[llvm] e664d05 - [gcov] Improve tests and lower the minimum supported version to gcov 3.4

Fangrui Song via llvm-commits llvm-commits at lists.llvm.org
Sat Jun 6 23:14:12 PDT 2020


Author: Fangrui Song
Date: 2020-06-06T23:11:32-07:00
New Revision: e664d0543f8ce5e1000593a6e881cdb7eb401c84

URL: https://github.com/llvm/llvm-project/commit/e664d0543f8ce5e1000593a6e881cdb7eb401c84
DIFF: https://github.com/llvm/llvm-project/commit/e664d0543f8ce5e1000593a6e881cdb7eb401c84.diff

LOG: [gcov] Improve tests and lower the minimum supported version to gcov 3.4

global-ctor.ll no longer checks what it intended to check
(@_GLOBAL__sub_I_global-ctor.ll needs a !dbg to work).
Rewrite it.

gcov 3.4 and gcov 4.2 use the same format, thus we can lower the version
requirement to 3.4

Added: 
    compiler-rt/test/profile/gcov-basic.c

Modified: 
    clang/test/CodeGen/code-coverage.c
    llvm/include/llvm/ProfileData/GCOV.h
    llvm/lib/ProfileData/GCOV.cpp
    llvm/test/Transforms/GCOVProfiling/global-ctor.ll

Removed: 
    


################################################################################
diff  --git a/clang/test/CodeGen/code-coverage.c b/clang/test/CodeGen/code-coverage.c
index 3a11cb2c7df7..251e8bc77b31 100644
--- a/clang/test/CodeGen/code-coverage.c
+++ b/clang/test/CodeGen/code-coverage.c
@@ -1,8 +1,9 @@
-/// We support coverage versions 4.2, 4.7 and 4.8.
+/// We support coverage versions 3.4, 4.7 and 4.8.
+/// 3.4 redesigns the format and changed .da to .gcda
 /// 4.7 enables cfg_checksum.
 /// 4.8 (default, compatible with gcov 7) emits the exit block the second.
-// RUN: %clang_cc1 -emit-llvm -disable-red-zone -femit-coverage-data -coverage-version='402*' %s -o - | \
-// RUN:   FileCheck --check-prefixes=CHECK,402 %s
+// RUN: %clang_cc1 -emit-llvm -disable-red-zone -femit-coverage-data -coverage-version='304*' %s -o - | \
+// RUN:   FileCheck --check-prefixes=CHECK,304 %s
 // RUN: %clang_cc1 -emit-llvm -disable-red-zone -femit-coverage-data -coverage-version='407*' %s -o - | \
 // RUN:   FileCheck --check-prefixes=CHECK,407 %s
 // RUN: %clang_cc1 -emit-llvm -disable-red-zone -femit-coverage-data %s -o - | \
@@ -40,8 +41,8 @@ int test2(int b) {
 // CHECK-SAME: [%0 zeroinitializer, %0 { i32 1, i32 0, i32 0 }]
 
 // CHECK: @__llvm_internal_gcov_emit_file_info = internal unnamed_addr constant [1 x %2]
-/// 0x3430322a '4' '0' '2' '*'
-// 402-SAME: i32 875573802
+/// 0x3330342a '3' '0' '4' '*'
+// 304-SAME: i32 858797098
 /// 0x3430372a '4' '0' '7' '*'
 // 407-SAME: i32 875575082
 /// 0x3430382a '4' '0' '8' '*'

diff  --git a/compiler-rt/test/profile/gcov-basic.c b/compiler-rt/test/profile/gcov-basic.c
new file mode 100644
index 000000000000..f29dfd49b0a7
--- /dev/null
+++ b/compiler-rt/test/profile/gcov-basic.c
@@ -0,0 +1,20 @@
+// RUN: mkdir -p %t.dir && cd %t.dir
+
+/// gcov 3.4 redesigned the format and changed the extension from .da to .gcda
+// RUN: %clang --coverage -Xclang -coverage-version='304*' %s -o %t
+// RUN: rm -f gcov-basic.gcda && %run %t
+// RUN: llvm-cov gcov -t gcov-basic.gcno | FileCheck %s
+
+/// r173147: split checksum into cfg checksum and line checksum.
+// RUN: %clang --coverage -Xclang -coverage-version='407*' %s -o %t
+// RUN: rm -f gcov-basic.gcda && %run %t
+// RUN: llvm-cov gcov -t gcov-basic.gcno | FileCheck %s
+
+/// r189778: the exit block moved from the last to the second.
+// RUN: %clang --coverage -Xclang -coverage-version='408*' %s -o %t
+// RUN: rm -f gcov-basic.gcda && %run %t
+// RUN: llvm-cov gcov -t gcov-basic.gcno
+
+int main() {       // CHECK:      1: [[@LINE]]:int main
+  return 0;        // CHECK-NEXT: 1: [[@LINE]]:
+}

