Commit 97c742e6 authored by Sajjad Mirza's avatar Sajjad Mirza
Browse files

[llvm-cov] Fix illegal cast from uint64_t to int64_t 

Summary:
Counters are stored as uint64_t in the coverage mapping, but
exporting in JSON requires signed integers. Clamp the values to the
smaller range to make the conversion safe.

Reviewers: Dor1s, vsk

Reviewed By: Dor1s

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70200
parent 2c7c528d

llvm/tools/llvm-cov/CoverageExporterJson.cpp

+13 −3
Original line number Diff line number Diff line
@@ -48,6 +48,7 @@ 
#include "llvm/Support/ThreadPool.h"

#include "llvm/Support/Threading.h"

#include <algorithm>

#include <limits>

#include <mutex>

#include <utility>
@@ -61,14 +62,23 @@ using namespace llvm; 


namespace {



// The JSON library accepts int64_t, but profiling counts are stored as uint64_t.

// Therefore we need to explicitly convert from unsigned to signed, since a naive

// cast is implementation-defined behavior when the unsigned value cannot be

// represented as a signed value. We choose to clamp the values to preserve the

// invariant that counts are always >= 0.

int64_t clamp_uint64_to_int64(uint64_t u) {

  return std::min(u, static_cast<uint64_t>(std::numeric_limits<int64_t>::max()));

}



json::Array renderSegment(const coverage::CoverageSegment &Segment) {

  return json::Array({Segment.Line, Segment.Col, int64_t(Segment.Count),

  return json::Array({Segment.Line, Segment.Col, clamp_uint64_to_int64(Segment.Count),

                      Segment.HasCount, Segment.IsRegionEntry});

}



json::Array renderRegion(const coverage::CountedRegion &Region) {

  return json::Array({Region.LineStart, Region.ColumnStart, Region.LineEnd,

                      Region.ColumnEnd, int64_t(Region.ExecutionCount),

                      Region.ColumnEnd, clamp_uint64_to_int64(Region.ExecutionCount),

                      Region.FileID, Region.ExpandedFileID,

                      int64_t(Region.Kind)});

}
@@ -182,7 +192,7 @@ json::Array renderFunctions( 
  for (const auto &F : Functions)

    FunctionArray.push_back(

        json::Object({{"name", F.Name},

                      {"count", int64_t(F.ExecutionCount)},

                      {"count", clamp_uint64_to_int64(F.ExecutionCount)},

                      {"regions", renderRegions(F.CountedRegions)},

                      {"filenames", json::Array(F.Filenames)}}));

  return FunctionArray;