Merge the C wrapper.

config/toolchain.in

@@ -296,4 +296,42 @@ config TARGET_SUFFIX
 
 endif # CROSS_NATIVE || CANADIAN
 
+# Kept as a separate if block, even if it could go into the above block,
+# because it seems better. No real reason, only that it seems right...
+if CANADIAN
+
+comment "Host specifics"
+
+choice
+    bool
+    prompt "|  Install tools wrapper as:"
+    default TOOLS_WRAPPER_SHELL
+
+config TOOLS_WRAPPER_SCRIPT
+    bool
+    prompt "shell script"
+    help
+      If your host has a shell, then you should say 'Y' here, to use
+      a (very very simple) shell script as wrapper.
+      
+      See docs/overview.txt, section "Tools wrapper".
+
+config TOOLS_WRAPPER_EXEC
+    bool
+    prompt "executable"
+    help
+      If your host lacks a shell, then you should say 'Y' here, to use
+      an executable.
+      
+      See docs/overview.txt, section "Tools wrapper".
+
+endchoice
+
+config TOOLS_WRAPPER
+    string
+    default "script" if TOOLS_WRAPPER_SCRIPT
+    default "exec"   if TOOLS_WRAPPER_EXEC
+
+endif # CROSS_NATIVE || CANADIAN
+
 endmenu

docs/overview.txt

@@ -24,6 +24,8 @@ Running crosstool-NG
   Stopping and restarting a build
   Testing all toolchains at once
   Overriding the number of // jobs
+  Note on // jobs
+  Tools wrapper
 Using the toolchain
 Toolchain types
 Internals
@@ -145,7 +147,6 @@ If you go the hacker's way, then the usage is a bit different, although very
 simple:
   ./configure --local
   make
-  make install
 
 Now, *do not* remove crosstool-NG sources. They are needed to run crosstool-NG!
 Stay in the directory holding the sources, and run:
@@ -382,6 +383,52 @@ in parallel (there is not much to gain). When speaking of // jobs, we are
 refering to the number of // jobs when making the *components*. That is, we
 speak of the number of // jobs used to build gcc, glibc, and so on...
 
+Tools wrapper |
+--------------+
+
+Starting with gcc-4.3 come two new dependencies: GMP and MPFR. With gcc-4.4,
+come three new ones: GMP, PPL and CLooG/ppl. These are libraries that enable
+advanced features to gcc. Additionally, some of the libraries can be used by
+binutils and gdb. Unfortunately, not all systems on which crosstool-NG runs
+have all of those libraries. And for those that do, the versions of those
+libraries may be older than the version required by gcc.
+
+This is why crosstool-NG builds its own set of libraries as part of the
+toolchain.
+
+The libraries are built as shared libraries, because building them as static
+libraries has some short-comings. This poses no problem at build time, as
+crosstool-NG correctly points gcc (and binutiols and gdb) to the correct
+place where our own version of the libraries are installed. But it poses
+a problem when gcc et al. are run: the place where the libraries are is most
+probably not known to the host dynamic linker. Still worse, if the host system
+has its own versions, then ld.so would load the wrong library!
+
+So we have to force the dynamic linker to load the correct version. We do this
+by using the LD_LIBRARY_PATH variable, that informs the dynamic linker where
+to look for shared libraries prior to searching its standard places. But we
+can't impose that burden on all the system (because it'd be a nightmare to
+configure, and because two tolchains on the same system may use different
+versions of the libraries); so we have to do it on a per-toolchain basis.
+
+So we rename all binaries of the toolchain (by adding a dot '.' as their first
+character), and add a small program, the so-called "tools wrapper", that
+correctly sets LD_LIBRARY_PATH prior to running the real tool.
+
+First, the wrapper was written as a POSIX-compliant shell script. That shell
+script is very simple, if not trivial, and works great. The only drawback is
+that it does not work on host systems that lack a shell, for example the
+MingW32 environment. To solve the issue, the wrapper has been re-written in C,
+and compiled at build time. This C wrapper is much more complex than the shell
+script, and although it sems to be working, it's been only lightly tested.
+Some of the expected short-comings with this C wrapper are;
+ - multi-byte file names may not be handled correctly
+ - it's really big for what it does
+
+So, the default wrapper installed with your toolchain is the shell script.
+If you know that your system is missing a shell, then you shall use the C
+wrapper (and report back whether it works, or does not work, for you).
+
 
 _______________________
                       /

scripts/build/internals.sh

@@ -46,9 +46,25 @@ do_finish() {
         CT_DoLog EXTRA "Installing toolchain wrappers"
         CT_Pushd "${CT_PREFIX_DIR}/bin"
 
