path: root/contrib/libs/hyperscan/src/rose/rose_build_matchers.cpp

/* 
 * Copyright (c) 2016-2019, Intel Corporation
 * 
 * Redistribution and use in source and binary forms, with or without 
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 * 
 *  * Redistributions of source code must retain the above copyright notice, 
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 *  * Neither the name of Intel Corporation nor the names of its contributors 
 *    may be used to endorse or promote products derived from this software 
 *    without specific prior written permission. 
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
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/** 
 * \file 
 * \brief Rose build: code for constructing literal tables. 
 */ 
 
#include "rose_build_matchers.h" 
 
#include "rose_build_dump.h" 
#include "rose_build_impl.h" 
#include "rose_build_lit_accel.h" 
#include "rose_build_width.h" 
#include "hwlm/hwlm_build.h" 
#include "hwlm/hwlm_internal.h" 
#include "hwlm/hwlm_literal.h" 
#include "nfa/castlecompile.h" 
#include "nfa/nfa_api_queue.h" 
#include "util/charreach_util.h" 
#include "util/compile_context.h" 
#include "util/compile_error.h" 
#include "util/dump_charclass.h" 
#include "util/make_unique.h" 
#include "util/report.h" 
#include "util/report_manager.h" 
#include "util/verify_types.h" 
#include "ue2common.h" 
 
#include <iomanip> 
#include <sstream> 
 
#include <boost/range/adaptor/map.hpp> 
#include <boost/range/adaptor/reversed.hpp> 
 
using namespace std; 
using boost::adaptors::map_values; 
 
namespace ue2 { 
 
static const size_t MAX_ACCEL_STRING_LEN = 16; 
 
#if defined(DEBUG) || defined(DUMP_SUPPORT) 
static UNUSED 
string dumpMask(const vector<u8> &v) { 
    ostringstream oss; 
    for (u8 e : v) { 
        oss << setfill('0') << setw(2) << hex << (unsigned int)e; 
    } 
    return oss.str(); 
} 
#endif 
 
static 
bool maskFromLeftGraph(const LeftEngInfo &left, vector<u8> &msk, 
                       vector<u8> &cmp) { 
    const u32 lag = left.lag; 
    const ReportID report = left.leftfix_report; 
 
    DEBUG_PRINTF("leftfix with lag %u, report %u\n", lag, report); 
 
    assert(left.graph); 
    const NGHolder &h = *left.graph; 
    assert(in_degree(h.acceptEod, h) == 1); // no eod reports 
 
    // Start with the set of reporter vertices for this leftfix. 
    set<NFAVertex> curr; 
    for (auto u : inv_adjacent_vertices_range(h.accept, h)) { 
        if (contains(h[u].reports, report)) { 
            curr.insert(u); 
        } 
    } 
    assert(!curr.empty()); 
 
    size_t i = HWLM_MASKLEN - lag - 1; 
    do { 
        if (curr.empty() || contains(curr, h.start) 
            || contains(curr, h.startDs)) { 
            DEBUG_PRINTF("end of the road\n"); 
            break; 
        } 
 
        set<NFAVertex> next; 
        CharReach cr; 
        for (NFAVertex v : curr) { 
            const auto &v_cr = h[v].char_reach; 
            DEBUG_PRINTF("vertex %zu, reach %s\n", h[v].index, 
                         describeClass(v_cr).c_str()); 
            cr |= v_cr; 
            insert(&next, inv_adjacent_vertices(v, h)); 
        } 
        make_and_cmp_mask(cr, &msk.at(i), &cmp.at(i)); 
        DEBUG_PRINTF("%zu: reach=%s, msk=%u, cmp=%u\n", i, 
                     describeClass(cr).c_str(), msk[i], cmp[i]); 
        curr.swap(next); 
    } while (i-- > 0); 
 
    return true; 
} 
 
static 
bool maskFromLeftCastle(const LeftEngInfo &left, vector<u8> &msk, 
                        vector<u8> &cmp) { 
    const u32 lag = left.lag; 
    const ReportID report = left.leftfix_report; 
 
    DEBUG_PRINTF("leftfix with lag %u, report %u\n", lag, report); 
 
    assert(left.castle); 
    const CastleProto &c = *left.castle; 
 
    depth min_width(depth::infinity()); 
    for (const PureRepeat &repeat : c.repeats | map_values) { 
        if (contains(repeat.reports, report)) { 
            min_width = min(min_width, repeat.bounds.min); 
        } 
    } 
 
