Index: test/tools/llvm-cov/Inputs/zeroFunctionFile.h
===================================================================
--- /dev/null
+++ test/tools/llvm-cov/Inputs/zeroFunctionFile.h
@@ -0,0 +1,3 @@
+// This header has no functions
+
+#define NOFUNCTIONS(x) (x) > 0 ? 0 : 1
Index: test/tools/llvm-cov/zeroFunctionFile.c
===================================================================
--- /dev/null
+++ test/tools/llvm-cov/zeroFunctionFile.c
@@ -0,0 +1,17 @@
+#include "test.h"
+
+int foo(int x) {
+  return NOFUNCTIONS(x);
+}
+int main() {
+  return foo(2);
+}
+
+// RUN: llvm-cov report %S/Inputs/zeroFunctionFile.covmapping -instr-profile %S/Inputs/zeroFunctionFile.profdata 2>&1 | FileCheck --check-prefix=REPORT --strict-whitespace %s
+// REPORT: 0                 0         -           0                 0         -               0               0         -           0                 0         -
+// REPORT-NO: 0%
+
+// RUN: llvm-cov show %S/Inputs/zeroFunctionFile.covmapping -format html -instr-profile %S/Inputs/zeroFunctionFile.profdata -o %t.dir
+// RUN: FileCheck %s -input-file=%t.dir/index.html -check-prefix=HTML
+// HTML: <td class='column-entry-green'><pre>- (0/0)
+// HTML-NO: 0.00% (0/0)
Index: tools/llvm-cov/CoverageReport.cpp
===================================================================
--- tools/llvm-cov/CoverageReport.cpp
+++ tools/llvm-cov/CoverageReport.cpp
@@ -154,36 +154,48 @@
                (unsigned)File.RegionCoverage.NumRegions);
   Options.colored_ostream(OS, FileCoverageColor) << format(
       "%*u", FileReportColumns[2], (unsigned)File.RegionCoverage.NotCovered);
-  Options.colored_ostream(OS, FileCoverageColor)
-      << format("%*.2f", FileReportColumns[3] - 1,
-                File.RegionCoverage.getPercentCovered())
-      << '%';
+  if (File.RegionCoverage.NumRegions)
+    Options.colored_ostream(OS, FileCoverageColor)
+        << format("%*.2f", FileReportColumns[3] - 1,
+                  File.RegionCoverage.getPercentCovered())
+        << '%';
+  else
+    OS << column("-", FileReportColumns[3], Column::RightAlignment);
   OS << format("%*u", FileReportColumns[4],
                (unsigned)File.FunctionCoverage.NumFunctions);
   OS << format("%*u", FileReportColumns[5],
                (unsigned)(File.FunctionCoverage.NumFunctions -
                           File.FunctionCoverage.Executed));
-  Options.colored_ostream(OS, FuncCoverageColor)
-      << format("%*.2f", FileReportColumns[6] - 1,
-                File.FunctionCoverage.getPercentCovered())
-      << '%';
+  if (File.FunctionCoverage.NumFunctions)
+    Options.colored_ostream(OS, FuncCoverageColor)
+        << format("%*.2f", FileReportColumns[6] - 1,
+                  File.FunctionCoverage.getPercentCovered())
+        << '%';
+  else
+    OS << column("-", FileReportColumns[6], Column::RightAlignment);
   OS << format("%*u", FileReportColumns[7],
                (unsigned)File.InstantiationCoverage.NumFunctions);
   OS << format("%*u", FileReportColumns[8],
                (unsigned)(File.InstantiationCoverage.NumFunctions -
                           File.InstantiationCoverage.Executed));
-  Options.colored_ostream(OS, InstantiationCoverageColor)
-      << format("%*.2f", FileReportColumns[9] - 1,
-                File.InstantiationCoverage.getPercentCovered())
-      << '%';
+  if (File.InstantiationCoverage.NumFunctions)
+    Options.colored_ostream(OS, InstantiationCoverageColor)
+        << format("%*.2f", FileReportColumns[9] - 1,
+                  File.InstantiationCoverage.getPercentCovered())
+        << '%';
+  else
+    OS << column("-", FileReportColumns[9], Column::RightAlignment);
   OS << format("%*u", FileReportColumns[10],
                (unsigned)File.LineCoverage.NumLines);
   Options.colored_ostream(OS, LineCoverageColor) << format(
       "%*u", FileReportColumns[11], (unsigned)File.LineCoverage.NotCovered);
-  Options.colored_ostream(OS, LineCoverageColor)
-      << format("%*.2f", FileReportColumns[12] - 1,
-                File.LineCoverage.getPercentCovered())
-      << '%';
+  if (File.LineCoverage.NumLines)
+    Options.colored_ostream(OS, LineCoverageColor)
+        << format("%*.2f", FileReportColumns[12] - 1,
+                  File.LineCoverage.getPercentCovered())
+        << '%';
+  else
+    OS << column("-", FileReportColumns[12], Column::RightAlignment);
   OS << "\n";
 }
 
Index: tools/llvm-cov/SourceCoverageViewHTML.cpp
===================================================================
--- tools/llvm-cov/SourceCoverageViewHTML.cpp
+++ tools/llvm-cov/SourceCoverageViewHTML.cpp
@@ -307,13 +307,17 @@
     std::string S;
     {
       raw_string_ostream RSO{S};
-      RSO << format("%*.2f", 7, Pctg) << "% (" << Hit << '/' << Total << ')';
+      if (Total)
+        RSO << format("%*.2f", 7, Pctg) << "% ";
+      else
+        RSO << "- ";
+      RSO << '(' << Hit << '/' << Total << ')';
     }
     const char *CellClass = "column-entry-yellow";
-    if (Pctg < 80.0)
-      CellClass = "column-entry-red";
-    else if (Hit == Total)
+    if (Hit == Total)
       CellClass = "column-entry-green";
+    else if (Pctg < 80.0)
+      CellClass = "column-entry-red";
     Columns.emplace_back(tag("td", tag("pre", S), CellClass));
   };