logwrap: convert to C++, rename function logwrap_fork_execvp().
am: ff7d067ffa

Change-Id: I2ee848ca9fabc69b22b563e098b3dcc81d00a7e4
diff --git a/logwrapper/Android.bp b/logwrapper/Android.bp
index c378646..e360a85 100644
--- a/logwrapper/Android.bp
+++ b/logwrapper/Android.bp
@@ -13,11 +13,12 @@
     name: "liblogwrap",
     defaults: ["logwrapper_defaults"],
     recovery_available: true,
-    srcs: ["logwrap.c"],
+    srcs: ["logwrap.cpp"],
     shared_libs: [
         "libcutils",
         "liblog",
     ],
+    header_libs: ["libbase_headers"],
     export_include_dirs: ["include"],
     local_include_dirs: ["include"],
 }
@@ -31,9 +32,10 @@
     defaults: ["logwrapper_defaults"],
     local_include_dirs: ["include"],
     srcs: [
-        "logwrap.c",
-        "logwrapper.c",
+        "logwrap.cpp",
+        "logwrapper.cpp",
     ],
+    header_libs: ["libbase_headers"],
     shared_libs: ["libcutils", "liblog"],
 }
 
diff --git a/logwrapper/include/logwrap/logwrap.h b/logwrapper/include/logwrap/logwrap.h
index b1f6410..c329586 100644
--- a/logwrapper/include/logwrap/logwrap.h
+++ b/logwrapper/include/logwrap/logwrap.h
@@ -17,11 +17,6 @@
 
 #pragma once
 
-#include <stdbool.h>
-#include <stdint.h>
-
-__BEGIN_DECLS
-
 /*
  * Run a command while logging its stdout and stderr
  *
@@ -56,35 +51,32 @@
  *
  */
 
-/* Values for the log_target parameter android_fork_execvp_ext() */
+/* Values for the log_target parameter logwrap_fork_execvp() */
 #define LOG_NONE        0
 #define LOG_ALOG        1
 #define LOG_KLOG        2
 #define LOG_FILE        4
 
-int android_fork_execvp_ext2(int argc, char* argv[], int* status, bool forward_signals,
-                             int log_target, bool abbreviated, char* file_path);
+int logwrap_fork_execvp(int argc, const char* const* argv, int* status, bool forward_signals,
+                        int log_target, bool abbreviated, const char* file_path);
 
 // TODO: Actually deprecate this and the below.
 static inline int android_fork_execvp_ext(int argc, char* argv[], int* status, bool ignore_int_quit,
-                                          int log_target, bool abbreviated, char* file_path,
+                                          int log_target, bool abbreviated, const char* file_path,
                                           void* unused_opts, int unused_opts_len) {
     (void)ignore_int_quit;
     (void)unused_opts;
     (void)unused_opts_len;
-    return android_fork_execvp_ext2(argc, argv, status, false, log_target, abbreviated, file_path);
+    return logwrap_fork_execvp(argc, argv, status, false, log_target, abbreviated, file_path);
 }
 
 /* Similar to above, except abbreviated logging is not available, and if logwrap
  * is true, logging is to the Android system log, and if false, there is no
  * logging.
  */
-static inline int android_fork_execvp(int argc, char* argv[], int *status,
-                                     bool ignore_int_quit, bool logwrap)
-{
-    return android_fork_execvp_ext(argc, argv, status, ignore_int_quit,
-                                   (logwrap ? LOG_ALOG : LOG_NONE), false, NULL,
-                                   NULL, 0);
+static inline int android_fork_execvp(int argc, char* argv[], int* status, bool ignore_int_quit,
+                                      bool logwrap) {
+    (void)ignore_int_quit;
+    return logwrap_fork_execvp(argc, argv, status, false, (logwrap ? LOG_ALOG : LOG_NONE), false,
+                               nullptr);
 }
-
-__END_DECLS
diff --git a/logwrapper/logwrap.c b/logwrapper/logwrap.cpp
similarity index 77%
rename from logwrapper/logwrap.c
rename to logwrapper/logwrap.cpp
index 0314f37..5337801 100644
--- a/logwrapper/logwrap.c
+++ b/logwrapper/logwrap.cpp
@@ -19,7 +19,6 @@
 #include <libgen.h>
 #include <poll.h>
 #include <pthread.h>
-#include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -28,13 +27,13 @@
 #include <sys/wait.h>
 #include <unistd.h>
 
