Hi,
If I have an instance of DISubprogram, can I get the debug info of local
variables of the function, including parameters?
I tried to use the getVariables() function defined in DISubprogram, but
it seemed to return an empty DIArray node when I ran my pass alone using
opt. Do I need to enable any other analysis passes in order to populate
the data?
My related snippet of code is like the following:
NamedMDNode *M_Nodes = M.getNamedMetadata("llvm.dbg.cu");
for (unsigned i = 0, e = M_Nodes->getNumOperands(); i != e; ++i) {
DIArray SPs = CU.getSubprograms();
for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++ i) {
DISubprogram SP(SPs.getElement(i));
DIArray Vars = SP.getVariables();
for (unsigned i2 = 0, e2 = Vars.getNumElements(); i2 != e2; ++i2) {
DIVariable DV(Vars.getElement(i));
DV.print(errs()); errs() << " : ";
DV.getType().dump();
}
}
}
In addition, can I use DebegInfo to get the list of parameters (var
names and types) of a subprogram? or I have to parse the underlying
metadata and build the relationship?
Thanks,
Lu
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Hi David, Thank you! Your suggested method works. I think that you or someone should write what you said in the comments for the getVariable() function. :) Best, Lu On 11/03/2013 06:30 AM, David Blaikie wrote:> > > > On Sat, Nov 2, 2013 at 4:17 PM, lu zhao <luzhao at cs.utah.edu > <mailto:luzhao at cs.utah.edu>> wrote: > > Hi, > > If I have an instance of DISubprogram, can I get the debug info of > local variables of the function, including parameters? > > I tried to use the getVariables() function defined in > DISubprogram, but it seemed to return an empty DIArray node when I > ran my pass alone using opt. Do I need to enable any other > analysis passes in order to populate the data? > > My related snippet of code is like the following: > > NamedMDNode *M_Nodes = M.getNamedMetadata("llvm.dbg.cu > <http://llvm.dbg.cu>"); > for (unsigned i = 0, e = M_Nodes->getNumOperands(); i != e; ++i) { > DIArray SPs = CU.getSubprograms(); > for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++ i) { > DISubprogram SP(SPs.getElement(i)); > DIArray Vars = SP.getVariables(); > for (unsigned i2 = 0, e2 = Vars.getNumElements(); i2 !> e2; ++i2) { > DIVariable DV(Vars.getElement(i)); > DV.print(errs()); errs() << " : "; DV.getType().dump(); > } > } > } > > In addition, can I use DebegInfo to get the list of parameters > (var names and types) of a subprogram? or I have to parse the > underlying metadata and build the relationship? > > > Basically this /\. We use the variables list (the getVariables > function you mentioned) to persist the variables in optimized (above > -O0) builds, but at -O0 we save metadata space by not emitting the > list and relying on the dbg_value/declare intrinsics to keep the > variable metadata alive and the variables to refer to their scope > (lexical blocks (that refer to subprograms) or subprograms). > > So you'd have to walk all the instructions looking for > dbg_declare/value (I forget which, perhaps both) and trace those back > to the DIVariables, etc... > > > Thanks, > Lu > > > _______________________________________________ > LLVM Developers mailing list > LLVMdev at cs.uiuc.edu <mailto:LLVMdev at cs.uiuc.edu> > http://llvm.cs.uiuc.edu > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev > >-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20131103/37a56dc0/attachment.html>
