compile-i386.c: don't ignore return value of write(2)
PATCH 1/1 compile-i386.c: don't ignore return value of write(2)
Some versions of gcc (e.g. v4.8.2) complain about ignoring the return value of a call to the write(2) system call, since the system header files have marked its declaration with the warn_unused_result attribute.
In order to suppress the compiler warning, check the return value from 'write' and, if it indicates an error (a negative return value), exit the process using 'die' to display an error message. Replace a second call to 'write', which does not provoke a compiler warning, with similar code for consistency.
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Hi Chris,
This is an (almost) minimal patch to suppress the compiler warning. You could drop the second hunk (and edit the commit message) if you prefer an absolutely minimal patch. :-D
ATB,
Ramsay Jones
compile-i386.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
compile-i386.c +4 -4
@@ -732,7 +732,8 @@ static void emit_insn_atom(struct function *f, struct atom *atom) atom->insn, comment[0] ? "\t\t" : "", comment); -write (STDOUT_FILENO , s,strlen (s)); +if (write (STDOUT_FILENO , s,strlen (s)) <0 ) +die ("can't write to stdout" ); }static void emit_atom_list (struct function *f)
@@ -742,9 +743,8 @@ static void emit_atom_list(struct function *f) FOR_EACH_PTR(f->atom_list, atom) {switch (atom->type) {case ATOM_TEXT : { -ssize_t rc =write (STDOUT_FILENO , atom->text, - atom->text_len); - (void ) rc;/* FIXME */ +if (write (STDOUT_FILENO , atom->text, atom->text_len) <0 ) +die ("can't write to stdout" );break ; }case ATOM_INSN :
Signature · 1 line
2.1.0
Quoted 5 lines · Ramsay Jones
Some versions of gcc (e.g. v4.8.2) complain about ignoring the return value of a call to the write(2) system call, since the system header files have marked its declaration with the
warn_unused_resultattribute.
Quoted 7 lines
In order to suppress the compiler warning, check the return value from 'write' and, if it indicates an error (a negative return value), exit the process using 'die' to display an error message. Replace a second call to 'write', which does not provoke a compiler warning, with similar code for consistency.
Signed-off-by Ramsay Jones <[email protected]>
That isn't the only way write() can fail; it can also do a partial write, in which case you need to loop and write the rest. You might consider adding an xwrite() function which includes that logic. (Alternatively, you could use standard C IO, which doesn't have that problem.)
Quoted 45 lines
Hi Chris,
This is an (almost) minimal patch to suppress the compiler warning. You could drop the second hunk (and edit the commit message) if you prefer an absolutely minimal patch. :-D
ATB,
Ramsay Jonescompile-i386.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)compile-i386.c +4
-4@@ -732,7 +732,8 @@ static void emit_insn_atom(struct function *f, struct atom *atom) atom->insn, comment[0] ? "\t\t" : "", comment); -write (STDOUT_FILENO , s,strlen (s)); +if (write (STDOUT_FILENO , s,strlen (s)) <0 ) +die ("can't write to stdout" ); }static void emit_atom_list (struct function *f)@@ -742,9 +743,8 @@ static void emit_atom_list(struct function *f) FOR_EACH_PTR(f->atom_list, atom) {switch (atom->type) {case ATOM_TEXT : { -ssize_t rc =write (STDOUT_FILENO , atom->text, - atom->text_len); - (void ) rc;/* FIXME */ +if (write (STDOUT_FILENO , atom->text, atom->text_len) <0 ) +die ("can't write to stdout" );break ; }case ATOM_INSN :Signature · 5 lines
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Quoted 12 lines · Josh Triplett
Quoted 11 lines · Ramsay Jones
Some versions of gcc (e.g. v4.8.2) complain about ignoring the return value of a call to the write(2) system call, since the system header files have marked its declaration with the
warn_unused_resultattribute.In order to suppress the compiler warning, check the return value from 'write' and, if it indicates an error (a negative return value), exit the process using 'die' to display an error message. Replace a second call to 'write', which does not provoke a compiler warning, with similar code for consistency.
Quoted 5 lines
Quoted 1 line
Signed-off-by Ramsay Jones <[email protected]>That isn't the only way
write()can fail; it can also do a partial write, in which case you need to loop and write the rest. You might consider adding anxwrite()function which includes that logic.
I did consider doing exactly that, but I wanted a _minimal_ fix for a program that is basically unmaintained. However, if Chris would like such a patch, I will happily provide one! ;-)
Quoted 2 lines
(Alternatively, you could use standard C IO, which doesn't have that problem.)
See the very first version of this patch. :-D (I still slightly prefer the first patch, very closely followed by the second version; this is the third attempt).
ATB,
Ramsay Jones