str: add an overloaded startswith() utility method

for various string types and use it in a few places.

src/base/hostinfo.cc

@@ -45,6 +45,7 @@
 #include <string>
 
 #include "base/misc.hh"
+#include "base/str.hh"
 #include "base/types.hh"
 
 using namespace std;
@@ -77,7 +78,7 @@ procInfo(const char *filename, const char *target)
 
     while (fp && !feof(fp) && !done) {
         if (fgets(line, 80, fp)) {
-            if (strncmp(line, target, strlen(target)) == 0) {
+            if (startswith(line, target)) {
                 snprintf(format, sizeof(format), "%s %%ld", target);
                 sscanf(line, format, &usage);
 

src/base/str.hh

@@ -33,6 +33,7 @@
 #define __STR_HH__
 
 #include <cctype>
+#include <cstring>
 #include <sstream>
 #include <string>
 #include <vector>
@@ -140,4 +141,35 @@ quote(const std::string &s)
     return ret;
 }
 
+
+/**
+ * Return true if 's' starts with the prefix string 'prefix'.
+ */
+inline bool
+startswith(const char *s, const char *prefix)
+{
+    return (strncmp(s, prefix, strlen(prefix)) == 0);
+}
+
+
+/**
+ * Return true if 's' starts with the prefix string 'prefix'.
+ */
+inline bool
+startswith(const std::string &s, const char *prefix)
+{
+    return (s.compare(0, strlen(prefix), prefix) == 0);
+}
+
+
+/**
+ * Return true if 's' starts with the prefix string 'prefix'.
+ */
+inline bool
+startswith(const std::string &s, const std::string &prefix)
+{
+    return (s.compare(0, prefix.size(), prefix) == 0);
+}
+
+
 #endif //__STR_HH__

src/sim/syscall_emul.hh

@@ -640,8 +640,8 @@ openFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
     DPRINTF(SyscallVerbose, "opening file %s\n", path.c_str());
 
     int fd;
-    if (!path.compare(0, 6, "/proc/") || !path.compare(0, 8, "/system/") ||
-        !path.compare(0, 10, "/platform/") || !path.compare(0, 5, "/sys/")) {
+    if (startswith(path, "/proc/") || startswith(path, "/system/") ||
+        startswith(path, "/platform/") || startswith(path, "/sys/")) {
         // It's a proc/sys entery and requires special handling
         fd = OS::openSpecialFile(path, process, tc);
         return (fd == -1) ? -1 : process->alloc_fd(fd,path.c_str(),hostFlags,mode, false);

src/sim/system.cc

@@ -51,6 +51,7 @@
 #include "arch/vtophys.hh"
 #include "base/loader/object_file.hh"
 #include "base/loader/symtab.hh"
+#include "base/str.hh"
 #include "base/trace.hh"
 #include "config/the_isa.hh"
 #include "cpu/thread_context.hh"
@@ -402,8 +403,7 @@ MasterID
 System::getMasterId(std::string master_name)
 {
     // strip off system name if the string starts with it
-    if (master_name.size() > name().size() &&
-                          master_name.compare(0, name().size(), name()) == 0)
+    if (startswith(master_name, name()))
         master_name = master_name.erase(0, name().size() + 1);
 
     // CPUs in switch_cpus ask for ids again after switching