Re: [patch+7.9] compile: Filter out -fpreprocessed
On Tue, Feb 3, 2015 at 11:10 AM, Mark Wielaard wrote: > On Tue, 2015-02-03 at 19:59 +0100, Jan Kratochvil wrote: >> On Tue, 03 Feb 2015 19:50:40 +0100, Doug Evans wrote: >> > On Fri, Jan 16, 2015 at 2:42 PM, Jan Kratochvil >> > wrote: >> > > [...] >> > > It is wrong that gcc puts -fpreprocessed into DW_AT_producer - I may >> > > post a gcc >> > > patch for it. >> > >> > I wasn't aware there are now rules for what can and cannot go in >> > DW_AT_producer. >> > DW_AT_producer has gone from being informational to having a formal >> > spec (in the sense that something will break if, for example, a >> > particular option is mentioned). >> > Is this spec written down somewhere? [At least guidelines for what >> > things may lead to breakage?] >> >> No. Do you have a suggestion where to put it? Should it be only a GNU >> extension or should it be even DWARF-standardized? > > The gcc documentation describes it: > https://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html > > -grecord-gcc-switches > This switch causes the command-line options used to invoke the > compiler that may affect code generation to be appended to the > DW_AT_producer attribute in DWARF debugging information. The > options are concatenated with spaces separating them from each > other and from the compiler version. See also > -frecord-gcc-switches for another way of storing compiler > options into the object file. This is the default. > > -gno-record-gcc-switches > Disallow appending command-line options to the DW_AT_producer > attribute in DWARF debugging information. > > So Jan is right that gcc adding -fpreprocessed, which doesn't affect > code generation, but is a preprocessor option, shouldn't be there. Thanks. Still, there's no hint to the reader that things may break if certain rules are not followed. It still seems like it's for informational purposes for human readers, with no suggestion that programs use this information too. [For completeness sake, I'm setting aside the compiler and version string. That seemed common enough knowledge to not need documentation as much as this does. I realize we're now talking about -grecord-gcc-switches, but this thread was originally about DW_AT_producer in general.]
Re: [patch+7.9] compile: Filter out -fpreprocessed
On Tue, 2015-02-03 at 19:59 +0100, Jan Kratochvil wrote: > On Tue, 03 Feb 2015 19:50:40 +0100, Doug Evans wrote: > > On Fri, Jan 16, 2015 at 2:42 PM, Jan Kratochvil > > wrote: > > > [...] > > > It is wrong that gcc puts -fpreprocessed into DW_AT_producer - I may post > > > a gcc > > > patch for it. > > > > I wasn't aware there are now rules for what can and cannot go in > > DW_AT_producer. > > DW_AT_producer has gone from being informational to having a formal > > spec (in the sense that something will break if, for example, a > > particular option is mentioned). > > Is this spec written down somewhere? [At least guidelines for what > > things may lead to breakage?] > > No. Do you have a suggestion where to put it? Should it be only a GNU > extension or should it be even DWARF-standardized? The gcc documentation describes it: https://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html -grecord-gcc-switches This switch causes the command-line options used to invoke the compiler that may affect code generation to be appended to the DW_AT_producer attribute in DWARF debugging information. The options are concatenated with spaces separating them from each other and from the compiler version. See also -frecord-gcc-switches for another way of storing compiler options into the object file. This is the default. -gno-record-gcc-switches Disallow appending command-line options to the DW_AT_producer attribute in DWARF debugging information. So Jan is right that gcc adding -fpreprocessed, which doesn't affect code generation, but is a preprocessor option, shouldn't be there. Cheers, Mark
Re: [patch+7.9] compile: Filter out -fpreprocessed
On Tue, 03 Feb 2015 19:50:40 +0100, Doug Evans wrote: > On Fri, Jan 16, 2015 at 2:42 PM, Jan Kratochvil > wrote: > > [...] > > It is wrong that gcc puts -fpreprocessed into DW_AT_producer - I may post a > > gcc > > patch for it. > > Hi. > I wasn't aware there are now rules for what can and cannot go in > DW_AT_producer. > DW_AT_producer has gone from being informational to having a formal > spec (in the sense that something will break if, for example, a > particular option is mentioned). > Is this spec written down somewhere? [At least guidelines for what > things may lead to breakage?] No. Do you have a suggestion where to put it? Should it be only a GNU extension or should it be even DWARF-standardized? Jan
Re: [patch+7.9] compile: Filter out -fpreprocessed
On Fri, Jan 16, 2015 at 2:42 PM, Jan Kratochvil wrote: > [...] > It is wrong that gcc puts -fpreprocessed into DW_AT_producer - I may post a > gcc > patch for it. Hi. I wasn't aware there are now rules for what can and cannot go in DW_AT_producer. DW_AT_producer has gone from being informational to having a formal spec (in the sense that something will break if, for example, a particular option is mentioned). Is this spec written down somewhere? [At least guidelines for what things may lead to breakage?]
