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Diffstat (limited to '')
| -rw-r--r-- | tools/frr-llvm-cg.c | 950 |
1 files changed, 950 insertions, 0 deletions
diff --git a/tools/frr-llvm-cg.c b/tools/frr-llvm-cg.c new file mode 100644 index 0000000..3a7222e --- /dev/null +++ b/tools/frr-llvm-cg.c @@ -0,0 +1,950 @@ +// SPDX-License-Identifier: Unlicense +/* based on example code: https://github.com/sheredom/llvm_bc_parsing_example + * which came under the above (un-)license. does not depend on any FRR + * pieces, so no reason to change the license. + * + * please note that while included in the FRR sources, this tool is in no way + * supported or maintained by the FRR community. it is provided as a + * "convenience"; while it worked at some point (using LLVM 8 / 9), it may + * easily break with a future LLVM version or any other factors. + * + * 2020-05-04, David Lamparter + */ + +#include <string.h> +#include <strings.h> +#include <stdbool.h> +#include <stdlib.h> +#include <stdio.h> +#include <unistd.h> +#include <errno.h> +#include <assert.h> + +#include <llvm-c/BitReader.h> +#include <llvm-c/BitWriter.h> +#include <llvm-c/Core.h> + +#include <json-c/json.h> + +#include "frr-llvm-debuginfo.h" + +/* if you want to use this without the special FRRouting defines, + * remove the following #define + */ +#define FRR_SPECIFIC + +static struct dbginfo *dbginfo; + +static void dbgloc_add(struct json_object *jsobj, LLVMValueRef obj) +{ + unsigned file_len = 0; + const char *file = LLVMGetDebugLocFilename(obj, &file_len); + unsigned line = LLVMGetDebugLocLine(obj); + + if (!file) + file = "???", file_len = 3; + else if (file[0] == '.' && file[1] == '/') + file += 2, file_len -= 2; + + json_object_object_add(jsobj, "filename", + json_object_new_string_len(file, file_len)); + json_object_object_add(jsobj, "line", json_object_new_int64(line)); +} + +static struct json_object *js_get_or_make(struct json_object *parent, + const char *key, + struct json_object *(*maker)(void)) +{ + struct json_object *ret; + + ret = json_object_object_get(parent, key); + if (ret) + return ret; + ret = maker(); + json_object_object_add(parent, key, ret); + return ret; +} + +static bool try_struct_fptr(struct json_object *js_call, LLVMValueRef gep, + const char *prefix) +{ + unsigned long long val = 0; + bool ret = false; + LLVMTypeRef ptrtype = LLVMTypeOf(LLVMGetOperand(gep, 0)); + LLVMValueRef idx; + + /* middle steps like struct a -> struct b a_member; -> fptr */ + for (int i = 1; ptrtype && i < LLVMGetNumOperands(gep) - 1; i++) { + if (LLVMGetTypeKind(ptrtype) == LLVMPointerTypeKind + || LLVMGetTypeKind(ptrtype) == LLVMArrayTypeKind + || LLVMGetTypeKind(ptrtype) == LLVMVectorTypeKind) { + ptrtype = LLVMGetElementType(ptrtype); + continue; + } + + if (LLVMGetTypeKind(ptrtype) != LLVMStructTypeKind) + return false; + + idx = LLVMGetOperand(gep, i); + if (!LLVMIsConstant(idx)) + return false; + val = LLVMConstIntGetZExtValue(idx); + + unsigned n = LLVMGetNumContainedTypes(ptrtype); + LLVMTypeRef arr[n]; + + if (val > n) + return false; + + LLVMGetSubtypes(ptrtype, arr); + ptrtype = arr[val]; + } + + if (!ptrtype) + return false; + + idx = LLVMGetOperand(gep, LLVMGetNumOperands(gep) - 1); + if (!LLVMIsConstant(idx)) + return false; + + val = LLVMConstIntGetZExtValue(idx); + + char *sname = NULL, *mname = NULL; + + if (dbginfo_struct_member(dbginfo, ptrtype, val, &sname, &mname)) { + fprintf(stderr, "%s: call to struct %s->%s\n", prefix, sname, + mname); + + json_object_object_add(js_call, "type", + json_object_new_string("struct_memb")); + json_object_object_add(js_call, "struct", + json_object_new_string(sname)); + json_object_object_add(js_call, "member", + json_object_new_string(mname)); + ret = true; + } + free(sname); + free(mname); + + return ret; +} + +static bool details_fptr_vars = false; +static bool details_fptr_consts = true; + +enum called_fn { + FN_GENERIC = 0, + FN_NONAME, + FN_INSTALL_ELEMENT, + FN_THREAD_ADD, +}; + +static void walk_const_fptrs(struct json_object *js_call, LLVMValueRef value, + const char *prefix, bool *hdr_written) +{ + LLVMTypeRef type; + LLVMValueKind kind; + + if (LLVMIsAGlobalVariable(value)) { + type = LLVMGlobalGetValueType(value); + value = LLVMGetInitializer(value); + } else { + type = LLVMTypeOf(value); + } + + if (LLVMIsAFunction(value)) { + struct json_object *js_fptrs; + + js_fptrs = js_get_or_make(js_call, "funcptrs", + json_object_new_array); + + size_t fn_len; + const char *fn_name = LLVMGetValueName2(value, &fn_len); + + size_t curlen = json_object_array_length(js_fptrs); + struct json_object *jsobj; + const char *s; + + for (size_t i = 0; i < curlen; i++) { + jsobj = json_object_array_get_idx(js_fptrs, i); + s = json_object_get_string(jsobj); + + if (s && !strcmp(s, fn_name)) + return; + } + + if (details_fptr_consts && !*hdr_written) { + fprintf(stderr, + "%s: calls function pointer from constant or global data\n", + prefix); + *hdr_written = true; + } + if (details_fptr_consts) + fprintf(stderr, "%s- constant: %.*s()\n", + prefix, (int)fn_len, fn_name); + + json_object_array_add(js_fptrs, + json_object_new_string_len(fn_name, + fn_len)); + return; + } + + kind = LLVMGetValueKind(value); + + unsigned len; + char *dump; + + switch (kind) { + case LLVMUndefValueValueKind: + case LLVMConstantAggregateZeroValueKind: + case LLVMConstantPointerNullValueKind: + /* null pointer / array - ignore */ + break; + + case LLVMConstantIntValueKind: + /* integer - ignore */ + break; + + case LLVMConstantStructValueKind: + len = LLVMCountStructElementTypes(type); + for (unsigned i = 0; i < len; i++) + walk_const_fptrs(js_call, LLVMGetOperand(value, i), + prefix, hdr_written); + break; + + case LLVMConstantArrayValueKind: + len = LLVMGetArrayLength(type); + for (unsigned i = 0; i < len; i++) + walk_const_fptrs(js_call, LLVMGetOperand(value, i), + prefix, hdr_written); + return; + + case LLVMConstantExprValueKind: + switch (LLVMGetConstOpcode(value)) { + case LLVMGetElementPtr: + if (try_struct_fptr(js_call, value, prefix)) { + *hdr_written = true; + return; + } + + fprintf(stderr, + "%s: calls function pointer from unhandled const GEP\n", + prefix); + *hdr_written = true; + /* fallthru */ + default: + /* to help the user / development */ + if (!*hdr_written) { + fprintf(stderr, + "%s: calls function pointer from constexpr\n", + prefix); + *hdr_written = true; + } + dump = LLVMPrintValueToString(value); + fprintf(stderr, "%s- [opcode=%d] %s\n", prefix, + LLVMGetConstOpcode(value), dump); + LLVMDisposeMessage(dump); + } + return; + + default: + /* to help the user / development */ + if (!