+#include <algorithm>
+
+#include <android-base/macros.h>
 #include <cutils/klog.h>
 #include <log/log.h>
 #include <logwrap/logwrap.h>
 
-#define ARRAY_SIZE(x)   (sizeof(x) / sizeof(*(x)))
-#define MIN(a,b) (((a)<(b))?(a):(b))
-
 static pthread_mutex_t fd_mutex = PTHREAD_MUTEX_INITIALIZER;
 // Protected by fd_mutex.  These signals must be blocked while modifying as well.
 static pid_t child_pid;
@@ -42,17 +41,17 @@
 static struct sigaction old_quit;
 static struct sigaction old_hup;
 
-#define ERROR(fmt, args...)                                                   \
-do {                                                                          \
-    fprintf(stderr, fmt, ## args);                                            \
-    ALOG(LOG_ERROR, "logwrapper", fmt, ## args);                              \
-} while(0)
+#define ERROR(fmt, args...)                         \
+    do {                                            \
+        fprintf(stderr, fmt, ##args);               \
+        ALOG(LOG_ERROR, "logwrapper", fmt, ##args); \
+    } while (0)
 
-#define FATAL_CHILD(fmt, args...)                                             \
-do {                                                                          \
-    ERROR(fmt, ## args);                                                      \
-    _exit(-1);                                                                \
-} while(0)
+#define FATAL_CHILD(fmt, args...) \
+    do {                          \
+        ERROR(fmt, ##args);       \
+        _exit(-1);                \
+    } while (0)
 
 #define MAX_KLOG_TAG 16
 
@@ -61,7 +60,7 @@
  */
 #define BEGINNING_BUF_SIZE 0x1000
 struct beginning_buf {
-    char *buf;
+    char* buf;
     size_t alloc_len;
     /* buf_size is the usable space, which is one less than the allocated size */
     size_t buf_size;
@@ -74,7 +73,7 @@
  */
 #define ENDING_BUF_SIZE 0x1000
 struct ending_buf {
-    char *buf;
+    char* buf;
     ssize_t alloc_len;
     /* buf_size is the usable space, which is one less than the allocated size */
     ssize_t buf_size;
@@ -84,7 +83,7 @@
     int write;
 };
 
- /* A structure to hold all the abbreviated buf data */
+/* A structure to hold all the abbreviated buf data */
 struct abbr_buf {
     struct beginning_buf b_buf;
     struct ending_buf e_buf;
@@ -95,19 +94,17 @@
 struct log_info {
     int log_target;
     char klog_fmt[MAX_KLOG_TAG * 2];
-    char *btag;
+    const char* btag;
     bool abbreviated;
-    FILE *fp;
+    FILE* fp;
     struct abbr_buf a_buf;
 };
 
 /* Forware declaration */
-static void add_line_to_abbr_buf(struct abbr_buf *a_buf, char *linebuf, int linelen);
+static void add_line_to_abbr_buf(struct abbr_buf* a_buf, char* linebuf, int linelen);
 
 /* Return 0 on success, and 1 when full */
-static int add_line_to_linear_buf(struct beginning_buf *b_buf,
-                                   char *line, ssize_t line_len)
-{
+static int add_line_to_linear_buf(struct beginning_buf* b_buf, char* line, ssize_t line_len) {
     int full = 0;
 
     if ((line_len + b_buf->used_len) > b_buf->buf_size) {
@@ -121,20 +118,18 @@
     return full;
 }
 
-static void add_line_to_circular_buf(struct ending_buf *e_buf,
-                                     char *line, ssize_t line_len)
-{
+static void add_line_to_circular_buf(struct ending_buf* e_buf, char* line, ssize_t line_len) {
     ssize_t free_len;
     ssize_t needed_space;
     int cnt;
 
