Fix GetProgramName not contains absolute path from cmdline

src/brpc/builtin/common.cpp

@@ -339,17 +339,35 @@ static void CreateProgramName() {
         s_program_name = s_cmdline;
     }
 }
+
 const char* GetProgramName() {
     pthread_once(&create_program_name_once, CreateProgramName);
     return s_program_name;
 }
 
+static pthread_once_t create_program_path_once = PTHREAD_ONCE_INIT;
+static const char* s_program_path = "unknown";
+static char s_program_exec_path[PATH_MAX];
+static void CreateProgramPath() {
+    const ssize_t nr = butil::GetProcessAbsolutePath(s_program_exec_path, sizeof(s_program_exec_path) - 1);
+    if (nr > 0) {
+        s_program_exec_path[nr] = '\0';
+        s_program_path = s_program_exec_path;
+    }
+}
+
+const char* GetProgramPath() {
+    pthread_once(&create_program_path_once, CreateProgramPath);
+    return s_program_path;
+}
+
+
 static pthread_once_t compute_program_checksum_once = PTHREAD_ONCE_INIT;
 static char s_program_checksum[33];
 static const char s_alphabet[] = "0123456789abcdef";
 static void ComputeProgramCHECKSUM() {
     unsigned char checksum[16];
-    FileChecksum(GetProgramName(), checksum);
+    FileChecksum(GetProgramPath(), checksum);
     for (size_t i = 0, j = 0; i < 16; ++i, j+=2) {
         s_program_checksum[j] = s_alphabet[checksum[i] >> 4];
         s_program_checksum[j+1] = s_alphabet[checksum[i] & 0xF];

src/brpc/builtin/common.h

@@ -112,6 +112,9 @@ int FileChecksum(const char* file_path, unsigned char* checksum);
 // Get name of current program.
 const char* GetProgramName();
 
+// Get absolute path of current program.
+const char* GetProgramPath();
+
 // Get checksum of current program image.
 const char* GetProgramChecksum();
 

src/brpc/builtin/hotspots_service.cpp

@@ -493,7 +493,7 @@ static void DisplayResult(Controller* cntl,
         cmd_builder << "--base " << *base_name << ' ';
     }
 
-    cmd_builder << GetProgramName() << " " << prof_name;
+    cmd_builder << GetProgramPath() << " " << prof_name;
 
     if (display_type == DisplayType::kFlameGraph) {
         // For flamegraph, we don't care about pprof error msg, 
@@ -509,7 +509,7 @@ static void DisplayResult(Controller* cntl,
     if (base_name) {
         cmd_builder << "-base " << *base_name << ' ';
     }
-    cmd_builder << GetProgramName() << " " << prof_name << " 2>&1 ";
+    cmd_builder << GetProgramPath() << " " << prof_name << " 2>&1 ";
 #endif
 
     const std::string cmd = cmd_builder.str();

src/butil/process_util.cc

@@ -30,6 +30,9 @@
 #include "butil/popen.h"                // read_command_output
 #include "butil/process_util.h"
 
+#if defined(OS_MACOSX)
+#include <libproc.h>                   // proc_pidpath
+#endif
 namespace butil {
 
 ssize_t ReadCommandLine(char* buf, size_t len, bool with_args) {
@@ -85,4 +88,16 @@ ssize_t ReadCommandLine(char* buf, size_t len, bool with_args) {
     }
 }
 
+ssize_t GetProcessAbsolutePath(char *buf, size_t len) {
+#if defined(OS_LINUX)
+    memset(buf, 0, len);
+    ssize_t nr = readlink("/proc/self/exe", buf, len);
+    return nr;
+#elif defined(OS_MACOSX)
+    memset(buf, 0, len);
+    int ret = proc_pidpath(getpid(), buf, len);
+    return ret;
+#endif
+}
+
 } // namespace butil

src/butil/process_util.h

@@ -32,6 +32,11 @@ namespace butil {
 // NOTE: `buf' does not end with zero.
 ssize_t ReadCommandLine(char* buf, size_t len, bool with_args);
 
+// Get absolute path of this program.
+// Returns length of the absolute path on sucess, -1 otherwise.
+// NOTE: `buf' does not end with zero.
+ssize_t GetProcessAbsolutePath(char* buf, size_t len);
+
 } // namespace butil
 
 #endif // BUTIL_PROCESS_UTIL_H