Hi
I am using LLVM to help me do some code analysis. I wrote a LLVM Function
Pass to help me to generate some information. I use the code below to get
the source line information for every instruction.
for (BasicBlock &BB : F){
for(Instruction &I: BB){
DILocation* Loc = I.getDebugLoc().get();
unsigned Line = Loc->getLine()
}
}
I think the function's first block's first instruction's source line
should
be the beginning of the function. Most of the functions inside the binary
follow the rules. However, I found the file system.h in the coreutils-8.28
has a function like below:
611 static inline void
612 emit_backup_suffix_note (void)
613 {
614 fputs (_("\
615 \n\
616 The backup suffix is '~', unless set with --suffix or
SIMPLE_BACKUP_SUFFIX.\n\
617 The version control method may be selected via the --backup option or
through\n\
618 the VERSION_CONTROL environment variable. Here are the values:\n\
619 \n\
620 "), stdout);
621 fputs (_("\
622 none, off never make backups (even if --backup is given)\n\
623 numbered, t make numbered backups\n\
624 existing, nil numbered if numbered backups exist, simple
otherwise\n\
625 simple, never always make simple backups\n\
626 "), stdout);
627 }
When analysis this function. The first block's first instruction's
source
line is 614 rather than 612 or 613. Is it a bug or any other meaning
resulting in such case. Below is the IR. The first IR's source line if 614.
%call = call i8* @gettext(i8* getelementptr inbounds ([221 x i8], [221 x
i8]* @.str.42, i32 0 , i32 0)) #12, !dbg !1295
%0 = load %struct._IO_FILE*, %struct._IO_FILE** @stdout, align 4, !dbg
!1295
%call1 = call i32 @fputs_unlocked(i8* %call, %struct._IO_FILE* %0), !dbg
!1295
%call2 = call i8* @gettext(i8* getelementptr inbounds ([222 x i8], [222 x
i8]* @.str.43, i32 0, i32 0)) #12, !dbg !1296
%1 = load %struct._IO_FILE*, %struct._IO_FILE** @stdout, align 4, !dbg
!1296
%call3 = call i32 @fputs_unlocked(i8* %call2, %struct._IO_FILE* %1), !dbg
!1296
ret void, !dbg !1297
Can anyone help me or give me some suggestions? Many Thanks
Regards
Muhui
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.llvm.org/pipermail/llvm-dev/attachments/20180529/5a5a2dbe/attachment.html>
On Tue, May 29, 2018 at 5:25 AM Muhui Jiang via llvm-dev < llvm-dev at lists.llvm.org> wrote:> Hi > > I am using LLVM to help me do some code analysis. I wrote a LLVM Function > Pass to help me to generate some information. I use the code below to get > the source line information for every instruction. > > for (BasicBlock &BB : F){ > for(Instruction &I: BB){ > DILocation* Loc = I.getDebugLoc().get(); > unsigned Line = Loc->getLine() > } > } > > I think the function's first block's first instruction's source line > should be the beginning of the function. >I'm not sure why that would necessarily be true - if there are no instructions associated with the beginning of the function. (no frame setup, no allocas, etc)> Most of the functions inside the binary follow the rules. However, I found > the file system.h in the coreutils-8.28 has a function like below: > > 611 static inline void > 612 emit_backup_suffix_note (void) > 613 { > 614 fputs (_("\ > 615 \n\ > > 616 The backup suffix is '~', unless set with --suffix or > SIMPLE_BACKUP_SUFFIX.\n\ > 617 The version control method may be selected via the --backup option or > through\n\ > 618 the VERSION_CONTROL environment variable. Here are the values:\n\ > 619 \n\ > 620 "), stdout); > 621 fputs (_("\ > 622 none, off never make backups (even if --backup is given)\n\ > 623 numbered, t make numbered backups\n\ > 624 existing, nil numbered if numbered backups exist, simple > otherwise\n\ > 625 simple, never always make simple backups\n\ > 626 "), stdout); > 627 } > > When analysis this function. The first block's first instruction's source > line is 614 rather than 612 or 613. >The first instruction is the call to gettext (presumably expressed by the _ macro) that is on line 614. Doesn't look like there's any instruction that could/should be attributed to 612 or 613. The DISubprogram describing the function should probably have some a "scopeLine" attribute of 613, which might be what you want.