    DEBUG_PRINTF("castle min width for this report is %s\n", 
                 min_width.str().c_str()); 
 
    if (!min_width.is_finite() || min_width == depth(0)) { 
        DEBUG_PRINTF("bad min width\n"); 
        return false; 
    } 
 
    u32 len = min_width; 
    u32 end = HWLM_MASKLEN - lag; 
    for (u32 i = end; i > end - min(end, len); i--) { 
        make_and_cmp_mask(c.reach(), &msk.at(i - 1), &cmp.at(i - 1)); 
    } 
 
    return true; 
} 
 
static 
bool maskFromLeft(const LeftEngInfo &left, vector<u8> &msk, vector<u8> &cmp) { 
    if (left.lag >= HWLM_MASKLEN) { 
        DEBUG_PRINTF("too much lag\n"); 
        return false; 
    } 
 
    if (left.graph) { 
        return maskFromLeftGraph(left, msk, cmp); 
    } else if (left.castle) { 
        return maskFromLeftCastle(left, msk, cmp); 
    } 
 
    return false; 
} 
 
static 
bool maskFromPreds(const RoseBuildImpl &build, const rose_literal_id &id, 
                   const RoseVertex v, vector<u8> &msk, vector<u8> &cmp) { 
    const RoseGraph &g = build.g; 
 
    // For right now, wuss out and only handle cases with one pred. 
    if (in_degree(v, g) != 1) { 
        return false; 
    } 
 
    // Root successors have no literal before them. 
    if (build.isRootSuccessor(v)) { 
        return false; 
    } 
 
    // If we have a single predecessor with a short bound, we may be able to 
    // fill out a mask with the trailing bytes of the previous literal. This 
    // allows us to improve literals like the 'bar' in 'fo.bar'. 
 
    RoseEdge e = *(in_edges(v, g).first); 
    u32 bound = g[e].maxBound; 
    if (bound != g[e].minBound || bound >= HWLM_MASKLEN) { 
        return false; 
    } 
 
    bound += id.s.length(); 
    if (bound >= HWLM_MASKLEN) { 
        return false; 
    } 
 
    DEBUG_PRINTF("bound %u\n", bound); 
 
    RoseVertex u = source(e, g); 
    if (g[u].literals.size() != 1) { 
        DEBUG_PRINTF("u has %zu literals\n", g[u].literals.size()); 
        return false; 
    } 
 
    u32 u_lit_id = *(g[u].literals.begin()); 
    const rose_literal_id &u_id = build.literals.at(u_lit_id); 
    DEBUG_PRINTF("u has lit: %s\n", escapeString(u_id.s).c_str()); 
 
    // Number of characters to take from the back of u's literal. 
    size_t u_len = u_id.s.length(); 
    size_t u_sublen = min(u_len, (size_t)HWLM_MASKLEN - bound); 
 
    size_t i = HWLM_MASKLEN - (bound + u_sublen); 
 
    ue2_literal::const_iterator it, ite; 
    for (it = u_id.s.begin() + (u_len - u_sublen), ite = u_id.s.end(); 
            it != ite; ++it) { 
        make_and_cmp_mask(*it, &msk.at(i), &cmp.at(i)); 
        ++i; 
    } 
 
    return true; 
} 
 
static 
bool addSurroundingMask(const RoseBuildImpl &build, const rose_literal_id &id, 
                        const RoseVertex v, vector<u8> &msk, vector<u8> &cmp) { 
    // Start with zero masks. 
    msk.assign(HWLM_MASKLEN, 0); 
    cmp.assign(HWLM_MASKLEN, 0); 
 
    const LeftEngInfo &left = build.g[v].left; 
    if (left && left.lag < HWLM_MASKLEN) { 
        if (maskFromLeft(left, msk, cmp)) { 
            DEBUG_PRINTF("mask from a leftfix!\n"); 
            return true; 
        } 
    } 
 
    if (id.s.length() < HWLM_MASKLEN) { 
        if (maskFromPreds(build, id, v, msk, cmp)) { 
            DEBUG_PRINTF("mask from preds!\n"); 
            return true; 
        } 
    } 
 
    return false; 
} 
 
static 
bool hamsterMaskCombine(vector<u8> &msk, vector<u8> &cmp, 
                        const vector<u8> &v_msk, const vector<u8> &v_cmp) { 
    assert(msk.size() == HWLM_MASKLEN && cmp.size() == HWLM_MASKLEN); 
    assert(v_msk.size() == HWLM_MASKLEN && v_cmp.size() == HWLM_MASKLEN); 
 
    u8 all_masks = 0; 
 
    for (size_t i = 0; i < HWLM_MASKLEN; i++) { 
        u8 filter = ~(cmp[i] ^ v_cmp[i]); 
        msk[i] &= v_msk[i]; 
        msk[i] &= filter; 
        cmp[i] &= filter; 
 
        all_masks |= msk[i]; 
    } 
 
    // Return false if we have no bits on in any mask elements. 
    return all_masks != 0; 
} 
 
static 
bool addSurroundingMask(const RoseBuildImpl &build, const rose_literal_id &id, 
                        const rose_literal_info &info, vector<u8> &msk, 
                        vector<u8> &cmp) { 
    if (!build.cc.grey.roseHamsterMasks) { 
        return false; 
    } 
 
