Fix function base address lookup on Win32 and FreeBSD

* Add a (slow but cross-platform) fallback lookup method of function name and base address
  using LLVM debug info reader
* Remove windows exported symbol lookup that never worked for sysimg function address lookup
  (since they are never exported)

Fix #17251
Fix #20798

src/debuginfo.cpp

@@ -746,35 +746,12 @@ bool jl_dylib_DI_for_fptr(size_t pointer, const llvm::object::ObjectFile **obj,
     if (onlySysImg && !insysimage) {
         return false;
     }
-    static char frame_info_func[
-        sizeof(SYMBOL_INFO) +
-        MAX_SYM_NAME * sizeof(TCHAR)];
-    DWORD64 dwDisplacement64 = 0;
-    DWORD64 dwAddress = pointer;
-    PSYMBOL_INFO pSymbol = (PSYMBOL_INFO)frame_info_func;
-    pSymbol->SizeOfStruct = sizeof(SYMBOL_INFO);
-    pSymbol->MaxNameLen = MAX_SYM_NAME;
-    jl_in_stackwalk = 1;
-    if (SymFromAddr(GetCurrentProcess(), dwAddress, &dwDisplacement64,
-                    pSymbol)) {
-        // SymFromAddr returned success
-        // errors are ignored, but are hopefully patched up by
-        // using llvm to read the object (below)
-        if (name)
-            jl_copy_str(name, pSymbol->Name);
-        if (saddr)
-            *saddr = (void*)(uintptr_t)pSymbol->Address;
-    }
-    else if (saddr) {
-        *saddr = NULL;
-    }
-
     // If we didn't find the filename before in the debug
     // info, use the dll name
     if (filename && !*filename)
         jl_copy_str(filename, fname.data());
-
-    jl_in_stackwalk = 0;
+    if (saddr)
+        *saddr = NULL;
 
 #else // ifdef _OS_WINDOWS_
     Dl_info dlinfo;
@@ -998,33 +975,66 @@ static int jl_getDylibFunctionInfo(jl_frame_t **frames, size_t pointer, int skip
         frame0->fromC = 1;
         return 1;
     }
+    bool need_saddr = isSysImg && sysimg_fvars;
     frame0->fromC = !isSysImg;
-    if (isSysImg && sysimg_fvars) {
+    // Try platform specific methods first since they are usually faster
+    if (need_saddr && !saddr) {
 #if defined(_OS_LINUX_) && !defined(JL_DISABLE_LIBUNWIND)
         unw_proc_info_t pip;
-        if (!saddr && unw_get_proc_info_by_ip(unw_local_addr_space,
-                                              pointer, &pip, NULL) == 0)
+        if (unw_get_proc_info_by_ip(unw_local_addr_space, pointer, &pip, NULL) == 0) {
             saddr = (void*)pip.start_ip;
+        }
 #endif
 #if defined(_OS_WINDOWS_) && defined(_CPU_X86_64_)
-        if (!saddr) {
-            DWORD64 ImageBase;
-            PRUNTIME_FUNCTION fn = RtlLookupFunctionEntry(pointer, &ImageBase, NULL);
-            if (fn)
-                saddr = (void*)(ImageBase + fn->BeginAddress);
+        DWORD64 ImageBase;
+        PRUNTIME_FUNCTION fn = RtlLookupFunctionEntry(pointer, &ImageBase, NULL);
+        if (fn) {
+            saddr = (void*)(ImageBase + fn->BeginAddress);
         }
 #endif
-        if (saddr) {
-            for (size_t i = 0; i < sysimg_fvars_n; i++) {
-                if (saddr == sysimg_fvars[i]) {
-                    frame0->linfo = sysimg_fvars_linfo[i];
-                    break;
+    }
+    if (((need_saddr && !saddr) || !frame0->func_name) && object) {
+        size_t distance = (size_t)-1;
+        SymRef sym_found;
+        for (auto sym: object->symbols()) {
+            auto addr = sym.getAddress();
+            if (!addr)
+                continue;
+            size_t symptr = addr.get();
+            if (symptr > pointer + slide)
+                continue;
+            size_t new_dist = pointer + slide - symptr;
+            if (new_dist > distance)
+                continue;
+            distance = new_dist;
+            sym_found = sym;
+        }
+        if (distance != (size_t)-1) {
+            if (!saddr) {
+                auto addr = sym_found.getAddress();
+                assert(addr);
+                saddr = (void*)(uintptr_t)addr.get();
+            }
+            if (!frame0->func_name) {
+                if (auto name_or_err = sym_found.getName()) {
+                    auto name = name_or_err.get();
+                    size_t len = name.size();
+                    frame0->func_name = (char*)malloc(len + 1);
+                    frame0->func_name[len] = 0;
+                    memcpy(frame0->func_name, name.data(), len);
                 }
             }
         }
-        return lookup_pointer(context, frames, pointer+slide, isSysImg, noInline);
     }
-    return lookup_pointer(context, frames, pointer+slide, isSysImg, noInline);
+    if (need_saddr && saddr) {
+        for (size_t i = 0; i < sysimg_fvars_n; i++) {
+            if (saddr == sysimg_fvars[i]) {
+                frame0->linfo = sysimg_fvars_linfo[i];
+                break;
+            }
+        }
+    }
+    return lookup_pointer(context, frames, pointer + slide, isSysImg, noInline);
 }
 
 int jl_DI_for_fptr(uint64_t fptr, uint64_t *symsize, int64_t *slide, int64_t *section_slide,

test/cmdlineargs.jl

@@ -423,13 +423,7 @@ end
 for precomp in ("yes", "no")
     bt = readstring(pipeline(ignorestatus(`$(Base.julia_cmd()) --startup-file=no --precompiled=$precomp
         -E 'include("____nonexistent_file")'`), stderr=catcmd))
-    @test contains(bt, "include_from_node1")
-    if ((is_windows() && Sys.WORD_SIZE == 32) || (is_bsd() && !is_apple())) && precomp == "yes"
-        # FIXME: Issue #17251 (Windows), #20798 (FreeBSD)
-        @test_broken contains(bt, "include_from_node1(::Module, ::String) at $(joinpath(".", "loading.jl"))")
-    else
-        @test contains(bt, "include_from_node1(::Module, ::String) at $(joinpath(".", "loading.jl"))")
-    end
+    @test contains(bt, "include_from_node1(::Module, ::String) at $(joinpath(".", "loading.jl"))")
     lno = match(r"at \.[\/\\]loading\.jl:(\d+)", bt)
     @test length(lno.captures) == 1
     @test parse(Int, lno.captures[1]) > 0