#compiler-construction

Solution: How are gcc/g++ bootstrapped? #computers #dev #answer

How are gcc/g++ bootstrapped?

This has been bugging me for a while. How do gcc/g++ compile themselves? I’m guessing that every revision gets compiled with a previously built revision. Is this true? And if it is, does it mean that the oldest g++/gcc versions were written in assembly?

Answer [by larsmans]: How are gcc/g++ bootstrapped?

The oldest version of GCC was compiled using another C…

Resolved: What does a just-in-time (JIT) compiler do? #development #fix #answer

What does a just-in-time (JIT) compiler do?

What does a JIT compiler specifically do as opposed to a non-JIT compiler? Can someone give a succinct and easy to understand description?

Answer [by Mark Cidade]: What does a just-in-time (JIT) compiler do?

A JIT compiler runs afterthe program has started and compiles the code (usually bytecode or some kind of VM instructions) on the fly (or…

How to: gcc makefile error: "No rule to make target …" #computers #it #fix

gcc makefile error: "No rule to make target …"

I’m trying to use GCC (linux) with a makefile to compile my project.

I get the following error which is can’t seem to decipher in this context:

"No rule to make target 'vertex.cpp', needed by 'vertex.o'. Stop."

This is the makefile:

a.out: vertex.o edge.o elist.o main.o vlist.o enode.o vnode.o g++ vertex.o edge.o elist.o main.o vlist.o enode.o…

Answer: Writing a compiler in its own language #answer #it #computers

Writing a compiler in its own language

Intuitively, it would seems that a compiler for language Foo, cannot itself be written in Foo. More specifically, the first compiler for language Foo cannot be written in Foo, but any subsequent compiler could be written for Foo.

But is this actually true? I have some very vague recollection of reading about a language whose first compiler was written in…

How to: Can a recursive function be inline? #dev #answer #fix

Can a recursive function be inline?

inline int factorial(int n) { if(!n) return 1; else return n*factorial(n-1); }

As I was reading this, found that the above code would lead to “infinite compilation” if not handled by compiler correctly.

How does the compiler decide whether to inline a function or not ?

Answer [by mattlant]: Can a recursive function be inline?

The compiler will make a call…

How to: What kinds of patterns could I enforce on the code to make it easier to translate to another programming language? #dev #solution #computers

What kinds of patterns could I enforce on the code to make it easier to translate to another programming language?

I am setting out to do a side project that has the goal of translating code from one programming language to another. The languages I am starting with are PHP and Python (Python to PHP should be easier to start with), but ideally I would be able to add other languages with (relative)…

Fix: Do compilers produce better code for do-while loops versus other types of loops? #fix #development #computers

Do compilers produce better code for do-while loops versus other types of loops?

There’s a comment in the zlib compression library (which is used in the Chromium project among many others) which implies that a do-while loop in C generates “better” code on most compilers. Here is the snippet of code where it appears.

do { } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) && *(ushf*)(scan+=2) ==…

Resolved: Why does this (null || !TryParse) conditional result in "use of unassigned local variable"? #answer #fix #solution

Why does this (null || !TryParse) conditional result in "use of unassigned local variable"?

The following code results in use of unassigned local variable “numberOfGroups”:

int numberOfGroups; if(options.NumberOfGroups == null || !int.TryParse(options.NumberOfGroups, out numberOfGroups)) { numberOfGroups = 10; }

However, this code works fine (though, ReSharper says the = 10 is redundant):

int…