Alloca is a function to allocate dynamically memory on the Stack in C. Such memory will be automatically deallocated when leaving the function.
Questions tagged [alloca]
87 questions
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Why is the use of alloca() not considered good practice?
alloca() allocates memory on the stack rather than on the heap, as in the case of malloc(). So, when I return from the routine the memory is freed. So, actually this solves my problem of freeing up dynamically allocated memory. Freeing of memory…
Vaibhav
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How does alloca() work on a memory level?
I'm trying to figure out how alloca() actually works on a memory level. From the linux man page:
The alloca() function allocates size bytes of space in the stack
frame of the caller. This temporary space is automatically freed
when the function…
glades
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alloc, malloc, and alloca — What's the difference?
I was under the impression that alloc in Objective-C (when we invoke [anyObject alloc] is actually implementing C function malloc and the memory getting allocated in heap, but could not find anywhere the answer for this.
Also, while searching for…
Anindya Sengupta
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Alloca implementation
How does one implement alloca() using inline x86 assembler in languages like D, C, and C++? I want to create a slightly modified version of it, but first I need to know how the standard version is implemented. Reading the disassembly from…
dsimcha
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Header alloca.h in Windows
I can't see any alloca.h equivalent in Visual C 2010. How can one perform stack allocation in Visual C on Windows? I miss the function alloca.
Cartesius00
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11
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alloca function in C
I was revising C and came across to alloca/free functions which is described as allocating storage on a stack like space. Is this same as the malloc/free ? or this is something different ? Thanks.
Cemre Mengü
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Is there an allocator that uses alloca and is otherwise C++ STL compliant?
I have two questions:
1) Is it possible to implement an allocator that uses alloca to allocate memory on the stack and is otherwise C++ STL compliant?
If there is code out there, you can make me happy by simply pointing me to the URL. :-)
If there…
Bjoern
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What is the purpose of the %"alloca point" line which occurs in llvm code?
I've been looking at some LLVM assembly produced by llvm-gcc lately and I've noticed a recurring statement of which I'm not sure its purpose.
For example, the following C program:
int main(void)
{
void (*f)(void) = (0x21332);
f();
}
When…
David Terei
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can we use alloca() or variable length array extentions in c++20 coroutines?
The GCC C++ compiler (any many other C++ compilers as well) provide nonstandard extentions such as
alloca() for stack based allocation
variable length arrays, as they are part of the C standard
Can these be used inside of C++20 coroutines from a…
Andreas H.
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Is alloca completely replaceable?
I've read quite a few places that alloca is obsolete and should not be used and Variable Length Arrays should be used instead.
My question is this: Is alloca completely replaceable by variable length arrays?
In my particular instance I have…
Earlz
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Can alloca() memory be reallocated?
Memory allocated by malloc can be reallocated with realloc. Is there a similar function for alloca? Reallocating stack memory could be useful when you don't want memory to be allocated on the heap, and you need to allocate variable stack memory…
Phridge
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Is it a good practice to hide structure definition in C?
In my opinion, hiding the definition of a structure in C generally makes code safer, as you enforce—with the help of the compiler—that no member of the structure can be accessed directly.
However, it has a downside in that a user of the structure…
Alexander Solovets
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What's the difference between alloca(n) and char x[n]?
What is the difference between
void *bytes = alloca(size);
and
char bytes[size]; //Or to be more precise, char x[size]; void *bytes = x;
...where size is a variable whose value is unknown at compile-time.
Jared Pochtar
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Is a goto in alloca's function scope valid?
The C standard prohibits a goto into a function scope where a VLA exists.
A VLA and the call to alloca function should have the same result on low level.
(I could be wrong, as I'm just a C, not a low level programmer, but in my imagin that appears…
dhein
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