    if (!info.delayed_ids.empty()) { 
        // Not safe to add masks to delayed literals at this late stage. 
        return false; 
    } 
 
    msk.assign(HWLM_MASKLEN, 0); 
    cmp.assign(HWLM_MASKLEN, 0); 
 
    size_t num = 0; 
    vector<u8> v_msk, v_cmp; 
 
    for (RoseVertex v : info.vertices) { 
        if (!addSurroundingMask(build, id, v, v_msk, v_cmp)) { 
            DEBUG_PRINTF("no mask\n"); 
            return false; 
        } 
 
        if (!num++) { 
            // First (or only) vertex, this becomes the mask/cmp pair. 
            msk = v_msk; 
            cmp = v_cmp; 
        } else { 
            // Multiple vertices with potentially different masks. We combine 
            // them into an 'advisory' mask. 
            if (!hamsterMaskCombine(msk, cmp, v_msk, v_cmp)) { 
                DEBUG_PRINTF("mask went to zero\n"); 
                return false; 
            } 
        } 
    } 
 
    normaliseLiteralMask(id.s, msk, cmp); 
 
    if (msk.empty()) { 
        DEBUG_PRINTF("no mask\n"); 
        return false; 
    } 
 
    DEBUG_PRINTF("msk=%s, cmp=%s\n", dumpMask(msk).c_str(), 
                 dumpMask(cmp).c_str()); 
    return true; 
} 
 
void findMoreLiteralMasks(RoseBuildImpl &build) { 
    if (!build.cc.grey.roseHamsterMasks) { 
        return; 
    } 
 
    vector<u32> candidates; 
    for (u32 id = 0; id < build.literals.size(); id++) { 
        const auto &lit = build.literals.at(id); 
 
        if (lit.delay || build.isDelayed(id)) { 
            continue; 
        } 
 
        // Literal masks are only allowed for literals that will end up in an 
        // HWLM table. 
        switch (lit.table) { 
        case ROSE_FLOATING: 
        case ROSE_EOD_ANCHORED: 
        case ROSE_ANCHORED_SMALL_BLOCK: 
            break; 
        default: 
            continue; 
        } 
 
        candidates.push_back(id); 
    } 
 
    for (const u32 &id : candidates) { 
        const auto &lit = build.literals.at(id); 
        auto &lit_info = build.literal_info.at(id); 
 
        vector<u8> msk, cmp; 
        if (!addSurroundingMask(build, lit, lit_info, msk, cmp)) { 
            continue; 
        } 
        DEBUG_PRINTF("found surrounding mask for lit_id=%u (%s)\n", id, 
                     dumpString(lit.s).c_str()); 
        u32 new_id = build.getLiteralId(lit.s, msk, cmp, lit.delay, lit.table); 
        if (new_id == id) { 
            continue; 
        } 
        DEBUG_PRINTF("replacing with new lit_id=%u\n", new_id); 
 
        // Note that our new literal may already exist and have vertices, etc. 
        // We assume that this transform is happening prior to group assignment. 
        assert(lit_info.group_mask == 0); 
        auto &new_info = build.literal_info.at(new_id); 
 
        // Move the vertices across. 
        new_info.vertices.insert(begin(lit_info.vertices), 
                                 end(lit_info.vertices)); 
        for (auto v : lit_info.vertices) { 
            build.g[v].literals.erase(id); 
            build.g[v].literals.insert(new_id); 
        } 
        lit_info.vertices.clear(); 
 
        // Preserve other properties. 
        new_info.requires_benefits = lit_info.requires_benefits; 
    } 
} 
 
// The mask already associated with the literal and any mask due to 
// mixed-case is mandatory. 
static 
void addLiteralMask(const rose_literal_id &id, vector<u8> &msk, 
                    vector<u8> &cmp) { 
    const size_t suffix_len = min(id.s.length(), size_t{HWLM_MASKLEN}); 
    bool mixed_suffix = mixed_sensitivity_in(id.s.end() - suffix_len, 
                                             id.s.end()); 
 
    if (id.msk.empty() && !mixed_suffix) { 
        return; 
    } 
 
    while (msk.size() < HWLM_MASKLEN) { 
        msk.insert(msk.begin(), 0); 
        cmp.insert(cmp.begin(), 0); 
    } 
 
    if (!id.msk.empty()) { 
        assert(id.msk.size() <= HWLM_MASKLEN); 
        assert(id.msk.size() == id.cmp.size()); 
        for (size_t i = 0; i < id.msk.size(); i++) { 
            size_t mand_offset = msk.size() - i - 1; 
            size_t lit_offset = id.msk.size() - i - 1; 
            msk[mand_offset] = id.msk[lit_offset]; 
            cmp[mand_offset] = id.cmp[lit_offset]; 
        } 
    } 
 
