fix(extgen): escape quotes and control chars in C string literals

Author: alexandre-daubois

internal/extgen/cfile.go

@@ -76,7 +76,25 @@ func (cg *cFileGenerator) getTemplateContent() (string, error) {
 	return buf.String(), nil
 }
 
-// escapeCString escapes backslashes for C string literals
+// escapeCString escapes characters that would break a C double-quoted string literal.
 func escapeCString(s string) string {
-	return strings.ReplaceAll(s, `\`, `\\`)
+	var b strings.Builder
+	b.Grow(len(s))
+	for _, r := range s {
+		switch r {
+		case '\\':
+			b.WriteString(`\\`)
+		case '"':
+			b.WriteString(`\"`)
+		case '\n':
+			b.WriteString(`\n`)
+		case '\r':
+			b.WriteString(`\r`)
+		case '\t':
+			b.WriteString(`\t`)
+		default:
+			b.WriteRune(r)
+		}
+	}
+	return b.String()
 }

internal/extgen/cfile_test.go

@@ -521,6 +521,16 @@ func TestEscapeCString(t *testing.T) {
 			input:    `Namespace\Über\Test`,
 			expected: `Namespace\\Über\\Test`,
 		},
+		{
+			name:     "double quote is escaped",
+			input:    `say "hi"`,
+			expected: `say \"hi\"`,
+		},
+		{
+			name:     "newline, carriage return and tab are escaped",
+			input:    "line1\nline2\r\tend",
+			expected: `line1\nline2\r\tend`,
+		},
 	}
 
 	for _, tt := range tests {