mikros/rust
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Rollup merge of #30404 - Shiney:ImprovedStackHeap, r=steveklabnik

Browse Source 
…entation clearer

I could not use colors as suggested for #29854 because Github doesn't support these in markdown, however this solution may be better for color-blind readers.
This commit is contained in:
Steve Klabnik 2015-12-17 14:47:13 -05:00
commit 7963529b6b
1 changed files with 22 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

42
src/doc/book/the-stack-and-the-heap.md
View File

@ -130,63 +130,64 @@ on the stack is the first one you retrieve from it.
Let’s try a three-deep example:
```rust
fn bar() {
fn italic() {
let i = 6;
}
fn foo() {
fn bold() {
let a = 5;
let b = 100;
let c = 1;
bar();
italic();
}
fn main() {
let x = 42;
foo();
bold();
}
```
We have some kooky function names to make the diagrams clearer.
Okay, first, we call `main()`:
| Address | Name | Value |
|---------|------|-------|
| 0 | x | 42 |
Next up, `main()` calls `foo()`:
Next up, `main()` calls `bold()`:
| Address | Name | Value |
|---------|------|-------|
| 3 | c | 1 |
| 2 | b | 100 |
| 1 | a | 5 |
| **3** | **c**|**1** |
| **2** | **b**|**100**|
| **1** | **a**| **5** |
| 0 | x | 42 |
And then `foo()` calls `bar()`:
And then `bold()` calls `italic()`:
| Address | Name | Value |
|---------|------|-------|
| 4 | i | 6 |
| 3 | c | 1 |
| 2 | b | 100 |
| 1 | a | 5 |
| *4* | *i* | *6* |
| **3** | **c**|**1** |
| **2** | **b**|**100**|
| **1** | **a**| **5** |
| 0 | x | 42 |
Whew! Our stack is growing tall.
After `bar()` is over, its frame is deallocated, leaving just `foo()` and
After `italic()` is over, its frame is deallocated, leaving just `bold()` and
`main()`:
| Address | Name | Value |
|---------|------|-------|
| 3 | c | 1 |
| 2 | b | 100 |
| 1 | a | 5 |
| 0 | x | 42 |
| **3** | **c**|**1** |
| **2** | **b**|**100**|
| **1** | **a**| **5** |
| 0 | x | 42 |
And then `foo()` ends, leaving just `main()`:
And then `bold()` ends, leaving just `main()`:
| Address | Name | Value |
|---------|------|-------|
@ -578,3 +579,4 @@ comes at the cost of either significant runtime support (e.g. in the form of a
garbage collector) or significant programmer effort (in the form of explicit
memory management calls that require verification not provided by the Rust
compiler).