From 51a433ef04d2c89874c2bd0a2c91f1e509e43c9b Mon Sep 17 00:00:00 2001
From: James <49045138+ghidracadabra@users.noreply.github.com>
Date: Mon, 23 May 2022 17:05:20 -0400
Subject: [PATCH] GP-2048 addressing code review comments GP-2048 offcut format
 strings

---
 .../string/variadic/PcodeFunctionParser.java  | 19 +++++++++++++++++++
 .../model/data/StringDataInstance.java        | 18 ++++++++----------
 2 files changed, 27 insertions(+), 10 deletions(-)

diff --git a/Ghidra/Features/DecompilerDependent/src/main/java/ghidra/app/plugin/core/string/variadic/PcodeFunctionParser.java b/Ghidra/Features/DecompilerDependent/src/main/java/ghidra/app/plugin/core/string/variadic/PcodeFunctionParser.java
index 5dd6069e78..14692acecb 100644
--- a/Ghidra/Features/DecompilerDependent/src/main/java/ghidra/app/plugin/core/string/variadic/PcodeFunctionParser.java
+++ b/Ghidra/Features/DecompilerDependent/src/main/java/ghidra/app/plugin/core/string/variadic/PcodeFunctionParser.java
@@ -109,6 +109,25 @@ public class PcodeFunctionParser {
 					functionName, data.getDefaultValueRepresentation()));
 				hasDefinedFormatString = true;
 			}
+			else {
+				//check for offcut references into a larger defined string
+				Data containing = program.getListing().getDataContaining(ramSpaceAddress);
+				if (containing == null) {
+					continue;
+				}
+				if (addressToCandidateData.containsKey(containing.getAddress())) {
+					StringDataInstance entire =
+						StringDataInstance.getStringDataInstance(containing);
+					String subString = entire.getByteOffcut(
+						(int) (ramSpaceAddress.getOffset() - containing.getAddress().getOffset()))
+							.getStringValue();
+					if (subString != null) {
+						functionCallDataList.add(new FunctionCallData(ast.getSeqnum().getTarget(),
+							functionName, subString));
+						hasDefinedFormatString = true;
+					}
+				}
+			}
 		}
 		return hasDefinedFormatString;
 	}
diff --git a/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/data/StringDataInstance.java b/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/data/StringDataInstance.java
index 19cc91856c..7ca9dce920 100644
--- a/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/data/StringDataInstance.java
+++ b/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/data/StringDataInstance.java
@@ -353,8 +353,7 @@ public class StringDataInstance {
 		return StringLayoutEnum.NULL_TERMINATED_BOUNDED;
 	}
 
-	static String getCharsetNameFromDataTypeOrSettings(DataType dataType,
-			Settings settings) {
+	static String getCharsetNameFromDataTypeOrSettings(DataType dataType, Settings settings) {
 		if (dataType instanceof BitFieldDataType) {
 			dataType = ((BitFieldDataType) dataType).getBaseDataType();
 		}
@@ -639,9 +638,9 @@ public class StringDataInstance {
 		}
 
 		byte[] unpaddedBytes = new byte[(paddedBytes.length / paddedCharSize) * charSize];
-		for (int srcOffset = buf.isBigEndian() ? paddedCharSize - charSize : 0, destOffset =
-			0; srcOffset < paddedBytes.length; srcOffset += paddedCharSize, destOffset +=
-				charSize) {
+		for (int srcOffset = buf.isBigEndian() ? paddedCharSize - charSize : 0,
+				destOffset = 0; srcOffset < paddedBytes.length; srcOffset +=
+					paddedCharSize, destOffset += charSize) {
 			System.arraycopy(paddedBytes, srcOffset, unpaddedBytes, destOffset, charSize);
 		}
 
@@ -961,8 +960,7 @@ public class StringDataInstance {
 			return false;
 		}
 		long origCodePointValue = DataConverter.getInstance(buf.isBigEndian())
-				.getValue(stringBytes,
-					byteOffset, charSize);
+				.getValue(stringBytes, byteOffset, charSize);
 		return origCodePointValue == StringUtilities.UNICODE_REPLACEMENT;
 	}
 
@@ -1023,12 +1021,12 @@ public class StringDataInstance {
 	 * Returns a new {@link StringDataInstance} that points to the string characters that start at
 	 * {@code byteOffset} from the start of this instance.
 	 * <p>
-	 * If the requested offset is not valid, the base string instance (itself) will be returned
-	 * instead of a new instance.
+	 * If the requested offset is not valid, StringDataInstance.NULL_INSTANCE is returned.
 	 * <p>
 	 * 
 	 * @param byteOffset number of bytes from start of data instance to start new instance.
-	 * @return new StringDataInstance, or <code>this</code> if offset not valid.
+	 * @return new StringDataInstance, or <code>StringDataInstance.NULL_INSTANCE</code> if 
+	 * offset not valid.
 	 */
 	public StringDataInstance getByteOffcut(int byteOffset) {
 		if (isBadCharSize() || isProbe() || !isValidOffcutOffset(byteOffset)) {