wine users - Apr 2008 - HeapAlloc vs. malloc. How does HeapAlloc work?

Hi,
I am little bit interested in Wine source code. There is one thing I don't
understand. How does HeapAlloc() work? Is it the same behavior as Winapi
HeapAlloc()? If so then I have to check NULL value after each calling of this
function, don't I?

I have found this code in Wine 0.9.57:

In dlls/dbghelp/stabs.c function 'static int stabs_new_include(const char*
file, unsigned long val)' line 163:

??????? if (!include_defs)
??????????? include_defs = HeapAlloc(GetProcessHeap(), 0, 
???????????????????????????????????? sizeof(include_defs[0]) *
num_alloc_include_def);
??????? else
??????????? include_defs = HeapReAlloc(GetProcessHeap(), 0, include_defs,
?????????????????????????????????????? sizeof(include_defs[0]) *
num_alloc_include_def);
??????? memset(include_defs + num_include_def, 0, sizeof(include_defs[0]) *
256);
??? }
??? include_defs[num_include_def].name = strcpy(HeapAlloc(GetProcessHeap(), 0,
strlen(file) + 1), file);
??? include_defs[num_include_def].value = val;
??? include_defs[num_include_def].vector = NULL;
??? include_defs[num_include_def].nrofentries = 0;

Nobody is checking NULL value of include_defs and later there is strcpy() with
HeapAlloc as parameter.

In dlls/winspool.drv/info.c function 'static LPDEVMODEA
DEVMODEdupWtoA(HANDLE heap, const DEVMODEW *dmW)' line 1709

???? if (pName) {
???????? len = MultiByteToWideChar(CP_ACP, 0, pName, -1, NULL, 0);
??????? nameW = HeapAlloc(GetProcessHeap(), 0, len * sizeof(WCHAR));
???????? MultiByteToWideChar(CP_ACP, 0, pName, -1, nameW, len);
???? }

Again nobody is checking the nameW value. Maybe it is checked inside
'MultiByteToWideChar()' but this function doesn't return any value
in this case.

There are places where value returned by HeapAlloc() is checked:

In dlls/wininet/internet.h 'static inline LPWSTR WININET_strdupW( LPCWSTR
str )' line 82:

??? LPWSTR ret = HeapAlloc( GetProcessHeap(), 0, (strlenW(str) +
1)*sizeof(WCHAR) );
??? if (ret) strcpyW( ret, str );
??? return ret;

Could somebody explain me the behavior of Wine HeapAlloc() and its family?

Thank you,
cunha

Petr Svoboda skrev:
> I am little bit interested in Wine source code. There is one thing I
don't understand. How does HeapAlloc() work? Is it the same behavior as
Winapi HeapAlloc()?
Yes.
> If so then I have to check NULL value after each calling of this function,
don't I?
Yes. You have to do that with malloc() too, so why "vs malloc"?
> Nobody is checking NULL value of include_defs and later there is strcpy()
with HeapAlloc as parameter.
Well, it's the age-old hazards of programming in C: people get lazy 
about error checking, which has caused various problems in all kinds of 
software. (In this case, perhaps thinking that if you're out of memory, 
then you're in so much trouble anyway that the null-pointer-dereference 
exception to follow isn't such a big deal...)