src/tint/utils/text/base64.cc

// Copyright 2023 The Dawn & Tint Authors
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#include "src/tint/utils/text/base64.h"

#include <string>

namespace tint {

Vector<std::byte, 0> DecodeBase64FromComments(std::string_view wgsl) {
    Vector<std::byte, 0> out;
    size_t block_nesting = 0;
    bool line_comment = false;
    for (size_t i = 0, n = wgsl.length(); i < n; i++) {
        char curr = wgsl[i];
        if (curr == '\n') {
            line_comment = false;
            continue;
        }

        char next = (i + 1) < n ? wgsl[i + 1] : 0;
        if (curr == '/' && next == '*') {
            block_nesting++;
            i++;  // skip '*'
            continue;
        }
        if (block_nesting > 0 && curr == '*' && next == '/') {
            block_nesting--;
            i++;  // skip '/'
            continue;
        }
        if (block_nesting == 0 && curr == '/' && next == '/') {
            line_comment = true;
            i++;  // skip '/'
            continue;
        }

        if (block_nesting > 0 || line_comment) {
            if (auto v = DecodeBase64(curr)) {
                out.Push(std::byte{*v});
            }
        }
    }
    return out;
}

}  // namespace tint