Use more std::string in fastboot.

Change-Id: Ic8c77eac1e0088627ab650050d9c97c5749e5c39
diff --git a/fastboot/engine.cpp b/fastboot/engine.cpp
index 47567c0..db5d0e0 100644
--- a/fastboot/engine.cpp
+++ b/fastboot/engine.cpp
@@ -351,21 +351,21 @@
         }
         if (a->op == OP_DOWNLOAD) {
             status = fb_download_data(transport, a->data, a->size);
-            status = a->func(a, status, status ? fb_get_error() : "");
+            status = a->func(a, status, status ? fb_get_error().c_str() : "");
             if (status) break;
         } else if (a->op == OP_COMMAND) {
             status = fb_command(transport, a->cmd);
-            status = a->func(a, status, status ? fb_get_error() : "");
+            status = a->func(a, status, status ? fb_get_error().c_str() : "");
             if (status) break;
         } else if (a->op == OP_QUERY) {
             status = fb_command_response(transport, a->cmd, resp);
-            status = a->func(a, status, status ? fb_get_error() : resp);
+            status = a->func(a, status, status ? fb_get_error().c_str() : resp);
             if (status) break;
         } else if (a->op == OP_NOTICE) {
             fprintf(stderr,"%s\n",(char*)a->data);
         } else if (a->op == OP_DOWNLOAD_SPARSE) {
             status = fb_download_data_sparse(transport, reinterpret_cast<sparse_file*>(a->data));
-            status = a->func(a, status, status ? fb_get_error() : "");
+            status = a->func(a, status, status ? fb_get_error().c_str() : "");
             if (status) break;
         } else if (a->op == OP_WAIT_FOR_DISCONNECT) {
             transport->WaitForDisconnect();
diff --git a/fastboot/fastboot.cpp b/fastboot/fastboot.cpp
index fa8f19a..94efcc3 100644
--- a/fastboot/fastboot.cpp
+++ b/fastboot/fastboot.cpp
@@ -49,6 +49,7 @@
 
 #include <android-base/parseint.h>
 #include <android-base/parsenetaddress.h>
+#include <android-base/stringprintf.h>
 #include <android-base/strings.h>
 #include <sparse/sparse.h>
 #include <ziparchive/zip_archive.h>
@@ -108,12 +109,9 @@
     {"vendor.img", "vendor.sig", "vendor", true},
 };
 
-static char* find_item(const char* item, const char* product) {
-    char *dir;
+static std::string find_item(const char* item, const char* product) {
     const char *fn;
-    char path[PATH_MAX + 128];
-
-    if(!strcmp(item,"boot")) {
+    if (!strcmp(item,"boot")) {
         fn = "boot.img";
     } else if(!strcmp(item,"recovery")) {
         fn = "recovery.img";
@@ -129,24 +127,22 @@
         fn = "android-info.txt";
     } else {
         fprintf(stderr,"unknown partition '%s'\n", item);
-        return 0;
+        return "";
     }
 
-    if(product) {
-        get_my_path(path);
-        sprintf(path + strlen(path),
-                "../../../target/product/%s/%s", product, fn);
-        return strdup(path);
+    if (product) {
+        std::string path = get_my_path();
+        path.erase(path.find_last_of('/'));
+        return android::base::StringPrintf("%s/../../../target/product/%s/%s",
+                                           path.c_str(), product, fn);
     }
 
-    dir = getenv("ANDROID_PRODUCT_OUT");
-    if((dir == 0) || (dir[0] == 0)) {
+    char* dir = getenv("ANDROID_PRODUCT_OUT");
+    if (dir == nullptr || dir[0] == '\0') {
         die("neither -p product specified nor ANDROID_PRODUCT_OUT set");
-        return 0;
     }
 
-    sprintf(path, "%s/%s", dir, fn);
-    return strdup(path);
+    return android::base::StringPrintf("%s/%s", dir, fn);
 }
 
 static int64_t get_file_size(int fd) {
@@ -179,8 +175,8 @@
     return 0;
 }
 
-static void* load_file(const char* fn, int64_t* sz) {
-    int fd = open(fn, O_RDONLY | O_BINARY);
+static void* load_file(const std::string& path, int64_t* sz) {
+    int fd = open(path.c_str(), O_RDONLY | O_BINARY);
     if (fd == -1) return nullptr;
     return load_fd(fd, sz);
 }
@@ -964,18 +960,19 @@
     CloseArchive(zip);
 }
 
