[PATCH v1 1/8] gdb/linux-tdep: use pid_t consistently for process IDs

[Matthieu Longo <matthieu.longo@arm.com>]

Use `pid_t' consistently instead of a mix of `pid_t', `int', and `long'
when representing process IDs in gdb/linux-tdep.c.

Also change inferior::pid to `pid_t' so that the inferior's process ID
uses the appropriate type throughout GDB.

Finally, factor out path templates "/proc/%d/{maps,smaps}" into named
constants.
---
 gdb/inferior.h   |  2 +-
 gdb/linux-tdep.c | 41 ++++++++++++++++++++---------------------
 2 files changed, 21 insertions(+), 22 deletions(-)

diff --git a/gdb/inferior.h b/gdb/inferior.h
index 9c031035a23..dc71cbdb264 100644
--- a/gdb/inferior.h
+++ b/gdb/inferior.h
@@ -590,7 +590,7 @@ class inferior : public refcounted_object,
 
   /* Actual target inferior id, usually, a process id.  This matches
      the ptid_t.pid member of threads of this inferior.  */
-  int pid = 0;
+  pid_t pid = 0;
   /* True if the PID was actually faked by GDB.  */
   bool fake_pid_p = false;
 
diff --git a/gdb/linux-tdep.c b/gdb/linux-tdep.c
index d5b0e6e7011..9f8f9f1af5e 100644
--- a/gdb/linux-tdep.c
+++ b/gdb/linux-tdep.c
@@ -48,6 +48,9 @@
 
 #include <algorithm>
 
+constexpr const char *PROC_PID_SMAPS = "/proc/%d/smaps";
+constexpr const char *PROC_PID_MAPS = "/proc/%d/maps";
+
 /* This enum represents the values that the user can choose when
    informing the Linux kernel about which memory mappings will be
    dumped in a corefile.  They are described in the file
@@ -842,9 +845,7 @@ static void
 linux_info_proc (struct gdbarch *gdbarch, const char *args,
 		 enum info_proc_what what)
 {
-  /* A long is used for pid instead of an int to avoid a loss of precision
-     compiler warning from the output of strtoul.  */
-  long pid;
+  pid_t pid;
   int cmdline_f = (what == IP_MINIMAL || what == IP_CMDLINE || what == IP_ALL);
   int cwd_f = (what == IP_MINIMAL || what == IP_CWD || what == IP_ALL);
   int environ_f = (what == IP_ENVIRON || what == IP_ALL);
@@ -876,10 +877,10 @@ linux_info_proc (struct gdbarch *gdbarch, const char *args,
   if (args && args[0])
     error (_("Too many parameters: %s"), args);
 
-  gdb_printf (_("process %ld\n"), pid);
+  gdb_printf (_("process %d\n"), pid);
   if (cmdline_f)
     {
-      xsnprintf (filename, sizeof filename, "/proc/%ld/cmdline", pid);
+      xsnprintf (filename, sizeof filename, "/proc/%d/cmdline", pid);
       gdb_byte *buffer;
       LONGEST len = target_fileio_read_alloc (nullptr, filename, &buffer);
 
@@ -901,7 +902,7 @@ linux_info_proc (struct gdbarch *gdbarch, const char *args,
     }
   if (cwd_f)
     {
-      xsnprintf (filename, sizeof filename, "/proc/%ld/cwd", pid);
+      xsnprintf (filename, sizeof filename, "/proc/%d/cwd", pid);
       std::optional<std::string> contents
 	= target_fileio_readlink (NULL, filename, &target_errno);
       if (contents.has_value ())
@@ -911,7 +912,7 @@ linux_info_proc (struct gdbarch *gdbarch, const char *args,
     }
   if (environ_f)
     {
-      xsnprintf (filename, sizeof filename, "/proc/%ld/environ", pid);
+      xsnprintf (filename, sizeof filename, "/proc/%d/environ", pid);
       gdb_byte *buffer;
       LONGEST len = target_fileio_read_alloc (nullptr, filename, &buffer);
 
@@ -935,7 +936,7 @@ linux_info_proc (struct gdbarch *gdbarch, const char *args,
     }
   if (exe_f)
     {
-      xsnprintf (filename, sizeof filename, "/proc/%ld/exe", pid);
+      xsnprintf (filename, sizeof filename, "/proc/%d/exe", pid);
       std::optional<std::string> contents
 	= target_fileio_readlink (NULL, filename, &target_errno);
       if (contents.has_value ())
@@ -945,7 +946,7 @@ linux_info_proc (struct gdbarch *gdbarch, const char *args,
     }
   if (mappings_f)
     {
-      xsnprintf (filename, sizeof filename, "/proc/%ld/maps", pid);
+      xsnprintf (filename, sizeof filename, "/proc/%d/maps", pid);
       gdb::unique_xmalloc_ptr<char> map
 	= target_fileio_read_stralloc (NULL, filename);
       if (map != NULL)
@@ -990,7 +991,7 @@ linux_info_proc (struct gdbarch *gdbarch, const char *args,
     }
   if (status_f)
     {
-      xsnprintf (filename, sizeof filename, "/proc/%ld/status", pid);
+      xsnprintf (filename, sizeof filename, "/proc/%d/status", pid);
       gdb::unique_xmalloc_ptr<char> status
 	= target_fileio_read_stralloc (NULL, filename);
       if (status)
@@ -1000,7 +1001,7 @@ linux_info_proc (struct gdbarch *gdbarch, const char *args,
     }
   if (stat_f)
     {
-      xsnprintf (filename, sizeof filename, "/proc/%ld/stat", pid);
+      xsnprintf (filename, sizeof filename, "/proc/%d/stat", pid);
       gdb::unique_xmalloc_ptr<char> statstr
 	= target_fileio_read_stralloc (NULL, filename);
       if (statstr)
@@ -1673,7 +1674,7 @@ linux_process_address_in_memtag_page (CORE_ADDR address)
 