    if (mixed_suffix) { 
        auto it = id.s.rbegin(); 
        for (size_t i = 0; i < suffix_len; ++i, ++it) { 
            const auto &c = *it; 
            if (!c.nocase) { 
                size_t offset = HWLM_MASKLEN - i - 1; 
                DEBUG_PRINTF("offset %zu must match 0x%02x exactly\n", offset, 
                             c.c); 
                make_and_cmp_mask(c, &msk[offset], &cmp[offset]); 
            } 
        } 
    } 
 
    normaliseLiteralMask(id.s, msk, cmp); 
} 
 
static 
bool isDirectHighlander(const RoseBuildImpl &build, const u32 id, 
                        const rose_literal_info &info) { 
    if (!build.isDirectReport(id)) { 
        return false; 
    } 
 
    auto is_simple_exhaustible = [&build](ReportID rid) { 
        const Report &report = build.rm.getReport(rid); 
        return isSimpleExhaustible(report); 
    }; 
 
    assert(!info.vertices.empty()); 
    for (const auto &v : info.vertices) { 
        const auto &reports = build.g[v].reports; 
        assert(!reports.empty()); 
        if (!all_of(begin(reports), end(reports), 
                    is_simple_exhaustible)) { 
            return false; 
        } 
    } 
    return true; 
} 
 
// Called by isNoRunsLiteral below. 
static 
bool isNoRunsVertex(const RoseBuildImpl &build, RoseVertex u) { 
    const RoseGraph &g = build.g; 
    if (!g[u].isBoring()) { 
        DEBUG_PRINTF("u=%zu is not boring\n", g[u].index); 
        return false; 
    } 
 
    if (!g[u].reports.empty()) { 
        DEBUG_PRINTF("u=%zu has accept\n", g[u].index); 
        return false; 
    } 
 
    /* TODO: handle non-root roles as well. It can't be that difficult... */ 
 
    if (in_degree(u, g) != 1) { 
        DEBUG_PRINTF("u=%zu is not a root role\n", g[u].index); 
        return false; 
    } 
 
    RoseEdge e = edge(build.root, u, g); 
 
    if (!e) { 
        DEBUG_PRINTF("u=%zu is not a root role\n", g[u].index); 
        return false; 
    } 
 
    if (g[e].minBound != 0 || g[e].maxBound != ROSE_BOUND_INF) { 
        DEBUG_PRINTF("u=%zu has bounds from root\n", g[u].index); 
        return false; 
    } 
 
    for (const auto &oe : out_edges_range(u, g)) { 
        RoseVertex v = target(oe, g); 
        if (g[oe].maxBound != ROSE_BOUND_INF) { 
            DEBUG_PRINTF("edge (%zu,%zu) has max bound\n", g[u].index, 
                         g[v].index); 
            return false; 
        } 
        if (g[v].left) { 
            DEBUG_PRINTF("v=%zu has rose prefix\n", g[v].index); 
            return false; 
        } 
    } 
    return true; 
} 
 
static 
bool isNoRunsLiteral(const RoseBuildImpl &build, const u32 id, 
                     const rose_literal_info &info, const size_t max_len) { 
    DEBUG_PRINTF("lit id %u\n", id); 
 
    if (info.requires_benefits) { 
        DEBUG_PRINTF("requires benefits\n"); // which would need confirm 
        return false; 
    } 
 
    size_t len = build.literals.at(id).s.length(); 
    if (len > max_len) { 
        DEBUG_PRINTF("long literal, requires confirm\n"); 
        return false; 
    } 
 
    if (len > ROSE_SHORT_LITERAL_LEN_MAX) { 
        DEBUG_PRINTF("medium-length literal, requires confirm\n"); 
        return false; 
    } 
 
    if (isDirectHighlander(build, id, info)) { 
        DEBUG_PRINTF("highlander direct report\n"); 
        return true; 
    } 
 
    // Undelayed vertices. 
    for (RoseVertex v : info.vertices) { 
        if (!isNoRunsVertex(build, v)) { 
            return false; 
        } 
    } 
 
    // Delayed vertices. 
    for (u32 d : info.delayed_ids) { 
        assert(d < build.literal_info.size()); 
        const rose_literal_info &delayed_info = build.literal_info.at(d); 
        assert(delayed_info.undelayed_id == id); 
        for (RoseVertex v : delayed_info.vertices) { 
            if (!isNoRunsVertex(build, v)) { 
                return false; 
            } 
        } 
    } 
 
