Rust FlameGraph

cargo install Flamegraph 

cargo flamegraph --bin <my binary>

Please note that <my binary> does not need to add .exe on windows. 

The call stack is up side down. The top most element is the funnction at lower level. Now let's see if i can get more time on debuggin rather than waiting for the code finish. 

Left & Right Asscociate in Parsing

I made the same mistake again when using Pratt parsing. I almost messed up the left asscociate and right asscociate. If an operator is left asscociate, the generated AST will be a tree lean-to-left. For struct, union, and other composite types, left asscoiate can expose the member as the right node. This can make the code generation much easier, because I know the type for the dot operator. 

For example, StructA.structB.a, the lean-to-left tree can expose the "a" as the right node and I can easily find out the whole expression StructA.structB.a is what type. I did not set assignment as an operator, the assignment can be lean-to-right tree. 

Hopefully this self-note can let me remember this rule and won't miss this case in the future. 

RiscV GCC Dynamic GOT layout

I've been struggling with the Linux ELF's dynamic link format for days. All GPT's provided wrong answer and they're wrong in the same way. 

The correct GOT layout for Linux ELF for RiscV are like the following if there are two external funtions. These two functions are funct0 and funct1. 

1. ffffffff ffffffff is reserved data
2. 00000000 00000000 is reserved data
3. GOT[funct0]
4. GOT[funct1]
5. .dynamic virutal address 

#1 and #2 are linker map and resolver address. These fields will be set by dynamic linker (or called dynamic loader). 

Unlike GPT's info, .dynamic virtual address is set to the first slot. The .dynamic virtual address is set as the last element.