diff  --git a/llvm/include/llvm/ProfileData/GCOV.h b/llvm/include/llvm/ProfileData/GCOV.h
index a212e0d7f14d..91a345ca00ae 100644
--- a/llvm/include/llvm/ProfileData/GCOV.h
+++ b/llvm/include/llvm/ProfileData/GCOV.h
@@ -42,7 +42,7 @@ class FileInfo;
 
 namespace GCOV {
 
-enum GCOVVersion { V402, V407, V408, V800, V900 };
+enum GCOVVersion { V304, V407, V408, V800, V900 };
 
 /// A struct for passing gcov options between functions.
 struct Options {
@@ -132,8 +132,8 @@ class GCOVBuffer {
       // r173147: split checksum into cfg checksum and line checksum.
       Version = GCOV::V407;
       return true;
-    } else {
-      Version = GCOV::V402;
+    } else if (Major == 4 || (Major == 3 && Minor >= 4)) {
+      Version = GCOV::V304;
       return true;
     }
     errs() << "unexpected version: " << str << "\n";

diff  --git a/llvm/lib/ProfileData/GCOV.cpp b/llvm/lib/ProfileData/GCOV.cpp
index 137928426f47..2e0d32074d3c 100644
--- a/llvm/lib/ProfileData/GCOV.cpp
+++ b/llvm/lib/ProfileData/GCOV.cpp
@@ -179,14 +179,13 @@ bool GCOVFile::readGCDA(GCOVBuffer &buf) {
       if (length == 0) // Placeholder
         continue;
       // As of GCC 10, GCOV_TAG_FUNCTION_LENGTH has never been larger than 3.
-      if (length != 3 || !buf.readInt(ident))
+      if ((length != 2 && length != 3) || !buf.readInt(ident))
         return false;
       auto It = IdentToFunction.find(ident);
-      uint32_t linenoChecksum, cfgChecksum;
+      uint32_t linenoChecksum, cfgChecksum = 0;
       buf.readInt(linenoChecksum);
-      buf.readInt(cfgChecksum);
-      if (Version < GCOV::V407)
-        cfgChecksum = 0;
+      if (Version >= GCOV::V407)
+        buf.readInt(cfgChecksum);
       if (It != IdentToFunction.end()) {
         fn = It->second;
         if (linenoChecksum != fn->linenoChecksum ||

diff  --git a/llvm/test/Transforms/GCOVProfiling/global-ctor.ll b/llvm/test/Transforms/GCOVProfiling/global-ctor.ll
index 7df4f6a513a4..596a2ad77635 100644
--- a/llvm/test/Transforms/GCOVProfiling/global-ctor.ll
+++ b/llvm/test/Transforms/GCOVProfiling/global-ctor.ll
@@ -1,60 +1,43 @@
-; RUN: rm -rf %t && mkdir -p %t
-; RUN: echo '!16 = !{!"%/t/global-ctor.ll", !0}' > %t/1
-; RUN: cat %s %t/1 > %t/2
-; RUN: opt -insert-gcov-profiling -disable-output < %t/2
-; RUN: not grep '_GLOBAL__sub_I_global-ctor' %t/global-ctor.gcno
-; RUN: rm %t/global-ctor.gcno
-
-; RUN: opt -passes=insert-gcov-profiling -disable-output < %t/2
-; RUN: not grep '_GLOBAL__sub_I_global-ctor' %t/global-ctor.gcno
-; RUN: rm %t/global-ctor.gcno
-
- at x = global i32 0, align 4
- at llvm.global_ctors = appending global [1 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 65535, void ()* @_GLOBAL__sub_I_global-ctor.ll, i8* null }]
-
-; Function Attrs: nounwind
-define internal void @__cxx_global_var_init() #0 section ".text.startup" !dbg !4 {
+;; For a global constructor, _GLOBAL__sub_I_ only has artificial lines.
+;; Test that we don't instrument those functions.
+; RUN: opt -S -insert-gcov-profiling < %s | FileCheck %s
+; RUN: opt -S -passes=insert-gcov-profiling < %s | FileCheck %s
+
+ at var = dso_local global i32 0, align 4
+ at llvm.global_ctors = appending global [1 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 65535, void ()* @_GLOBAL__sub_I_a.cc, i8* null }]
+
+define internal void @__cxx_global_var_init() section ".text.startup" !dbg !7 {
+; CHECK: define internal void @__cxx_global_var_init()
+; CHECK: @__llvm_gcov_ctr
+; CHECK: call i32 @_Z3foov()
 entry:
-  br label %0
-
-; <label>:0                                       ; preds = %entry
-  %call = call i32 @_Z1fv(), !dbg !13
-  store i32 %call, i32* @x, align 4, !dbg !13
-  ret void, !dbg !13
+  %call = call i32 @_Z3foov(), !dbg !9
+  store i32 %call, i32* @var, align 4, !dbg !9
+  ret void, !dbg !9
 }
 
