1 files changed, 177 insertions, 0 deletions
diff --git a/js/src/vm/CodeCoverage.h b/js/src/vm/CodeCoverage.h
new file mode 100644
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+++ b/js/src/vm/CodeCoverage.h
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef vm_CodeCoverage_h
+#define vm_CodeCoverage_h
+
+#include "mozilla/Vector.h"
+
+#include "ds/LifoAlloc.h"
+
+#include "vm/Printer.h"
+
+struct JSCompartment;
+class JSScript;
+class JSObject;
+
+namespace js {
+
+class ScriptSourceObject;
+
+namespace coverage {
+
+class LCovCompartment;
+
+class LCovSource
+{
+  public:
+    explicit LCovSource(LifoAlloc* alloc, JSObject* sso);
+
+    // Whether the given script source object matches this LCovSource.
+    bool match(JSObject* sso) const {
+        return sso == source_;
+    }
+
+    // Whether the current source is complete and if it can be flushed.
+    bool isComplete() const {
+        return hasFilename_ && hasTopLevelScript_;
+    }
+
+    // Iterate over the bytecode and collect the lcov output based on the
+    // ScriptCounts counters.
+    bool writeScript(JSScript* script);
+
+    // Write the Lcov output in a buffer, such as the one associated with
+    // the runtime code coverage trace file.
+    void exportInto(GenericPrinter& out) const;
+
+    // Write the script name in out.
+    bool writeSourceFilename(ScriptSourceObject* sso);
+
+  private:
+    // Write the script name in out.
+    bool writeScriptName(LSprinter& out, JSScript* script);
+
+  private:
+    // Weak pointer of the Script Source Object used by the current source.
+    JSObject *source_;
+
+    // LifoAlloc string which hold the filename of the source.
+    LSprinter outSF_;
+
+    // LifoAlloc strings which hold the filename of each function as
+    // well as the number of hits for each function.
+    LSprinter outFN_;
+    LSprinter outFNDA_;
+    size_t numFunctionsFound_;
+    size_t numFunctionsHit_;
+
+    // LifoAlloc string which hold branches statistics.
+    LSprinter outBRDA_;
+    size_t numBranchesFound_;
+    size_t numBranchesHit_;
+
+    // LifoAlloc string which hold lines statistics.
+    LSprinter outDA_;
+    size_t numLinesInstrumented_;
+    size_t numLinesHit_;
+
+    // Status flags.
+    bool hasFilename_ : 1;
+    bool hasTopLevelScript_ : 1;
+};
+
+class LCovCompartment
+{
+  public:
+    LCovCompartment();
+
+    // Collect code coverage information for the given source.
+    void collectCodeCoverageInfo(JSCompartment* comp, JSObject* sso, JSScript* topLevel);
+
+    // Create an ebtry for the current ScriptSourceObject.
+    void collectSourceFile(JSCompartment* comp, ScriptSourceObject* sso);
+
+    // Write the Lcov output in a buffer, such as the one associated with
+    // the runtime code coverage trace file.
+    void exportInto(GenericPrinter& out, bool* isEmpty) const;
+
+  private:
+    // Write the script name in out.
+    bool writeCompartmentName(JSCompartment* comp);
+
+    // Return the LCovSource entry which matches the given ScriptSourceObject.
+    LCovSource* lookupOrAdd(JSCompartment* comp, JSObject* sso);
+
+  private:
+    typedef mozilla::Vector<LCovSource, 16, LifoAllocPolicy<Fallible>> LCovSourceVector;
+
+    // LifoAlloc backend for all temporary allocations needed to stash the
+    // strings to be written in the file.
+    LifoAlloc alloc_;
+
+    // LifoAlloc string which hold the name of the compartment.
+    LSprinter outTN_;
+
+    // Vector of all sources which are used in this compartment.
+    LCovSourceVector* sources_;
+};
+
+class LCovRuntime
+{
+  public:
+    LCovRuntime();
+    ~LCovRuntime();
+
+    // If the environment variable JS_CODE_COVERAGE_OUTPUT_DIR is set to a
+    // directory, create a file inside this directory which uses the process
+    // ID, the thread ID and a timestamp to ensure the uniqueness of the
+    // file.
+    //
+    // At the end of the execution, this file should contains the LCOV output of
+    // all the scripts executed in the current JSRuntime.
+    void init();
+
+    // Check if we should collect code coverage information.
+    bool isEnabled() const { return out_.isInitialized(); }
+
+    // Write the aggregated result of the code coverage of a compartment
+    // into a file.
+    void writeLCovResult(LCovCompartment& comp);
+
+  private:
+    // When a process forks, the file will remain open, but 2 processes will
+    // have the same file. To avoid conflicting writes, we open a new file for
+    // the child process.
+    void maybeReopenAfterFork();
+
+    // Fill an array with the name of the file. Return false if we are unable to
+    // serialize the filename in this array.
+    bool fillWithFilename(char *name, size_t length);
+
+    // Finish the current opened file, and remove if it does not have any
+    // content.
+    void finishFile();
+
+  private:
+    // Output file which is created if code coverage is enabled.
+    Fprinter out_;
+
+    // The process' PID is used to watch for fork. When the process fork,
+    // we want to close the current file and open a new one.
+    size_t pid_;
+
+    // Flag used to report if the generated file is empty or not. If it is empty
+    // when the runtime is destroyed, then the file would be removed as an empty
+    // file is not a valid LCov file.
+    bool isEmpty_;
+};
+
+} // namespace coverage
+} // namespace js
+
+#endif // vm_Printer_h
+