8> wrongSize = bytes;
    ++wrongSize[4];
    EXPECT_FALSE(DecodeProgramArtifacts(wrongSize.data(), wrongSize.size(), link, spirv));

    // A null pointer is refused rather than dereferenced.
    EXPECT_FALSE(DecodeProgramArtifacts(nullptr, 0, link, spirv));
}

// The codec walks the VisitFields tables and nothing else, so what those tables visit IS the
// archive. LinkArtifacts has 58 members and its table visits 57: the 58th is the live glslang
// TProgram, which is null for every archived instance by construction and points into an arena
// no archive owns. A codec arm for it would be a use-after-free waiting for a cache hit.
TEST(ProgramArtifactsCodec, TheTablesVisitEveryMemberExceptTheLiveProgram) {
    // P7 OQ-8: 59 members, 58 visited. The 59th is still the live TProgram; the 58th is
    // storageBlocks, which follows the record arm's guard (ProgramArtifacts.h).
    EXPECT_EQ(ProgramArtifactsVisitedFieldCount<LinkArtifacts>(), 58u);
    EXPECT_EQ(ProgramArtifactsVisitedFieldCount<StorageBlockReflection>(), 3u);
    EXPECT_EQ(ProgramArtifactsVisitedFieldCount<SpirvArtifacts>(), 8u);
    EXPECT_EQ(ProgramArtifactsVisitedFieldCount<ResourceReflection>(), 14u);
    EXPECT_EQ(ProgramArtifactsVisitedFieldCount<XfbVarying>(), 11u);
    EXPECT_EQ(ProgramArtifactsVisitedFieldCount<TypeFacts>(), 20u);
}

TEST(ProgramArtifactsCodec, PortableHeaderUsesWireSchemaRatherThanNativeContainerSize) {
#if MOBILEGL_BUILD_DISAGGREGATED
    Vector<Uint8> bytes;
    EncodeProgramArtifacts(MakeLinkArtifacts(), MakeSpirvArtifacts(), bytes);
    ASSERT_GT(bytes.size(), 12u);
    Uint32 version = 0;
    Uint64 schema = 0;
    std::memcpy(&version, bytes.data(), sizeof(version));
    std::memcpy(&schema, bytes.data() + sizeof(version), sizeof(schema));
    // 3 since P7 OQ-8 (CONTRACT-P7 §5.3): LinkArtifacts gained storageBlocks, so a v2 reader
    // would run out of bytes mid-stream rather than notice. The schema word beside it moved
    // too - it is derived from the VisitFields tables - and so did `wireFingerprint`, which is
    // what makes a mixed-version pair refuse at the handshake instead of at the first program.
    EXPECT_EQ(version, kProgramArtifactsCodecVersion);
    EXPECT_EQ(version, 3u);
    EXPECT_EQ(schema, ProgramArtifactsSchemaFingerprint());
    EXPECT_NE(schema, 0u);
    EXPECT_NE(schema, sizeof(LinkArtifacts));
    RecordProperty("program_archive_wire_schema", std::to_string(schema));

    // The old Linux/native echo (1056) and unpinned libc++ echo (0) both fail.
    // This control distinguishes a portable schema from simply deleting the check.
    for (const Uint64 legacyEcho : {Uint64{1056}, Uint64{0}}) {
        auto legacy = bytes;
        std::memcpy(legacy.data() + sizeof(version), &legacyEcho, sizeof(legacyEcho));
        LinkArtifacts link;
        SpirvArtifacts spirv;
        EXPECT_FALSE(DecodeProgramArtifacts(legacy.data(), legacy.size(), link, spirv));
        EXPECT_TRUE(link.uniformReflection.empty());
        EXPECT_TRUE(spirv.generatedSpirv.empty());
    }
    auto v1 = bytes;
    v1[0] = 1;
    LinkArtifacts link;
    SpirvArtifacts spirv;
    EXPECT_FALSE(DecodeProgramArtifacts(v1.data(), v1.size(), link, spirv));
#else
    GTEST_SKIP() << "portable archive headers apply to the disaggregated wire";
#endif
}