On Sat, Nov 2, 2013 at 4:17 PM, lu zhao <luzhao at cs.utah.edu> wrote:> Hi, > > If I have an instance of DISubprogram, can I get the debug info of local > variables of the function, including parameters? > > I tried to use the getVariables() function defined in DISubprogram, but it > seemed to return an empty DIArray node when I ran my pass alone using opt. > Do I need to enable any other analysis passes in order to populate the data? > > My related snippet of code is like the following: > > NamedMDNode *M_Nodes = M.getNamedMetadata("llvm.dbg.cu"); > for (unsigned i = 0, e = M_Nodes->getNumOperands(); i != e; ++i) { > DIArray SPs = CU.getSubprograms(); > for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++ i) { > DISubprogram SP(SPs.getElement(i)); > DIArray Vars = SP.getVariables(); > for (unsigned i2 = 0, e2 = Vars.getNumElements(); i2 != e2; ++i2) { > DIVariable DV(Vars.getElement(i)); > DV.print(errs()); errs() << " : "; DV.getType().dump(); > } > } > } > > In addition, can I use DebegInfo to get the list of parameters (var names > and types) of a subprogram? or I have to parse the underlying metadata and > build the relationship? >Basically this /\. We use the variables list (the getVariables function you mentioned) to persist the variables in optimized (above -O0) builds, but at -O0 we save metadata space by not emitting the list and relying on the dbg_value/declare intrinsics to keep the variable metadata alive and the variables to refer to their scope (lexical blocks (that refer to subprograms) or subprograms). So you'd have to walk all the instructions looking for dbg_declare/value (I forget which, perhaps both) and trace those back to the DIVariables, etc...> > Thanks, > Lu > > > _______________________________________________ > LLVM Developers mailing list > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev > >-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20131102/380fc486/attachment.html>
As far as I can tell, the web page only has an example saying
;;
;; Define the anchor for subprograms.
;;
!6 = metadata !{
...
null, ;; List of function variables (emitted when optimizing)
1 ;; Line number of the opening '{' of the function
}
I didn't fully get what that meant when reading it for the first time
and thought that I should use it with an optimization pass. I understand
now why it says that. It's not very instrumental in terms of how to use
it, but it makes sense after I understand it.
Thanks,
Lu
On 11/03/2013 02:58 PM, David Blaikie wrote:>
> +llvmdev because I accidentally dropped it
>
> On Nov 3, 2013 6:57 AM, "David Blaikie" <dblaikie at gmail.com
> <mailto:dblaikie at gmail.com>> wrote:
>
> You're welcome to provide a patch or I might get to it myself.
> Also this should be described in
> http://llvm.org/docs/SourceLevelDebugging.html if it isn't already
>
> On Nov 3, 2013 12:11 AM, "lu zhao" <luzhao at cs.utah.edu
> <mailto:luzhao at cs.utah.edu>> wrote:
>
> Hi David,
>
> Thank you! Your suggested method works.
>
> I think that you or someone should write what you said in the
> comments for the getVariable() function. :)
>
> Best,
> Lu
>
> On 11/03/2013 06:30 AM, David Blaikie wrote:
>>
>>
>>
>> On Sat, Nov 2, 2013 at 4:17 PM, lu zhao <luzhao at
cs.utah.edu
>> <mailto:luzhao at cs.utah.edu>> wrote:
>>
>> Hi,
>>
>> If I have an instance of DISubprogram, can I get the
>> debug info of local variables of the function, including
>> parameters?
>>
>> I tried to use the getVariables() function defined in
>> DISubprogram, but it seemed to return an empty DIArray
>> node when I ran my pass alone using opt. Do I need to
>> enable any other analysis passes in order to populate the
>> data?
>>
>> My related snippet of code is like the following:
>>
>> NamedMDNode *M_Nodes >>
M.getNamedMetadata("llvm.dbg.cu <http://llvm.dbg.cu>");
>> for (unsigned i = 0, e = M_Nodes->getNumOperands();
i
>> != e; ++i) {
>> DIArray SPs = CU.getSubprograms();
>> for (unsigned i = 0, e = SPs.getNumElements(); i
!>> e; ++ i) {
>> DISubprogram SP(SPs.getElement(i));
>> DIArray Vars = SP.getVariables();
>> for (unsigned i2 = 0, e2 = Vars.getNumElements();
>> i2 != e2; ++i2) {
>> DIVariable DV(Vars.getElement(i));
>> DV.print(errs()); errs() << " :
";
>> DV.getType().dump();
>> }
>> }
>> }
>>
>> In addition, can I use DebegInfo to get the list of
>> parameters (var names and types) of a subprogram? or I
>> have to parse the underlying metadata and build the
>> relationship?
