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digitalmars.D.learn - DLang/Wiki/'Hello World'/Run Code/Disassembly

reply DLearner <bm.email01 gmail.com> writes:
Code ran with expected output, but Disassembly seemed to go in a 
loop?
Oct 21 2016
parent reply cym13 <cpicard openmailbox.org> writes:
On Friday, 21 October 2016 at 08:58:50 UTC, DLearner wrote:

 Code ran with expected output, but Disassembly seemed to go in 
 a loop?


What makes you think that? It's hard to tell if you don't give 
any information.

Let's do that! I'll use only naive flags and all and use radare2 
to
disassemble the main D function which is _Dmain (the entry point 
has to
launch the runtime etc... we aren't very interested in that):

$ cat >test.d <<EOF
     import std.stdio;
     void main() {
         writeln("Hello World!");
     }
EOF
$ dmd test.d
$ ./test
Hello World!
$ r2 -q -c "afr; pdf   sym._Dmain" test
┌ (fcn) sym._Dmain 24
│   sym._Dmain ();
│           ; CALL XREF from 0x08078258 (sym.main)
│           ; DATA XREF from 0x0807825b (sym.main)
│           0x08077e70      55             push ebp
│           0x08077e71      8bec           mov ebp, esp
│           0x08077e73      b9d02b0a08     mov ecx, 
str.Hello_World_;
"Hello World!"   0x80a2bd0
│           0x08077e78      b80c000000     mov eax, 0xc
│           0x08077e7d      51             push ecx
│           0x08077e7e      50             push eax
│           0x08077e7f      e804000000     call
sym._D3std5stdio16__T7writelnTAyaZ7writelnFNfAyaZv
│           0x08077e84      31c0           xor eax, eax
│           0x08077e86      5d             pop ebp
└           0x08077e87      c3             ret

No loop. Not even a jump. I'm in x86 so arguments are simply 
pushed on the
stack. No brainer.
Oct 21 2016
parent reply DLearner <bm.email01 gmail.com> writes:
On Friday, 21 October 2016 at 09:07:35 UTC, cym13 wrote:

 On Friday, 21 October 2016 at 08:58:50 UTC, DLearner wrote:

 [...]


 What makes you think that? It's hard to tell if you don't give 
 any information.


I pressed the 'Run' button and got the 'Hello World'.
I pressed the 'Disassembly' button and got...nothing.
Oct 21 2016
next sibling parent Daniel Kozak via Digitalmars-d-learn <digitalmars-d-learn puremagic.com> writes:
Dne 21.10.2016 v 21:03 DLearner via Digitalmars-d-learn napsal(a):


 On Friday, 21 October 2016 at 09:07:35 UTC, cym13 wrote:

 On Friday, 21 October 2016 at 08:58:50 UTC, DLearner wrote:

 [...]


 What makes you think that? It's hard to tell if you don't give any 
 information.


 I pressed the 'Run' button and got the 'Hello World'.
 I pressed the 'Disassembly' button and got...nothing.


Okey so some page does not work correctly, and you think this? Wow :D
you should try one of these this pages
http://asm.dlang.org
http://d.godbolt.org
Oct 21 2016
prev sibling parent reply cym13 <cpicard openmailbox.org> writes:
On Friday, 21 October 2016 at 19:03:30 UTC, DLearner wrote:

 On Friday, 21 October 2016 at 09:07:35 UTC, cym13 wrote:

 On Friday, 21 October 2016 at 08:58:50 UTC, DLearner wrote:

 [...]


 What makes you think that? It's hard to tell if you don't give 
 any information.


 I pressed the 'Run' button and got the 'Hello World'.
 I pressed the 'Disassembly' button and got...nothing.


That's a problem about the debugger/disassembler that you use, 
not about D.

We can't do anything else to help as you give no information. See 
my post:
- I gave the exact source code
- I gave the compiler that I used with all its flags
- I explained what tool I used to analyse it, what I was 
analysing exactly and how
- At each step I gave the exact output of the tools with 
potential errors

This means this is reproducible. Anybody can try it at home and 
check for himself that it works.

There is *no way* to fix a bug that we can't reproduce, and there 
is *no way* to reproduce it unless we have all the informations 
stated above.
Oct 21 2016
parent cym13 <cpicard openmailbox.org> writes:
On Friday, 21 October 2016 at 19:27:59 UTC, cym13 wrote:

 On Friday, 21 October 2016 at 19:03:30 UTC, DLearner wrote:

 [...]


 That's a problem about the debugger/disassembler that you use, 
 not about D.

 We can't do anything else to help as you give no information. 
 See my post:
 - I gave the exact source code
 - I gave the compiler that I used with all its flags
 - I explained what tool I used to analyse it, what I was 
 analysing exactly and how
 - At each step I gave the exact output of the tools with 
 potential errors

 This means this is reproducible. Anybody can try it at home and 
 check for himself that it works.

 There is *no way* to fix a bug that we can't reproduce, and 
 there is *no way* to reproduce it unless we have all the 
 informations stated above.


Apologies, I didn't understand that you put all that in the title.
Oct 21 2016