scc

commit f149a192176c7109ebd6f1826a88e324901eff14
parent dd861f58cf7db6cfd625d0540886002ed202b77c
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Wed, 26 Oct 2022 21:52:13 +0200

cc1: Detect duplication of parameters in macros

Install() fails when the symbol already exists in the current
context and it return NULL.

Diffstat:
M
src/cmd/cc/cc1/cpp.c
 | 
9
++++++---

1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/src/cmd/cc/cc1/cpp.c b/src/cmd/cc/cc1/cpp.c
@@ -449,9 +449,12 @@ getpars(Symbol *args[NR_MACROARG])
 			cpperror("macro arguments must be identifiers");
 			return NR_MACROARG;
 		}
-		sym = install(NS_IDEN, yylval.sym);
-		sym->flags |= SUSED;
-		args[n++] = sym;
+		if ((sym = install(NS_IDEN, yylval.sym)) == NULL) {
+			errorp("duplicated macro parameter '%s'", yytext);
+		} else {
+			sym->flags |= SUSED;
+			args[n++] = sym;
+		}
 		next();
 	} while (accept(','));
 	expect(')');