*hdr_written) { + fprintf(stderr, + "%s: calls function pointer from constant or global data\n", + prefix); + *hdr_written = true; + } + dump = LLVMPrintValueToString(value); + fprintf(stderr, + "%s- value could not be processed:\n" + "%s- [kind=%d] %s\n", + prefix, prefix, kind, dump); + LLVMDisposeMessage(dump); + return; + } + return; +} + +#ifdef FRR_SPECIFIC +static bool is_thread_sched(const char *name, size_t len) +{ +#define thread_prefix "_" + static const char *const names[] = { + thread_prefix "event_add_read_write", + thread_prefix "event_add_timer", + thread_prefix "event_add_timer_msec", + thread_prefix "event_add_timer_tv", + thread_prefix "event_add_event", + thread_prefix "event_execute", + }; + size_t i; + + for (i = 0; i < sizeof(names) / sizeof(names[0]); i++) { + if (strlen(names[i]) != len) + continue; + if (!memcmp(names[i], name, len)) + return true; + } + return false; +} +#endif + +static bool _check_val(bool cond, const char *text, LLVMValueRef dumpval) +{ + if (cond) + return true; + + char *dump = LLVMPrintValueToString(dumpval); + fprintf(stderr, "check failed: %s\ndump:\n\t%s\n", text, dump); + LLVMDisposeMessage(dump); + return false; +} + +#define check_val(cond, dump) \ + if (!_check_val(cond, #cond, dump)) \ + return; + +static char *get_string(LLVMValueRef value) +{ + if (!LLVMIsAConstant(value)) + return strdup("!NOT-A-CONST"); + + if (LLVMGetValueKind(value) == LLVMConstantExprValueKind + && LLVMGetConstOpcode(value) == LLVMGetElementPtr) { + value = LLVMGetOperand(value, 0); + + if (!LLVMIsAConstant(value)) + return strdup("!NOT-A-CONST-2"); + } + + if (LLVMIsAGlobalVariable(value)) + value = LLVMGetInitializer(value); + + size_t len = 0; + const char *sval = LLVMGetAsString(value, &len); + + return strndup(sval, len); +} + +static void handle_yang_module(struct json_object *js_special, + LLVMValueRef yang_mod) +{ + check_val(LLVMIsAGlobalVariable(yang_mod), yang_mod); + + LLVMValueRef value; + + value = LLVMGetInitializer(yang_mod); + LLVMValueKind kind = LLVMGetValueKind(value); + + check_val(kind == LLVMConstantStructValueKind, value); + + size_t var_len = 0; + const char *var_name = LLVMGetValueName2(yang_mod, &var_len); + char buf_name[var_len + 1]; + + memcpy(buf_name, var_name, var_len); + buf_name[var_len] = '\0'; + + struct json_object *js_yang, *js_yangmod, *js_items; + + js_yang = js_get_or_make(js_special, "yang", json_object_new_object); + js_yangmod = js_get_or_make(js_yang, buf_name, json_object_new_object); + js_items = js_get_or_make(js_yangmod, "items", json_object_new_array); + + char *mod_name = get_string(LLVMGetOperand(value, 0)); + json_object_object_add(js_yangmod, "name", + json_object_new_string(mod_name)); + free(mod_name); + + value = LLVMGetOperand(value, 1); + kind = LLVMGetValueKind(value); + check_val(kind == LLVMConstantArrayValueKind, value); + + unsigned len = LLVMGetArrayLength(LLVMTypeOf(value)); + + for (unsigned i = 0; i < len - 1; i++) { + struct json_object *js_item, *js_cbs; + LLVMValueRef item = LLVMGetOperand(value, i); + char *xpath = get_string(LLVMGetOperand(item, 0)); + + js_item = json_object_new_object(); + json_object_array_add(js_items, js_item); + + json_object_object_add(js_item, "xpath", + json_object_new_string(xpath)); + js_cbs = js_get_or_make(js_item, "cbs", json_object_new_object); + + free(xpath); + + LLVMValueRef cbs = LLVMGetOperand(item, 1); + + check_val(LLVMGetValueKind(cbs) == LLVMConstantStructValueKind, + value); + + LLVMTypeRef cbs_type = LLVMTypeOf(cbs); + unsigned cblen = LLVMCountStructElementTypes(cbs_type); + + for (unsigned i = 0; i < cblen; i++) { + LLVMValueRef cb = LLVMGetOperand(cbs, i); + + char *sname = NULL; + char *mname = NULL; + + if (dbginfo_struct_member(dbginfo, cbs_type, i, &sname, + &mname)) { + (void)0; + } + + if (LLVMIsAFunction(cb)) { + size_t fn_len; + const char *fn_name; + + fn_name = LLVMGetValueName2(cb, &fn_len); + + json_object_object_add( + js_cbs, mname, + json_object_new_string_len(fn_name, + fn_len)); + } + + free(sname); + free(mname); + } + } +} + +static