-static void do_send_signature(char* fn) {
-    char* xtn = strrchr(fn, '.');
-    if (!xtn) return;
+static void do_send_signature(const char* filename) {
+    if (android::base::EndsWith(filename, ".img") == false) {
+        return;
+    }
 
-    if (strcmp(xtn, ".img")) return;
-
-    strcpy(xtn, ".sig");
+    std::string sig_path = filename;
+    sig_path.erase(sig_path.size() - 4);
+    sig_path += ".sig";
 
     int64_t sz;
-    void* data = load_file(fn, &sz);
-    strcpy(xtn, ".img");
+    void* data = load_file(sig_path, &sz);
     if (data == nullptr) return;
+
     fb_queue_download("signature", data, sz);
     fb_queue_command("signature", "installing signature");
 }
@@ -985,8 +982,8 @@
 
     fb_queue_query_save("product", cur_product, sizeof(cur_product));
 
-    char* fname = find_item("info", product);
-    if (fname == nullptr) die("cannot find android-info.txt");
+    std::string fname = find_item("info", product);
+    if (fname.empty()) die("cannot find android-info.txt");
 
     int64_t sz;
     void* data = load_file(fname, &sz);
@@ -997,14 +994,14 @@
     for (size_t i = 0; i < ARRAY_SIZE(images); i++) {
         fname = find_item(images[i].part_name, product);
         fastboot_buffer buf;
-        if (load_buf(transport, fname, &buf)) {
+        if (load_buf(transport, fname.c_str(), &buf)) {
             if (images[i].is_optional)
                 continue;
             die("could not load %s\n", images[i].img_name);
         }
 
         auto flashall = [&](const std::string &partition) {
-            do_send_signature(fname);
+            do_send_signature(fname.c_str());
             if (erase_first && needs_erase(transport, partition.c_str())) {
                 fb_queue_erase(partition.c_str());
             }
@@ -1180,7 +1177,7 @@
         fprintf(stderr, "Erase successful, but not automatically formatting.\n");
         if (errMsg) fprintf(stderr, "%s", errMsg);
     }
-    fprintf(stderr,"FAILED (%s)\n", fb_get_error());
+    fprintf(stderr, "FAILED (%s)\n", fb_get_error().c_str());
 }
 
 int main(int argc, char **argv)
@@ -1441,8 +1438,8 @@
             fb_queue_download("boot.img", data, sz);
             fb_queue_command("boot", "booting");
         } else if(!strcmp(*argv, "flash")) {
-            char *pname = argv[1];
-            char *fname = 0;
+            char* pname = argv[1];
+            std::string fname;
             require(2);
             if (argc > 2) {
                 fname = argv[2];
@@ -1451,13 +1448,13 @@
                 fname = find_item(pname, product);
                 skip(2);
             }
-            if (fname == 0) die("cannot determine image filename for '%s'", pname);
+            if (fname.empty()) die("cannot determine image filename for '%s'", pname);
 
             auto flash = [&](const std::string &partition) {
                 if (erase_first && needs_erase(transport, partition.c_str())) {
                     fb_queue_erase(partition.c_str());
                 }
-                do_flash(transport, partition.c_str(), fname);
+                do_flash(transport, partition.c_str(), fname.c_str());
             };
             do_for_partitions(transport, pname, slot_override.c_str(), flash, true);
         } else if(!strcmp(*argv, "flash:raw")) {
diff --git a/fastboot/fastboot.h b/fastboot/fastboot.h
index 1932bab..c2ea551 100644
--- a/fastboot/fastboot.h
+++ b/fastboot/fastboot.h
@@ -43,7 +43,7 @@
 int fb_command_response(Transport* transport, const char* cmd, char* response);
 int fb_download_data(Transport* transport, const void* data, uint32_t size);
 int fb_download_data_sparse(Transport* transport, struct sparse_file* s);
-char *fb_get_error(void);
+const std::string fb_get_error();
 
