Add support for .lz and .lz4 compression algorithms

C/Lz4Dec.c

@@ -0,0 +1,140 @@
+/* Lz4Dec.c -- LZ4 Decoder
+2025 : Igor Pavlov : Public domain */
+
+#include "Precomp.h"
+
+#include <string.h>
+
+#include "Lz4Dec.h"
+
+/*
+LZ4 block format:
+  A block is composed of sequences.
+  Each sequence: [token][literals][match]
+
+  Token (1 byte):
+    - High 4 bits: literal length (0-15, 15 means more bytes follow)
+    - Low 4 bits: match length - 4 (0-15, 15 means more bytes follow)
+
+  If literal length == 15, read additional bytes until byte < 255
+  Literals: raw bytes
+
+  Match:
+    - Offset: 2 bytes little-endian (must be > 0)
+    - If match length field == 15, read additional bytes until byte < 255
+    - Actual match length = field value + 4
+
+  Last sequence has no match (ends after literals)
+*/
+
+SRes Lz4Dec_DecodeBlock(
+    const Byte *src, SizeT srcLen,
+    Byte *dest, SizeT *destLen,
+    SizeT *srcConsumed)
+{
+  const Byte *srcEnd = src + srcLen;
+  const Byte *srcStart = src;
+  Byte *destStart = dest;
+  Byte *destEnd = dest + *destLen;
+
+  *srcConsumed = 0;
+  *destLen = 0;
+
+  while (src < srcEnd)
+  {
+    unsigned token;
+    SizeT litLen;
+    SizeT matchLen;
+
+    // Read token
+    token = *src++;
+    litLen = token >> 4;
+    matchLen = token & 0x0F;
+
+    // Extended literal length
+    if (litLen == 15)
+    {
+      for (;;)
+      {
+        unsigned b;
+        if (src >= srcEnd)
+          return SZ_ERROR_INPUT_EOF;
+        b = *src++;
+        litLen += b;
+        if (b != 255)
+          break;
+      }
+    }
+
+    // Copy literals (non-overlapping)
+    if (litLen > 0)
+    {
+      if (src + litLen > srcEnd)
+        return SZ_ERROR_INPUT_EOF;
+      if (dest + litLen > destEnd)
+        return SZ_ERROR_OUTPUT_EOF;
+
+      memcpy(dest, src, litLen);
+      src += litLen;
+      dest += litLen;
+    }
+
+    // Is last sequence ? (no match)
+    if (src >= srcEnd)
+      break;
+
+    // Read match offset (2 bytes, little-endian)
+    {
+      SizeT offset;
+      const Byte *matchSrc;
+
+      if (src + 2 > srcEnd)
+        return SZ_ERROR_INPUT_EOF;
+
+      offset = (SizeT)src[0] | ((SizeT)src[1] << 8);
+      src += 2;
+
+      if (offset == 0)
+        return SZ_ERROR_DATA; // Offset 0 is invalid
+
+      // Extended match length
+      matchLen += 4; // Minimum match length is 4
+
+      if ((token & 0x0F) == 15)
+      {
+        for (;;)
+        {
+          unsigned b;
+          if (src >= srcEnd)
+            return SZ_ERROR_INPUT_EOF;
+          b = *src++;
+          matchLen += b;
+          if (b != 255)
+            break;
+        }
+      }
+
+      // Validate offset
+      if (offset > (SizeT)(dest - destStart))
+        return SZ_ERROR_DATA; // Offset too large
+
+      // Copy match
+      if (dest + matchLen > destEnd)
+        return SZ_ERROR_OUTPUT_EOF;
+
+      matchSrc = dest - offset;
+
+      // Handle overlapping copies
+      {
+        SizeT i;
+        for (i = 0; i < matchLen; i++)
+          dest[i] = matchSrc[i];
+      }
+      dest += matchLen;
+    }
+  }
+
+  *srcConsumed = (SizeT)(src - srcStart);
+  *destLen = (SizeT)(dest - destStart);
+  return SZ_OK;
+}

C/Lz4Dec.h

@@ -0,0 +1,27 @@
+/* Lz4Dec.h -- LZ4 Decoder
+2025 : Igor Pavlov : Public domain */
+
+#ifndef Z7_LZ4_DEC_H
+#define Z7_LZ4_DEC_H
+
+#include "7zTypes.h"
+
+EXTERN_C_BEGIN
+
+/*
+LZ4 block decoder
+Returns:
+  SZ_OK - success
+  SZ_ERROR_DATA - data error
+  SZ_ERROR_INPUT_EOF - need more input
+  SZ_ERROR_OUTPUT_EOF - need more output space
+*/
+
+SRes Lz4Dec_DecodeBlock(
+    const Byte *src, SizeT srcLen,
+    Byte *dest, SizeT *destLen,
+    SizeT *srcConsumed);
+
+EXTERN_C_END
+
+#endif

CPP/7zip/7zip_gcc.mak

@@ -544,6 +544,10 @@ $O/LvmHandler.o: ../../Archive/LvmHandler.cpp
 	$(CXX) $(CXXFLAGS) $<
 $O/LzhHandler.o: ../../Archive/LzhHandler.cpp
 	$(CXX) $(CXXFLAGS) $<
+$O/Lz4Handler.o: ../../Archive/Lz4Handler.cpp
+	$(CXX) $(CXXFLAGS) $<
+$O/LzipHandler.o: ../../Archive/LzipHandler.cpp
+	$(CXX) $(CXXFLAGS) $<
 $O/LzmaHandler.o: ../../Archive/LzmaHandler.cpp
 	$(CXX) $(CXXFLAGS) $<
 $O/MachoHandler.o: ../../Archive/MachoHandler.cpp
@@ -1192,6 +1196,8 @@ $O/HuffEnc.o: ../../../../C/HuffEnc.c
 	$(CC) $(CFLAGS) $<
 $O/LzFind.o: ../../../../C/LzFind.c
 	$(CC) $(CFLAGS) $<
+$O/Lz4Dec.o: ../../../../C/Lz4Dec.c
+	$(CC) $(CFLAGS) $<
 
 # ifdef MT_FILES
 $O/LzFindMt.o: ../../../../C/LzFindMt.c