[RFC 2/5] [gdb/testsuite] Make lib/gdb.exp emacs indent compatible

[Tom de Vries <tdevries@suse.de>]

There are cases in gdb/testsuite/lib/gdb.exp where we have inline C sources.

Say we start out by writing something like this:
...
set src {
  int main (int argc) {
    if (argc == 3)
      return 0;
  }
}
...

When editing with emacs, and using tcl-mode, auto indent will change this to:
...
set src {
    int main (int argc) {
	if (argc == 3)
	return 0;
    }
}
...

The 2 vs 4 spacing is fine, but removing indentation is not.  We can fix this
by adding braces:
...
set src {
    int main (int argc) {
	if (argc == 3) {
	    return 0;
	}
    }
}
...

But that approach breaks down when we have a for loop.  Auto indent gives us:
...
set src {
    int main (int argc) {
	for (int i = 0; i < 1) {
				argc++;
			    }
	return argc;
    }
}
...

This can be fixed with a trick: adding an if:
...
set src {
    int main (int argc) {
	for (int i = 0; i < 1) if (1) {
	    argc++;
	}
	return argc;
    }
}
...

Use these methods to make the inline sources in lib/gdb.exp compatible with
emacs auto indent.

Note: this does not yet use emacs indentation.
---
 gdb/testsuite/lib/gdb.exp | 30 ++++++++++++++++++++----------
 1 file changed, 20 insertions(+), 10 deletions(-)

diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
index ea8bffc9e89..d4a471ff7c4 100644
--- a/gdb/testsuite/lib/gdb.exp
+++ b/gdb/testsuite/lib/gdb.exp
@@ -3134,6 +3134,9 @@ gdb_caching_proc allow_dlmopen_tests {} {
 	    return 42;
 	}
     }
+
+    # Note: we use a "for ... if (1) ..." trick to make emacs tcl-mode indent
+    # the for loop as if it was an if.
     set src {
 	#define _GNU_SOURCE
 	#include <dlfcn.h>
@@ -3155,9 +3158,11 @@ gdb_caching_proc allow_dlmopen_tests {} {
 
 	    r_debug = 0;
 	    /* Taken from /usr/include/link.h.  */
-	    for (dyn = _DYNAMIC; dyn->d_tag != DT_NULL; ++dyn)
-		if (dyn->d_tag == DT_DEBUG)
+	    for (dyn = _DYNAMIC; dyn->d_tag != DT_NULL; ++dyn) if (1) {
+		if (dyn->d_tag == DT_DEBUG) {
 		    r_debug = (struct r_debug *) dyn->d_un.d_ptr;
+		}
+	    }
 
 	    if (!r_debug) {
 		printf ("r_debug not found.\n");
@@ -11487,14 +11492,16 @@ gdb_caching_proc have_avx {} {
 	int main() {
 	  unsigned int eax, ebx, ecx, edx;
 
-	if (!x86_cpuid (1, &eax, &ebx, &ecx, &edx))
+	if (!x86_cpuid (1, &eax, &ebx, &ecx, &edx)) {
 	  return 0;
+	}
 
-	if ((ecx & (bit_AVX | bit_OSXSAVE)) == (bit_AVX | bit_OSXSAVE))
+	if ((ecx & (bit_AVX | bit_OSXSAVE)) == (bit_AVX | bit_OSXSAVE)) {
 	  return 1;
-	else
+	} else {
 	  return 0;
 	}
+	}
     }
     set compile_flags "incdir=${srcdir}/.."
     if {![gdb_simple_compile $me $src executable $compile_flags]} {
@@ -11532,14 +11539,16 @@ gdb_caching_proc have_avx2 {} {
 	    int main() {
 	      unsigned int eax, ebx, ecx, edx;
 
-	    if (!x86_cpuid_count (7, 0, &eax, &ebx, &ecx, &edx))
-	      return 0;
+	    if (!x86_cpuid_count (7, 0, &eax, &ebx, &ecx, &edx)) {
+		return 0;
+	    }
 
-	    if ((ebx & bit_AVX2) == bit_AVX2)
+	    if ((ebx & bit_AVX2) == bit_AVX2) {
 	      return 1;
-	    else
+	    } else {
 	      return 0;
 	    }
+	    }
 	}
 	set compile_flags "incdir=${srcdir}/.."
 	if {![gdb_simple_compile $me $src executable $compile_flags]} {
@@ -11642,8 +11651,9 @@ gdb_caching_proc has_hw_wp_support {} {
 	int main (void) {
 	    volatile int local;
 	    local = 1;
-	    if (local == 1)
+	    if (local == 1) {
 		return 1;
+	    }
 	    return 0;
 	}
     }
-- 
2.51.0