 #define FB_COMMAND_SZ 64
 #define FB_RESPONSE_SZ 64
@@ -72,7 +72,7 @@
 char *mkmsg(const char *fmt, ...);
 __attribute__((__noreturn__)) void die(const char *fmt, ...);
 
-void get_my_path(char *path);
+std::string get_my_path();
 
 /* Current product */
 extern char cur_product[FB_RESPONSE_SZ + 1];
diff --git a/fastboot/protocol.cpp b/fastboot/protocol.cpp
index 1785b76..bfa83b0 100644
--- a/fastboot/protocol.cpp
+++ b/fastboot/protocol.cpp
@@ -36,16 +36,16 @@
 
 #include <algorithm>
 
+#include <android-base/stringprintf.h>
 #include <sparse/sparse.h>
 
 #include "fastboot.h"
 #include "transport.h"
 
-static char ERROR[128];
+static std::string g_error;
 
-char *fb_get_error(void)
-{
-    return ERROR;
+const std::string fb_get_error() {
+    return g_error;
 }
 
 static int check_response(Transport* transport, uint32_t size, char* response) {
@@ -54,14 +54,14 @@
     while (true) {
         int r = transport->Read(status, 64);
         if (r < 0) {
-            snprintf(ERROR, sizeof(ERROR), "status read failed (%s)", strerror(errno));
+            g_error = android::base::StringPrintf("status read failed (%s)", strerror(errno));
             transport->Close();
             return -1;
         }
         status[r] = 0;
 
         if (r < 4) {
-            snprintf(ERROR, sizeof(ERROR), "status malformed (%d bytes)", r);
+            g_error = android::base::StringPrintf("status malformed (%d bytes)", r);
             transport->Close();
             return -1;
         }
@@ -80,9 +80,9 @@
 
         if (!memcmp(status, "FAIL", 4)) {
             if (r > 4) {
-                snprintf(ERROR, sizeof(ERROR), "remote: %s", status + 4);
+                g_error = android::base::StringPrintf("remote: %s", status + 4);
             } else {
-                strcpy(ERROR, "remote failure");
+                g_error = "remote failure";
             }
             return -1;
         }
@@ -90,14 +90,14 @@
         if (!memcmp(status, "DATA", 4) && size > 0){
             uint32_t dsize = strtol(status + 4, 0, 16);
             if (dsize > size) {
-                strcpy(ERROR, "data size too large");
+                g_error = android::base::StringPrintf("data size too large (%d)", dsize);
                 transport->Close();
                 return -1;
             }
             return dsize;
         }
 
-        strcpy(ERROR,"unknown status code");
+        g_error = "unknown status code";
         transport->Close();
         break;
     }
@@ -108,7 +108,7 @@
 static int _command_start(Transport* transport, const char* cmd, uint32_t size, char* response) {
     size_t cmdsize = strlen(cmd);
     if (cmdsize > 64) {
-        snprintf(ERROR, sizeof(ERROR), "command too large");
+        g_error = android::base::StringPrintf("command too large (%zu)", cmdsize);
         return -1;
     }
 
@@ -117,7 +117,7 @@
     }
 
     if (transport->Write(cmd, cmdsize) != static_cast<int>(cmdsize)) {
-        snprintf(ERROR, sizeof(ERROR), "command write failed (%s)", strerror(errno));
+        g_error = android::base::StringPrintf("command write failed (%s)", strerror(errno));
         transport->Close();
         return -1;
     }
@@ -128,12 +128,12 @@
 static int _command_data(Transport* transport, const void* data, uint32_t size) {
     int r = transport->Write(data, size);
     if (r < 0) {
-        snprintf(ERROR, sizeof(ERROR), "data transfer failure (%s)", strerror(errno));
+        g_error = android::base::StringPrintf("data transfer failure (%s)", strerror(errno));
         transport->Close();
         return -1;
     }
     if (r != ((int) size)) {
-        snprintf(ERROR, sizeof(ERROR), "data transfer failure (short transfer)");
+        g_error = "data transfer failure (short transfer)";
         transport->Close();
         return -1;
     }
@@ -216,7 +216,7 @@
 
