Support new FST writer API (#6871) (#6992)

include/fstcpp/fstcpp.h

@@ -0,0 +1,260 @@
+// SPDX-FileCopyrightText: 2025-2026 Yu-Sheng Lin <[email protected]>
+// SPDX-FileCopyrightText: 2025-2026 Yoda Lee <[email protected]>
+// SPDX-License-Identifier: MIT
+// Project: libfstwriter
+// Website: https://github.com/gtkwave/libfstwriter
+#pragma once
+// direct include
+// C system headers
+// C++ standard library headers
+#include <cstddef>
+#include <cstdint>
+#include <cstring>
+#include <string>
+// Other libraries' .h files.
+// Your project's .h files.
+#if defined(MSC_VER_) || defined(FORCE_MSC_VER_)
+#	define USE_GCC_INTRINSIC 0
+// Note: we do not support MSVC intrinsic for now
+#	define USE_MSVC_INTRINSIC 0
+#elif defined(__GNUC__) || defined(__clang__)
+#	define USE_GCC_INTRINSIC 1
+#	define USE_MSVC_INTRINSIC 0
+#else
+#	define USE_GCC_INTRINSIC 0
+#	define USE_MSVC_INTRINSIC 0
+#endif
+
+// Remove these when we upgrade to C++20
+#pragma GCC diagnostic ignored "-Wpragmas"
+#pragma GCC diagnostic ignored "-Wc++17-attribute-extensions"
+#pragma GCC diagnostic ignored "-Wc++20-attribute-extensions"
+
+namespace fst {
+
+typedef uint32_t Handle;
+typedef uint32_t EnumHandle;
+struct string_view_pair {
+	const char *m_data = nullptr;
+	size_t m_size = 0;
+
+	// implicit conversion from const char*, std::string, std::string_view
+	string_view_pair(const char *data)
+		: m_data{data}, m_size{data == nullptr ? 0 : std::strlen(data)} {}
+	string_view_pair(const char *data, size_t size) : m_data{data}, m_size{size} {}
+	string_view_pair(const std::string &s) : m_data{s.c_str()}, m_size{s.size()} {}
+#if __cplusplus >= 201703L
+	string_view_pair(std::string_view s) : m_data{s.data()}, m_size{s.size()} {}
+#endif
+};
+
+[[maybe_unused]]
+static inline string_view_pair make_string_view_pair(const char *data) {
+	if (!data) {
+		return {nullptr, 0};
+	}
+	return {data, std::strlen(data)};
+}
+
+[[maybe_unused]]
+static inline string_view_pair make_string_view_pair(const char *data, std::size_t size) {
+	return {data, size};
+}
+
+enum class WriterPackType : uint8_t {
+	ZLIB = 0,    // not supported
+	FASTLZ = 1,  // not supported
+	LZ4 = 2,
+	// usually for testing, you should use eLz4
+	// This will turn off compression for geometry/hierarchy/wave data
+	NO_COMPRESSION = 3,
+};
+
+enum class FileType : uint8_t {
+	VERILOG = 0,
+	VHDL,
+	VERILOG_VHDL,
+};
+
+enum class EncodingType : uint8_t {
+	BINARY = 0,   // 1 bit per bit to represent 0,1
+	VERILOG = 1,  // 2 bits per bit to represent X,Z
+	VHDL = 2,     // 4 bits per bit to represent H,U,W,L,-,?
+};
+
+[[maybe_unused]]
+static inline constexpr unsigned bitPerEncodedBit(EncodingType type) {
+	return 1 << static_cast<uint8_t>(type);
+}
+
+[[maybe_unused]]
+static const char* kEncodedBitToCharTable = (
+	"01" // Binary
+	"xzhu" // Verilog
+	"wl-?    " // Vhdl (padded with ' ')
+);
+
+struct Hierarchy {
+	enum class ScopeType : uint8_t {
+		VCD_MODULE = 0,
+		VCD_TASK = 1,
+		VCD_FUNCTION = 2,
+		VCD_BEGIN = 3,
+		VCD_FORK = 4,
+		VCD_GENERATE = 5,
+		VCD_STRUCT = 6,
+		VCD_UNION = 7,
+		VCD_CLASS = 8,
+		VCD_INTERFACE = 9,
+		VCD_PACKAGE = 10,
