Prefix perror(3) messages with program name.

It make it easier while debugging to know who is reporting the error:
Ninja itself or one of the command called by Ninja during the build
process or one of the generator which called Ninja.

4 files changed, 8 insertions, 8 deletions

diff --git a/src/browse.cc b/src/browse.cc
index db89db0..f65e537 100644
--- a/src/browse.cc
+++ b/src/browse.cc
@@ -25,13 +25,13 @@ void RunBrowsePython(State* state, const char* ninja_command) {
   // (Actually the Python process becomes the parent.)
   int pipefd[2];
   if (pipe(pipefd) < 0) {
-    perror("pipe");
+    perror("ninja: pipe");
     return;
   }
 
   pid_t pid = fork();
   if (pid < 0) {
-    perror("fork");
+    perror("ninja: fork");
     return;
   }
 
@@ -39,7 +39,7 @@ void RunBrowsePython(State* state, const char* ninja_command) {
     close(pipefd[1]);
     do {
       if (dup2(pipefd[0], 0) < 0) {
-        perror("dup2");
+        perror("ninja: dup2");
         break;
       }
 
@@ -48,7 +48,7 @@ void RunBrowsePython(State* state, const char* ninja_command) {
         "python", "-", ninja_command, NULL
       };
       execvp(command[0], (char**)command);
-      perror("execvp");
+      perror("ninja: execvp");
     } while (false);
     _exit(1);
   } else {  // Child.
@@ -57,7 +57,7 @@ void RunBrowsePython(State* state, const char* ninja_command) {
     // Write the script file into the stdin of the Python process.
     ssize_t len = write(pipefd[1], kBrowsePy, sizeof(kBrowsePy));
     if (len < (ssize_t)sizeof(kBrowsePy))
-      perror("write");
+      perror("ninja: write");
     close(pipefd[1]);
     exit(0);
   }
diff --git a/src/ninja.cc b/src/ninja.cc
index 5e26f6a..cd64c84 100644
--- a/src/ninja.cc
+++ b/src/ninja.cc
@@ -186,7 +186,7 @@ int main(int argc, char** argv) {
 
   char cwd[PATH_MAX];
   if (!getcwd(cwd, sizeof(cwd))) {
-    perror("getcwd");
+    perror("ninja: getcwd");
     return 1;
   }
 
diff --git a/src/parsers.cc b/src/parsers.cc
index b9c1190..4aeb73c 100644
--- a/src/parsers.cc
+++ b/src/parsers.cc
@@ -291,7 +291,7 @@ bool ManifestParser::Parse(const string& input, string* err) {
           // XXX remove this hack, or make it more principled.
           char cwd[1024];
           if (!getcwd(cwd, sizeof(cwd))) {
-            perror("getcwd");
+            perror("ninja: getcwd");
             return 1;
           }
           value = cwd + value.substr(9);
diff --git a/src/subprocess.cc b/src/subprocess.cc
index 1043e65..cef0ad3 100644
--- a/src/subprocess.cc
+++ b/src/subprocess.cc
@@ -157,7 +157,7 @@ void SubprocessSet::DoWork() {
   int ret = poll(fds.data(), fds.size(), -1);
   if (ret == -1) {
     if (errno != EINTR)
-      perror("poll");
+      perror("ninja: poll");
     return;
   }