implement external interface to library and use it in tests. need to be

reworked a bit to use file descriptor or buffer provided to callse

include/libpst.h

@@ -10,31 +10,39 @@
 
 //system
 #include <ucontext.h>
-/*
-#include <netdb.h>
 #include <stdio.h>
-#include <stdlib.h>
-#include <errno.h>
-#include <vector>
-#include <string.h>
-#include <libunwind.h>
-#include <elfutils/libdwfl.h>
-#include <dlfcn.h>
-#include <stdlib.h>
-*/
+#include <stdint.h>
 
-#include "utils/list_head.h"
-#include "context.h"
+typedef struct pst_handler pst_handler;
 
-typedef struct pst_handler {
-	pst_context					ctx;		// context of unwinding
-	list_head	                functions;	// list of functions in stack frame
-} pst_handler;
-void pst_handler_init(pst_handler* h, ucontext_t* hctx);
-void pst_handler_fini(pst_handler* h);
+// allocate and initialize libpst handler.
+pst_handler* pst_new_handler(ucontext_t* hctx);
 
-bool pst_handler_handle_dwarf(pst_handler* h);
-void pst_handler_print_dwarf(pst_handler* h);
-bool pst_handler_unwind(pst_handler* h);
+// deallocate libpst handler
+void pst_del_handler(pst_handler* h);
+
+
+//
+// Base unwind routines.
+// Unwinds current stack trace using base information about program (i.e. print out address, function name)
+//
+
+// write stack trace information to provided file descriptor
+int pst_unwind_simple(pst_handler* h, FILE* fd);
+
+// save stack trace information to provided buffer in RAM
+int pst_unwind_simple(pst_handler* h, char* buff, uint32_t buff_size);
+
+
+// Advanced unwind routines.
+// Unwinds current stack trace using DWARF debug sections in file if they present and print it to provided file descriptor.
+// Additionally to pst_unwind_simple(...) provides types of parameters and variables in functions and their values
+//
+
+// write stack trace information to provided file descriptor
+int pst_unwind_pretty(pst_handler* h, FILE* fd);
+
+// save stack trace information to provided buffer in RAM
+int pst_unwind_pretty(pst_handler* h, char* buff, uint32_t buff_size);
 
 #endif /* PST_HANDLER_H_ */

src/Makefile

@@ -31,7 +31,7 @@ SOFT_BUILD	= $(shell STR=`cat $(BUILD_DIR)/version.h 2> /dev/null | grep 'SOFT_B
 DATE_BUILD	= $(shell date +"%D %T")
 
 #source and header files search path. add here new directories which contains files specified for $(SRC)
-VPATH 		= . dwarf arch utils
+VPATH 		= ./ ./dwarf ./arch ./utils
 
 SRC			= $(wildcard $(addsuffix /*.cpp,${VPATH}))
 OBJ			= $(patsubst %.cpp,%.o,$(addprefix $(BUILD_DIR)/,$(notdir $(SRC))))

src/context.cpp

@@ -151,10 +151,6 @@ bool print_expr_block (pst_context* ctx, Dwarf_Op *exprs, int exprlen, Dwarf_Att
 
 void pst_context_init(pst_context* ctx, ucontext_t* hctx)
 {
-    // global
-    pst_alloc_init(&allocator);
-    pst_log_init_console(&logger);
-
     // methods
     ctx->clean_print = clean_print;
     ctx->print = print;
@@ -184,10 +180,6 @@ void pst_context_fini(pst_context* ctx)
     ctx->frame = NULL;
     ctx->dwfl = NULL;
     ctx->module = NULL;
-
-    // global
-    pst_log_fini(&logger);
-    pst_alloc_fini(&allocator);
 }
 
 

src/libpst.cpp

@@ -0,0 +1,91 @@
+/*
+ * libpst.c
+ *
+ *  Created on: Feb 5, 2020
+ *      Author: nnosov
+ */
+
+#include <ucontext.h>
+#include <stdio.h>
+#include <stdint.h>
+
+#include "utils/allocator.h"
+#include "dwarf/dwarf_handler.h"
+
+// allocate and initialize libpst handler.
+pst_handler* pst_new_handler(ucontext_t* hctx)
+{
+    // global
+    pst_alloc_init(&allocator);
+    pst_log_init_console(&logger);
+
+    pst_new(pst_handler, handler, hctx);
+    return handler;
+}
+
+// deallocate libpst handler
+void pst_del_handler(pst_handler* h)
+{
+    pst_free(h);
+
+    // global
+    pst_log_fini(&logger);
+    pst_alloc_fini(&allocator);
+}
+
+// write stack trace information to provided file descriptor
+int pst_unwind_simple(pst_handler* h, FILE* fd)
+{
+    int ret = pst_handler_unwind(h);
+    if(ret) {
+        fwrite(h->ctx.buff, 1, strlen(h->ctx.buff), fd);
+        return 0;
+    }
+
+    return -1;
+}
+
+// save stack trace information to provided buffer in RAM
+int pst_unwind_simple(pst_handler* h, char* buff, uint32_t buff_size)
+{
+    int ret = pst_handler_unwind(h);
+    if(ret) {
+        uint32_t cnt = buff_size < sizeof(h->ctx.buff) ? buff_size : sizeof(h->ctx.buff);
+        memcpy(buff, h->ctx.buff, cnt - 2);
+        buff[cnt - 1] = 0;
+
+        return 0;
+    }
+
+    return -1;
+}
+
+
+// write stack trace information to provided file descriptor
+int pst_unwind_pretty(pst_handler* h, FILE* fd)
+{
+    int ret = pst_handler_handle_dwarf(h);
+    if(ret) {
+        pst_handler_print_dwarf(h);
+        fwrite(h->ctx.buff, 1, strlen(h->ctx.buff), fd);
+        return 0;
+    }
+
+    return -1;
+}
+
+// save stack trace information to provided buffer in RAM
+int pst_unwind_pretty(pst_handler* h, char* buff, uint32_t buff_size)
+{
+    int ret = pst_handler_handle_dwarf(h);
+    if(ret) {
+        pst_handler_print_dwarf(h);
+        uint32_t cnt = buff_size < sizeof(h->ctx.buff) ? buff_size : sizeof(h->ctx.buff);
+        memcpy(buff, h->ctx.buff, cnt - 2);
+        buff[cnt - 1] = 0;
+
+        return 0;
+    }
+
+    return -1;
+}

