Fix assigning integers to pointers

dkorpel · Jul 24, 2023 · ee21019 · ee21019
1 parent 7767f69
commit ee21019
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Showing 4 changed files with 40 additions and 13 deletions.
diff --git a/source/ctod/cexpr.d b/source/ctod/cexpr.d
@@ -227,10 +227,24 @@ bool ctodExpression(ref CtodCtx ctx, ref Node node) {
 	return false;
 }
 
+/// Fix assignment/initialization of node `r` to a node of type `lType`
+///
 /// C allows implicitly converting any T* -> U*, in D only T* -> `void*` gets that treatment
 /// Try to fix this by adding explicit casts
+/// C also allows converting numbers to pointers.
 void convertPointerTypes(ref CtodCtx ctx, CType lType, ref Node r) {
 	CType rType = ctx.expType(r);
+
+	void castR() {
+		const castStr = "cast(" ~ lType.toString() ~ ") ";
+		if (!mayNeedParens(r)) {
+			r.prepend(castStr);
+		} else {
+			r.prepend(castStr ~ "(");
+			r.append(")");
+		}
+	}
+
 	if (lType.isPointer && rType.isPointer) {
 		if (lType.next[0] == rType.next[0]) {
 			return;
@@ -243,12 +257,15 @@ void convertPointerTypes(ref CtodCtx ctx, CType lType, ref Node r) {
 			// we don't want to simply cast away const with D string literals
 			return;
 		}
-		const castStr = "cast(" ~ lType.toString() ~ ") ";
-		if (!mayNeedParens(r)) {
-			r.prepend(castStr);
+		castR();
+	}
+	if (lType.isPointer && r.typeEnum == Sym.number_literal) {
+		if (r.source == "0") {
+			// int* x = 0; => int* x = null;
+			r.replace("null");
 		} else {
-			r.prepend(castStr ~ "(");
-			r.append(")");
+			// int* x = 3; => int* x = cast(int*) 3;
+			castR();
 		}
 	}
 }

diff --git a/source/ctod/test.d b/source/ctod/test.d
@@ -227,6 +227,9 @@ void main() {
 }
 ");
 
+	// convert 0 to `null`
+	test(`void f() { FILE *f = 0; f = 0; f = 1; }`, `void f() { FILE* f = null; f = null; f = cast(FILE*) 1; }`);
+
 	test("typedef int intArr[3], intScalar;", "alias intArr = int[3];\nalias intScalar = int;");
 
 	test("typedef struct X X;", "");
@@ -739,6 +742,19 @@ double f(int count, ...)
 }
 `);
 
+	// TODO: prevent disappearing source code
+	test(`void main(void) {
+	if (1) {}
+#if defined(SUPPORT_XXX)
+	else if (cmp(n, "XXX")) x = LoadX(n, 0);
+#endif
+}`, `void main() {
+	if (1) {}
+version (SUPPORT_XXX) {
+	else if = LoadX(n, 0);
+}
+}`);
+
 	// tree-sitter doesn't parse this right, need to do manual preprocessing
 	version(none) test("
 #ifdef __cplusplus

diff --git a/source/ctod/translate.d b/source/ctod/translate.d
@@ -8,13 +8,6 @@ import ctod.cdeclaration;
 import ctod.cexpr;
 import ctod.cpreproc;
 
-// Enable switching to custom Associative Array type
-version(none) {
-	import bops.ds.hashtable: Map = HashTable;
-} else {
-	alias Map(K, V) = V[K];
-}
-
 import tree_sitter.api;
 
 private immutable hasVersion = `

diff --git a/source/ctod/tree_sitter.d b/source/ctod/tree_sitter.d
@@ -2,8 +2,9 @@ module ctod.tree_sitter;
 
 nothrow @safe:
 
+// Enable switching to custom Associative Array type
 version(none) {
-	import bops.ds.hashtable: Map = HashTable;
+	public import bops.ds.hashtable: Map = HashTable;
 } else {
 	alias Map(K, V) = V[K];
 }