1 files changed, 192 insertions, 0 deletions
diff --git a/src/win32/w32_stack.c b/src/win32/w32_stack.c
new file mode 100644
index 000000000..15af3dcb7
--- /dev/null
+++ b/src/win32/w32_stack.c
@@ -0,0 +1,192 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#if defined(GIT_MSVC_CRTDBG)
+#include "Windows.h"
+#include "Dbghelp.h"
+#include "win32/posix.h"
+#include "w32_stack.h"
+#include "hash.h"
+
+/**
+ * This is supposedly defined in WinBase.h (from Windows.h) but there were linker issues.
+ */
+USHORT WINAPI RtlCaptureStackBackTrace(ULONG, ULONG, PVOID*, PULONG);
+
+static bool   g_win32_stack_initialized = false;
+static HANDLE g_win32_stack_process = INVALID_HANDLE_VALUE;
+static git_win32__stack__aux_cb_alloc  g_aux_cb_alloc  = NULL;
+static git_win32__stack__aux_cb_lookup g_aux_cb_lookup = NULL;
+
+int git_win32__stack__set_aux_cb(
+	git_win32__stack__aux_cb_alloc cb_alloc,
+	git_win32__stack__aux_cb_lookup cb_lookup)
+{
+	g_aux_cb_alloc = cb_alloc;
+	g_aux_cb_lookup = cb_lookup;
+
+	return 0;
+}
+
+void git_win32__stack_init(void)
+{
+	if (!g_win32_stack_initialized) {
+		g_win32_stack_process = GetCurrentProcess();
+		SymSetOptions(SYMOPT_LOAD_LINES);
+		SymInitialize(g_win32_stack_process, NULL, TRUE);
+		g_win32_stack_initialized = true;
+	}
+}
+
+void git_win32__stack_cleanup(void)
+{
+	if (g_win32_stack_initialized) {
+		SymCleanup(g_win32_stack_process);
+		g_win32_stack_process = INVALID_HANDLE_VALUE;
+		g_win32_stack_initialized = false;
+	}
+}
+
+int git_win32__stack_capture(git_win32__stack__raw_data *pdata, int skip)
+{
+	if (!g_win32_stack_initialized) {
+		giterr_set(GITERR_INVALID, "git_win32_stack not initialized.");
+		return GIT_ERROR;
+	}
+
+	memset(pdata, 0, sizeof(*pdata));
+	pdata->nr_frames = RtlCaptureStackBackTrace(
+		skip+1, GIT_WIN32__STACK__MAX_FRAMES, pdata->frames, NULL);
+
+	/* If an "aux" data provider was registered, ask it to capture
+	 * whatever data it needs and give us an "aux_id" to it so that
+	 * we can refer to it later when reporting.
+	 */
+	if (g_aux_cb_alloc)
+		(g_aux_cb_alloc)(&pdata->aux_id);
+
+	return 0;
+}
+
+int git_win32__stack_compare(
+	git_win32__stack__raw_data *d1,
+	git_win32__stack__raw_data *d2)
+{
+	return memcmp(d1, d2, sizeof(*d1));
+}
+
+int git_win32__stack_format(
+	char *pbuf, int buf_len,
+	const git_win32__stack__raw_data *pdata,
+	const char *prefix, const char *suffix)
+{
+#define MY_MAX_FILENAME 255
+
+	/* SYMBOL_INFO has char FileName[1] at the end.  The docs say to
+	 * to malloc it with extra space for your desired max filename.
+	 */
+	struct {
+		SYMBOL_INFO symbol;
+		char extra[MY_MAX_FILENAME + 1];
+	} s;
+
+	IMAGEHLP_LINE64 line;
+	int buf_used = 0;
+	unsigned int k;
+	char detail[MY_MAX_FILENAME * 2]; /* filename plus space for function name and formatting */
+	int detail_len;
+
+	if (!g_win32_stack_initialized) {
+		giterr_set(GITERR_INVALID, "git_win32_stack not initialized.");
+		return GIT_ERROR;
+	}
+
+	if (!prefix)
+		prefix = "\t";
+	if (!suffix)
+		suffix = "\n";
+
+	memset(pbuf, 0, buf_len);
+
+	memset(&s, 0, sizeof(s));
+	s.symbol.MaxNameLen = MY_MAX_FILENAME;
+	s.symbol.SizeOfStruct = sizeof(SYMBOL_INFO);
+
+	memset(&line, 0, sizeof(line));
+	line.SizeOfStruct = sizeof(IMAGEHLP_LINE64);
+
+	for (k=0; k < pdata->nr_frames; k++) {
+		DWORD64 frame_k = (DWORD64)pdata->frames[k];
+		DWORD dwUnused;
+
+		if (SymFromAddr(g_win32_stack_process, frame_k, 0, &s.symbol) &&
+			SymGetLineFromAddr64(g_win32_stack_process, frame_k, &dwUnused, &line)) {
+			const char *pslash;
+			const char *pfile;
+
+			pslash = strrchr(line.FileName, '\\');
+			pfile = ((pslash) ? (pslash+1) : line.FileName);
+			p_snprintf(detail, sizeof(detail), "%s%s:%d> %s%s",
+					   prefix, pfile, line.LineNumber, s.symbol.Name, suffix);
+		} else {
+			/* This happens when we cross into another module.
+			 * For example, in CLAR tests, this is typically
+			 * the CRT startup code.  Just print an unknown
+			 * frame and continue.
+			 */
+			p_snprintf(detail, sizeof(detail), "%s??%s", prefix, suffix);
+		}
+		detail_len = strlen(detail);
+
+		if (buf_len < (buf_used + detail_len + 1)) {
+			/* we don't have room for this frame in the buffer, so just stop. */
+			break;
+		}
+
+		memcpy(&pbuf[buf_used], detail, detail_len);
+		buf_used += detail_len;
+	}
+
+	/* "aux_id" 0 is reserved to mean no aux data. This is needed to handle
+	 * allocs that occur before the aux callbacks were registered.
+	 */
+	if (pdata->aux_id > 0) {
+		p_snprintf(detail, sizeof(detail), "%saux_id: %d%s",
+				   prefix, pdata->aux_id, suffix);
+		detail_len = strlen(detail);
+		if ((buf_used + detail_len + 1) < buf_len) {
+			memcpy(&pbuf[buf_used], detail, detail_len);
+			buf_used += detail_len;
+		}
+
+		/* If an "aux" data provider is still registered, ask it to append its detailed
+		 * data to the end of ours using the "aux_id" it gave us when this de-duped
+		 * item was created.
+		 */
+		if (g_aux_cb_lookup)
+			(g_aux_cb_lookup)(pdata->aux_id, &pbuf[buf_used], (buf_len - buf_used - 1));
+	}
+
+	return GIT_OK;
+}
+
+int git_win32__stack(
+	char * pbuf, int buf_len,
+	int skip,
+	const char *prefix, const char *suffix)
+{
+	git_win32__stack__raw_data data;
+	int error;
+
+	if ((error = git_win32__stack_capture(&data, skip)) < 0)
+		return error;
+	if ((error = git_win32__stack_format(pbuf, buf_len, &data, prefix, suffix)) < 0)
+		return error;
+	return 0;
+}
+
+#endif