+		VCD_PROGRAM = 11,
+		VHDL_ARCHITECTURE = 12,
+		VHDL_PROCEDURE = 13,
+		VHDL_FUNCTION = 14,
+		VHDL_RECORD = 15,
+		VHDL_PROCESS = 16,
+		VHDL_BLOCK = 17,
+		VHDL_FORGENERATE = 18,
+		VHDL_IFGENERATE = 19,
+		VHDL_GENERATE = 20,
+		VHDL_PACKAGE = 21,
+		SV_ARRAY = 22,
+	};
+
+	enum class ScopeControlType : uint8_t {
+		GEN_ATTR_BEGIN = 252,
+		GEN_ATTR_END = 253,
+		VCD_SCOPE = 254,
+		VCD_UPSCOPE = 255,
+	};
+
+	enum class VarType : uint8_t {
+		VCD_EVENT = 0,
+		VCD_INTEGER = 1,
+		VCD_PARAMETER = 2,
+		VCD_REAL = 3,
+		VCD_REAL_PARAMETER = 4,
+		VCD_REG = 5,
+		VCD_SUPPLY0 = 6,
+		VCD_SUPPLY1 = 7,
+		VCD_TIME = 8,
+		VCD_TRI = 9,
+		VCD_TRIAND = 10,
+		VCD_TRIOR = 11,
+		VCD_TRIREG = 12,
+		VCD_TRI0 = 13,
+		VCD_TRI1 = 14,
+		VCD_WAND = 15,
+		VCD_WIRE = 16,
+		VCD_WOR = 17,
+		VCD_PORT = 18,
+		VCD_SPARRAY = 19,
+		VCD_REALTIME = 20,
+		GEN_STRING = 21,
+		SV_BIT = 22,
+		SV_LOGIC = 23,
+		SV_INT = 24,
+		SV_SHORTINT = 25,
+		SV_LONGINT = 26,
+		SV_BYTE = 27,
+		SV_ENUM = 28,
+		SV_SHORTREAL = 29,
+	};
+
+	enum class VarDirection : uint8_t {
+		MIN = 0,
+
+		IMPLICIT = 0,
+		INPUT = 1,
+		OUTPUT = 2,
+		INOUT = 3,
+		BUFFER = 4,
+		LINKAGE = 5,
+
+		MAX = 5,
+	};
+
+	enum class AttrType : uint8_t {
+		MIN = 0,
+		MISC = 0,
+		ARRAY = 1,
+		ENUM = 2,
+		PACK = 3,
+		MAX = 3,
+	};
+
+	enum class AttrSubType : uint8_t {
+		// For AttrType::eMisc
+		MISC_MIN = 0,
+		MISC_COMMENT = 0,
+		MISC_ENVVAR = 1,
+		MISC_SUPVAR = 2,
+		MISC_PATHNAME = 3,
+		MISC_SOURCESTEM = 4,
+		MISC_SOURCEISTEM = 5,
+		MISC_VALUELIST = 6,
+		MISC_ENUMTABLE = 7,
+		MISC_UNKNOWN = 8,
+		MISC_MAX = 8,
+
+		// For AttrType::eArray
+		ARRAY_MIN = 0,
+		ARRAY_NONE = 0,
+		ARRAY_UNPACKED = 1,
+		ARRAY_PACKED = 2,
+		ARRAY_SPARSE = 3,
+		ARRAY_MAX = 3,
+
+		// For AttrType::eEnum
+		ENUM_MIN = 0,
+		ENUM_SV_INTEGER = 0,
+		ENUM_SV_BIT = 1,
+		ENUM_SV_LOGIC = 2,
+		ENUM_SV_INT = 3,
+		ENUM_SV_SHORTINT = 4,
+		ENUM_SV_LONGINT = 5,
+		ENUM_SV_BYTE = 6,
+		ENUM_SV_UNSIGNED_INTEGER = 7,
+		ENUM_SV_UNSIGNED_BIT = 8,
+		ENUM_SV_UNSIGNED_LOGIC = 9,
+		ENUM_SV_UNSIGNED_INT = 10,
+		ENUM_SV_UNSIGNED_SHORTINT = 11,
+		ENUM_SV_UNSIGNED_LONGINT = 12,
+		ENUM_SV_UNSIGNED_BYTE = 13,
+		ENUM_REG = 14,
+		ENUM_TIME = 15,
+		ENUM_MAX = 15,
+
+		// For AttrType::ePack
+		PACK_MIN = 0,
+		PACK_NONE = 0,
+		PACK_UNPACKED = 1,
+		PACK_PACKED = 2,
+		PACK_SPARSE = 3,
+		PACK_MAX = 3,
+	};
+
+	enum class SupplementalVarType : uint8_t {};
+
+	enum class SupplementalDataType : uint8_t {};
+};
+
+struct Header {
+	uint64_t m_start_time{uint64_t(-1)};
+	uint64_t m_end_time{0};
+	int64_t m_timezero{0};
+	// Match the original fstapi.c. Just for information, not used in FST.
+	uint64_t m_writer_memory_use{1ull << 27};
+	uint64_t m_num_scopes{0};
+	uint64_t m_num_vars{0};     // #CreateVar calls, including aliases
+	uint64_t m_num_handles{0};  // #unique handles, excluding aliases, shall be <= m_num_vars
+	uint64_t m_num_value_change_data_blocks{0};
+	char m_writer[128]{};
+	char m_date[26]{};
+	FileType m_filetype{FileType::VERILOG};
+	int8_t m_timescale{-9};
+};
+
+static constexpr uint64_t kInvalidTime = uint64_t(-1);
+
+}  // namespace fst