    DEBUG_PRINTF("is no-runs literal\n"); 
    return true; 
} 
 
static 
bool isNoRunsFragment(const RoseBuildImpl &build, const LitFragment &f, 
                      const size_t max_len) { 
    // For the fragment to be marked "no runs", every literal it fires must 
    // need no further confirmation work. 
    return all_of_in(f.lit_ids, [&](u32 lit_id) { 
        const auto &info = build.literal_info.at(lit_id); 
        return isNoRunsLiteral(build, lit_id, info, max_len); 
    }); 
} 
 
static 
const raw_puff &getChainedPuff(const RoseBuildImpl &build, 
                               const Report &report) { 
    DEBUG_PRINTF("chained report, event %u\n", report.onmatch); 
 
    // MPV has already been moved to the outfixes vector. 
    assert(!build.mpv_outfix); 
 
    auto mpv_outfix_it = find_if( 
        begin(build.outfixes), end(build.outfixes), 
        [](const OutfixInfo &outfix) { return outfix.is_nonempty_mpv(); }); 
    assert(mpv_outfix_it != end(build.outfixes)); 
    const auto *mpv = mpv_outfix_it->mpv(); 
 
    u32 puff_index = report.onmatch - MQE_TOP_FIRST; 
    assert(puff_index < mpv->triggered_puffettes.size()); 
    return mpv->triggered_puffettes.at(puff_index); 
} 
 
/** 
 * \brief Returns a conservative estimate of the minimum offset at which the 
 * given literal can lead to a report. 
 * 
 * TODO: This could be made more precise by calculating a "distance to accept" 
 * for every vertex in the graph; right now we're only accurate for leaf nodes. 
 */ 
static 
u64a literalMinReportOffset(const RoseBuildImpl &build, 
                           const rose_literal_id &lit, 
                           const rose_literal_info &info) { 
    const auto &g = build.g; 
 
    const u32 lit_len = verify_u32(lit.elength()); 
 
    u64a lit_min_offset = UINT64_MAX; 
 
    for (const auto &v : info.vertices) { 
        DEBUG_PRINTF("vertex %zu min_offset=%u\n", g[v].index, g[v].min_offset); 
 
        u64a vert_offset = g[v].min_offset; 
 
        if (vert_offset >= lit_min_offset) { 
            continue; 
        } 
 
        u64a min_offset = UINT64_MAX; 
 
        for (const auto &id : g[v].reports) { 
            const Report &report = build.rm.getReport(id); 
            DEBUG_PRINTF("report id %u, min offset=%llu\n", id, 
                         report.minOffset); 
            if (report.type == INTERNAL_ROSE_CHAIN) { 
                // This vertex triggers an MPV, which will fire reports after 
                // repeating for a while. 
                assert(report.minOffset == 0); // Should not have bounds. 
                const auto &puff = getChainedPuff(build, report); 
                DEBUG_PRINTF("chained puff repeats=%u\n", puff.repeats); 
                const Report &puff_report = build.rm.getReport(puff.report); 
                DEBUG_PRINTF("puff report %u, min offset=%llu\n", puff.report, 
                              puff_report.minOffset); 
                min_offset = min(min_offset, max(vert_offset + puff.repeats, 
                                                 puff_report.minOffset)); 
            } else { 
                DEBUG_PRINTF("report min offset=%llu\n", report.minOffset); 
                min_offset = min(min_offset, max(vert_offset, 
                                                 report.minOffset)); 
            } 
        } 
 
        if (g[v].suffix) { 
            depth suffix_width = findMinWidth(g[v].suffix, g[v].suffix.top); 
            assert(suffix_width.is_reachable()); 
            DEBUG_PRINTF("suffix with width %s\n", suffix_width.str().c_str()); 
            min_offset = min(min_offset, vert_offset + suffix_width); 
        } 
 
        if (!isLeafNode(v, g) || min_offset == UINT64_MAX) { 
            min_offset = vert_offset; 
        } 
 
        lit_min_offset = min(lit_min_offset, min_offset); 
    } 
 
    // If this literal in the undelayed literal corresponding to some delayed 
    // literals, we must take their minimum offsets into account. 
    for (const u32 &delayed_id : info.delayed_ids) { 
        const auto &delayed_lit = build.literals.at(delayed_id); 
        const auto &delayed_info = build.literal_info.at(delayed_id); 
        u64a delayed_min_offset = literalMinReportOffset(build, delayed_lit, 
                                                         delayed_info); 
        DEBUG_PRINTF("delayed_id=%u, min_offset = %llu\n", delayed_id, 
                     delayed_min_offset); 
        lit_min_offset = min(lit_min_offset, delayed_min_offset); 
    } 
 
    // If we share a vertex with a shorter literal, our min offset might dip 
    // below the length of this one. 
    lit_min_offset = max(lit_min_offset, u64a{lit_len}); 
 
    return lit_min_offset; 
} 
 
template<class Container> 
void trim_to_suffix(Container &c, size_t len) { 
    if (c.size() <= len) { 
        return; 
    } 
 
    size_t suffix_len = c.size() - len; 
    c.erase(c.begin(), c.begin() + suffix_len); 
} 
 
namespace { 
 
/** \brief Prototype for literal matcher construction. */ 
struct MatcherProto { 
    /** \brief Literal fragments used to construct the literal matcher. */ 
    vector<hwlmLiteral> lits; 
 
