From a51dc7db4ca61a6cfe53926ff900767e7e40c52f Mon Sep 17 00:00:00 2001
From: Lephenixnoir <sebastien.michelland@protonmail.com>
Date: Sat, 15 Feb 2020 19:32:46 +0100
Subject: [PATCH] add syscall headers at the start of functions

---
 include/fxos/disasm-passes/print.h |  9 +++++----
 lib/passes/print.cpp               | 21 +++++++++++++++++++--
 2 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/include/fxos/disasm-passes/print.h b/include/fxos/disasm-passes/print.h
index b489976..c300a6f 100644
--- a/include/fxos/disasm-passes/print.h
+++ b/include/fxos/disasm-passes/print.h
@@ -10,6 +10,7 @@
 
 #include <fxos/disassembly.h>
 #include <fxos/symbols.h>
+#include <fxos/os.h>
 
 namespace FxOS {
 
@@ -59,11 +60,13 @@ public:
 private:
 	/* Symbol tables to look up names */
 	std::vector<SymbolTable> const &m_symtables;
-
 	/* Query symbol tables, most recent first */
 	std::optional<std::string> symquery(Symbol::Type type, uint32_t value);
 
-	/** Internal promotion printing stuff **/
+	/* OS for the target, to mark syscalls before instructions */
+	std::unique_ptr<OS> m_os;
+
+	/** Internal promotion tree printers **/
 
 	void queue(std::string, bool = false);
 	void queue_flush();
@@ -75,8 +78,6 @@ private:
 	void syscall(ConcreteInstructionArg const &);
 	void syscallname(ConcreteInstructionArg const &);
 	void symbol(ConcreteInstructionArg const &);
-
-	/* To be removed */
 };
 
 } /* namespace FxOS */
diff --git a/lib/passes/print.cpp b/lib/passes/print.cpp
index d8f9cc6..3e5138b 100644
--- a/lib/passes/print.cpp
+++ b/lib/passes/print.cpp
@@ -13,8 +13,12 @@ PrintPass::PrintPass(Disassembly &disasm,
 	std::vector<SymbolTable> const &symtables):
 	DisassemblyPass(disasm), m_symtables(symtables)
 {
-	/* Default parameter set */
-	/* All 0 */
+	/* Default parameters: all 0 */
+
+	/* Use an OS observer to describe syscalls in header lines */
+	Target &t = disasm.target();
+	if(t.covers(MemoryRegion::ROM))
+		m_os = std::make_unique<OS>(t);
 }
 
 void PrintPass::run(void)
@@ -29,6 +33,19 @@ void PrintPass::analyze(uint32_t pc, ConcreteInstruction &ci)
 {
 	Instruction const &i = ci.inst;
 
+	/* Preliminary syscall number */
+
+	int syscall_id;
+	if(m_os && (syscall_id = m_os->find_syscall(pc)) >= 0)
+	{
+		printf("\n<%%%03x", syscall_id);
+
+		auto maybe_str = symquery(Symbol::Syscall, syscall_id);
+		if(maybe_str) printf(" %s", (*maybe_str).c_str());
+
+		printf(">\n");
+	}
+
 	/* Mnemonic */
 
 	static std::map<int, std::string> suffixes = {