-    if (e_buf->buf == NULL) {
+    if (e_buf->buf == nullptr) {
         return;
     }
 
-   if (line_len > e_buf->buf_size) {
-       return;
-   }
+    if (line_len > e_buf->buf_size) {
+        return;
+    }
 
     free_len = e_buf->buf_size - e_buf->used_len;
 
@@ -149,7 +144,7 @@
     /* Copy the line into the circular buffer, dealing with possible
      * wraparound.
      */
-    cnt = MIN(line_len, e_buf->buf_size - e_buf->write);
+    cnt = std::min(line_len, e_buf->buf_size - e_buf->write);
     memcpy(e_buf->buf + e_buf->write, line, cnt);
     if (cnt < line_len) {
         memcpy(e_buf->buf, line + cnt, line_len - cnt);
@@ -159,7 +154,7 @@
 }
 
 /* Log directly to the specified log */
-static void do_log_line(struct log_info *log_info, char *line) {
+static void do_log_line(struct log_info* log_info, const char* line) {
     if (log_info->log_target & LOG_KLOG) {
         klog_write(6, log_info->klog_fmt, line);
     }
@@ -174,7 +169,7 @@
 /* Log to either the abbreviated buf, or directly to the specified log
  * via do_log_line() above.
  */
-static void log_line(struct log_info *log_info, char *line, int len) {
+static void log_line(struct log_info* log_info, char* line, int len) {
     if (log_info->abbreviated) {
         add_line_to_abbr_buf(&log_info->a_buf, line, len);
     } else {
@@ -189,9 +184,8 @@
  * than buf_size (the usable size of the buffer) to make sure there is
  * room to temporarily stuff a null byte to terminate a line for logging.
  */
-static void print_buf_lines(struct log_info *log_info, char *buf, int buf_size)
-{
-    char *line_start;
+static void print_buf_lines(struct log_info* log_info, char* buf, int buf_size) {
+    char* line_start;
     char c;
     int i;
 
@@ -217,17 +211,17 @@
      */
 }
 
-static void init_abbr_buf(struct abbr_buf *a_buf) {
-    char *new_buf;
+static void init_abbr_buf(struct abbr_buf* a_buf) {
+    char* new_buf;
 
     memset(a_buf, 0, sizeof(struct abbr_buf));
-    new_buf = malloc(BEGINNING_BUF_SIZE);
+    new_buf = static_cast<char*>(malloc(BEGINNING_BUF_SIZE));
     if (new_buf) {
         a_buf->b_buf.buf = new_buf;
         a_buf->b_buf.alloc_len = BEGINNING_BUF_SIZE;
         a_buf->b_buf.buf_size = BEGINNING_BUF_SIZE - 1;
     }
-    new_buf = malloc(ENDING_BUF_SIZE);
+    new_buf = static_cast<char*>(malloc(ENDING_BUF_SIZE));
     if (new_buf) {
         a_buf->e_buf.buf = new_buf;
         a_buf->e_buf.alloc_len = ENDING_BUF_SIZE;
@@ -235,23 +229,22 @@
     }
 }
 
-static void free_abbr_buf(struct abbr_buf *a_buf) {
+static void free_abbr_buf(struct abbr_buf* a_buf) {
     free(a_buf->b_buf.buf);
     free(a_buf->e_buf.buf);
 }
 
-static void add_line_to_abbr_buf(struct abbr_buf *a_buf, char *linebuf, int linelen) {
+static void add_line_to_abbr_buf(struct abbr_buf* a_buf, char* linebuf, int linelen) {
     if (!a_buf->beginning_buf_full) {
-        a_buf->beginning_buf_full =
-            add_line_to_linear_buf(&a_buf->b_buf, linebuf, linelen);
+        a_buf->beginning_buf_full = add_line_to_linear_buf(&a_buf->b_buf, linebuf, linelen);
     }
     if (a_buf->beginning_buf_full) {
         add_line_to_circular_buf(&a_buf->e_buf, linebuf, linelen);
     }
 }
 
