rt: Factor out stack walking into rust_abi.cpp

3 files changed, 48 insertions, 31 deletions

diff --git a/src/rt/rust_abi.cpp b/src/rt/rust_abi.cpp
index 98b80fb41bd..2a08a25a9fa 100644
--- a/src/rt/rust_abi.cpp
+++ b/src/rt/rust_abi.cpp
@@ -1,10 +1,35 @@
+// ABI-specific routines.
+
+#include <vector>
 #include <cstdlib>
 #include <stdint.h>
 #include "rust_abi.h"
 
+#define END_OF_STACK_RA     (void (*)())0xdeadbeef
+
 weak_symbol<uint32_t> abi_version("rust_abi_version");
 
 uint32_t get_abi_version() {
     return (*abi_version == NULL) ? 0 : **abi_version;
 }
 
+namespace stack_walk {
+
+std::vector<frame>
+backtrace() {
+    std::vector<frame> frames;
+
+    // Ideally we would use the current value of EIP here, but there's no
+    // portable way to get that and there are never any GC roots in our C++
+    // frames anyhow.
+    frame f(__builtin_frame_address(0), (void (*)())NULL);
+
+    while (f.ra != END_OF_STACK_RA) {
+        frames.push_back(f);
+        f.next();
+    }
+    return frames;
+}
+
+}   // end namespace stack_walk
+
diff --git a/src/rt/rust_abi.h b/src/rt/rust_abi.h
index 9c22ea3fe7e..884eed4b717 100644
--- a/src/rt/rust_abi.h
+++ b/src/rt/rust_abi.h
@@ -1,7 +1,10 @@
+// ABI-specific routines.
+
 #ifndef RUST_ABI_H
 #define RUST_ABI_H
 
 #include <cstdlib>
+#include <vector>
 
 #ifdef __WIN32__
 #include <windows.h>
@@ -36,6 +39,25 @@ public:
     T *&operator*() { fill(); return data; }
 };
 
+namespace stack_walk {
+
+struct frame {
+    uint8_t *bp;    // The frame pointer.
+    void (*ra)();   // The return address.
+
+    frame(void *in_bp, void (*in_ra)()) : bp((uint8_t *)in_bp), ra(in_ra) {}
+
+    inline void next() {
+        ra = *(void (**)())(bp + sizeof(void *));
+        bp = *(uint8_t **)bp;
+    }
+};
+
+std::vector<frame> backtrace();
+
+}   // end namespace stack_walk
+
+
 uint32_t get_abi_version();
 
 #endif
diff --git a/src/rt/rust_gc.cpp b/src/rt/rust_gc.cpp
index 6e698de59db..ae3c5a01031 100644
--- a/src/rt/rust_gc.cpp
+++ b/src/rt/rust_gc.cpp
@@ -18,24 +18,12 @@
 #include <dlfcn.h>
 #endif
 
-#define END_OF_STACK_RA     (void (*)())0xdeadbeef
+using namespace stack_walk;
 
 namespace gc {
 
 weak_symbol<const uintptr_t> safe_point_data("rust_gc_safe_points");
 
-struct frame {
-    uint8_t *bp;    // The frame pointer.
-    void (*ra)();   // The return address.
-
-    frame(void *in_bp, void (*in_ra)()) : bp((uint8_t *)in_bp), ra(in_ra) {}
-
-    inline void next() {
-        ra = *(void (**)())(bp + sizeof(void *));
-        bp = *(uint8_t **)bp;
-    }
-};
-
 struct root_info {
     intptr_t frame_offset;
     uintptr_t dynamic;  // 0 = static, 1 = dynamic
@@ -98,9 +86,7 @@ private:
 
 public:
     gc(rust_task *in_task) : task(in_task) {}
-
     void run();
-    std::vector<frame> backtrace();
 };
 
 const safe_point *
@@ -135,22 +121,6 @@ gc::sweep() {
     // TODO
 }
 
-std::vector<frame>
-gc::backtrace() {
-    std::vector<frame> frames;
-
-    // Ideally we would use the current value of EIP here, but there's no
-    // portable way to get that and there are never any GC roots in our C++
-    // frames anyhow.
-    frame f(__builtin_frame_address(0), (void (*)())NULL);
-
-    while (f.ra != END_OF_STACK_RA) {
-        frames.push_back(f);
-        f.next();
-    }
-    return frames;
-}
-
 void
 gc::run() {
     safe_point_map map;