-declare i32 @_Z1fv() #1
+declare i32 @_Z3foov()
 
-; Function Attrs: nounwind
-define internal void @_GLOBAL__sub_I_global-ctor.ll() #0 section ".text.startup" {
+;; Artificial lines only. Don't instrument.
+define internal void @_GLOBAL__sub_I_a.cc() section ".text.startup" !dbg !10 {
+; CHECK: define internal void @_GLOBAL__sub_I_a.cc()
+; CHECK-NOT: @__llvm_gcov_ctr
+; CHECK: call void @__cxx_global_var_init()
 entry:
-  br label %0
-
-; <label>:0                                       ; preds = %entry
-  call void @__cxx_global_var_init(), !dbg !14
-  ret void, !dbg !14
+  call void @__cxx_global_var_init(), !dbg !11
+  ret void
 }
 
-attributes #0 = { nounwind }
-attributes #1 = { "less-precise-fpmad"="false" "frame-pointer"="none" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "no-realign-stack" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
-
 !llvm.dbg.cu = !{!0}
-!llvm.module.flags = !{!10, !11}
-!llvm.gcov = !{!16}
-!llvm.ident = !{!12}
+!llvm.module.flags = !{!3, !4}
 
-!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, producer: "clang version 3.5.0 (trunk 210217)", isOptimized: false, emissionKind: LineTablesOnly, file: !1, enums: !2, retainedTypes: !2, globals: !2, imports: !2)
-!1 = !DIFile(filename: "<stdin>", directory: "/home/nlewycky")
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, emissionKind: LineTablesOnly)
+!1 = !DIFile(filename: "a.cc", directory: "/")
 !2 = !{}
-!4 = distinct !DISubprogram(name: "__cxx_global_var_init", line: 2, isLocal: true, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, unit: !0, scopeLine: 2, file: !5, scope: !6, type: !7, retainedNodes: !2)
-!5 = !DIFile(filename: "global-ctor.ll", directory: "/home/nlewycky")
-!6 = !DIFile(filename: "global-ctor.ll", directory: "/home/nlewycky")
-!7 = !DISubroutineType(types: !2)
-!8 = distinct !DISubprogram(name: "", linkageName: "_GLOBAL__sub_I_global-ctor.ll", isLocal: true, isDefinition: true, virtualIndex: 6, flags: DIFlagArtificial, isOptimized: false, unit: !0, file: !1, scope: !9, type: !7, retainedNodes: !2)
-!9 = !DIFile(filename: "<stdin>", directory: "/home/nlewycky")
-!10 = !{i32 2, !"Dwarf Version", i32 4}
-!11 = !{i32 2, !"Debug Info Version", i32 3}
-!12 = !{!"clang version 3.5.0 (trunk 210217)"}
-!13 = !DILocation(line: 2, scope: !4)
-!14 = !DILocation(line: 0, scope: !15)
-!15 = !DILexicalBlockFile(discriminator: 0, file: !5, scope: !8)
+!3 = !{i32 7, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!7 = distinct !DISubprogram(name: "__cxx_global_var_init", scope: !1, file: !1, line: 2, type: !8, scopeLine: 2, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition, unit: !0, retainedNodes: !2)
+!8 = !DISubroutineType(types: !2)
+!9 = !DILocation(line: 2, column: 11, scope: !7)
+!10 = distinct !DISubprogram(linkageName: "_GLOBAL__sub_I_a.cc", scope: !1, file: !1, type: !8, flags: DIFlagArtificial, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition, unit: !0, retainedNodes: !2)
+!11 = !DILocation(line: 0, scope: !10)


        


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