void handle_daemoninfo(struct json_object *js_special, + LLVMValueRef daemoninfo) +{ + check_val(LLVMIsAGlobalVariable(daemoninfo), daemoninfo); + + LLVMTypeRef type; + LLVMValueRef value; + unsigned len; + + type = LLVMGlobalGetValueType(daemoninfo); + value = LLVMGetInitializer(daemoninfo); + LLVMValueKind kind = LLVMGetValueKind(value); + + check_val(kind == LLVMConstantStructValueKind, value); + + int yang_idx = -1; + + len = LLVMCountStructElementTypes(type); + + LLVMTypeRef fieldtypes[len]; + LLVMGetSubtypes(type, fieldtypes); + + for (unsigned i = 0; i < len; i++) { + LLVMTypeRef t = fieldtypes[i]; + + if (LLVMGetTypeKind(t) != LLVMPointerTypeKind) + continue; + t = LLVMGetElementType(t); + if (LLVMGetTypeKind(t) != LLVMPointerTypeKind) + continue; + t = LLVMGetElementType(t); + if (LLVMGetTypeKind(t) != LLVMStructTypeKind) + continue; + + const char *name = LLVMGetStructName(t); + if (!strcmp(name, "struct.frr_yang_module_info")) + yang_idx = i; + } + + if (yang_idx == -1) + return; + + LLVMValueRef yang_mods = LLVMGetOperand(value, yang_idx); + LLVMValueRef yang_size = LLVMGetOperand(value, yang_idx + 1); + + check_val(LLVMIsConstant(yang_size), yang_size); + + unsigned long long ival = LLVMConstIntGetZExtValue(yang_size); + + check_val(LLVMGetValueKind(yang_mods) == LLVMConstantExprValueKind + && LLVMGetConstOpcode(yang_mods) == LLVMGetElementPtr, + yang_mods); + + yang_mods = LLVMGetOperand(yang_mods, 0); + + check_val(LLVMIsAGlobalVariable(yang_mods), yang_mods); + + yang_mods = LLVMGetInitializer(yang_mods); + + check_val(LLVMGetValueKind(yang_mods) == LLVMConstantArrayValueKind, + yang_mods); + + len = LLVMGetArrayLength(LLVMTypeOf(yang_mods)); + + if (len != ival) + fprintf(stderr, "length mismatch - %llu vs. %u\n", ival, len); + + for (unsigned i = 0; i < len; i++) { + char *dump; + + LLVMValueRef item = LLVMGetOperand(yang_mods, i); + LLVMValueKind kind = LLVMGetValueKind(item); + + check_val(kind == LLVMGlobalVariableValueKind + || kind == LLVMConstantExprValueKind, + item); + + if (kind == LLVMGlobalVariableValueKind) + continue; + + LLVMOpcode opcode = LLVMGetConstOpcode(item); + switch (opcode) { + case LLVMBitCast: + item = LLVMGetOperand(item, 0); + handle_yang_module(js_special, item); + break; + + default: + dump = LLVMPrintValueToString(item); + printf("[%u] = [opcode=%u] %s\n", i, opcode, dump); + LLVMDisposeMessage(dump); + } + } +} + +static void process_call(struct json_object *js_calls, + struct json_object *js_special, + LLVMValueRef instr, + LLVMValueRef function) +{ + struct json_object *js_call, *js_fptrs = NULL; + + LLVMValueRef called = LLVMGetCalledValue(instr); + + if (LLVMIsAInlineAsm(called)) + return; + + if (LLVMIsAConstantExpr(called)) { + LLVMOpcode opcode = LLVMGetConstOpcode(called); + + if (opcode == LLVMBitCast) { + LLVMValueRef op0 = LLVMGetOperand(called, 0); + + if (LLVMIsAFunction(op0)) + called = op0; + } + } + + size_t called_len = 0; + const char *called_name = LLVMGetValueName2(called, &called_len); + unsigned n_args = LLVMGetNumArgOperands(instr); + + bool is_external = LLVMIsDeclaration(called); + + js_call = json_object_new_object(); + json_object_array_add(js_calls, js_call); + dbgloc_add(js_call, instr); + json_object_object_add(js_call, "is_external", + json_object_new_boolean(is_external)); + + if (!called_name || called_len == 0) { + json_object_object_add(js_call, "type", + json_object_new_string("indirect")); + + LLVMValueRef last = called; + + size_t name_len = 0; + const char *name_c = LLVMGetValueName2(function, &name_len); + +#ifdef FRR_SPECIFIC + /* information for FRR hooks is dumped for the registration + * in _hook_typecheck; we can safely ignore the funcptr here + */ + if (strncmp(name_c, "hook_call_", 10) == 0) + return; +#endif + + unsigned file_len = 0; + const char *file = LLVMGetDebugLocFilename(instr, &file_len); + unsigned line = LLVMGetDebugLocLine(instr); + + char prefix[256]; + snprintf(prefix, sizeof(prefix), "%.