    /** \brief Longer literals used for acceleration analysis. */ 
    vector<AccelString> accel_lits; 
 
    /** \brief The history required by the literal matcher. */ 
    size_t history_required = 0; 
 
    /** \brief Insert the contents of another MatcherProto. */ 
    void insert(const MatcherProto &a); 
}; 
} 
 
static 
void addFragmentLiteral(const RoseBuildImpl &build, MatcherProto &mp, 
                        const LitFragment &f, u32 id, size_t max_len) { 
    const rose_literal_id &lit = build.literals.at(id); 
 
    DEBUG_PRINTF("lit='%s' (len %zu)\n", dumpString(lit.s).c_str(), 
                 lit.s.length()); 
 
    vector<u8> msk = lit.msk; // copy 
    vector<u8> cmp = lit.cmp; // copy 
 
    bool noruns = isNoRunsFragment(build, f, max_len); 
    DEBUG_PRINTF("fragment is %s\n", noruns ? "noruns" : "not noruns"); 
 
    auto lit_final = lit.s; // copy 
 
    if (lit_final.length() > ROSE_SHORT_LITERAL_LEN_MAX) { 
        DEBUG_PRINTF("truncating to tail of length %zu\n", 
                     size_t{ROSE_SHORT_LITERAL_LEN_MAX}); 
        lit_final.erase(0, lit_final.length() - ROSE_SHORT_LITERAL_LEN_MAX); 
        // We shouldn't have set a threshold below 8 chars. 
        assert(msk.size() <= ROSE_SHORT_LITERAL_LEN_MAX); 
        assert(!noruns); 
    } 
 
    addLiteralMask(lit, msk, cmp); 
 
    const auto &s_final = lit_final.get_string(); 
    bool nocase = lit_final.any_nocase(); 
 
    DEBUG_PRINTF("id=%u, s='%s', nocase=%d, noruns=%d, msk=%s, cmp=%s\n", 
                 f.fragment_id, escapeString(s_final).c_str(), (int)nocase, 
                 noruns, dumpMask(msk).c_str(), dumpMask(cmp).c_str()); 
 
    if (!maskIsConsistent(s_final, nocase, msk, cmp)) { 
        DEBUG_PRINTF("msk/cmp for literal can't match, skipping\n"); 
        return; 
    } 
 
    const auto &groups = f.groups; 
 
    mp.lits.emplace_back(move(s_final), nocase, noruns, f.fragment_id, 
                         groups, msk, cmp); 
} 
 
static 
void addAccelLiteral(MatcherProto &mp, const rose_literal_id &lit, 
                     const rose_literal_info &info, size_t max_len) { 
    const auto &s = lit.s; // copy 
 
    DEBUG_PRINTF("lit='%s' (len %zu)\n", dumpString(s).c_str(), s.length()); 
 
    vector<u8> msk = lit.msk; // copy 
    vector<u8> cmp = lit.cmp; // copy 
    addLiteralMask(lit, msk, cmp); 
 
    if (!maskIsConsistent(s.get_string(), s.any_nocase(), msk, cmp)) { 
        DEBUG_PRINTF("msk/cmp for literal can't match, skipping\n"); 
        return; 
    } 
 
    // Literals used for acceleration must be limited to max_len, as that's all 
    // we can see in history. 
    string s_final = lit.s.get_string(); 
    trim_to_suffix(s_final, max_len); 
    trim_to_suffix(msk, max_len); 
    trim_to_suffix(cmp, max_len); 
 
    mp.accel_lits.emplace_back(s_final, lit.s.any_nocase(), msk, cmp, 
                               info.group_mask); 
} 
 
/** 
 * \brief Build up a vector of literals (and associated other data) for the 
 * given table. 
 * 
 * If max_offset is specified (and not ROSE_BOUND_INF), then literals that can 
 * only lead to a pattern match after max_offset may be excluded. 
 */ 
static 
MatcherProto makeMatcherProto(const RoseBuildImpl &build, 
                              const vector<LitFragment> &fragments, 
                              rose_literal_table table, bool delay_rebuild, 
                              size_t max_len, u32 max_offset = ROSE_BOUND_INF) { 
    MatcherProto mp; 
 
    if (delay_rebuild) { 
        assert(table == ROSE_FLOATING); 
        assert(build.cc.streaming); 
    } 
 
    vector<u32> used_lit_ids; 
 
    for (const auto &f : fragments) { 
        assert(!f.lit_ids.empty()); 
 
        // All literals that share a fragment are in the same table. 
        if (build.literals.at(f.lit_ids.front()).table != table) { 
            continue; // next fragment. 
        } 
 
