Implement the first set of changes for PR3963 and rdar://6759604,

which tries to do better error recovery when it is "obvious" that an
identifier is a mis-typed typename.  In this case, we try to parse
it as a typename instead of as the identifier in a declarator, which
gives us several options for better error recovery and immediately
makes diagnostics more useful.  For example, we now produce:

t.c:4:8: error: unknown type name 'foo_t'
static foo_t a = 4;
       ^

instead of:

t.c:4:14: error: invalid token after top level declarator
static foo_t a = 4;
             ^

Also, since we now parse "a" correctly, we make a decl for it,
preventing later uses of 'a' from emitting things like:

t.c:12:20: error: use of undeclared identifier 'a'
int bar() { return a + b; }
                   ^

I'd really appreciate any scrutiny possible on this, it 
is a tricky area.

llvm-svn: 68911

1 files changed, 18 insertions, 1 deletions

diff --git a/clang/test/Parser/declarators.c b/clang/test/Parser/declarators.c
index 8a533ee53d8..09b43e50571 100644
--- a/clang/test/Parser/declarators.c
+++ b/clang/test/Parser/declarators.c
@@ -12,7 +12,7 @@ char ((((*X))));
 
 void (*signal(int, void (*)(int)))(int);
 
-int a, ***C, * const D, b(int);
+int a, ***C, * const D, B(int);
 
 int *A;
 
@@ -36,3 +36,20 @@ int test4(x, x) int x; {} /* expected-error {{redefinition of parameter 'x'}} */
 // PR3031
 int (test5), ;  // expected-error {{expected identifier or '('}}
 
+
+
+// PR3963 & rdar://6759604 - test error recovery for mistyped "typenames".
+
+struct xyz { int y; };
+
+foo_t a = 4;   // expected-error {{unknown type name 'foo_t'}}
+xyz b;         // expected-error {{unknown type name 'xyz'}}
+
+foo_t *d;      // expected-error {{unknown type name 'foo_t'}}
+
+static f;      // expected-warning {{type specifier missing, defaults to 'int'}}
+static g = 4;  // expected-warning {{type specifier missing, defaults to 'int'}}
+static h        // expected-warning {{type specifier missing, defaults to 'int'}} 
+      __asm__("foo"); // expected-warning {{extension used}}
+
+int bar() { return a; }