sebald.ziegler.maillist at ikolus.de
2013-Aug-07 16:57 UTC
[LLVMdev] DSA - LocalDataStructures pass does not create DSGraphs
Hallo.
I wanted to use the DSA from the poolalloc project as a starting point for
static C code analysis (for me it has some benefits to work on LLVM-IR
(generated by clang) instead of C code).
Currently there is no poolalloc version 3.3. Therefore I wrote a quick patch
to make poolalloc 3.2 compile with llvm 3.3 (mostly adaptions to file
relocations were necessary). The patch is attached as it is quite small.
With the foundations working a simple test before getting serious seemed to be
a good idea. So I tried to perform the LocalAnalysis (LocalDataStructures pass
in poolalloc) on the running example (LLVM-IR obtained by clang) of Chris
Lattner's PHD thesis (p. 44) (code attached).
When this pass(LocalDataStructures) is run I can call dumpCallGraph() on it
and get the correct result. But calls to hasDSGraph(const Function &F) all
return false although they should not. DSGraphs should have been built.
Does anyone see what I am doing wrong? Or is this a bug?
Thank you for any help and comments!
Sebald
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; ModuleID = '../tests/lattnersRunningExample.c'
target datalayout =
"e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
%struct.list = type { %struct.list*, i32 }
@Global = global i32 10, align 4
; Function Attrs: nounwind uwtable
define void @do_all(%struct.list* %L, void (i32*)* %FP) #0 {
entry:
%L.addr = alloca %struct.list*, align 8
%FP.addr = alloca void (i32*)*, align 8
store %struct.list* %L, %struct.list** %L.addr, align 8
store void (i32*)* %FP, void (i32*)** %FP.addr, align 8
br label %do.body
do.body: ; preds = %do.cond, %entry
%0 = load void (i32*)** %FP.addr, align 8
%1 = load %struct.list** %L.addr, align 8
%Data = getelementptr inbounds %struct.list* %1, i32 0, i32 1
call void %0(i32* %Data)
%2 = load %struct.list** %L.addr, align 8
%Next = getelementptr inbounds %struct.list* %2, i32 0, i32 0
%3 = load %struct.list** %Next, align 8
store %struct.list* %3, %struct.list** %L.addr, align 8
br label %do.cond
do.cond: ; preds = %do.body
%4 = load %struct.list** %L.addr, align 8
%tobool = icmp ne %struct.list* %4, null
br i1 %tobool, label %do.body, label %do.end
do.end: ; preds = %do.cond
ret void
}
; Function Attrs: nounwind uwtable
define void @addG(i32* %X) #0 {
entry:
%X.addr = alloca i32*, align 8
store i32* %X, i32** %X.addr, align 8
%0 = load i32* @Global, align 4
%1 = load i32** %X.addr, align 8
%2 = load i32* %1, align 4
%add = add nsw i32 %2, %0
store i32 %add, i32* %1, align 4
ret void
}
; Function Attrs: nounwind uwtable
define void @addGToList(%struct.list* %L) #0 {
entry:
%L.addr = alloca %struct.list*, align 8
store %struct.list* %L, %struct.list** %L.addr, align 8
%0 = load %struct.list** %L.addr, align 8
call void @do_all(%struct.list* %0, void (i32*)* @addG)
ret void
}
; Function Attrs: nounwind uwtable
define %struct.list* @makeList(i32 %Num) #0 {
entry:
%Num.addr = alloca i32, align 4
%New = alloca %struct.list*, align 8
store i32 %Num, i32* %Num.addr, align 4
%call = call noalias i8* @malloc(i64 16) #2
%0 = bitcast i8* %call to %struct.list*
store %struct.list* %0, %struct.list** %New, align 8
%1 = load i32* %Num.addr, align 4
%tobool = icmp ne i32 %1, 0
br i1 %tobool, label %cond.true, label %cond.false
cond.true: ; preds = %entry
%2 = load i32* %Num.addr, align 4
%sub = sub nsw i32 %2, 1
%call1 = call %struct.list* @makeList(i32 %sub)
