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The global variable behavior I think I understand, and I believe the original authors did it this way on purpose, but I agree it seems quite bad.<BR>
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<BR>
The way the code is generated, all the internal globals for a module are in one large struct, per module.<BR>
There aren't symbols for each one.<BR>
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<BR>
The code translates like this:<BR>
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<BR>
Modula-3:<BR>
<BR>
<BR>
Foo.i3:<BR>
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<BR>
INTERFACE Foo;<BR>
<BR>
<BR>
PROCEDURE GetI() : INTEGER;<BR>
PROCEDURE GetJ() : INTEGER;<BR>
<BR>
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END Foo.<BR>
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<BR>
Foo.m3:<BR>
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<BR>
MODULE Foo;<BR>
<BR>
<BR>
VAR i, j: INTEGER;<BR>
<BR>
<BR>
PROCEDURE GetI() = BEGIN RETURN i; END GetI;<BR>
PROCEDURE GetJ() = BEGIN RETURN j; END GetJ;<BR>
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<BR>
C:<BR>
<BR>
<BR>
foo.h:<BR>
<BR>
<BR>
ptrdiff_t Foo__GetI(void);<BR>
ptrdiff_t Foo__GetJ(void);<BR>
<BR>
<BR>
foo.c:<BR>
<BR>
<BR>
struct<BR>
{<BR>
int i, j;<BR>
} Foo_M3;<BR>
<BR>
<BR>
ptrdiff_t Foo__GetI(void) { return Foo_M3.i; }<BR>
<BR>
ptrdiff_t Foo__GetJ(void) { return Foo_M3.j; }<BR>
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<BR>
I personally would much prefer one of:<BR>
<BR>
<BR>
<BR>
static int i, j;<BR>
<BR>
<BR>
ptrdiff_t Foo__GetI(void) { return i; }<BR>
<BR>
<BR>
ptrdiff_t Foo__GetJ(void) { return j; }<BR>
<BR>
<BR>
or:<BR>
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<BR>
int Foo_i, Foo_j;<BR>
<BR>
<BR>
ptrdiff_t Foo__GetI(void) { return Foo_i; }<BR>
<BR>
<BR>
ptrdiff_t Foo__GetJ(void) { return Foo_j; }<BR>
<BR>
<BR>
or two underscores.<BR>
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<BR>
Can anyone explain why it is done this way? And why it shouldn't be changed to how I showed?<BR>
<BR>
Here are some advantages/disadvanges:<BR>
symbols, debuggability, as discussed <BR>
The current way pretty much guaranteeds none of the data gets dead-stripped, for better and worse.<BR>
But really, even if you changed it to "my way", there's probably another bit needed on the data to dead-strip it,<BR>
so that behavior can be preserved, for better and worse.<BR>
"My way" probably also allows for not using bitfields in load/store, in fact, the offseting would often go away too.<BR>
<BR>
<BR>
> Should I compile m3gdb towards 32bit on an x86_64 platform if the<BR>> m3build I am using is 32bit?<BR>
<BR>
<BR>
It should build either way, but for it to be useful, yes, I expect so.<BR>
I believe current versions of gdb can have multiple targets though.<BR>
<BR>
<BR>
- Jay<BR><BR> <BR>> Date: Wed, 10 Jun 2009 15:26:09 +0100<BR>> From: estellnb@yahoo.de<BR>> To: m3devel@elegosoft.com<BR>> Subject: [M3devel] recent m3gdb does not want to compile<BR>> <BR>> For any kind of reason recent m3gdbs refuse to compile at me:<BR>> <BR>> ../gdb/configure<BR>> ...<BR>> checking for x86_64-unknown-linux-gnu-ar... no<BR>> checking for ar... ar<BR>> ...<BR>> <BR>> > which ar<BR>> /usr/bin/ar<BR>> <BR>> setting --bindir to /usr/bin or /usr does not help.<BR>> full error log: see attachement<BR>> <BR>> Should I compile m3gdb towards 32bit on an x86_64 platform if the<BR>> m3build I am using is 32bit?<BR>> <BR>> Besides this I am in wonder why a plain gdb can not access global<BR>> Modula-3 variables using PM3/EZM3 although I have specified -gstabs in<BR>> m3config/src/COMMON:<BR>> ASM = ["as","--32","-gstabs","-o"] % Assembler<BR>> DEBUG_FLAG = "-gstabs" % debugging info<BR>> BDEBUG_FLAG = "-gstabs" % debugging info<BR>> LDEBUG_FLAG = "-gstabs"<BR>> <BR>> i.e.<BR>> > gdb -batch --directory=<BR>> --directory=/home/elm/m3/Benchmark/LINUXLIBC6/../src -ex 'info<BR>> variables' /home/elm/m3/Benchmark/LINUXLIBC6/./pureDCT-queue >smbls<BR>> <BR>> > grep myglobal smbls -> nothing found<BR>> <BR></body>
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