[ir] Sketch out tree walk
This CL adds the sketch of how to walk the IR tree in order to rebuild
the format of the original control flow.
Bug: tint:1718
Change-Id: Id9376d51907ea2a60f32506a152928b3a82d14ed
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/110481
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Dan Sinclair <dsinclair@chromium.org>
Reviewed-by: Ben Clayton <bclayton@google.com>
diff --git a/src/tint/ir/debug.cc b/src/tint/ir/debug.cc
index 755d9de..749c654 100644
--- a/src/tint/ir/debug.cc
+++ b/src/tint/ir/debug.cc
@@ -26,6 +26,33 @@
#include "src/tint/program.h"
namespace tint::ir {
+namespace {
+
+class ScopedStopNode {
+ public:
+ ScopedStopNode(std::unordered_set<const FlowNode*>* stop_nodes, const FlowNode* node)
+ : stop_nodes_(stop_nodes), node_(node) {
+ stop_nodes_->insert(node_);
+ }
+
+ ~ScopedStopNode() { stop_nodes_->erase(node_); }
+
+ private:
+ std::unordered_set<const FlowNode*>* stop_nodes_;
+ const FlowNode* node_;
+};
+
+class ScopedIndent {
+ public:
+ explicit ScopedIndent(uint32_t* indent) : indent_(indent) { (*indent_) += 2; }
+
+ ~ScopedIndent() { (*indent_) -= 2; }
+
+ private:
+ uint32_t* indent_;
+};
+
+} // namespace
// static
std::string Debug::AsDotGraph(const Module* mod) {
@@ -157,9 +184,100 @@
}
// static
-std::string Debug::AsString(const Module*) {
+std::string Debug::AsString(const Module* mod) {
std::stringstream out;
- out << "IR" << std::endl;
+
+ std::unordered_set<const FlowNode*> visited;
+ std::unordered_set<const FlowNode*> stop_nodes;
+ uint32_t indent_size = 0;
+
+ std::function<std::ostream&(void)> indent = [&]() -> std::ostream& {
+ for (uint32_t i = 0; i < indent_size; i++) {
+ out << " ";
+ }
+ return out;
+ };
+
+ std::function<void(const FlowNode*)> Walk = [&](const FlowNode* node) {
+ if ((visited.count(node) > 0) || (stop_nodes.count(node) > 0)) {
+ return;
+ }
+ visited.insert(node);
+
+ tint::Switch(
+ node,
+ [&](const ir::Function* f) {
+ out << "Function" << std::endl;
+
+ {
+ ScopedIndent func_indent(&indent_size);
+ ScopedStopNode scope(&stop_nodes, f->end_target);
+ Walk(f->start_target);
+ }
+ Walk(f->end_target);
+ },
+ [&](const ir::Block* b) {
+ indent() << "Block" << std::endl;
+ Walk(b->branch_target);
+ },
+ [&](const ir::Switch* s) {
+ indent() << "Switch" << std::endl;
+
+ {
+ ScopedIndent switch_indent(&indent_size);
+ ScopedStopNode scope(&stop_nodes, s->merge_target);
+ for (const auto& c : s->cases) {
+ indent() << "Case" << std::endl;
+ ScopedIndent case_indent(&indent_size);
+ Walk(c.start_target);
+ }
+ }
+
+ indent() << "Switch Merge" << std::endl;
+ Walk(s->merge_target);
+ },
+ [&](const ir::If* i) {
+ indent() << "if" << std::endl;
+ {
+ ScopedIndent if_indent(&indent_size);
+ ScopedStopNode scope(&stop_nodes, i->merge_target);
+
+ indent() << "If true" << std::endl;
+ Walk(i->true_target);
+
+ indent() << "If false" << std::endl;
+ Walk(i->false_target);
+ }
+
+ indent() << "if merge" << std::endl;
+ Walk(i->merge_target);
+ },
+ [&](const ir::Loop* l) {
+ indent() << "loop" << std::endl;
+ {
+ ScopedStopNode loop_scope(&stop_nodes, l->merge_target);
+ ScopedIndent loop_indent(&indent_size);
+ {
+ ScopedStopNode inner_scope(&stop_nodes, l->continuing_target);
+ indent() << "loop start" << std::endl;
+ Walk(l->start_target);
+ }
+
+ indent() << "loop continuing" << std::endl;
+ ScopedIndent continuing_indent(&indent_size);
+ Walk(l->continuing_target);
+ }
+
+ indent() << "loop merge" << std::endl;
+ Walk(l->merge_target);
+ },
+ [&](const ir::Terminator*) { indent() << "Function end" << std::endl; });
+ };
+
+ for (const auto* func : mod->functions) {
+ Walk(func);
+ }
+
return out.str();
}