        DEBUG_PRINTF("fragment %u, %zu lit_ids\n", f.fragment_id, 
                     f.lit_ids.size()); 
 
        used_lit_ids.clear(); 
        for (u32 id : f.lit_ids) { 
            const rose_literal_id &lit = build.literals.at(id); 
            assert(id < build.literal_info.size()); 
            const auto &info = build.literal_info.at(id); 
            if (lit.delay) { 
                continue; /* delay id's are virtual-ish */ 
            } 
 
            // When building the delay rebuild table, we only want to include 
            // literals that have delayed variants. 
            if (delay_rebuild && info.delayed_ids.empty()) { 
                DEBUG_PRINTF("not needed for delay rebuild\n"); 
                continue; 
            } 
 
            if (max_offset != ROSE_BOUND_INF) { 
                u64a min_report = literalMinReportOffset(build, lit, info); 
                if (min_report > max_offset) { 
                    DEBUG_PRINTF("min report offset=%llu exceeds " 
                                 "max_offset=%u\n", min_report, max_offset); 
                    continue; 
                } 
            } 
 
            used_lit_ids.push_back(id); 
        } 
 
        if (used_lit_ids.empty()) { 
            continue; // next fragment. 
        } 
 
        // Build our fragment (for the HWLM matcher) from the first literal. 
        addFragmentLiteral(build, mp, f, used_lit_ids.front(), max_len); 
 
        for (u32 id : used_lit_ids) { 
            const rose_literal_id &lit = build.literals.at(id); 
            assert(id < build.literal_info.size()); 
            const auto &info = build.literal_info.at(id); 
 
            // All literals contribute accel information. 
            addAccelLiteral(mp, lit, info, max_len); 
 
            // All literals contribute to history requirement in streaming mode. 
            if (build.cc.streaming) { 
                size_t lit_hist_len = 
                    max(lit.msk.size(), min(lit.s.length(), max_len)); 
                lit_hist_len = lit_hist_len ? lit_hist_len - 1 : 0; 
                DEBUG_PRINTF("lit requires %zu bytes of history\n", 
                             lit_hist_len); 
                assert(lit_hist_len <= build.cc.grey.maxHistoryAvailable); 
                mp.history_required = max(mp.history_required, lit_hist_len); 
            } 
        } 
    } 
 
    sort_and_unique(mp.lits); 
    sort_and_unique(mp.accel_lits); 
 
    return mp; 
} 
 
void MatcherProto::insert(const MatcherProto &a) { 
    ::ue2::insert(&lits, lits.end(), a.lits); 
    ::ue2::insert(&accel_lits, accel_lits.end(), a.accel_lits); 
    sort_and_unique(lits); 
    sort_and_unique(accel_lits); 
    history_required = max(history_required, a.history_required); 
} 
 
static 
void buildAccel(const RoseBuildImpl &build, 
                const vector<AccelString> &accel_lits, HWLM &hwlm) { 
    if (!build.cc.grey.hamsterAccelForward) { 
        return; 
    } 
 
    if (hwlm.type == HWLM_ENGINE_NOOD) { 
        return; 
    } 
 
    buildForwardAccel(&hwlm, accel_lits, build.getInitialGroups()); 
} 
 
bytecode_ptr<HWLM> 
buildHWLMMatcher(const RoseBuildImpl &build, LitProto *litProto) { 
    if (!litProto) { 
        return nullptr; 
    } 
    auto hwlm = hwlmBuild(*litProto->hwlmProto, build.cc, 
                          build.getInitialGroups()); 
    if (!hwlm) { 
        throw CompileError("Unable to generate bytecode."); 
    } 
 
    buildAccel(build, litProto->accel_lits, *hwlm); 
 
    DEBUG_PRINTF("built eod-anchored literal table size %zu bytes\n", 
                 hwlm.size()); 
    return hwlm; 
} 
 
unique_ptr<LitProto> 
buildFloatingMatcherProto(const RoseBuildImpl &build, 
                          const vector<LitFragment> &fragments, 
                          size_t longLitLengthThreshold, 
                          rose_group *fgroups, 
                          size_t *historyRequired) { 
    DEBUG_PRINTF("Floating literal matcher\n"); 
    *fgroups = 0; 
 
     auto mp = makeMatcherProto(build, fragments, ROSE_FLOATING, false, 
                                           longLitLengthThreshold); 
     if (mp.lits.empty()) { 
         DEBUG_PRINTF("empty floating matcher\n"); 
         return nullptr; 
     } 
     dumpMatcherLiterals(mp.lits, "floating", build.cc.grey); 
 
     for (const hwlmLiteral &lit : mp.lits) { 
         *fgroups |= lit.groups; 
     } 
 
     if (build.cc.streaming) { 
         DEBUG_PRINTF("history_required=%zu\n", mp.history_required); 
         assert(mp.history_required <= build.cc.grey.maxHistoryAvailable); 
         *historyRequired = max(*historyRequired, mp.history_required); 
     } 
 