-static void print_abbr_buf(struct log_info *log_info) {
-    struct abbr_buf *a_buf = &log_info->a_buf;
+static void print_abbr_buf(struct log_info* log_info) {
+    struct abbr_buf* a_buf = &log_info->a_buf;
 
     /* Add the abbreviated output to the kernel log */
     if (a_buf->b_buf.alloc_len) {
@@ -274,14 +267,13 @@
      * and then cal print_buf_lines on it */
     if (a_buf->e_buf.read < a_buf->e_buf.write) {
         /* no wrap around, just print it */
-        print_buf_lines(log_info, a_buf->e_buf.buf + a_buf->e_buf.read,
-                        a_buf->e_buf.used_len);
+        print_buf_lines(log_info, a_buf->e_buf.buf + a_buf->e_buf.read, a_buf->e_buf.used_len);
     } else {
         /* The circular buffer will always have at least 1 byte unused,
          * so by allocating alloc_len here we will have at least
          * 1 byte of space available as required by print_buf_lines().
          */
-        char * nbuf = malloc(a_buf->e_buf.alloc_len);
+        char* nbuf = static_cast<char*>(malloc(a_buf->e_buf.alloc_len));
         if (!nbuf) {
             return;
         }
@@ -307,7 +299,7 @@
 }
 
 static void unblock_signals(sigset_t* oldset) {
-    pthread_sigmask(SIG_SETMASK, oldset, NULL);
+    pthread_sigmask(SIG_SETMASK, oldset, nullptr);
 }
 
 static void setup_signal_handlers(pid_t pid) {
@@ -320,9 +312,9 @@
 }
 
 static void restore_signal_handlers() {
-    sigaction(SIGINT, &old_int, NULL);
-    sigaction(SIGQUIT, &old_quit, NULL);
-    sigaction(SIGHUP, &old_hup, NULL);
+    sigaction(SIGINT, &old_int, nullptr);
+    sigaction(SIGQUIT, &old_quit, nullptr);
+    sigaction(SIGHUP, &old_hup, nullptr);
     child_pid = 0;
 }
 
@@ -334,14 +326,14 @@
 }
 
 static int parent(const char* tag, int parent_read, pid_t pid, int* chld_sts, int log_target,
-                  bool abbreviated, char* file_path, bool forward_signals) {
+                  bool abbreviated, const char* file_path, bool forward_signals) {
     int status = 0;
     char buffer[4096];
     struct pollfd poll_fds[] = {
-        [0] = {
-            .fd = parent_read,
-            .events = POLLIN,
-        },
+            {
+                    .fd = parent_read,
+                    .events = POLLIN,
+            },
     };
     int rc = 0;
     int fd;
@@ -361,7 +353,7 @@
 
     log_info.btag = basename(tag);
     if (!log_info.btag) {
-        log_info.btag = (char*) tag;
+        log_info.btag = tag;
     }
 
     if (abbreviated && (log_target == LOG_NONE)) {
@@ -372,8 +364,8 @@
     }
 
     if (log_target & LOG_KLOG) {
-        snprintf(log_info.klog_fmt, sizeof(log_info.klog_fmt),
-                 "<6>%.*s: %%s\n", MAX_KLOG_TAG, log_info.btag);
+        snprintf(log_info.klog_fmt, sizeof(log_info.klog_fmt), "<6>%.*s: %%s\n", MAX_KLOG_TAG,
+                 log_info.btag);
     }
 
     if ((log_target & LOG_FILE) && !file_path) {
@@ -397,7 +389,7 @@
 
     while (!found_child) {
         int timeout = received_messages ? -1 : 1000;
-        if (TEMP_FAILURE_RETRY(poll(poll_fds, ARRAY_SIZE(poll_fds), timeout)) < 0) {
+        if (TEMP_FAILURE_RETRY(poll(poll_fds, arraysize(poll_fds), timeout)) < 0) {
             ERROR("poll failed\n");
             rc = -1;
             goto err_poll;
@@ -405,8 +397,7 @@
 
         if (poll_fds[0].revents & POLLIN) {
             received_messages = true;
-            sz = TEMP_FAILURE_RETRY(
-                read(parent_read, &buffer[b], sizeof(buffer) - 1 - b));
+            sz = TEMP_FAILURE_RETRY(read(parent_read, &buffer[b], sizeof(buffer) - 1 - b));
 
             sz += b;
             // Log one line at a time
@@ -479,19 +470,19 @@
         }
     }
 
