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C++ va_list wromng code generation in class::method(...,va_list args) only
- From: Bernd Roesch <nospamname at gmx dot de>
- To: gcc at gcc dot gnu dot org
- Date: Fri, 30 Mar 2012 18:31:43 +0100
- Subject: C++ va_list wromng code generation in class::method(...,va_list args) only
hello
there is a C++ game called dunelegacy which work on other GCC architecture ok
On G++ 68k it compile ok, but produce wrong code, because there seem something diffrent in
va_list. The value of
SDL_RWops is transfer wrong.
I do not understand what backend problem is possible to cause this. Please help.va_list use the
builtin GCC functions
this happen on all 68k compilers i test. (3.x and some 4.x)
See also the source attached of this class
the program flow of the critical part begin here.
Wsafile::Wsafile(SDL_RWops* RWop)
{
readdata(1,RWop);
}
......
now there are 2 Methods named readdata, and gcc call the 2. one. This work wrong. Only when called
the first is ok.
.....
void Wsafile::readdata(int NumFiles, ...) {
va_list args;
va_start(args,NumFiles);
readdata(NumFiles,args);
va_end(args);
}
/// Helper method for reading and concatinating various WSA-Files.
/**
This methods reads from the RWops all data and concatinates all the frames to one animation. The
SDL_RWops
can be readonly but must support seeking.
\param NumFiles Number of SDL_RWops
\param args SDL_RWops for each wsa-File should be in this va_list. (can be readonly)
*/
void Wsafile::readdata(int NumFiles, va_list args) {
unsigned char** Filedata;
Uint32** Index;
Uint16* NumberOfFrames;
bool* extended;
if((Filedata = (unsigned char**) malloc(sizeof(unsigned char*) * NumFiles)) == NULL) {
fprintf(stderr, "Wsafile::readdata(): Unable to allocate memory!\n");
exit(EXIT_FAILURE);
}
.....................
when i change code to this and rename the first readdata method to readdata_first then it work
Wsafile::Wsafile(SDL_RWops* RWop)
{
readdata_first(1,RWop); <---- I change that line
}
now there is called this method before and all work ok
void Wsafile::readdata_frist(int NumFiles, ...) { <---- I rename readdata to readdata_first.
va_list args;
va_start(args,NumFiles);
readdata(NumFiles,args);
va_end(args);
}
/// Helper method for reading and concatinating various WSA-Files.
/**
This methods reads from the RWops all data and concatinates all the frames to one animation. The
SDL_RWops
can be readonly but must support seeking.
\param NumFiles Number of SDL_RWops
\param args SDL_RWops for each wsa-File should be in this va_list. (can be readonly)
*/
void Wsafile::readdata(int NumFiles, va_list args) {
unsigned char** Filedata;
Uint32** Index;
Uint16* NumberOfFrames;
bool* extended;
if((Filedata = (unsigned char**) malloc(sizeof(unsigned char*) * NumFiles)) == NULL) {
fprintf(stderr, "Wsafile::readdata(): Unable to allocate memory!\n");
exit(EXIT_FAILURE);
}
..........
int WsaFilesize;
RWop = va_arg(args,SDL_RWops*);
Filedata[i] = readfile(RWop,&WsaFilesize); <--- here crash, when not the 1. method is called
before
Bye