     auto proto = hwlmBuildProto(mp.lits, false, build.cc); 
 
     if (!proto) { 
        throw CompileError("Unable to generate literal matcher proto."); 
     } 
 
     return ue2::make_unique<LitProto>(move(proto), mp.accel_lits); 
} 
 
unique_ptr<LitProto> 
buildDelayRebuildMatcherProto(const RoseBuildImpl &build, 
                              const vector<LitFragment> &fragments, 
                              size_t longLitLengthThreshold) { 
    DEBUG_PRINTF("Delay literal matcher\n"); 
    if (!build.cc.streaming) { 
        DEBUG_PRINTF("not streaming\n"); 
        return nullptr; 
    } 
 
    auto mp = makeMatcherProto(build, fragments, ROSE_FLOATING, true, 
                               longLitLengthThreshold); 
    if (mp.lits.empty()) { 
        DEBUG_PRINTF("empty delay rebuild matcher\n"); 
        return nullptr; 
    } 
    dumpMatcherLiterals(mp.lits, "delay_rebuild", build.cc.grey); 
 
 
    auto proto = hwlmBuildProto(mp.lits, false, build.cc); 
 
    if (!proto) { 
        throw CompileError("Unable to generate literal matcher proto."); 
    } 
 
    return ue2::make_unique<LitProto>(move(proto), mp.accel_lits); 
} 
 
unique_ptr<LitProto> 
buildSmallBlockMatcherProto(const RoseBuildImpl &build, 
                            const vector<LitFragment> &fragments) { 
    DEBUG_PRINTF("Small block literal matcher\n"); 
    if (build.cc.streaming) { 
        DEBUG_PRINTF("streaming mode\n"); 
        return nullptr; 
    } 
 
    u32 float_min = findMinWidth(build, ROSE_FLOATING); 
    if (float_min > ROSE_SMALL_BLOCK_LEN) { 
        DEBUG_PRINTF("floating table has large min width %u, fail\n", 
                     float_min); 
        return nullptr; 
    } 
 
    auto mp = makeMatcherProto(build, fragments, ROSE_FLOATING, false, 
                               ROSE_SMALL_BLOCK_LEN, ROSE_SMALL_BLOCK_LEN); 
    if (mp.lits.empty()) { 
        DEBUG_PRINTF("no floating table\n"); 
        return nullptr; 
    } else if (mp.lits.size() == 1) { 
        DEBUG_PRINTF("single floating literal, noodle will be fast enough\n"); 
        return nullptr; 
    } 
 
    auto mp_anchored = makeMatcherProto(build, fragments, 
                                        ROSE_ANCHORED_SMALL_BLOCK, false, 
                                        ROSE_SMALL_BLOCK_LEN, 
                                        ROSE_SMALL_BLOCK_LEN); 
    if (mp_anchored.lits.empty()) { 
        DEBUG_PRINTF("no small-block anchored literals\n"); 
        return nullptr; 
    } 
 
    mp.insert(mp_anchored); 
    dumpMatcherLiterals(mp.lits, "smallblock", build.cc.grey); 
 
    // None of our literals should be longer than the small block limit. 
    assert(all_of(begin(mp.lits), end(mp.lits), [](const hwlmLiteral &lit) { 
        return lit.s.length() <= ROSE_SMALL_BLOCK_LEN; 
    })); 
 
    if (mp.lits.empty()) { 
        DEBUG_PRINTF("no literals shorter than small block len\n"); 
        return nullptr; 
    } 
 
    auto proto = hwlmBuildProto(mp.lits, false, build.cc); 
 
    if (!proto) { 
        throw CompileError("Unable to generate literal matcher proto."); 
    } 
 
    return ue2::make_unique<LitProto>(move(proto), mp.accel_lits); 
} 
 
unique_ptr<LitProto> 
buildEodAnchoredMatcherProto(const RoseBuildImpl &build, 
                             const vector<LitFragment> &fragments) { 
    DEBUG_PRINTF("Eod anchored literal matcher\n"); 
    auto mp = makeMatcherProto(build, fragments, ROSE_EOD_ANCHORED, false, 
                               build.ematcher_region_size); 
 
    if (mp.lits.empty()) { 
        DEBUG_PRINTF("no eod anchored literals\n"); 
        assert(!build.ematcher_region_size); 
        return nullptr; 
    } 
    dumpMatcherLiterals(mp.lits, "eod", build.cc.grey); 
 
    assert(build.ematcher_region_size); 
 
    auto proto = hwlmBuildProto(mp.lits, false, build.cc); 
 
    if (!proto) { 
        throw CompileError("Unable to generate literal matcher proto."); 
    } 
 
    return ue2::make_unique<LitProto>(move(proto), mp.accel_lits); 
} 
 
} // namespace ue2