[Coverage] Do not map regions from system headers

Do not assign source regions located within system headers file ID's,
and do not construct counter mapping regions out of them.

This makes coverage reports less cluttered and less mysterious. E.g
using the "assert" macro doesn't cause assert.h to appear in reports,
and it no longer shows the "assertion failed" branch as an uncovered
region.

It also makes coverage mapping sections a bit smaller (e.g a 1%
reduction in a stage2 build of bin/llvm-as).

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@275121 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/CoverageMappingGen.cpp b/lib/CodeGen/CoverageMappingGen.cpp
index 7055e3a356867a8ac7ee5839b566f29b904b2e03..b4dd1a930325f9d67db318b631823518f63ee874 100644 (file)
--- a/lib/CodeGen/CoverageMappingGen.cpp
+++ b/lib/CodeGen/CoverageMappingGen.cpp
@@ -172,6 +172,10 @@ public:
       if (!Visited.insert(File).second)
         continue;
 
+      // Do not map FileID's associated with system headers.
+      if (SM.isInSystemHeader(SM.getSpellingLoc(Loc)))
+        continue;
+
       unsigned Depth = 0;
       for (SourceLocation Parent = getIncludeOrExpansionLoc(Loc);
            Parent.isValid(); Parent = getIncludeOrExpansionLoc(Parent))
@@ -251,6 +255,10 @@ public:
       SourceLocation LocStart = Region.getStartLoc();
       assert(SM.getFileID(LocStart).isValid() && "region in invalid file");
 
+      // Ignore regions from system headers.
+      if (SM.isInSystemHeader(SM.getSpellingLoc(LocStart)))
+        continue;
+
       auto CovFileID = getCoverageFileID(LocStart);
       // Ignore regions that don't have a file, such as builtin macros.
       if (!CovFileID)

diff --git a/test/CoverageMapping/system_macro.c b/test/CoverageMapping/system_macro.c
index f199612f8d6efbc81e424630d8cce973dd98cf96..bddc822b0d90bd73833bc8f3580a3d5e0ce69136 100644 (file)
--- a/test/CoverageMapping/system_macro.c
+++ b/test/CoverageMapping/system_macro.c
@@ -13,9 +13,8 @@
 
 // CHECK-LABEL: doSomething:
 void doSomething(int x) { // CHECK: File 0, [[@LINE]]:25 -> {{[0-9:]+}} = #0
-  Func(x); // CHECK: Expansion,File 0, [[@LINE]]:3 -> [[@LINE]]:7
+  Func(x);
   return;
-  // CHECK: Expansion,File 0, [[@LINE+1]]:3 -> [[@LINE+1]]:11
   SomeType *f; // CHECK: File 0, [[@LINE]]:11 -> {{[0-9:]+}} = 0
 }