fix compilation errors related to C specifics

src/common.c

@@ -0,0 +1,128 @@
+/*
+ * common.cpp
+ *
+ *  Created on: Jan 8, 2020
+ *      Author: nnosov
+ */
+
+#include <inttypes.h>
+#include <stddef.h>
+#include <dwarf.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <limits.h>
+#include <elfutils/libdwfl.h>
+#include <libunwind.h>
+
+#include "common.h"
+
+#include "dwarf/dwarf_operations.h"
+#include "utils/log.h"
+#include "arch/registers.h"
+
+int32_t decode_sleb128(uint8_t *sleb128)
+{
+	int32_t num = 0, shift = 0, size = 0;
+	do {
+		num |= ((*sleb128 & 0x7f) << shift);
+		shift += 7;
+		size += 8;
+	} while(*sleb128++ & 0x80);
+	if((shift < size) && (*(--sleb128) & 0x40)) {
+		num |= - (1 << shift);
+	}
+	return num;
+}
+
+uint32_t decode_uleb128(uint8_t *uleb128)
+{
+	uint32_t num = 0, shift = 0;
+	do {
+		num |= ((*uleb128 & 0x7f) << shift);
+		shift += 7;
+	} while(*uleb128++ & 0x80);
+	return num;
+}
+
+// Utility function to encode a ULEB128 value to a buffer. Returns
+// the length in bytes of the encoded value. by default PadTo = 0
+inline unsigned encode_uleb128(uint64_t value, uint8_t *p, unsigned PadTo)
+{
+	uint8_t *orig_p = p;
+	unsigned count = 0;
+	do {
+		uint8_t Byte = value & 0x7f;
+		value >>= 7;
+		count++;
+		if (value != 0 || count < PadTo)
+			Byte |= 0x80; // Mark this byte to show that more bytes will follow.
+		*p++ = Byte;
+	} while (value != 0);
+
+	// Pad with 0x80 and emit a null byte at the end.
+	if (count < PadTo) {
+		for (; count < PadTo - 1; ++count)
+			*p++ = '\x80';
+		*p++ = '\x00';
+	}
+
+	return (unsigned)(p - orig_p);
+}
+
+// Utility function to encode a SLEB128 value to a buffer. Returns
+// the length in bytes of the encoded value. by default PadTo = 0
+inline unsigned encode_sleb128(int64_t value, uint8_t *p, unsigned PadTo)
+{
+	uint8_t *orig_p = p;
+	unsigned count = 0;
+	bool More;
+	do {
+		uint8_t Byte = value & 0x7f;
+		// NOTE: this assumes that this signed shift is an arithmetic right shift.
+		value >>= 7;
+		More = !((((value == 0 ) && ((Byte & 0x40) == 0)) ||
+				((value == -1) && ((Byte & 0x40) != 0))));
+		count++;
+		if (More || count < PadTo)
+			Byte |= 0x80; // Mark this byte to show that more bytes will follow.
+		*p++ = Byte;
+	} while (More);
+
+	// Pad with 0x80 and emit a terminating byte at the end.
+	if (count < PadTo) {
+		uint8_t PadValue = value < 0 ? 0x7f : 0x00;
+		for (; count < PadTo - 1; ++count)
+			*p++ = (PadValue | 0x80);
+		*p++ = PadValue;
+	}
+	return (unsigned)(p - orig_p);
+}
+
+// Utility function to get the size of the ULEB128-encoded value.
+unsigned getULEB128Size(uint64_t Value)
+{
+	unsigned Size = 0;
+	do {
+		Value >>= 7;
+		Size += sizeof(int8_t);
+	} while (Value);
+
+	return Size;
+}
+
+// Utility function to get the size of the SLEB128-encoded value.
+unsigned getSLEB128Size(int64_t Value)
+{
+	unsigned Size = 0;
+	int Sign = Value >> (8 * sizeof(Value) - 1);
+	bool IsMore;
+
+	do {
+		unsigned Byte = Value & 0x7f;
+		Value >>= 7;
+		IsMore = Value != Sign || ((Byte ^ Sign) & 0x40) != 0;
+		Size += sizeof(int8_t);
+	} while (IsMore);
+
+	return Size;
+}