https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94859
--- Comment #1 from doug mcilroy ---
gcc accepts
struct X {int a; int :0;} x;
and rejects
struct Y {int a; :0;} y;
in conflict with the final sentence in this quote from the C standard, Section
6.7.2.1, Structure and union
Assignee: unassigned at gcc dot gnu.org
Reporter: doug at cs dot dartmouth.edu
Target Milestone: ---
: unassigned at gcc dot gnu.org
Reporter: doug at cs dot dartmouth.edu
Target Milestone: ---
sizeof(struct{ unsigned int a:2; }) is 4. 3 out of the 4
bytes are gratuitously wasted.
A workaround is struct{ unsigned char a:2; }, whose size is 1,
but this is implementation-defined syntax
Assignee: unassigned at gcc dot gnu.org
Reporter: doug at cs dot dartmouth.edu
Target Milestone: ---
struct { char x:1; } is implementation-defined syntax
per www.open-std.org/jtc1/sc22/wg14/www/docs/n2433.pdf,
Section 6.7.2.1, Constraint 5, which requires support
of only _Bool, signed
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93278
--- Comment #11 from doug mcilroy ---
When I ran it on Linux, I did get catastrophe: "No space left on device". I do
not know what device; ~ and /tmp live in different file systems. It's been
decades since I last saw that diagnostic. It also
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93278
--- Comment #9 from doug mcilroy ---
If I can play with the assembler to accomplish the desired result, why can't
gcc? I notice that gcc is smart enough already to produce uninitialized space
for
char a[1000] = "\0";
int main(){
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93278
--- Comment #6 from doug mcilroy ---
The waste of time and space happens in the assembler, but the assembler only
does what it is told to do. There must be a way for gcc to tell it to put array
a in a partially filled ELF section.
$ cat junk.c
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93278
--- Comment #5 from doug mcilroy ---
The waste of time and space happens in the assembler, but the assembler only
does what it is told to do. There must be a way for gcc to tell it to put array
a in a partially filled ELF section.
$ cat junk.c
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93278
--- Comment #2 from doug mcilroy ---
My error. I omitted half the program. The bad behavior is exhibited by
char a{HUGE] = "x";
int main(){ return 0; }
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: doug at cs dot dartmouth.edu
Target Milestone: ---
Example, with HUGE varying from a million to a billion.
char a[HUGE] = "x";
Object file size varies a
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=8270
--- Comment #61 from doug mcilroy ---
Contrary to comment #57, the GCC convention does affect the interpretation of
C-style comments. GCC rejects this Christmas tree with trailing spaces.
/*
/\
/**\
/\
*/
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=8270
--- Comment #56 from doug mcilroy doug at cs dot dartmouth.edu ---
(In reply to Kai Tietz from comment #55)
Comment #55 overlooks the Standard's translation phase 1, which replaces an
implementation-defined end-of-line indicator with a new-line
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