>>
>>
>> Basically this /\. We use the variables list (the
>> getVariables function you mentioned) to persist the variables
>> in optimized (above -O0) builds, but at -O0 we save metadata
>> space by not emitting the list and relying on the
>> dbg_value/declare intrinsics to keep the variable metadata
>> alive and the variables to refer to their scope (lexical
>> blocks (that refer to subprograms) or subprograms).
>>
>> So you'd have to walk all the instructions looking for
>> dbg_declare/value (I forget which, perhaps both) and trace
>> those back to the DIVariables, etc...
>>
>>
>> Thanks,
>> Lu
>>
>>
>> _______________________________________________
>> LLVM Developers mailing list
>> LLVMdev at cs.uiuc.edu <mailto:LLVMdev at
cs.uiuc.edu>
>> http://llvm.cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>>
>>
>
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+llvmdev because I accidentally dropped it On Nov 3, 2013 6:57 AM, "David Blaikie" <dblaikie at gmail.com> wrote:> You're welcome to provide a patch or I might get to it myself. Also this > should be described in http://llvm.org/docs/SourceLevelDebugging.html if > it isn't already > On Nov 3, 2013 12:11 AM, "lu zhao" <luzhao at cs.utah.edu> wrote: > >> Hi David, >> >> Thank you! Your suggested method works. >> >> I think that you or someone should write what you said in the comments >> for the getVariable() function. :) >> >> Best, >> Lu >> >> On 11/03/2013 06:30 AM, David Blaikie wrote: >> >> >> >> >> On Sat, Nov 2, 2013 at 4:17 PM, lu zhao <luzhao at cs.utah.edu> wrote: >> >>> Hi, >>> >>> If I have an instance of DISubprogram, can I get the debug info of local >>> variables of the function, including parameters? >>> >>> I tried to use the getVariables() function defined in DISubprogram, but >>> it seemed to return an empty DIArray node when I ran my pass alone using >>> opt. Do I need to enable any other analysis passes in order to populate the >>> data? >>> >>> My related snippet of code is like the following: >>> >>> NamedMDNode *M_Nodes = M.getNamedMetadata("llvm.dbg.cu"); >>> for (unsigned i = 0, e = M_Nodes->getNumOperands(); i != e; ++i) { >>> DIArray SPs = CU.getSubprograms(); >>> for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++ i) { >>> DISubprogram SP(SPs.getElement(i)); >>> DIArray Vars = SP.getVariables(); >>> for (unsigned i2 = 0, e2 = Vars.getNumElements(); i2 != e2; >>> ++i2) { >>> DIVariable DV(Vars.getElement(i)); >>> DV.print(errs()); errs() << " : "; DV.getType().dump(); >>> } >>> } >>> } >>> >>> In addition, can I use DebegInfo to get the list of parameters (var >>> names and types) of a subprogram? or I have to parse the underlying >>> metadata and build the relationship? >>> >> >> Basically this /\. We use the variables list (the getVariables function >> you mentioned) to persist the variables in optimized (above -O0) builds, >> but at -O0 we save metadata space by not emitting the list and relying on >> the dbg_value/declare intrinsics to keep the variable metadata alive and >> the variables to refer to their scope (lexical blocks (that refer to >> subprograms) or subprograms). >> >> So you'd have to walk all the instructions looking for dbg_declare/value >> (I forget which, perhaps both) and trace those back to the DIVariables, >> etc... >> >> >>> >>> Thanks, >>> Lu >>> >>> >>> _______________________________________________ >>> LLVM Developers mailing list >>> LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu >>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev >>> >>> >> >>-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20131103/9df4fc9d/attachment.html>