Emit the entry block first and the exit block second, then all the blocks in between afterwards. This is what gcc always does, and some out of tree tools depend on that.

llvm-svn: 223193

2 files changed, 73 insertions, 3 deletions

diff --git a/llvm/lib/Transforms/Instrumentation/GCOVProfiling.cpp b/llvm/lib/Transforms/Instrumentation/GCOVProfiling.cpp
index 220d7f8b490..685428ee952 100644
--- a/llvm/lib/Transforms/Instrumentation/GCOVProfiling.cpp
+++ b/llvm/lib/Transforms/Instrumentation/GCOVProfiling.cpp
@@ -310,11 +310,15 @@ namespace {
 
       Function *F = SP.getFunction();
       DEBUG(dbgs() << "Function: " << getFunctionName(SP) << "\n");
-      uint32_t i = 0;
-      for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
+
+      Function::iterator BB = F->begin(), E = F->end();
+      Blocks[BB++] = new GCOVBlock(0, os);
+      ReturnBlock = new GCOVBlock(1, os);
+
+      uint32_t i = 2;
+      for (; BB != E; ++BB) {
         Blocks[BB] = new GCOVBlock(i++, os);
       }
-      ReturnBlock = new GCOVBlock(i++, os);
 
       std::string FunctionNameAndLine;
       raw_string_ostream FNLOS(FunctionNameAndLine);
diff --git a/llvm/test/Transforms/GCOVProfiling/return-block.ll b/llvm/test/Transforms/GCOVProfiling/return-block.ll
new file mode 100644
index 00000000000..7874895ad5b
--- /dev/null
+++ b/llvm/test/Transforms/GCOVProfiling/return-block.ll
@@ -0,0 +1,66 @@
+; Inject metadata to set the .gcno file location
+; RUN: echo '!19 = metadata !{metadata !"%/T/return-block.ll", metadata !0}' > %t1
+; RUN: cat %s %t1 > %t2
+; RUN: opt -insert-gcov-profiling -disable-output %t2
+; RUN: llvm-cov gcov -n -dump return-block.gcno 2>&1 | FileCheck %s
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+@A = common global i32 0, align 4
+
+; Function Attrs: nounwind uwtable
+define void @test() #0 {
+entry:
+  tail call void (...)* @f() #2, !dbg !14
+  %0 = load i32* @A, align 4, !dbg !15
+  %tobool = icmp eq i32 %0, 0, !dbg !15
+  br i1 %tobool, label %if.end, label %if.then, !dbg !15
+
+if.then:                                          ; preds = %entry
+  tail call void (...)* @g() #2, !dbg !16
+  br label %if.end, !dbg !16
+
+if.end:                                           ; preds = %entry, %if.then
+  ret void, !dbg !18
+}
+
+declare void @f(...) #1
+
+declare void @g(...) #1
+
+attributes #0 = { nounwind uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #2 = { nounwind }
+
+!llvm.gcov = !{!14}
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!11, !12}
+!llvm.ident = !{!13}
+
+!0 = metadata !{metadata !"0x11\0012\00clang version 3.6.0 (trunk 223182)\001\00\000\00\001", metadata !1, metadata !2, metadata !2, metadata !3, metadata !8, metadata !2} ; [ DW_TAG_compile_unit ] [return-block.c] [DW_LANG_C99]
+!1 = metadata !{metadata !".../llvm/test/Transforms/GCOVProfiling/return-block.ll", metadata !""}
+!2 = metadata !{}
+!3 = metadata !{metadata !4}
+!4 = metadata !{metadata !"0x2e\00test\00test\00\005\000\001\000\000\000\001\005", metadata !1, metadata !5, metadata !6, null, void ()* @test, null, null, metadata !2} ; [ DW_TAG_subprogram ] [line 5] [def] [test]
+!5 = metadata !{metadata !"0x29", metadata !1}    ; [ DW_TAG_file_type ] [return-block.c]
+!6 = metadata !{metadata !"0x15\00\000\000\000\000\000\000", null, null, null, metadata !7, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
+!7 = metadata !{null}
+!8 = metadata !{metadata !9}
+!9 = metadata !{metadata !"0x34\00A\00A\00\003\000\001", null, metadata !5, metadata !10, i32* @A, null} ; [ DW_TAG_variable ] [A] [line 3] [def]
+!10 = metadata !{metadata !"0x24\00int\000\0032\0032\000\000\005", null, null} ; [ DW_TAG_base_type ] [int] [line 0, size 32, align 32, offset 0, enc DW_ATE_signed]
+!11 = metadata !{i32 2, metadata !"Dwarf Version", i32 4}
+!12 = metadata !{i32 2, metadata !"Debug Info Version", i32 2}
+!13 = metadata !{metadata !"clang version 3.6.0 (trunk 223182)"}
+!14 = metadata !{i32 6, i32 3, metadata !4, null}
+!15 = metadata !{i32 7, i32 7, metadata !4, null}
+!16 = metadata !{i32 8, i32 5, metadata !17, null}
+!17 = metadata !{metadata !"0xb\007\007\000", metadata !1, metadata !4} ; [ DW_TAG_lexical_block ] [return-block.c]
+!18 = metadata !{i32 9, i32 1, metadata !4, null}
+
+; There should be no destination edges for block 1.
+; CHECK: Block : 0 Counter : 0
+; CHECK-NEXT:         Destination Edges : 2 (0), 
+; CHECK-NEXT: Block : 1 Counter : 0
+; CHECK-NEXT:         Source Edges : 4 (0), 
+; CHECK-NEXT: Block : 2 Counter : 0