tests/main.cpp

@@ -1,9 +1,9 @@
 //system
 #include <stdlib.h>
 #include <fcntl.h>
+#include <stdint.h>
 
-#include "dwarf/dwarf_handler.h"
-#include "context.h"
+#include "../include/libpst.h"
 
 typedef enum {
 	DEF_1 = 1,
@@ -35,6 +35,7 @@ uint32_t Fun1(const int arg1, my_int arg2, uint32_t arg3)
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
+#include <string.h>
 
 typedef void (*sig_handler_t)(int sig);
 
@@ -59,24 +60,26 @@ void FatalSignalHandler(int sig, siginfo_t* info, void* context)
 
     fatal_error_in_progress = 1;
 
-    pst_log(SEVERITY_ERROR, "%s signal handled", strsignal(sig));
-    bool ret = false;
-    pst_decl(pst_handler, handler, (ucontext_t*)context);
-
+    printf("%s signal handled\n", strsignal(sig));
 	if((context != 0) && (sig == SIGSEGV || sig == SIGABRT || sig == SIGBUS || sig == SIGFPE))
 	{
-	    ret = pst_handler_unwind(&handler);
+	    pst_handler* handler = pst_new_handler((ucontext_t*)context);
+	    if(!handler) {
+	        printf("Failed to allocate pst handler\n");
+	        return;
 	    }
 
-	if(ret) {
-	    pst_log(SEVERITY_INFO, "%s", handler.ctx.buff);
-	    pst_handler_handle_dwarf(&handler);
-	    pst_handler_print_dwarf(&handler);
-	    pst_log(SEVERITY_INFO, "%s", handler.ctx.buff);
+	    int ret = pst_unwind_simple(handler, stdout);
+	    if(!ret) {
+	        pst_unwind_pretty(handler, stdout);
 	    } else {
-	    pst_log(SEVERITY_ERROR, "No stack trace obtained");
+	        printf("No stack trace obtained\n");
 	    }
 
+	    pst_del_handler(handler);
+    }
+
+
     // comment out line below to prevent coredump
     // exit(EXIT_FAILURE);
 
@@ -90,20 +93,7 @@ void FatalSignalHandler(int sig, siginfo_t* info, void* context)
 
 void SignalHandler(int sig)
 {
-//	if (handled_error_in_progress)
-//		raise (sig);
-//	handled_error_in_progress = 1;
-
-//	const char* str_sig = strsignal(sig);
-//	logger->Log(SEVERITY_INFO, "%s received.", str_sig);
-	if(sig == SIGUSR1) {
-		pst_log(SEVERITY_INFO, "Maintenance mode enabled.");
-	} else if(sig == SIGUSR2) {
-		pst_log(SEVERITY_INFO, "Maintenance mode disabled.");
-	}
-//	signal (sig, SIG_DFL);
-//	raise(sig);
-	// reset to our handler back
+    // do nothing and reset to our handler back
 	SetSignalHandler();
 }
 
@@ -117,7 +107,6 @@ void SetSignalHandler(sig_handler_t handler)
 	sigfillset(&ss);
 
 	//remove previous handlers
-//	sigdelset(&ss, SIGINT);
 	sigdelset(&ss, SIGUSR1);
 	sigdelset(&ss, SIGUSR2);
 	sigdelset(&ss, SIGSEGV);
@@ -136,10 +125,6 @@ void SetSignalHandler(sig_handler_t handler)
 	sa.sa_handler = NULL;
 	sa.sa_sigaction = NULL;
 
-//	//set interrupt signal
-//	sa.sa_handler = SignalHandler;
-//	sigaction(SIGINT, &sa, 0);
-
 	//set stop signal
 	sa.sa_handler = (handler == NULL) ? SignalHandler : handler;
 	sigaction(SIGUSR1, &sa, 0);
@@ -176,7 +161,7 @@ void SetSignalHandler(sig_handler_t handler)
 	limit.rlim_max = 1073741824;
 	if (setrlimit(RLIMIT_CORE, &limit))
 	{
-		pst_log(SEVERITY_DEBUG, "Failed to set limit for core dump file size");
+		printf("Failed to set limit for core dump file size\n");
 	}
 }
 
@@ -192,8 +177,6 @@ void ResetSignalHandler() {
 
 int main(int argc, char* argv[])
 {
-    pst_log_init_console(&logger);
-    //logger->SetCurrentSeverity(SEVERITY_INFO);
     SetSignalHandler(SigusrHandler);
 
     Fun1(1, DEF_2, 5);