-        # Copy the wrapper
-        CT_DoExecLog DEBUG install -m 0755 "${CT_LIB_DIR}/scripts/wrapper.in"   \
-                                           ".${CT_TARGET}-wrapper"
+        # Install the wrapper
+        case "${CT_TOOLS_WRAPPER}" in
+            script)
+                CT_DoExecLog DEBUG install                              \
+                                   -m 0755                              \
+                                   "${CT_LIB_DIR}/scripts/wrapper.in"   \
+                                   ".${CT_TARGET}-wrapper"
+                ;;
+            exec)
+                _t="-s"
+                if [ "${CT_DEBUG_CT}" = "y" ]; then
+                  _t="" # If debugging crosstool-NG, don't strip the wrapper
+                fi
+                CT_DoExecLog "${HOST_CC}"                               \
+                             -Wall -Wextra -Wunreachable-code -Werror   \
+                             -O3 -static ${_t}                          \
+                             -o ".${CT_TARGET}-wrapper"
+                ;;
+        esac
 
         # Replace every tools with the wrapper
         # Do it unconditionally, even for those tools that happen to be shell

scripts/wrapper.c

@@ -0,0 +1,128 @@
+#include <limits.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <errno.h>
+
+
+/* Needed for execve */
+extern char **environ;
+
+int main( int argc,
+          char** argv )
+{
+  char *fullname;   /* 'fullname' is used to store the absolute path to the
+                       tool being executed; it serves as a base to compute
+                       the realname of that tool, and the directory holding
+                       our runtime libraries */
+  char *realname;   /* 'realname' is the real name of the tool, that is what
+                       the wrapper is currently impersonating */
+  char *basedir;    /* 'libdir' contains our runtime libraries */
+
+  char *lastslash;  /* Temporary variables now */
+  char *ldlibpath;
+  size_t len;
+  int execve_ret;
+
+  /* In case we have a relative or absolute pathname (ie. contains a slash),
+   * then realpath wll work. But if the tool was found in the PATH, realpath
+   * won't work, and we'll have to search ourselves.
+   * This if{}else{} block allocates memory for fullname. */
+  if( strchr( argv[0], '/' ) ) {
+    fullname = (char*) malloc( PATH_MAX * sizeof(char) );
+    if( ! realpath( argv[0], fullname ) ) {
+      perror( "tool wrapper" );
+      exit( 1 );
+    }
+  } else {
+    char *path;
+    char *mypath;
+    char *colon;
+    char *testname;
+    struct stat st;
+
+    fullname = NULL;
+    colon = mypath = path = strdup( getenv( "PATH" ) );
+    while( colon ) {
+      colon = strchr( mypath, ':' );
+      if( colon ) {
+        *colon = '\0';
+      }
+      testname = strdup( mypath );
+      testname = (char*) realloc( testname,   strlen( testname )
+                                            + strlen( argv[0] )
+                                            + 2 * sizeof(char) );
+      memset( testname + strlen( testname ),
+              0,
+              strlen( argv[0] ) + 2 * sizeof(char) );
+      strcat( testname, "/" );
+      strcat( testname, argv[0] );
+      if( stat( testname, &st ) == 0 ) {
+        /* OK, exists. Is it a regular file, or a
+         * symlink, which the current user may execute? */
+        if( S_ISREG( st.st_mode ) && ! access( testname, X_OK || R_OK ) ) {
+          fullname = strdup( testname );
+          break;
+        }
+      }
+      free( testname );
+      mypath = colon + 1;
+    }
+    free( path );
+    if( ! fullname ) {
+      fprintf( stderr, "tool wrapper: %s: command not found\n", argv[0] );
+      exit( 1 );
+    }
+  }
+
+  /* Duplicate my own name to add the 'dot' to tool name */
+  realname = strdup( fullname );
+  realname = (char*) realloc( realname, strlen( realname) + 2 * sizeof(char) );
+  realname[ strlen( realname ) + 1 ] = '\0';
+
+  /* Add the dot after the last '/' */
+  lastslash = strrchr( realname, '/' );
+  memmove( lastslash + 1, lastslash, strlen( lastslash ) );
+  *( lastslash + 1 ) = '.';
+
+  /* Compute the basedir of the tool */
+  basedir = strdup( fullname );
+  lastslash = strrchr( basedir, '/' );
+  *lastslash = '\0';
+  lastslash = strrchr( basedir, '/' );
+  *lastslash = '\0';
+
+  /* Append '/lib' */
+  len = strlen( basedir );
+  basedir = (char*) realloc( basedir, len + 5 );
+  *( basedir + len ) = '\0';
+  strcat( basedir, "/lib" );
+
+  /* Now add the directory with our runtime libraries to the
+     front of the library search path, LD_LIBRARY_PATH */
+  ldlibpath = getenv( "LD_LIBRARY_PATH" );
+  if( ldlibpath ) {
+    basedir = (char*) realloc( basedir,   strlen( basedir )
+                                        + strlen( ldlibpath )
+                                        + 2 * sizeof(char) );
+    strcat( basedir, ":" );
+    strcat( basedir, ldlibpath );
+  }
+
+  if( setenv( "LD_LIBRARY_PATH", basedir, 1 ) ) {
+    errno = ENOMEM;
+    perror( "tool wrapper" );
+    exit( 1 );
+  }
+
+  /* Execute the real tool, now */
+  execve_ret = execve( realname, argv, environ );
+
+  /* In case something went wrong above, print a
+     diagnostic message, and exit with error code 1 */
+  perror( "tool wrapper" );
+  return 1;
+}