> Is it a bug or any other meaning resulting in such case. Below is the IR. > The first IR's source line if 614. > > %call = call i8* @gettext(i8* getelementptr inbounds ([221 x i8], [221 x > i8]* @.str.42, i32 0 , i32 0)) #12, !dbg !1295 > %0 = load %struct._IO_FILE*, %struct._IO_FILE** @stdout, align 4, !dbg > !1295 > %call1 = call i32 @fputs_unlocked(i8* %call, %struct._IO_FILE* %0), !dbg > !1295 > %call2 = call i8* @gettext(i8* getelementptr inbounds ([222 x i8], [222 > x i8]* @.str.43, i32 0, i32 0)) #12, !dbg !1296 > %1 = load %struct._IO_FILE*, %struct._IO_FILE** @stdout, align 4, !dbg > !1296 > %call3 = call i32 @fputs_unlocked(i8* %call2, %struct._IO_FILE* %1), > !dbg !1296 > ret void, !dbg !1297 > > Can anyone help me or give me some suggestions? Many Thanks > > Regards > Muhui > _______________________________________________ > LLVM Developers mailing list > llvm-dev at lists.llvm.org > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev >-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20180529/045fa80c/attachment.html>
Hi David Thank you very much for your suggestions. ScopeLine works well. It could represent the start of a function. Do you know whether I can get the start column of this function? Many Thanks Regards Muhui 2018-05-30 3:25 GMT+08:00 David Blaikie <dblaikie at gmail.com>:> > > On Tue, May 29, 2018 at 5:25 AM Muhui Jiang via llvm-dev < > llvm-dev at lists.llvm.org> wrote: > >> Hi >> >> I am using LLVM to help me do some code analysis. I wrote a LLVM Function >> Pass to help me to generate some information. I use the code below to get >> the source line information for every instruction. >> >> for (BasicBlock &BB : F){ >> for(Instruction &I: BB){ >> DILocation* Loc = I.getDebugLoc().get(); >> unsigned Line = Loc->getLine() >> } >> } >> >> I think the function's first block's first instruction's source line >> should be the beginning of the function. >> > > I'm not sure why that would necessarily be true - if there are no > instructions associated with the beginning of the function. (no frame > setup, no allocas, etc) > > >> Most of the functions inside the binary follow the rules. However, I >> found the file system.h in the coreutils-8.28 has a function like below: >> >> 611 static inline void >> 612 emit_backup_suffix_note (void) >> 613 { >> 614 fputs (_("\ >> 615 \n\ >> >> 616 The backup suffix is '~', unless set with --suffix or >> SIMPLE_BACKUP_SUFFIX.\n\ >> 617 The version control method may be selected via the --backup option or >> through\n\ >> 618 the VERSION_CONTROL environment variable. Here are the values:\n\ >> 619 \n\ >> 620 "), stdout); >> 621 fputs (_("\ >> 622 none, off never make backups (even if --backup is given)\n\ >> 623 numbered, t make numbered backups\n\ >> 624 existing, nil numbered if numbered backups exist, simple >> otherwise\n\ >> 625 simple, never always make simple backups\n\ >> 626 "), stdout); >> 627 } >> >> When analysis this function. The first block's first instruction's source >> line is 614 rather than 612 or 613. >> > > The first instruction is the call to gettext (presumably expressed by the > _ macro) that is on line 614. Doesn't look like there's any instruction > that could/should be attributed to 612 or 613. > > The DISubprogram describing the function should probably have some a > "scopeLine" attribute of 613, which might be what you want. > > >> Is it a bug or any other meaning resulting in such case. Below is the IR. >> The first IR's source line if 614. >> >> %call = call i8* @gettext(i8* getelementptr inbounds ([221 x i8], [221 >> x i8]* @.str.42, i32 0 , i32 0)) #12, !dbg !1295 >> %0 = load %struct._IO_FILE*, %struct._IO_FILE** @stdout, align 4, !dbg >> !1295 >> %call1 = call i32 @fputs_unlocked(i8* %call, %struct._IO_FILE* %0), >> !dbg !1295 >> %call2 = call i8* @gettext(i8* getelementptr inbounds ([222 x i8], [222 >> x i8]* @.str.43, i32 0, i32 0)) #12, !dbg !1296 >> %1 = load %struct._IO_FILE*, %struct._IO_FILE** @stdout, align 4, !dbg >> !1296 >> %call3 = call i32 @fputs_unlocked(i8* %call2, %struct._IO_FILE* %1), >> !dbg !1296 >> ret void, !dbg !1297 >> >> Can anyone help me or give me some suggestions? Many Thanks >> >> Regards >> Muhui >> _______________________________________________ >> LLVM Developers mailing list >> llvm-dev at lists.llvm.org >> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev >> >-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20180530/18de0322/attachment.html>