-    if (chld_sts != NULL) {
+    if (chld_sts != nullptr) {
         *chld_sts = status;
     } else {
-      if (WIFEXITED(status))
-        rc = WEXITSTATUS(status);
-      else
-        rc = -ECHILD;
+        if (WIFEXITED(status))
+            rc = WEXITSTATUS(status);
+        else
+            rc = -ECHILD;
     }
 
     // Flush remaining data
     if (a != b) {
-      buffer[b] = '\0';
-      log_line(&log_info, &buffer[a], b - a);
+        buffer[b] = '\0';
+        log_line(&log_info, &buffer[a], b - a);
     }
 
     /* All the output has been processed, time to dump the abbreviated output */
@@ -500,21 +491,21 @@
     }
 
     if (WIFEXITED(status)) {
-      if (WEXITSTATUS(status)) {
-        snprintf(tmpbuf, sizeof(tmpbuf),
-                 "%s terminated by exit(%d)\n", log_info.btag, WEXITSTATUS(status));
-        do_log_line(&log_info, tmpbuf);
-      }
+        if (WEXITSTATUS(status)) {
+            snprintf(tmpbuf, sizeof(tmpbuf), "%s terminated by exit(%d)\n", log_info.btag,
+                     WEXITSTATUS(status));
+            do_log_line(&log_info, tmpbuf);
+        }
     } else {
-      if (WIFSIGNALED(status)) {
-        snprintf(tmpbuf, sizeof(tmpbuf),
-                       "%s terminated by signal %d\n", log_info.btag, WTERMSIG(status));
-        do_log_line(&log_info, tmpbuf);
-      } else if (WIFSTOPPED(status)) {
-        snprintf(tmpbuf, sizeof(tmpbuf),
-                       "%s stopped by signal %d\n", log_info.btag, WSTOPSIG(status));
-        do_log_line(&log_info, tmpbuf);
-      }
+        if (WIFSIGNALED(status)) {
+            snprintf(tmpbuf, sizeof(tmpbuf), "%s terminated by signal %d\n", log_info.btag,
+                     WTERMSIG(status));
+            do_log_line(&log_info, tmpbuf);
+        } else if (WIFSTOPPED(status)) {
+            snprintf(tmpbuf, sizeof(tmpbuf), "%s stopped by signal %d\n", log_info.btag,
+                     WSTOPSIG(status));
+            do_log_line(&log_info, tmpbuf);
+        }
     }
 
 err_waitpid:
@@ -528,23 +519,21 @@
     return rc;
 }
 
-static void child(int argc, char* argv[]) {
+static void child(int argc, const char* const* argv) {
     // create null terminated argv_child array
     char* argv_child[argc + 1];
-    memcpy(argv_child, argv, argc * sizeof(char *));
-    argv_child[argc] = NULL;
+    memcpy(argv_child, argv, argc * sizeof(char*));
+    argv_child[argc] = nullptr;
 
     if (execvp(argv_child[0], argv_child)) {
-        FATAL_CHILD("executing %s failed: %s\n", argv_child[0],
-                strerror(errno));
+        FATAL_CHILD("executing %s failed: %s\n", argv_child[0], strerror(errno));
     }
 }
 
-int android_fork_execvp_ext2(int argc, char* argv[], int* status, bool forward_signals,
-                             int log_target, bool abbreviated, char* file_path) {
+int logwrap_fork_execvp(int argc, const char* const* argv, int* status, bool forward_signals,
+                        int log_target, bool abbreviated, const char* file_path) {
     pid_t pid;
     int parent_ptty;
-    sigset_t blockset;
     sigset_t oldset;
     int rc = 0;
 
