Add 'thinlto_src_module' metadata to imported function

Added metadata to be able to make statistics on how many functions
that have been imported have been removed. Also module name might
be helpfull when debugging.

Reviewers: tejohnson, eraman

Subscribers: mehdi_amini, llvm-commits

Differential Revision: http://reviews.llvm.org/D21943

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@274668 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/IPO/FunctionImport.cpp

@@ -591,6 +591,12 @@ bool FunctionImporter::importFunctions(
                    << SrcModule->getSourceFileName() << "\n");
       if (Import) {
         F.materialize();
+        // Add 'thinlto_src_module' metadata for statistics and debugging.
+        F.setMetadata("thinlto_src_module",
+                      llvm::MDNode::get(DestModule.getContext(),
+                                        {llvm::MDString::get(
+                                            DestModule.getContext(),
+                                            SrcModule->getSourceFileName())}));
         GlobalsToImport.insert(&F);
       }
     }

test/Transforms/FunctionImport/funcimport.ll

@@ -14,7 +14,7 @@
 
 ; Test import with smaller instruction limit and without the -disable-force-link-odr
 ; RUN: opt -function-import -summary-file %t3.thinlto.bc %t.bc -import-instr-limit=5 -S | FileCheck %s --check-prefix=INSTLIM5ODR
-; INSTLIM5ODR: define linkonce_odr void @linkonceodr()
+; INSTLIM5ODR: define linkonce_odr void @linkonceodr() {
 
 
 define i32 @main() #0 {
@@ -47,7 +47,7 @@ declare void @analias(...) #1
 declare void @linkoncealias(...) #1
 
 ; INSTLIMDEF-DAG: Import referencestatics
-; INSTLIMDEF-DAG: define available_externally i32 @referencestatics(i32 %i)
+; INSTLIMDEF-DAG: define available_externally i32 @referencestatics(i32 %i) !thinlto_src_module !0 {
 ; INSTLIM5-DAG: declare i32 @referencestatics(...)
 declare i32 @referencestatics(...) #1
 
@@ -56,27 +56,27 @@ declare i32 @referencestatics(...) #1
 ; Ensure that the call is to the properly-renamed function.
 ; INSTLIMDEF-DAG: Import staticfunc
 ; INSTLIMDEF-DAG: %call = call i32 @staticfunc.llvm.
-; INSTLIMDEF-DAG: define available_externally hidden i32 @staticfunc.llvm.
+; INSTLIMDEF-DAG: define available_externally hidden i32 @staticfunc.llvm.{{.*}} !thinlto_src_module !0 {
 
 ; INSTLIMDEF-DAG: Import referenceglobals
-; CHECK-DAG: define available_externally i32 @referenceglobals(i32 %i)
+; CHECK-DAG: define available_externally i32 @referenceglobals(i32 %i) !thinlto_src_module !0 {
 declare i32 @referenceglobals(...) #1
 
 ; The import of referenceglobals will expose call to globalfunc1 that
 ; should in turn be imported.
 ; INSTLIMDEF-DAG: Import globalfunc1
-; CHECK-DAG: define available_externally void @globalfunc1()
+; CHECK-DAG: define available_externally void @globalfunc1() !thinlto_src_module !0
 
 ; INSTLIMDEF-DAG: Import referencecommon
-; CHECK-DAG: define available_externally i32 @referencecommon(i32 %i)
+; CHECK-DAG: define available_externally i32 @referencecommon(i32 %i) !thinlto_src_module !0 {
 declare i32 @referencecommon(...) #1
 
 ; INSTLIMDEF-DAG: Import setfuncptr
-; CHECK-DAG: define available_externally void @setfuncptr()
+; CHECK-DAG: define available_externally void @setfuncptr() !thinlto_src_module !0 {
 declare void @setfuncptr(...) #1
 
 ; INSTLIMDEF-DAG: Import callfuncptr
-; CHECK-DAG: define available_externally void @callfuncptr()
+; CHECK-DAG: define available_externally void @callfuncptr() !thinlto_src_module !0 {
 declare void @callfuncptr(...) #1
 
 ; Ensure that all uses of local variable @P which has used in setfuncptr
@@ -87,7 +87,7 @@ declare void @callfuncptr(...) #1
 
 ; Ensure that @referencelargelinkonce definition is pulled in, but later we
 ; also check that the linkonceodr function is not.
-; CHECK-DAG: define available_externally void @referencelargelinkonce()
+; CHECK-DAG: define available_externally void @referencelargelinkonce() !thinlto_src_module !0 {
 ; INSTLIM5-DAG: declare void @linkonceodr()
 declare void @referencelargelinkonce(...)
 
@@ -100,11 +100,12 @@ declare void @weakfunc(...) #1
 declare void @linkoncefunc2(...) #1
 
 ; INSTLIMDEF-DAG: Import funcwithpersonality
-; INSTLIMDEF-DAG: define available_externally hidden void @funcwithpersonality.llvm.{{.*}}() personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) {
+; INSTLIMDEF-DAG: define available_externally hidden void @funcwithpersonality.llvm.{{.*}}() personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) !thinlto_src_module !0 {
 ; INSTLIM5-DAG: declare hidden void @funcwithpersonality.llvm.{{.*}}()
 
 ; INSTLIMDEF-DAG: Import globalfunc2
 ; INSTLIMDEF-DAG: 13 function-import - Number of functions imported
+; CHECK-DAG: !0 = !{!"{{.*}}/Inputs/funcimport.ll"}
 
 ; The actual GUID values will depend on path to test.
 ; GUID-DAG: GUID {{.*}} is weakalias