===================================================================
@@ -50,6 +50,7 @@ go-warn = $(STRICT_WARN)
GO_OBJS = \
go/ast-dump.o \
+ go/escape.o \
go/export.o \
go/expressions.o \
go/go-backend.o \
===================================================================
@@ -1,4 +1,4 @@
-46b108136c0d102f181f0cc7c398e3db8c4d08a3
+33f1d1d151721305ba37f3e23652d21310f868af
The first line of this file holds the git revision number of the last
merge done from the gofrontend repository.
===================================================================
@@ -0,0 +1,95 @@
+// escape.cc -- Go escape analysis (based on Go compiler algorithm).
+
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "gogo.h"
+#include "escape.h"
+
+// Analyze the program flow for escape information.
+
+void
+Gogo::analyze_escape()
+{
+ // Discover strongly connected groups of functions to analyze for escape
+ // information in this package.
+ this->discover_analysis_sets();
+
+ for (std::vector<Analysis_set>::iterator p = this->analysis_sets_.begin();
+ p != this->analysis_sets_.end();
+ ++p)
+ {
+ std::vector<Named_object*> stack = p->first;
+ Escape_context* context = new Escape_context(p->second);
+
+ // Analyze the flow of each function; build the connection graph.
+ // This is the assign phase.
+ for (std::vector<Named_object*>::reverse_iterator fn = stack.rbegin();
+ fn != stack.rend();
+ ++fn)
+ {
+ context->set_current_function(*fn);
+ this->assign_connectivity(context, *fn);
+ }
+
+ // TODO(cmang): Introduce escape node.
+ // Propagate levels across each dst. This is the flood phase.
+ // std::vector<Node*> dsts = context->dsts();
+ // for (std::vector<Node*>::iterator n = dsts.begin();
+ // n != dsts.end();
+ // ++n)
+ // this->propagate_escape(context, *n);
+
+ // Tag each exported function's parameters with escape information.
+ for (std::vector<Named_object*>::iterator fn = stack.begin();
+ fn != stack.end();
+ ++fn)
+ this->tag_function(context, *fn);
+
+ delete context;
+ }
+}
+
+// Discover strongly connected groups of functions to analyze.
+
+void
+Gogo::discover_analysis_sets()
+{
+ // TODO(cmang): Implement Analysis_set discovery traversal.
+ // Escape_analysis_discover(this);
+ // this->traverse(&ead);
+}
+
+// Build a connectivity graph between nodes in the function being analyzed.
+
+void
+Gogo::assign_connectivity(Escape_context*, Named_object*)
+{
+ // TODO(cmang): Model the flow analysis of input parameters and results for a
+ // function.
+ // TODO(cmang): Analyze the current function's body.
+}
+
+// Propagate escape information across the nodes modeled in this Analysis_set,
+// TODO(cmang): Introduce escape analysis node.
+
+void
+Gogo::propagate_escape(Escape_context*)
+{
+ // TODO(cmang): Do a breadth-first traversal of a node's upstream, adjusting
+ // the Level appropriately.
+}
+
+
+// Tag each top-level function with escape information that will be used to
+// retain analysis results across imports.
+
+void
+Gogo::tag_function(Escape_context*, Named_object*)
+{
+ // TODO(cmang): Create escape information notes for each input and output
+ // parameter in a given function.
+ // Escape_analysis_tag eat(context, fn);
+ // this->traverse(&eat);
+}
===================================================================
@@ -0,0 +1,44 @@
+// escape.h -- Go escape analysis (based on Go compiler algorithm).
+
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef GO_ESCAPE_H
+#define GO_ESCAPE_H
+
+class Named_object;
+
+// The escape context for a set of functions being analyzed.
+
+class Escape_context
+{
+ public:
+ Escape_context(bool recursive)
+ : current_function_(NULL), recursive_(recursive)
+ { }
+
+ // Return the current function being analyzed.
+ Named_object*
+ current_function() const
+ { return this->current_function_; }
+
+ // Change the function being analyzed.
+ void
+ set_current_function(Named_object* fn)
+ { this->current_function_ = fn; }
+
+ // Return true if this is the context for a mutually recursive set of functions.
+ bool
+ recursive() const
+ { return this->recursive_; }
+
+ private:
+ // The current function being analyzed.
+ Named_object* current_function_;
+ // Return whether this is the context for a recursive function or a group of mutually
+ // recursive functions.
+ bool recursive_;
+};
+
+#endif // !defined(GO_ESCAPE_H)
===================================================================
@@ -50,6 +50,7 @@ class Bblock;
class Bvariable;
class Blabel;
class Bfunction;
+class Escape_context;
// This file declares the basic classes used to hold the internal
// representation of Go which is built by the parser.
@@ -345,6 +346,16 @@ class Gogo
add_label_reference(const std::string&, Location,
bool issue_goto_errors);
+ // An analysis set is a list of functions paired with a boolean that indicates
+ // whether the list of functions are recursive.
+ typedef std::pair<std::vector<Named_object*>, bool> Analysis_set;
+
+ // Add a GROUP of possibly RECURSIVE functions to the Analysis_set for this
+ // package.
+ void
+ add_analysis_set(const std::vector<Named_object*>& group, bool recursive)
+ { this->analysis_sets_.push_back(std::make_pair(group, recursive)); }
+
// Return a snapshot of the current binding state.
Bindings_snapshot*
bindings_snapshot(Location);
@@ -544,6 +555,28 @@ class Gogo
void
check_return_statements();
+ // Analyze the program flow for escape information.
+ void
+ analyze_escape();
+
+ // Discover the groups of possibly recursive functions in this package.
+ void
+ discover_analysis_sets();
+
+ // Build a connectivity graph between the objects in each analyzed function.
+ void
+ assign_connectivity(Escape_context*, Named_object*);
+
+ // Traverse the objects in the connecitivty graph from the sink, adjusting the
+ // escape levels of each object.
+ void
+ propagate_escape(Escape_context*);
+
+ // Add notes about the escape level of a function's input and output
+ // parameters for exporting and importing top level functions.
+ void
+ tag_function(Escape_context*, Named_object*);
+
// Do all exports.
void
do_exports();
@@ -762,6 +795,9 @@ class Gogo
bool specific_type_functions_are_written_;
// Whether named types have been converted.
bool named_types_are_converted_;
+ // A list containing groups of possibly mutually recursive functions to be
+ // considered during escape analysis.
+ std::vector<Analysis_set> analysis_sets_;
};
// A block of statements.