@@ -564,7 +553,7 @@
 
     char child_devname[64];
     if (grantpt(parent_ptty) || unlockpt(parent_ptty) ||
-            ptsname_r(parent_ptty, child_devname, sizeof(child_devname)) != 0) {
+        ptsname_r(parent_ptty, child_devname, sizeof(child_devname)) != 0) {
         ERROR("Problem with /dev/ptmx\n");
         rc = -1;
         goto err_ptty;
@@ -582,7 +571,9 @@
         goto err_fork;
     } else if (pid == 0) {
         pthread_mutex_unlock(&fd_mutex);
-        unblock_signals(&oldset);
+        if (forward_signals) {
+            unblock_signals(&oldset);
+        }
 
         setsid();
 
diff --git a/logwrapper/logwrapper.c b/logwrapper/logwrapper.cpp
similarity index 63%
rename from logwrapper/logwrapper.c
rename to logwrapper/logwrapper.cpp
index e786609..7118d12 100644
--- a/logwrapper/logwrapper.c
+++ b/logwrapper/logwrapper.cpp
@@ -24,27 +24,26 @@
 #include <log/log.h>
 #include <logwrap/logwrap.h>
 
-void fatal(const char *msg) {
+void fatal(const char* msg) {
     fprintf(stderr, "%s", msg);
     ALOG(LOG_ERROR, "logwrapper", "%s", msg);
     exit(-1);
 }
 
 void usage() {
-    fatal(
-        "Usage: logwrapper [-a] [-d] [-k] BINARY [ARGS ...]\n"
-        "\n"
-        "Forks and executes BINARY ARGS, redirecting stdout and stderr to\n"
-        "the Android logging system. Tag is set to BINARY, priority is\n"
-        "always LOG_INFO.\n"
-        "\n"
-        "-a: Causes logwrapper to do abbreviated logging.\n"
-        "    This logs up to the first 4K and last 4K of the command\n"
-        "    being run, and logs the output when the command exits\n"
-        "-d: Causes logwrapper to SIGSEGV when BINARY terminates\n"
-        "    fault address is set to the status of wait()\n"
-        "-k: Causes logwrapper to log to the kernel log instead of\n"
-        "    the Android system log\n");
+    fatal("Usage: logwrapper [-a] [-d] [-k] BINARY [ARGS ...]\n"
+          "\n"
+          "Forks and executes BINARY ARGS, redirecting stdout and stderr to\n"
+          "the Android logging system. Tag is set to BINARY, priority is\n"
+          "always LOG_INFO.\n"
+          "\n"
+          "-a: Causes logwrapper to do abbreviated logging.\n"
+          "    This logs up to the first 4K and last 4K of the command\n"
+          "    being run, and logs the output when the command exits\n"
+          "-d: Causes logwrapper to SIGSEGV when BINARY terminates\n"
+          "    fault address is set to the status of wait()\n"
+          "-k: Causes logwrapper to log to the kernel log instead of\n"
+          "    the Android system log\n");
 }
 
 int main(int argc, char* argv[]) {
@@ -69,7 +68,7 @@
                 break;
             case '?':
             default:
-              usage();
+                usage();
         }
     }
     argc -= optind;
@@ -79,7 +78,7 @@
         usage();
     }
 
-    rc = android_fork_execvp_ext2(argc, &argv[0], &status, true, log_target, abbreviated, NULL);
+    rc = logwrap_fork_execvp(argc, &argv[0], &status, true, log_target, abbreviated, nullptr);
     if (!rc) {
         if (WIFEXITED(status))
             rc = WEXITSTATUS(status);
@@ -88,8 +87,8 @@
     }
 
     if (seg_fault_on_exit) {
-        uintptr_t fault_address = (uintptr_t) status;
-        *(int *) fault_address = 0;  // causes SIGSEGV with fault_address = status
+        uintptr_t fault_address = (uintptr_t)status;
+        *(int*)fault_address = 0;  // causes SIGSEGV with fault_address = status
     }
 
     return rc;