*s:%d:%.*s()", + (int)file_len, file, line, (int)name_len, name_c); + + if (LLVMIsALoadInst(called) + && LLVMIsAGetElementPtrInst(LLVMGetOperand(called, 0)) + && try_struct_fptr(js_call, LLVMGetOperand(called, 0), + prefix)) + goto out_struct_fptr; + + while (LLVMIsALoadInst(last) || LLVMIsAGetElementPtrInst(last)) + /* skipping over details for GEP here, but meh. */ + last = LLVMGetOperand(last, 0); + + if (LLVMIsAAllocaInst(last)) { + /* "alloca" is just generically all variables on the + * stack, this does not refer to C alloca() calls + * + * looking at the control flow in the function can + * give better results here, it's just not implemented + * (yet?) + */ + fprintf(stderr, + "%s: call to a function pointer variable\n", + prefix); + + if (details_fptr_vars) { + char *dump = LLVMPrintValueToString(called); + printf("%s- %s\n", prefix, dump); + LLVMDisposeMessage(dump); + } + + json_object_object_add( + js_call, "type", + json_object_new_string("stack_fptr")); + } else if (LLVMIsACallInst(last)) { + /* calling the a function pointer returned from + * another function. + */ + struct json_object *js_indirect; + + js_indirect = js_get_or_make(js_call, "return_of", + json_object_new_array); + + process_call(js_indirect, js_special, last, function); + } else if (LLVMIsAConstant(last)) { + /* function pointer is a constant (includes loading + * from complicated constants like structs or arrays.) + */ + bool hdr_written = false; + walk_const_fptrs(js_call, last, prefix, &hdr_written); + if (details_fptr_consts && !hdr_written) + fprintf(stderr, + "%s: calls function pointer from constant or global data, but no non-NULL function pointers found\n", + prefix); + } else { + char *dump = LLVMPrintValueToString(called); + fprintf(stderr, "%s: ??? %s\n", prefix, dump); + LLVMDisposeMessage(dump); + } +#ifdef FRR_SPECIFIC + } else if (!strcmp(called_name, "_install_element")) { + LLVMValueRef param0 = LLVMGetOperand(instr, 0); + if (!LLVMIsAConstantInt(param0)) + goto out_nonconst; + + long long vty_node = LLVMConstIntGetSExtValue(param0); + json_object_object_add(js_call, "vty_node", + json_object_new_int64(vty_node)); + + LLVMValueRef param1 = LLVMGetOperand(instr, 1); + if (!LLVMIsAGlobalVariable(param1)) + goto out_nonconst; + + LLVMValueRef intlz = LLVMGetInitializer(param1); + assert(intlz && LLVMIsConstant(intlz)); + + LLVMValueKind intlzkind = LLVMGetValueKind(intlz); + assert(intlzkind == LLVMConstantStructValueKind); + + LLVMValueRef funcptr = LLVMGetOperand(intlz, 4); + assert(LLVMIsAFunction(funcptr)); + + size_t target_len = 0; + const char *target; + target = LLVMGetValueName2(funcptr, &target_len); + + json_object_object_add( + js_call, "type", + json_object_new_string("install_element")); + json_object_object_add( + js_call, "target", + json_object_new_string_len(target, target_len)); + return; + + out_nonconst: + json_object_object_add( + js_call, "target", + json_object_new_string("install_element")); + return; + } else if (is_thread_sched(called_name, called_len)) { + json_object_object_add(js_call, "type", + json_object_new_string("thread_sched")); + json_object_object_add( + js_call, "subtype", + json_object_new_string_len(called_name, called_len)); + + LLVMValueRef fparam; + fparam = LLVMGetOperand(instr, 2); + assert(fparam); + + size_t target_len = 0; + const char *target; + target = LLVMGetValueName2(fparam, &target_len); + + json_object_object_add(js_call, "target", + !target_len ? NULL : + json_object_new_string_len(target, target_len)); + if (!LLVMIsAFunction(fparam)) + json_object_object_add(js_call, "target_unresolved", + json_object_new_boolean(true)); + return; + } else if (!strncmp(called_name, "_hook_typecheck_", + strlen("_hook_typecheck_"))) { + struct json_object *js_hook, *js_this; + const char *hook_name; + + hook_name = called_name + strlen("_hook_typecheck_"); + + json_object_object_add(js_call, "type", + json_object_new_string("hook")); + + LLVMValueRef param0 = LLVMGetOperand(instr, 0); + if (!LLVMIsAFunction(param0)) + return; + + size_t target_len = 0; + const char *target; + target = LLVMGetValueName2(param0, &target_len); + + js_hook = js_get_or_make(js_special, "hooks", + json_object_new_object); + js_hook = js_get_or_make(js_hook, hook_name, + json_object_new_array); + + js_this = json_object_new_object(); + json_object_array_add(js_hook, js_this); + + dbgloc_add(js_this, instr); + json_object_object_add( + js_this, "target", + json_object_new_string_len(target, target_len)); + return; + + /* TODO (FRR specifics): + * - workqueues - not sure we can do much there + * - zclient->* ? + */ +#endif /* FRR_SPECIFIC */ + } else if (!strcmp(called_name, "frr_preinit")) { + LLVMValueRef daemoninfo = LLVMGetOperand(instr, 0); + + handle_daemoninfo(js_special, daemoninfo); + + json_object_object_add( + js_call, "target", + json_object_new_string_len(called_name, called_len)); + } else { + json_object_object_add( + js_call, "target", + json_object_new_string_len(called_name, called_len)); + } + +out_struct_fptr: + for (unsigned argno = 0; argno < n_args; argno++) { + LLVMValueRef param = LLVMGetOperand(instr, argno); + size_t target_len; + const char *target_name; + + if (LLVMIsAFunction(param)) { + js_fptrs = js_get_or_make(js_call, "funcptrs", + json_object_new_array); + + target_name = LLVMGetValueName2(param, &target_len); + + json_object_array_add(js_fptrs, + json_object_new_string_len( + target_name, target_len)); + } + } +} + +static void process_fn(struct json_object *funcs, + struct json_object *js_special, + LLVMValueRef function) +{ + struct json_object *js_func, *js_calls; + + size_t name_len = 0; + const char *name_c = LLVMGetValueName2(function, &name_len); + char *name; + + name = strndup(name_c, name_len); + + js_func = json_object_object_get(funcs, name); + if (js_func) { + unsigned file_len = 0; + const char *file = LLVMGetDebugLocFilename(function, &file_len); + unsigned line = LLVMGetDebugLocLine(function); + + fprintf(stderr, "%.*s:%d:%s(): duplicate definition!\n", + (int)file_len, file, line, name); + free(name); + return; + } + + js_func = json_object_new_object(); + json_object_object_add(funcs, name, js_func); + free(name); + + js_calls = json_object_new_array(); + json_object_object_add(js_func, "calls", js_calls); + + dbgloc_add(js_func, function); + + for (LLVMBasicBlockRef basicBlock = LLVMGetFirstBasicBlock(function); + basicBlock; basicBlock = LLVMGetNextBasicBlock(basicBlock)) { + + for (LLVMValueRef instr = LLVMGetFirstInstruction(basicBlock); + instr; instr = LLVMGetNextInstruction(instr)) { + + if (LLVMIsAIntrinsicInst(instr)) + continue; + + if (LLVMIsACallInst(instr) || LLVMIsAInvokeInst(instr)) + process_call(js_calls, js_special, instr, + function); + } + } +} + +static void help(int retcode) +{ + fprintf(stderr, + "FRR LLVM bitcode to callgraph analyzer\n" + "\n" + "usage: frr-llvm-cg [-q|-v] [-o <JSONOUTPUT>] BITCODEINPUT\n" + "\n" + "\t-o FILENAME\twrite JSON output to file instead of stdout\n" + "\t-v\t\tbe more verbose\n" + "\t-q\t\tbe quiet\n" + "\n" + "BITCODEINPUT must be a LLVM binary bitcode file (not text\n" + "representation.) Use - to read from stdin.\n" + "\n" + "Note it may be necessary to build this binary tool against\n" + "the specific LLVM version that created the bitcode file.\n"); + exit(retcode); +} + +int main(int argc, char **argv) +{ + int opt; + const char *out = NULL; + const char *inp = NULL; + char v_or_q = '\0'; + + while ((opt = getopt(argc, argv, "hvqo:")) != -1) { + switch (opt) { + case 'o': + if (out) + help(1); + out = optarg; + break; + case 'v': + if (v_or_q && v_or_q != 'v') + help(1); + details_fptr_vars = true; + details_fptr_consts = true; + v_or_q = 'v'; + break; + case 'q': + if (v_or_q && v_or_q != 'q') + help(1); + details_fptr_vars = false; + details_fptr_consts = false; + v_or_q = 'q'; + break; + case 'h': + help(0); + return 0; + default: + help(1); + } + } + + if (optind != argc - 1) + help(1); + + inp = argv[optind]; + + LLVMMemoryBufferRef memoryBuffer; + char *message; + int ret; + + // check if we are to read our input file from stdin + if (!strcmp(inp, "-")) { + inp = "<stdin>"; + ret = LLVMCreateMemoryBufferWithSTDIN(&memoryBuffer, &message); + } else { + ret = LLVMCreateMemoryBufferWithContentsOfFile( + inp, &memoryBuffer, &message); + } + + if (ret) { + fprintf(stderr, "failed to open %s: %s\n", inp, message); + free(message); + return 1; + } + + // now create our module using the memorybuffer + LLVMModuleRef module; + if (LLVMParseBitcode2(memoryBuffer, &module)) { + fprintf(stderr, "%s: invalid bitcode\n", inp); + LLVMDisposeMemoryBuffer(memoryBuffer); + return 1; + } + + // done with the memory buffer now, so dispose of it + LLVMDisposeMemoryBuffer(memoryBuffer); + + dbginfo = dbginfo_load(module); + + struct json_object *js_root, *js_funcs, *js_special; + + js_root = json_object_new_object(); + js_funcs = json_object_new_object(); + json_object_object_add(js_root, "functions", js_funcs); + js_special = json_object_new_object(); + json_object_object_add(js_root, "special", js_special); + + // loop through all the functions in the module + for (LLVMValueRef function = LLVMGetFirstFunction(module); function; + function = LLVMGetNextFunction(function)) { + if (LLVMIsDeclaration(function)) + continue; + + process_fn(js_funcs, js_special, function); + } + + if (out) { + char tmpout[strlen(out) + 5]; + + snprintf(tmpout, sizeof(tmpout), "%s.tmp", out); + ret = json_object_to_file_ext(tmpout, js_root, + JSON_C_TO_STRING_PRETTY | + JSON_C_TO_STRING_PRETTY_TAB | + JSON_C_TO_STRING_NOSLASHESCAPE); + if (ret < 0) { + fprintf(stderr, "could not write JSON to file\n"); + return 1; + } + if (rename(tmpout, out)) { + fprintf(stderr, "could not rename JSON output: %s\n", + strerror(errno)); + unlink(tmpout); + return 1; + } + } else { + ret = json_object_to_fd(1, js_root, + JSON_C_TO_STRING_PRETTY | + JSON_C_TO_STRING_PRETTY_TAB | + JSON_C_TO_STRING_NOSLASHESCAPE); + if (ret < 0) { + fprintf(stderr, "could not write JSON to stdout\n"); + return 1; + } + } + + LLVMDisposeModule(module); + + return 0; +} |