     if (len > TRANSPORT_BUF_SIZE) {
         if (transport_buf_len > 0) {
-            snprintf(ERROR, sizeof(ERROR), "internal error: transport_buf not empty\n");
+            g_error = "internal error: transport_buf not empty";
             return -1;
         }
         to_write = round_down(len, TRANSPORT_BUF_SIZE);
@@ -230,7 +230,7 @@
 
     if (len > 0) {
         if (len > TRANSPORT_BUF_SIZE) {
-            snprintf(ERROR, sizeof(ERROR), "internal error: too much left for transport_buf\n");
+            g_error = "internal error: too much left for transport_buf";
             return -1;
         }
         memcpy(transport_buf, ptr, len);
diff --git a/fastboot/util_linux.cpp b/fastboot/util_linux.cpp
index b788199..2c6aedb 100644
--- a/fastboot/util_linux.cpp
+++ b/fastboot/util_linux.cpp
@@ -28,27 +28,16 @@
 
 #include "fastboot.h"
 
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <errno.h>
-#include <fcntl.h>
 #include <unistd.h>
 #include <limits.h>
 
-void get_my_path(char *path)
-{
-    char proc[64];
-    char *x;
+#include <android-base/stringprintf.h>
 
-    sprintf(proc, "/proc/%d/exe", getpid());
-    int err = readlink(proc, path, PATH_MAX - 1);
-
-    if(err <= 0) {
-        path[0] = 0;
-    } else {
-        path[err] = 0;
-        x = strrchr(path,'/');
-        if(x) x[1] = 0;
-    }
+std::string get_my_path() {
+    std::string proc = android::base::StringPrintf("/proc/%d/exe", getpid());
+    char path[PATH_MAX + 1];
+    int rc = readlink(proc.c_str(), path, sizeof(path) - 1);
+    if (rc == -1) return "";
+    path[rc] = '\0';
+    return path;
 }
diff --git a/fastboot/util_osx.cpp b/fastboot/util_osx.cpp
index ae0b024..4bae7c4 100644
--- a/fastboot/util_osx.cpp
+++ b/fastboot/util_osx.cpp
@@ -31,19 +31,15 @@
 #import <Carbon/Carbon.h>
 #include <unistd.h>
 
-void get_my_path(char s[PATH_MAX])
-{
+std::string get_my_path() {
     CFBundleRef mainBundle = CFBundleGetMainBundle();
     CFURLRef executableURL = CFBundleCopyExecutableURL(mainBundle);
     CFStringRef executablePathString = CFURLCopyFileSystemPath(executableURL, kCFURLPOSIXPathStyle);
     CFRelease(executableURL);
 
-    CFStringGetFileSystemRepresentation(executablePathString, s, PATH_MAX-1);
+    char path[PATH_MAX + 1];
+    CFStringGetFileSystemRepresentation(executablePathString, path, sizeof(PATH_MAX)-1);
     CFRelease(executablePathString);
 
-	char *x;
-    x = strrchr(s, '/');
-    if(x) x[1] = 0;
+    return path;
 }
-
-
diff --git a/fastboot/util_windows.cpp b/fastboot/util_windows.cpp
index ec52f39..3b22c55 100644
--- a/fastboot/util_windows.cpp
+++ b/fastboot/util_windows.cpp
@@ -38,14 +38,12 @@
 
 #include <windows.h>
 
-void get_my_path(char exe[PATH_MAX])
-{
-	char*  r;
+std::string get_my_path() {
+    char path[PATH_MAX + 1];
 
-	GetModuleFileName( NULL, exe, PATH_MAX-1 );
-	exe[PATH_MAX-1] = 0;
-	r = strrchr( exe, '\\' );
-	if (r)
-		*r = 0;
+    DWORD result = GetModuleFileName(NULL, path, sizeof(path) - 1);
+    if (result == 0 || result == sizeof(path) - 1) return "";
+    path[PATH_MAX - 1] = 0;
+
+    return path;
 }
-