[LLVMdev] Pass Added as Required fails assert

Thomas Mason thomasr.mason at gmail.com
Thu Jul 17 14:54:28 PDT 2008


We have discovered the issue with our code.  It seems that when the first
call to doInitilization utilized one of the specified analyses, that
analysis had never been properly added as required.  Using gdb, we can see
that addRequired is getting called (seen below) but when doInitalization is
finally called, it still responds as if the analysis was not required.

Is this a bug or is doInitialization not permitted to access other analyses?

Our code functions correctly as a function pass as well as on any program
that has other functions prior to the main function.  It only fails in this
manner when main is the first (or only) function in the source file.


Debugging information:

Breakpoint 2, getAnalysisUsage (this=0x88072c8, AU=@0xbfa352f8) at
/home/pprabhu/llvm/llvm/lib/Transforms/Instrumentation/LAMPProfiling.cpp:93
93                AU.addRequired<LdStCallCounter>();
(gdb) c
Continuing.

Breakpoint 2, getAnalysisUsage (this=0x88072c8, AU=@0xbfa350b4) at
/home/pprabhu/llvm/llvm/lib/Transforms/Instrumentation/LAMPProfiling.cpp:93
93                AU.addRequired<LdStCallCounter>();
(gdb) c
Continuing.

Breakpoint 2, getAnalysisUsage (this=0x88072c8, AU=@0xbfa35088) at
/home/pprabhu/llvm/llvm/lib/Transforms/Instrumentation/LAMPProfiling.cpp:93
93                AU.addRequired<LdStCallCounter>();
(gdb) c
Continuing.
32 30 5

Breakpoint 3, doInitialization (this=0x88072c8, F=@0x8807d90) at
/home/pprabhu/llvm/llvm/lib/Transforms/Instrumentation/LAMPProfiling.cpp:135
135            const char* FnName = "LAMP_init";
(gdb) n
137            if (lampFuncs[0] == NULL)
(gdb) n
139                Module* M = F.getParent();
(gdb) n
140                createLampDeclarations(M);
(gdb) n
143            if (F.getName() == "main") {
(gdb) n
145                Module* M = F.getParent();
(gdb) n
146                LdStCallCounter& lscnts = getAnalysis<LdStCallCounter>();
(gdb) n
opt: /home/pprabhu/llvm/llvm/include/llvm/PassAnalysisSupport.h:193:
AnalysisType& llvm::Pass::getAnalysisID(const llvm::PassInfo*) const [with
AnalysisType = <unnamed>::LdStCallCounter]: Assertion `ResultPass &&
"getAnalysis*() called on an analysis that was not " "'required' by pass!"'
failed.



On Thu, Jul 17, 2008 at 3:55 PM, Thomas Mason <thomasr.mason at gmail.com>
wrote:

> Hey all,
>
> We have been working on a pass that uses another pass to count loads and
> stores prior to performing its own instrumentation.  The second pass adds
> the first as required via the usual getAnalysisUsage function.  On one
> machine, it has been tested and proven to function correctly.  On another
> machine, whenever the second pass is run, it consistently fails the
> assertion:
>
> opt: /home/tmason/llvm/llvm/include/llvm/PassAnalysisSupport.h:193:
> AnalysisType& llvm::Pass::getAnalysisID(const llvm::PassInfo*) const [with
> AnalysisType = <unnamed>::LdStCallCounter]: Assertion `ResultPass &&
> "getAnalysis*() called on an analysis that was not " "'required' by pass!"'
> failed.
>
> We have modified opt.cpp with the following lines:
>   addPass(PM, createLdStCallCounter());         // tmason
>   addPass(PM, createLAMPProfilerPass());         // tmason
>
> We have modified Instrumentation.h with the following lines:
> ModulePass* createLdStCallCounter();
> BasicBlockPass *createLAMPProfilerPass();
>
> The .cpp file generating the error is attached.
>
> Both machines run Ubuntu 8.0.4 with gcc 4.2.3.  Does anyone know what
> could be causing this error to occur on one machine but not another?
>
>
> Thanks,
> Thomas
>
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