   pid_t pid = current_inferior ()->pid;
 
-  std::string smaps_file = string_printf ("/proc/%d/smaps", pid);
+  std::string smaps_file = string_printf (PROC_PID_SMAPS, pid);
 
   gdb::unique_xmalloc_ptr<char> data
     = target_fileio_read_stralloc (NULL, smaps_file.c_str ());
@@ -1731,7 +1732,6 @@ linux_find_memory_regions_full (struct gdbarch *gdbarch,
 				linux_dump_mapping_p_ftype *should_dump_mapping_p,
 				linux_find_memory_region_ftype func)
 {
-  pid_t pid;
   /* Default dump behavior of coredump_filter (0x33), according to
      Documentation/filesystems/proc.txt from the Linux kernel
      tree.  */
@@ -1744,7 +1744,7 @@ linux_find_memory_regions_full (struct gdbarch *gdbarch,
   if (current_inferior ()->fake_pid_p)
     return false;
 
-  pid = current_inferior ()->pid;
+  pid_t pid = current_inferior ()->pid;
 
   if (use_coredump_filter)
     {
@@ -1763,7 +1763,7 @@ linux_find_memory_regions_full (struct gdbarch *gdbarch,
 	}
     }
 
-  std::string maps_filename = string_printf ("/proc/%d/smaps", pid);
+  std::string maps_filename = string_printf (PROC_PID_SMAPS, pid);
 
   gdb::unique_xmalloc_ptr<char> data
     = target_fileio_read_stralloc (NULL, maps_filename.c_str ());
@@ -1771,7 +1771,7 @@ linux_find_memory_regions_full (struct gdbarch *gdbarch,
   if (data == NULL)
     {
       /* Older Linux kernels did not support /proc/PID/smaps.  */
-      maps_filename = string_printf ("/proc/%d/maps", pid);
+      maps_filename = string_printf (PROC_PID_MAPS, pid);
       data = target_fileio_read_stralloc (NULL, maps_filename.c_str ());
 
       if (data == nullptr)
@@ -2805,7 +2805,6 @@ static bool
 linux_vsyscall_range_raw (struct gdbarch *gdbarch, struct mem_range *range)
 {
   char filename[100];
-  long pid;
 
   if (target_auxv_search (AT_SYSINFO_EHDR, &range->start) <= 0)
     return false;
@@ -2844,7 +2843,7 @@ linux_vsyscall_range_raw (struct gdbarch *gdbarch, struct mem_range *range)
   if (current_inferior ()->fake_pid_p)
     return false;
 
-  pid = current_inferior ()->pid;
+  pid_t pid = current_inferior ()->pid;
 
   /* Note that reading /proc/PID/task/PID/maps (1) is much faster than
      reading /proc/PID/maps (2).  The later identifies thread stacks
@@ -2854,7 +2853,7 @@ linux_vsyscall_range_raw (struct gdbarch *gdbarch, struct mem_range *range)
      a few thousand threads, (1) takes a few milliseconds, while (2)
      takes several seconds.  Also note that "smaps", what we read for
      determining core dump mappings, is even slower than "maps".  */
-  xsnprintf (filename, sizeof filename, "/proc/%ld/task/%ld/maps", pid, pid);
+  xsnprintf (filename, sizeof filename, "/proc/%d/task/%d/maps", pid, pid);
   gdb::unique_xmalloc_ptr<char> data
     = target_fileio_read_stralloc (NULL, filename);
   if (data != NULL)
@@ -3168,9 +3167,9 @@ linux_address_in_shadow_stack_mem_range
   if (!target_has_execution () || current_inferior ()->fake_pid_p)
     return false;
 
-  const int pid = current_inferior ()->pid;
+  pid_t pid = current_inferior ()->pid;
 
-  std::string smaps_file = string_printf ("/proc/%d/smaps", pid);
+  std::string smaps_file = string_printf (PROC_PID_SMAPS, pid);
 
   gdb::unique_xmalloc_ptr<char> data
     = target_fileio_read_stralloc (nullptr, smaps_file.c_str ());
-- 
2.55.0