Render Layers

1 files changed, 124 insertions, 0 deletions

diff --git a/plugins/stack_render_layer/plugin.cpp b/plugins/stack_render_layer/plugin.cpp
new file mode 100644
index 00000000..b32ee470
--- /dev/null
+++ b/plugins/stack_render_layer/plugin.cpp
@@ -0,0 +1,124 @@
+
+#include <binaryninjaapi.h>
+#include <thread>
+
+using namespace BinaryNinja;
+
+
+class StackRenderLayer: public RenderLayer
+{
+public:
+	StackRenderLayer(): RenderLayer("Annotate Stack Offset") {}
+
+	void ApplyToLines(
+		Ref<BasicBlock> block,
+		std::vector<DisassemblyTextLine>& lines
+	)
+	{
+		for (auto& line: lines)
+		{
+			// Skip blank lines (block separators)
+			if (line.tokens.empty())
+			{
+				continue;
+			}
+
+			// Insert tokens after the address separator
+			int64_t sep = -1;
+			for (int64_t i = 0; i < line.tokens.size(); i ++)
+			{
+				if (line.tokens[i].type == AddressSeparatorToken)
+				{
+					sep = i;
+					break;
+				}
+			}
+			// Don't annotate lines which don't have an address separator
+			// (these are usually annotations like { Does not return }
+			if (sep == -1)
+			{
+				continue;
+			}
+
+			// Grab stack offset value from function
+			auto stackOffset = block->GetFunction()->GetRegisterValueAtInstruction(
+				block->GetArchitecture(),
+				line.addr,
+				block->GetArchitecture()->GetStackPointerRegister()
+			);
+			auto stackOffsetAfter = block->GetFunction()->GetRegisterValueAfterInstruction(
+				block->GetArchitecture(),
+				line.addr,
+				block->GetArchitecture()->GetStackPointerRegister()
+			);
+			if (stackOffset.state == StackFrameOffset)
+			{
+				// Stack pointer is resolved to an offset: show the offset
+				// (but negative because that is how other tools do it)
+				line.tokens.emplace(
+					line.tokens.begin() + sep + 1,
+					IntegerToken,
+					fmt::format("{:4x}", -stackOffset.value),
+					-stackOffset.value
+				);
+			}
+			else
+			{
+				// Stack pointer is not resolved, show ??
+				line.tokens.emplace(
+					line.tokens.begin() + sep + 1,
+					IntegerToken,
+					"  ??",
+					0
+				);
+			}
+			// And put a spacer after the offset token
+			if (stackOffset != stackOffsetAfter)
+			{
+				line.tokens.emplace(
+					line.tokens.begin() + sep + 2,
+					TextToken,
+					"* "
+				);
+			}
+			else
+			{
+				line.tokens.emplace(
+					line.tokens.begin() + sep + 2,
+					TextToken,
+					"  "
+				);
+			}
+		}
+	}
+
+	virtual void ApplyToDisassemblyBlock(
+		Ref<BasicBlock> block,
+		std::vector<DisassemblyTextLine>& lines
+	) override
+	{
+		// Break this out into a helper so we don't have to write it twice
+		ApplyToLines(block, lines);
+	}
+
+	virtual void ApplyToLowLevelILBlock(
+		Ref<BasicBlock> block,
+		std::vector<DisassemblyTextLine>& lines
+	) override
+	{
+		// Break this out into a helper so we don't have to write it twice
+		ApplyToLines(block, lines);
+	}
+};
+
+
+extern "C" {
+	BN_DECLARE_CORE_ABI_VERSION
+
+	BINARYNINJAPLUGIN bool CorePluginInit()
+	{
+		static StackRenderLayer* layer = new StackRenderLayer();
+		RenderLayer::Register(layer, DisabledByDefaultRenderLayerDefaultEnableState);
+		return true;
+	}
+}
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