From 01c881d18d24305a33f053b8b2ac84f3b37c246a Mon Sep 17 00:00:00 2001
From: Vicki Pfau <vi@endrift.com>
Date: Wed, 6 Jul 2022 23:55:49 -0700
Subject: [PATCH] Debugger: Minor parser refactoring; fix crash

---
 include/mgba/internal/debugger/parser.h |  5 +++--
 src/debugger/cli-debugger.c             | 11 +++++------
 src/debugger/parser.c                   | 15 ++++++++-------
 3 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/include/mgba/internal/debugger/parser.h b/include/mgba/internal/debugger/parser.h
index 0b8f09d4c..1b06b7f60 100644
--- a/include/mgba/internal/debugger/parser.h
+++ b/include/mgba/internal/debugger/parser.h
@@ -67,10 +67,11 @@ struct ParseTree {
 };
 
 size_t lexExpression(struct LexVector* lv, const char* string, size_t length, const char* eol);
-void parseLexedExpression(struct ParseTree* tree, struct LexVector* lv);
-
 void lexFree(struct LexVector* lv);
+
+struct ParseTree* parseTreeCreate(void);
 void parseFree(struct ParseTree* tree);
+bool parseLexedExpression(struct ParseTree* tree, struct LexVector* lv);
 
 struct mDebugger;
 bool mDebuggerEvaluateParseTree(struct mDebugger* debugger, struct ParseTree* tree, int32_t* value, int* segment);
diff --git a/src/debugger/cli-debugger.c b/src/debugger/cli-debugger.c
index dbc10fe89..e3897cd3b 100644
--- a/src/debugger/cli-debugger.c
+++ b/src/debugger/cli-debugger.c
@@ -588,7 +588,7 @@ static struct ParseTree* _parseTree(const char** string) {
 	}
 	struct ParseTree* tree = NULL;
 	if (!error) {
-		tree = malloc(sizeof(*tree));
+		tree = parseTreeCreate();
 		parseLexedExpression(tree, &lv);
 	}
 	lexFree(&lv);
@@ -796,17 +796,16 @@ struct CLIDebugVector* CLIDVParse(struct CLIDebugger* debugger, const char* stri
 		dvTemp.type = CLIDV_ERROR_TYPE;
 	}
 
-	struct ParseTree tree;
-	parseLexedExpression(&tree, &lv);
-	if (tree.token.type == TOKEN_ERROR_TYPE) {
+	struct ParseTree* tree = parseTreeCreate();
+	if (!parseLexedExpression(tree, &lv)) {
 		dvTemp.type = CLIDV_ERROR_TYPE;
 	} else {
-		if (!mDebuggerEvaluateParseTree(&debugger->d, &tree, &dvTemp.intValue, &dvTemp.segmentValue)) {
+		if (!mDebuggerEvaluateParseTree(&debugger->d, tree, &dvTemp.intValue, &dvTemp.segmentValue)) {
 			dvTemp.type = CLIDV_ERROR_TYPE;
 		}
 	}
 
-	parseFree(&tree);
+	parseFree(tree);
 
 	lexFree(&lv);
 	LexVectorDeinit(&lv);
diff --git a/src/debugger/parser.c b/src/debugger/parser.c
index 4af61a14e..0d4924ea9 100644
--- a/src/debugger/parser.c
+++ b/src/debugger/parser.c
@@ -495,7 +495,7 @@ static const int _operatorPrecedence[] = {
 	[OP_DEREFERENCE] = 2,
 };
 
-static struct ParseTree* _parseTreeCreate(void) {
+struct ParseTree* parseTreeCreate(void) {
 	struct ParseTree* tree = malloc(sizeof(struct ParseTree));
 	tree->token.type = TOKEN_ERROR_TYPE;
 	tree->p = NULL;
@@ -529,12 +529,12 @@ static size_t _parseExpression(struct ParseTree* tree, struct LexVector* lv, int
 			}
 			break;
 		case TOKEN_SEGMENT_TYPE:
-			tree->lhs = _parseTreeCreate();
+			tree->lhs = parseTreeCreate();
 			tree->lhs->token.type = TOKEN_UINT_TYPE;
 			tree->lhs->token.uintValue = token->uintValue;
 			tree->lhs->p = tree;
 			tree->lhs->precedence = precedence;
-			tree->rhs = _parseTreeCreate();
+			tree->rhs = parseTreeCreate();
 			tree->rhs->p = tree;
 			tree->rhs->precedence = precedence;
 			tree->token.type = TOKEN_SEGMENT_TYPE;
@@ -572,7 +572,7 @@ static size_t _parseExpression(struct ParseTree* tree, struct LexVector* lv, int
 			}
 			newPrecedence = _operatorPrecedence[token->operatorValue];
 			if (newPrecedence < precedence) {
-				newTree = _parseTreeCreate();
+				newTree = parseTreeCreate();
 				memcpy(newTree, tree, sizeof(*tree));
 				if (newTree->lhs) {
 					newTree->lhs->p = newTree;
@@ -582,7 +582,7 @@ static size_t _parseExpression(struct ParseTree* tree, struct LexVector* lv, int
 				}
 				newTree->p = tree;
 				tree->lhs = newTree;
-				tree->rhs = _parseTreeCreate();
+				tree->rhs = parseTreeCreate();
 				tree->rhs->p = tree;
 				tree->rhs->precedence = newPrecedence;
 				precedence = newPrecedence;
@@ -617,9 +617,9 @@ static size_t _parseExpression(struct ParseTree* tree, struct LexVector* lv, int
 	return i;
 }
 
-void parseLexedExpression(struct ParseTree* tree, struct LexVector* lv) {
+bool parseLexedExpression(struct ParseTree* tree, struct LexVector* lv) {
 	if (!tree) {
-		return;
+		return false;
 	}
 
 	tree->token.type = TOKEN_ERROR_TYPE;
@@ -636,6 +636,7 @@ void parseLexedExpression(struct ParseTree* tree, struct LexVector* lv) {
 		}
 		tree->token.type = TOKEN_ERROR_TYPE;
 	}
+	return tree->token.type != TOKEN_ERROR_TYPE;
 }
 
 void lexFree(struct LexVector* lv) {