br label %cond.end
cond.false: ; preds = %entry
br label %cond.end
cond.end: ; preds = %cond.false,
%cond.true
%cond = phi %struct.list* [ %call1, %cond.true ], [ null, %cond.false ]
%3 = load %struct.list** %New, align 8
%Next = getelementptr inbounds %struct.list* %3, i32 0, i32 0
store %struct.list* %cond, %struct.list** %Next, align 8
%4 = load i32* %Num.addr, align 4
%5 = load %struct.list** %New, align 8
%Data = getelementptr inbounds %struct.list* %5, i32 0, i32 1
store i32 %4, i32* %Data, align 4
%6 = load %struct.list** %New, align 8
ret %struct.list* %6
}
; Function Attrs: nounwind
declare noalias i8* @malloc(i64) #1
; Function Attrs: nounwind uwtable
define i32 @main() #0 {
entry:
%retval = alloca i32, align 4
%X = alloca %struct.list*, align 8
%Y = alloca %struct.list*, align 8
store i32 0, i32* %retval
%call = call %struct.list* @makeList(i32 10)
store %struct.list* %call, %struct.list** %X, align 8
%call1 = call %struct.list* @makeList(i32 100)
store %struct.list* %call1, %struct.list** %Y, align 8
%0 = load %struct.list** %X, align 8
call void @addGToList(%struct.list* %0)
store i32 20, i32* @Global, align 4
%1 = load %struct.list** %Y, align 8
call void @addGToList(%struct.list* %1)
ret i32 0
}
attributes #0 = { nounwind uwtable
"less-precise-fpmad"="false"
"no-frame-pointer-elim"="true"
"no-frame-pointer-elim-non-leaf"="true"
"no-infs-fp-math"="false"
"no-nans-fp-math"="false"
"unsafe-fp-math"="false"
"use-soft-float"="false" }
attributes #1 = { nounwind "less-precise-fpmad"="false"
"no-frame-pointer-elim"="true"
"no-frame-pointer-elim-non-leaf"="true"
"no-infs-fp-math"="false"
"no-nans-fp-math"="false"
"unsafe-fp-math"="false"
"use-soft-float"="false" }
attributes #2 = { nounwind }
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sebald.ziegler.maillist at ikolus.de
2013-Aug-08 14:30 UTC
[LLVMdev] DSA - LocalDataStructures pass does not create DSGraphs
On Wednesday, August 07, 2013 18:57:16 sebald.ziegler.maillist at ikolus.de wrote:> Hallo. > > I wanted to use the DSA from the poolalloc project as a starting point for > static C code analysis (for me it has some benefits to work on LLVM-IR > (generated by clang) instead of C code). > > Currently there is no poolalloc version 3.3. Therefore I wrote a quick > patch to make poolalloc 3.2 compile with llvm 3.3 (mostly adaptions to > file relocations were necessary). The patch is attached as it is quite > small. > > With the foundations working a simple test before getting serious seemed to > be a good idea. So I tried to perform the LocalAnalysis > (LocalDataStructures pass in poolalloc) on the running example (LLVM-IR > obtained by clang) of Chris Lattner's PHD thesis (p. 44) (code attached). > > When this pass(LocalDataStructures) is run I can call dumpCallGraph() on it > and get the correct result. But calls to hasDSGraph(const Function &F) all > return false although they should not. DSGraphs should have been built. > > Does anyone see what I am doing wrong? Or is this a bug?Found out what I did wrong: - PassManager performs cleanup operations (I thought this would only happen if the PM's dtor gets called) - stuff gets deleted but parts are still accessible (call graph information) So this question has actually nothing to do with DSA. Solution: Acknowledge the existence of the PassManager environment -> write own pass that consumes the information of LocalDataStructures pass...> > Thank you for any help and comments! > > Sebald