digitalmars.D.bugs - Segmentation fault on de-referencing int field over 3 levels
- Oliver Moeller (46/46) Feb 23 2007 Compiling the following with DMD and executing the program
- Frank Benoit (keinfarbton) (7/71) Feb 23 2007 the Date is a struct and is of value type. (1) is OK so.
Compiling the following with DMD and executing the program yields an segmentation fault when accessing the public field 'the_date.year' of another public field 'birth': import std.c.stdio; import std.c.stdlib; import std.string; import std.date; public class MyDate { public: Date the_date; // only the field 'year' is relevant this(){ the_date.year = 1901; } }; public class Author { public: MyDate birth; }; int main(char[][] args) { Author author = new Author(); MyDate mydate = new MyDate(); printf("(1) accessing: mydate.the_date.year = %i\n", mydate.the_date.year); printf("(2) accessing: author.birth.the_date.year = \n"); printf("%i\n", author.birth.the_date.year); printf("Ok.\n"); return 0; } To my understanding, this access is legal; if not, then the compiler should refuse it. Enlighten me if I am doing something wrong here (I am new to D). Here is the screen output sniplet: ------------------------------------- phobos:~/Lang/D/Toy/segfault> make test /home/oli/Projects/D/DMD/dmd/bin/dmd -c -oftest_date.o test_date.d /home/oli/Projects/D/DMD/dmd/bin/dmd -oftest_date.exe test_date.o gcc test_date.o -o test_date.exe -m32 -lphobos -lpthread -lm phobos:~/Lang/D/Toy/segfault> ./test_date.exe (1) accessing: mydate.the_date.year = 1901 (2) accessing: author.birth.the_date.year = Segmentation fault ------------------------------------------------------------------------- Running test_date.d interpreted has the same effect (abort on (2)). Versions: dmd: Digital Mars D Compiler v1.0 gcc: gcc (GCC) 4.0.2 20050901 (prerelease) (SUSE Linux) platform: PC SuSE Linux 10.0 (64 bit) ** Computers will always make mistakes, but will do so much faster tomorrow. ** ------------------------------------------------- <omoeller verify-it.de>
Feb 23 2007
the Date is a struct and is of value type. (1) is OK so. The MyDate is a class and is a reference type. This is why (2) fails. You did not initialize Author.birth.public class Author { public: MyDate birth;this(){ birth=new MyDate(); }};Oliver Moeller schrieb:Compiling the following with DMD and executing the program yields an segmentation fault when accessing the public field 'the_date.year' of another public field 'birth': import std.c.stdio; import std.c.stdlib; import std.string; import std.date; public class MyDate { public: Date the_date; // only the field 'year' is relevant this(){ the_date.year = 1901; } }; public class Author { public: MyDate birth; }; int main(char[][] args) { Author author = new Author(); MyDate mydate = new MyDate(); printf("(1) accessing: mydate.the_date.year = %i\n", mydate.the_date.year); printf("(2) accessing: author.birth.the_date.year = \n"); printf("%i\n", author.birth.the_date.year); printf("Ok.\n"); return 0; } To my understanding, this access is legal; if not, then the compiler should refuse it. Enlighten me if I am doing something wrong here (I am new to D). Here is the screen output sniplet: ------------------------------------- phobos:~/Lang/D/Toy/segfault> make test /home/oli/Projects/D/DMD/dmd/bin/dmd -c -oftest_date.o test_date.d /home/oli/Projects/D/DMD/dmd/bin/dmd -oftest_date.exe test_date.o gcc test_date.o -o test_date.exe -m32 -lphobos -lpthread -lm phobos:~/Lang/D/Toy/segfault> ./test_date.exe (1) accessing: mydate.the_date.year = 1901 (2) accessing: author.birth.the_date.year = Segmentation fault ------------------------------------------------------------------------- Running test_date.d interpreted has the same effect (abort on (2)). Versions: dmd: Digital Mars D Compiler v1.0 gcc: gcc (GCC) 4.0.2 20050901 (prerelease) (SUSE Linux) platform: PC SuSE Linux 10.0 (64 bit) ** Computers will always make mistakes, but will do so much faster tomorrow. ** ------------------------------------------------- <omoeller verify-it.de>
Feb 23 2007