Better dependency checking.

git-svn-id: svn://svn.code.sf.net/p/sc2/code/trunk@1504 8092fc87-c524-0410-9efc-e669fe64eaf9

sc2/build/unix/build.docs

@@ -18,21 +18,21 @@ The files
 
 These are the files in the directory with the build script.
 Of these files only build.config should be modified for a specific build.
-For unknown dependancies, additions to config_proginfo might need to be
+For unknown dependencies, additions to config_proginfo might need to be
 made. The other files should not be modified.
 Only build.sh is to be called directly.
 
 ansi                ansi colour definitions.
 build.config        configuration options for the program to build.
                     It contains the description of the configuration
-                    menu, and specifies the dependancies.
+                    menu, and specifies the dependencies.
                     The format of the menu description is listed briefly
                     below.
 build.sh            the sh script that is to be called for configuration,
                     building, and installation.
 build_functions     auxiliary functions to build.sh for building.
 config_functions    auxiliary functions to build.sh for configuration.
-config_proginfo     contains descriptions of dependancies.
+config_proginfo     contains descriptions of dependencies.
                     The information in this file is used in particular for
                     detecting if those libraries and other external programs
                     are present.
@@ -127,13 +127,19 @@ Information about programs used should be supplied in the following form:
     This command may include a shell command that modifies any of the
     variables PROG_${PROGRAM}_FILE, PROG_${PROGRAM}_ACTION, or
     PROG_${PROGRAM}_VERSION.
+  - PROG_${LIB}_DEPEND_DETECT_BIN (optional)
+    A list of space-separated binaries the detection of this program
+    depends on.
+  - PROG_${LIB}_DEPEND_DETECT_LIB (optional)
+    A list of space-separated libraries the detection of this program
+    depends on.
   - PROG_${PROGRAM}_VERSION (optional)
     A string that evaluates to the version of the executable that is
     present, if it is present.
   - PROG_${PROGRAM}_PRESENT (set by the configuration program)
     0 if the program has been verified to be present
     1 if the program has been verified to be not present
-    <empty> if the program hasn't been verified to be present
+    <empty> if presence of the program hasn't been verified
 
 
 Library info (from config_proginfo)
@@ -154,14 +160,20 @@ Information about libraries used should be supplied in the following form:
     made to compile and link an empty C program with the flags as in
     LIB_${LIB}_CFLAGS and LIB_${LIB}_LDFLAGS.
     This command may include a shell command that modifies any of the
-    variables PROG_${LIB}_FILE, PROG_${LIB}_ACTION, or
+    variables PROG_${LIB}_CFLAGS, PROG_${LIB}_LDFLAGS, or
     PROG_${LIB}_VERSION.
+  - LIB_${LIB}_DEPEND_DETECT_BIN (optional)
+    A list of space-separated binaries the detection of this library depends
+    on.
+  - LIB_${LIB}_DEPEND_DETECT_LIB (optional)
+    A list of space-separated libraries the detection of this library depends
+    on.
   - LIB_${LIB}_VERSION (optional)
     A string that evaluates to the version of the library that is
     present, if it is present.
   - LIB_${LIB}_PRESENT (set by the configuration program)
     0 if the library has been verified to be present
     1 if the library has been verified to be not present
-    <empty> if the library hasn't been verified to be present
+    <empty> if presence of the library hasn't been verified