On 07.06.2012 21:11, Christoph Schwarz wrote: > Package: gcc-4.6 > Version: 4.6.3-1 > Severity: normal > > Dear Maintainer, > > I have a program that loops over const char * pointers in named sections. > In this loop, incorrect generated assembly code causes wrong output, e.g. > it outputs (null) instead of the string pointed to by the const char * > pointer. > This (null) can be tracked down to the generated assembly code where it > puts a static zero on the stack instead of the address of the string. > > This incorrect code is generated for 32 bit with optimization levels 1-3 > only. 64 bit is not affected, neither is unoptimized 32 bit. > > I found various versions of gcc 4.6.x containing this bug, including: > TDM-GCC 4.6.1, MinGW gcc 4.6.2 and Debian gcc 4.6.3-1 > so it seems to me it is a 4.6 issue. I can confirm that neither MinGW gcc > 4.5.2 > nor Debian gcc 4.4.5 (Debian Squeeze) contain this bug. > > I already filed a bug against TDM-GCC 4.6.1: > http://sourceforge.net/tracker/?func=detail&aid=3532366&group_id=200665&atid=974439 > > Quoting from this bug report: > ===== quote begin ===== > The expected and correct output is: > B: Handling call with 1 args > B: Handling call one > B: Handling call with 1 args > B: Handling call with 3 args > B: Handling call three > B: Handling call with 3 args > B: Handling call with 2 args > B: Handling call two > B: Handling call with 2 args > > The incorrect output is: > B: Handling call with 1 args > B: Handling call (null) > B: Handling call with 0 args > B: Handling call with 3 args > B: Handling call (null) > B: Handling call with 0 args > B: Handling call with 2 args > B: Handling call (null) > B: Handling call with 0 args > > The issue can be tracked down to the generated assembly code where the code > puts a static zero on the stack for printf (instead of the address of the > char array), resulting in the "(null)" output. Same goes for the "0 args" > output. > > The incorrect assembly code can be found in lines 30-35 of the attached s > file: > movl $0, 4(%esp) > movl $LC1, (%esp) > call _printf > movl $0, 4(%esp) > movl $LC0, (%esp) > call _printf > ===== quote end ===== > > I'll attach the test program and additional files. Please note that I had to > make slightly modifications to the section names and linker options in order > to get gcc 4.6.3-1 (or its ld) to sort the sections in alphabetic order > (compared to the test program that I filed with the TDM-GCC bug). > > thank you for looking into this issue, > Chris
please could you recheck with 4.7 from unstable? -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
